Todays Plan: 4/21/10Tests/Graded Work/Housekeeping (20 mins)AP Lab 10 (the rest of class)-Remember, were on early release!

Todays Plan: 4/26/2010Go over week (5 mins)Histology lab (55 mins)-Due today!Notes (the rest of class)

Todays Plan: 4/27/2010Set-up for dissection (5 mins)Begin Rat Dissection (50 mins)Animal Anatomy Notes (the rest of class)

Todays Plan: 4/29/2010Finish Rat Dissection Questions (20 mins)Rat Dissection Suppliment (40 mins)Continue Notes (the rest of class)

Todays Plan: 4/30/2010Finish Rat Dissection suppliment (50 mins)Notes (the rest of class)

Todays Plan: 12/1/09AP Lab 10Notes, continued

Todays Plan: 12/2/09Bellwork: AP Statistics Survey (5 mins)Finish AP Lab 10 (20 mins)Finish Notes (the rest of class)

Todays Plan: 12/3/09Bellwork: Test Q&A (10 mins)Animal Anatomy Test (as needed)If you finish early, finish up AP Lab 10 and turn in today!

Animal Form and Function NotesAnatomy-how the body is put togetherPhysiology-how the organs and tissues operateAnimal Systems:IntegumentaryRespiratorySkeletalCirculatoryExcretoryDigestiveNervousMuscular ImmuneEndocrineReproductive

Figure 41-7Tissues are organized into organs.Organs are organized into systems.Digestive system:Salivary glands secrete enzymesThe esophagus is a long,The stomach is a thick,The liver and pancreas containThe small intestine is a long,The large intestine is a largeTissues:EpitheliaConnective tissueSmooth muscleNervesSmall intestineOrgan:that begin to digest food.muscular sac whose contractions help break up food.muscular tube that transports food to the stomach.cells that secrete enzymes and other molecules that aid digestion.coiled tube where enzymes digest food and nutrients are absorbed.tube where water is resorbed and wastes are compacted.

Animal Tissue TypesRecall:cellstissuesorgansorgan systemsEpithelial tissue-most common tissue in the body (skin and protective coverings)Cuboidal-cube-shapedColumnar-rectangularSquamous-flatTransitional-changes shape (ex: lining of bladder)Connective tissue-bind and support the body partsLoose-Binds and cushions tissues to one anotherCartilage-cushions and supportsFibrous-tendons (muscle to bone) and ligaments (bone to bone)BoneAdipose-fatBloodMuscle tissue-Responsible for movementSkeletal-voluntary movementsSmooth-involuntary movementsCardiac-special muscle thats striated like skeletal, but involuntary like smoothNervous tissue-Regulates body functions, connects parts of body to brainNervesGlial cells-insulate and bind nervous cells

Figure 41-6Epithelium forms a surface layerCells in epithelial tissues are joined tightlyand have polarity.EpitheliumTight junctionEpithelial cellsFaces internal or external environmentConnects to other tissuesApical surface of epitheliumBasolateral surface of epithelium

Figure 41-3 Loose connective tissue has a softextracellular matrix; it provides padding.Bone and cartilage have a hard (bone) or stiff(cartilage) extracellular matrix; they support the body.Blood has a liquid extracellular matrix;it functions in transport.SoftextracellularmatrixCellsProtein fibersHardextracellularmatrixBone cellsLiquidextracellularmatrix(plasma)White blood cellsRed blood cellsStiffextracellularmatrixCartilage cells

Figure 41-19A cell in normal adipose tissueA cell in brown adipose tissueMitochondriaLipid dropletsNuclei

Homeostatic ControlInvolves nervous system and endocrine systemFeedback mechanismsAnimals mostly rely on negative feedback, where the stimulus is reduced (ex: exercise raises body temp, which makes you sweat for evaporative cooling)Occasionally, responses are controlled by positive feedback, where the stimulus is intensified (ex: childbirth)Temperature regulationEndotherms-warm blooded maintain a constant internal body temp (usually homeothermic)Ectotherms-cold blooded body temp is same as environment (usually poikilothermic)Remember, animal surface area (ex: African elephant ears), metabolism, and evaporation are involved in temperature regulation

Figure 41-16If body temp isabove set point:If body temp isbelow set point:Heat-loss centers activated:1. Blood vessels near skin dilate;blood flow increases, heat lossfrom skin surface increases.2. Sweat glands stimulated;evaporation results in heat lossfrom skin.3. Respiratory centers stimulated;panting results in heat loss.Heat-gain centers activated:1. Blood vessels near skinconstrict; blood flow lessens, heatloss from skin surface decreases.2. Shivering generates heat inmuscles.3. Chemical signals arrive at cells,stimulate increase in cellularrespiration and heat production.SENSORSRecord temperatureNEGATIVEFEEDBACKEFFECTORSChange body tempto return it to set pointTemperature receptors(skin, spinal cord,anterior hypothalamus)HeatorColdExternal stimuliTemperature control(centers in hypothalamus)Is body tempabove or belowset point?INTEGRATORCompares sensor input with setpoint, then instructs effectors

Figure 41-17EndothermsHeterotherms EctothermsHomeothermsMole-ratsSome small birds and mammalsBees and some other insectsA few fishPolar marine fish and invertebratesMost marine fishMarine invertebratesMany insectsAmphibians, lizards, snakes, turtles, crocodilesMost freshwater fishFreshwater invertebratesMost terrestrial invertebratesMost birds and mammals

Animal NutritionSince animals are consumers, they need to eat others to surviveAs with plants and other organisms, some nutrients are essential, meaning that the animal cant make them itselfEssential amino acids-without these, the animal cant growEssential fatty acids-its rare that animals are deficient in these b/c most organisms that animals eat have them.Essential vitamins-organic molecules required in small amounts for an animals metabolismMinerals are also necessary for many metabolic processes but are inorganic

Figure 43-00-Table 43-2

Figure 43-00-Table 43-1

Dietary deficienciesUndernourishment-organisms not eating enough, and therefore not having enough energy or essential nutrientsMalnourishment-long-term absence of essential nutrients from a dietYes, if you eat at McDonalds every day, youll be malnourished AND obese! Obesity and overnourishment (usually b/c of excess calories)-studies show that a restricted calorie diet leads to increased longevity

Stages of NutritionIngesting-Done by the oral cavity, which passes food through the pharynx, past the epiglotis, through the esophagus to the stomach (peristalic contractions of the smooth muscle that lines the esophagus)Digesting-Done by the stomach, glands, and intestinesExtracellular digestion in compartmentsCompartment can be stomach or gastrovascular cavityAbsorbing-Done by the intestines, kidneys and stomachEliminating-Done by kidneys, large intestine

Figure 43-5The digestive tract:1. MouthMechanical and chemical processing(chewing reduces size of food; salivadigests carbohydrates)2. EsophagusTransports food3. StomachMechanical and chemical processing(digestion of proteins)4. Small intestineChemical processing and absorption(digestion of proteins, fats, carbohydrates;absorption of nutrients and water)5. Large intestineWater absorption and fecesformation6. RectumHolds feces7. AnusFeces eliminationAccessory organs:Salivary glandsSecrete enzymes thatdigest carbohydrates;supply lubricatingmucusLiverSecretes moleculesrequired fordigestion of fatsGallbladderStores secretionsfrom liver; emptiesinto small intestinePancreasSecretes enzymesand other materialsinto small intestine

Figure 43-6Location in digestive tract1. Mouth2. Esophagus3. Stomach4. Small intestineLumenof smallintestineCell membrane of epithelial cellCarbohydratesLipidsProteinsSalivaryamylaseLinguallipasePepsinPolypeptidesTrypsinChymotrypsinElastaseCarboxypepitidaseShort peptidesAmino acidsPancreatic-amylaseBile saltsand pancreaticlipaseMonoglyceridesFatty acidsDisaccharidesTrisaccharidesMonosaccharides(simple sugars)DIFFUSIONEpithelium ofsmall intestineMonosaccharidesFACILITATEDDIFFUSION ANDCOTRANSPORTFACILITATEDDIFFUSIONTo bloodstreamTo bloodstreamTo lymph vessels,then bloodstreamEXOCYTOSISFACILITATEDDIFFUSION ANDCOTRANSPORTFACILITATEDDIFFUSION ANDCOTRANSPORTMonoglyceridesFatty acidsTriglyceridesChylomicron (protein-coated globules)Amino acids

Mouth and Stomach DigestionA bolus, or ball of chewed food is first worked on by amylase produced in the salivary glands, which breaks down carbohydratesGastric Juice in the stomach contains the following, and mainly breaks down small polypeptides:HClPepsin (an enzyme)Cells that produce the pepsin, parietal cells, synthesize pepsin as pepsinogen which isnt active until it comes into contact with the HCl in the stomach lumenThe stomach lining is also protected by mucus, and regenerates new epithelials every 3 days to prevent ulcersDigestion is also physical, since the stomach contracts to mix and break down the chyme (food and gastric juice)The release of food to the small intestine is controled by the pyloric sphincter

Figure 43-9Secretory cells in the stomach liningSecretion of HCl by parietal cellsStomachCanal empties intolumen of stomachGoblet cells(secrete mucus)Chief cells(secretepepsinogen)Parietal cells(secrete HCl)HClto lumenProton pumpChloride channelBloodvesselParietal cellCanal emptiesto lumen

Intestinal DigestionLarge complex carbs, most fats, and larger polypeptides have to be broken down in the small intestine (both in the lumen and epithelials)The 1st 25 cm of the sm. Intestine, the duodenum, does most of this digestionPancreas produces pancreatic amylase and lipase, as well as several proteases (trypsin and chymotrypsin) in an alkaline solution that is transferred to the duodenum via the pancreatic ductThe liver produces bile that emulsifies fats (breaks them into smaller droplets) so theres more fat surface area for lipases to work. This bile is stored in the gall bladder and flows through the bile duct in as well.Villi and Microvilli in the wall of the small intestine increase the surface area for absorptionOnce food passes through the small intestine, it goes to the large intestine, where beneficial bacteria break down what we cant and release vitamins for absorbtionWater is also absorbed, forming solid fecesThere are 3 parts of the colon, or large intestine, beginning with the ascending colon, which has a blind end called a caecumHanging from the caecum is the appendix

Figure 43-11The lining of the small intestine has extensive folds.Three-dimensional view of foldCross sectionof smallintestineMuscleFoldVilliFoldVilliBloodvesselsMuscleMicrovilli are extensions of epithelial cells in villi.VillusMicrovilli of epithelialcellsEpithelialcellsBloodvesselsLacteal(lymphsystem)

Figure 43-13DIGESTION OF LIPIDS IN SMALL INTESTINE1. Large fat globulesare not digestedefficiently by lipase.2. Bile salts (producedin liver) act asemulsifying agents.3. Small fatdroplets result fromemulsification.4. Lipase digests the small fatdroplets into monoglyceridesand free fatty acids.MonoglyceridesFattyacidsLipase

Hormonal Control of DigestionGastrin is produced in the cells of the stomach lining as soon as the animal detects food and stimulates cells to produce gastric juicesSecretin is produced in the cells lining the duodenum when food leaves the stomach. It stimulates the pancreas to produce the alkaline solution for its secretionsCholecystokinin is produced by the small intestine when fats are present, and stimulates the gallbladder to release bile.

Digestion AdaptationsRuminants have chambers in their stomachs and often re-chew their food multiple timesHerbivorous animals often have longer small intestines in order to break down the tough plant fibers that they eat. They also have a larger caecum with lots more bacteria. (Rabbits eat their dung to recapture these bacteria)

Figure 43-10Four-chamberedstomach:1. Rumen2. Reticulum3. Omasum4. AbomasumIntestineNewly eaten food(green arrows)Re-swallowed cud(red arrows)Regurgitatedcud(black arrow)

Osmoregulation and ExcretionWater balance is obviously important to maintain (cells die if they dehydrate, or burst if overhydrated)Marine fish constantly drink salt water and secrete urea or other salty solutions in their bodies since theyre hypoosmotic (live in a hypertonic soln)Freshwater fish constantly urinate and absorb salt through their gills because theyre hyperosmoticOther animal adaptations for osmoregulation:Flame cells (protonephridia)in planaria (a flat worm)-cilliated cells Nephridia (metanephridia) in annelids-paired organs that collect urine, reabsorb whats needed, and secrete excess waterMalpighian tubes in spiders contain high concentrations of potassium ion, so that the surrounding cells reabsorb water and conserve it

Figure 42-2SeawaterFreshwaterGain someelectrolytesin food andwaterReplacewater bydrinkingGain metabolicwaterGillGill tissue(lowerosmolarity)Gain manyelectrolytesby diffusionSeawater(higherosmolarity)Lose largeamounts ofwater byosmosisLose electrolytesthrough activetransport outLose waterin urineformationGain metabolicwaterGillLose waterin urineformationLose someelectrolytesin urineGain someelectrolytesin foodFreshwater(lowerosmolarity)Gill tissue(higherosmolarity)Gain electrolytesthrough activetransport inLose someelectrolytesin urineGainwater byosmosisLoseelectrolytesby diffusion

Nitrogenous WastesAs proteins and nucleic acids are broken down, lots of nitrogenous wastes are produced. The form that this waste takes reflects the animals phylogenyAmmonia-cant be tolerated in large amounts, so must be constantly diluted. Aquatic animals have this type of waste, and mostly across their gillsUrea-This is safer for land animals and is produced in the liver, however this is energetically expensive since the organism has to convert ammonia into ureaUric Acid-Insects, reptiles, and land snails. This is a semisolid, non-water soluble waste, and is also nontoxic. Its also energetically expensive

The Excretory ProcessFiltration-excretory tube collects filtrate from the blood. Filtration is accomplished by pressure and selectively permeable membranesReabsorption-reclamation of valuable substancesSecretion-toxins, etc are are added to the filtrateExcretion-removal of the altered filtrate (urine)

The KidneyIs part of the excretory system that produces urine, sends it through the ureters to the urinary bladder, and out through the urethraKidney parts include:MedullaCortexPelvis-collecting area for urine once its madeRenal arteries (in) and renal veins (out) carry blood for filtrationFunctional unit of the kidney is the nephronBowmans capsule= (glomerulus) blood is forced here first for filtration and into the proximal convoluted tubeConvoluted tubule=Proximal portion is closest to Bowmans capsule, is followed by the loop of Henle, and the distal convoluted tubuleCollecting ducts=lead to the renal pelvisAfferent arterioles feed Bowmans capsule and efferent arterioles take blood away

Figure 42-10UreterKidneyUrinary systemKidneyNephron structureCortexMedullaMedullaCortexNephronNephronRenalarteryRenalveinUreterBladderUrethraIn most nephrons,the loop of Henleis relatively shortand is located inthe cortexIn some nephronsthe loop of Henleis long and plungesinto the medulla

Processes in the NephronThe afferent arteriole brings blood to Bowmans capsule, where its Filtered by pressure that forces the solutes like glucose, salts, vitamins, and nitrogen wastes through fenestrations just small enough to pass. Blood components stay in the blood vesselsAs the filtrate passes through the proximal convoluted tubule, nitrogenous wastes, water and salts are Secreted into the filtrateAs the filtrate moves down the loop of Henle, water is Reabsorbed, and the urine becomes more concentrated. However, as it moves up the loop of Henle, salts move out and the urine becomes less concentrated

Figure 42-12Fluid and smallsolutes are pushedthrough the poresand the filtrationslits into Bowmanscapsule.Direction ofblood movementFiltration slitsin cells thatwrap aroundvesselLarge moleculesand cells remainin bloodstream.Pores in blood vesselBlood entersglomerulus.Pre-urineleavesBowmanscapsule.Bowmans capsuleGlomerulusBlood leavesglomerulusFiltrationAnatomy of the renal corpuscle

Figure 42-15bPermeabilityActivetransportPassivetransport1200600900300100300600PassivetransportAscending limb is impermeableto water but highly permeable toNa+ and ClDescending limb is highlypermeable to water butimpermeable to solutes

Figure 42-16Distal tubuleSolutes(electrolytes,urea)CollectingductLoop of HenleCortexMedulla

Hormonal Control of ExcretionAntidiuretic Hormone (ADH)-causes the reabsorption of water as the urine moves through the collecting duct, which re-concentrates the urineAldosterone-causes the reabsorption of water and Na+ by altering the permeability of the distal convoluted tubule

Figure 42-18aADH presentMedullaSolutesLoop ofHenleAquaporinsDistal tubuleCortexCollectingduct

Circulation and Gas ExchangeIn animals without a circulatory system (cnidarians), theres a gastrovascular cavity with fluid. The walls of the cavity are only a couple of cell layers thick. Open circulation occurs in organisms like insects, where blood (hemolymph)is pumped into an internal cavity (hemocoel or sinus), so that it can wash over the organs of the cavity. Ostia collect the hemolymph and return it to the heartClosed circulation occurs in most organisms and is where blood is confined to vessels. Arteries move away from the heartThese branch into arterioles and then capillariesVeins move toward the heartVenules collect deoxygenated blood from the capillaries and move it to the veins

Figure 44-3Closed system: Blood never leaves vessels.Blood travelsthrough closedblood vesselsTubular heartSingle heartLymph travelsthrough closedlymph vesselsHemolymph(blood-lymph)flows throughoutbody cavity Open system: Hemolymph leaves vessels and comes intodirect contact with tissues.

Figure 44-22RedbloodcellsNucleusCapillaries are small and extremely thin walled.Basement membraneEndothelial cellsCapillaryFibrous tissueMuscle tissueElastic tissueEndotheliumVein(Medium-sized)Artery(Medium-sized)Veins and arteries differ in structure.

Single vs. Double CirculationIn fishes, rays and sharks, the heart only contains 2 chambers (1 atrium, 1 ventricle). The blood goes into the atrium, ventricle, and then to the gills and the rest of the body. This is single circulation(1 loop)In other animals, theres a 3 or 4 chambered heart (2 atria, 1 or 2 ventricles)The blood goes into the right atrium and right ventricle. The pulmonary artery then takes the blood to the lungs (1st circulation, pulmonary curcuit) for oxygenation.When the blood is oxygenated, it returns to the left atrium, where its pumped into the left ventricle and out through the aorta (2nd circulation, systemic circuit)In animals with 3 chambered hearts, blood returns from the lungs into the ventricle, which has a divider that keeps 90% of the oxygenated and deoxygenated blood from mixing.

Figure 44-24FishTwo circulatory loops1 circuit2-chambered heartFrogsGillsLungTurtles, lizards2 circuits3-chambered heartLung2 circuits5-chambered heartCrocodilesLung2 circuits4-chambered heartBirdsLung2 circuits4-chambered heartMammalsLung2 circuits4-chambered heartBodyBodyBodyBodyBodyBodyThree-chambered heartVentricle divided into chambersA AtriumV VentricleA V A V A A V A A V A V A V A V A V A V

Figure 44-25AortaPulmonaryarteryPulmonaryveinLeftatriumSemilunarvalvesAtrioventricularvalveLeftventricleRightatriumAtrioventricularvalveRightventricleInferiorvena cavaSuperiorvena cava6Pulmonary circulation41253Blood returns to heartfrom body, enters rightatrium.Blood is pumpedfrom right ventricleto lungs.Blood entersright ventricle.Systemic circulationBlood is pumped fromleft ventricle to body.Blood returns to leftatrium from lungs.Blood enters leftventricle.6.4.1.2.5.3.

The Cardiac CycleThis is the rhythmic contraction of the heart muscles. This is regulated by autorhythmic cells that contract without being iniated by nerve cellsWithin the right atrium is the SA (sinoatrial)node, or pacemaker, on the top atrial wall, which contracts both atria simultaneously, and sends a delayed impulse to the AV (arterioventricular)node in the lower wall of the right atrium.The AV node is responsible for ventricular contractions (systole-top number on blood pressure), forcing blood into the pulmonary arteries and aortaWhen the ventricles relax (diastole-bottom number on blood pressure), blood flows back on the AV valves, closing them and the semilunar valves in the aorta and pulmonary artery (this is responsible for the heart sound)

Figure 44-28RightventricleSinoatrial nodeAtrioventricular nodeConducting fibersRightatriumLeftventricleLeftatrium

Figure 44-29SA nodeactivatesatriaAVnodedelayElectricalactivityin atriaElectrical activity in ventriclesVentricles recover

About the Mammalian HeartCardiac output=heart rate and stroke volumeHeart rate=number of bpmStroke volume=amount of blood pumped by a ventricle on a contraction (70mL is average for an adult human)For the avg individual at rest, cardiac output=72bpm(70mL)=5L/min, which is about equal to the total blood volumeHeart murmurs occur when a valve is faulty and is allowing backflow

Blood Vessels and PressureBlood pressure is highest in the aorta and pulmonary artery, closest to the contraction that caused the pressureWhen blood reaches the capillaries and venules, its pressure is virtually 0. Contractions of nearby skeletal muscles keep the blood flowing.Blood constantly moves toward the heart b/c veins have valves that prevent backflow.Blood pressure is regulated over the long term by changes in the smooth muscles in arteriole wallsVasoconstriction is caused by contractions of the smooth muscle in response to tension, physical stressVasodilation is caused by the relaxation of the smooth muscle

Figure 44-30From heartCapillariesReturn to heartVelocityTotal area

The Lymphatic System This is a network of vessels amongst the capillaries of the circulatory system. Approximately 4L of fluid per day leaves the capillaries and goes through the lymphatic systemLymph is that lost fluid, and it returns to the circulatory system at the base of the neck in the large veins thereLymph nodes filter lymph and attack any viruses and bacteria that may be traveling in the blood stream.Lymph nodes also produce and send out immune cells to fight infections in other body parts.

BloodBlood contains:Red Blood Cells (RBCs or erythrocytes)-biconcave disc-shaped cells that carry oxygen using hemoglobinWhite Blood Cells (WBCs or leucocytes)-disease-fighting cells Platelets-cell fragments that help with blood clottingPlasma-liquid portion of the blood

Figure 44-151.5% of oxygen loads to bloodplasmaThe rate of unloading depends on thepartial pressure of oxygen in the tissueHemoglobinEach hemoglobin molecule canbind up to fourmolecules ofoxygenO2 to tissuesO2 fromlung98.5% of oxygen loads to hemoglobinin red blood cells

Blood ClottingBlood vessel breaks expose proteins (like collagen) that attract platelets, which are sticky. Platelets release clotting factors.Fibrinogen is an inactive component of blood, but is converted to fibrin, which forms a net-like set of threads across the break. This traps blood cells that finish the clot

Gas ExchangeIs based on partial pressure (recall from chemistry the total pressure of a mixture of gasses=the sums of the pressures of each gas within it, the partial pressures)Oxygen diffuses out of the air into the blood not because its less concentrated there, but because it has a lower pressure there.This gas exchange for the entire organism is respiration. What cells do with the oxygen to break down sgars is cellular respiration

Respiratory challenges and mechanismsMarine organisms have to cope with less oxygen in their surrounding fluid than land-living organisms b/c oxygen is less soluble in water than in air.There are 3 main respiratory mechanisms that organisms employ:Direct contact with Oxygen from the environment-(Flatworms, sponges, etc) use diffusion through the skinGills-These are outgrowths from the body that can be covered or exposed to water. Covered gills require active water movement over them and they have countercurrent exchange between the capillaries in the gills and the water since they flow in opposite directions which is efficient (oxygen-poor blood is always in contact with water)Tracheae-These are a series of tubes that run through the bodies of insects. Spiracles are openings of the trachae on the outside of the bodyLungs-these are closely connected with the circulatory system (as discussed before) since theyre not connected to the rest of the organs of the body.

Figure 44-6External gills are in direct contact with water.Internal gills must have water brought to them.External gillsInternal gills (each contains manysmall filaments)Carapace removed

Figure 44-7Gill arches holdmany gill filamentsDetail of gill filament: Water flowBlood flowCapillariesGill lamellaTo bodyFromheartWater INWater OUT

Figure 44-10Tracheae are squeezed,air is pushed out.Tracheae expand,air enters.TracheaWingdownMusclerelaxesMusclescontractTracheaWingupMusclesrelaxMusclecontractsAiroutAirin

Figure 44-2AirLungsTubing conductsair to and from gas exchangesurfaces in the lung

Figure 44-11Airways into the lungDeoxygenated blood inTracheaAirBronchiBronchiolesLungAlveoliOxygenated blood outSmallestbronchioleAlveolusCapillariesAqueous filmBloodWall of capillaryECM0.2mEpithelium of alveolusAirOxygenThe alveolar gas-exchange surface

How lung-breathing occursAmphibians-positive pressure breathing (air is forced into the lungs). Buccopharyngeal respirationBirds-1-way flow of air through air sacs that act as billows, moving air through the lungs. Parabronchi (air tubes) do gas exchangeMammals-negative pressure breathing (a vacuum is created by the diaphragm)

Figure 44-14TracheaAnterior air sacs fill with airfrom lungsAnatomy of the avian respiratory systemAnteriorair sacsParabronchiPosteriorair sacsLungOne-way airflow through the avian lungLungs empty.Posterior air sacs fill with outside airLungs fill with airfrom posterior sacs.Anterior air sacs emptyPosterior air sacs empty

Figure 44-12Ventilatory forces can be modeled by a balloon in a jar. Lungs expand and contract is response to changes inpressure inside the chest cavity.When the diaphragm is pulleddown, the balloon inflates.DiaphragmINHALATIONEXHALATIONWhen the diaphragm is released, the balloon deflates.Pressure lessnegativePressure morenegative

Breathing controlCO2 is transported through the blood as bicarbonate (HCO3-). This is carried within the plasma, but made in the RBCsCO2+H20H2CO3H+ and HCO3- (acidic)Breathing control centers in the brain establish the breathing rhythmChemoreceptors in the carotid arteries monitor the pH of the blood and send this information to the diaphragm to increase respiration rate (negative feedback)

The Immune SystemPathogen-infectious agent (virus, bacteria, protist, fungus)Antigen-any molecule that can be recognized as foreignThe immune system protects against pathogens using barriers as well as many specific and non-specific responsesFirst-line of defense-barriers (innate defenses)Second-line of defense-general fighting of infection (non-specific, innate defenses)Third-line of defense-cells built to fight specific infections (acquired immunity)

Figure 49-4Components of theimmune systemLymphocyte origin:Bone marrowLymphocyte maturation:Bone marrow (B cells)Thymus (T cells)Lymphocyte activation:SpleenLymph nodesLymphocyte transport:Lymphatic ductsBlood vessels

First Line of DefenseSkin-covered in oily and acidic secretions from sweat glandsAntimicrobial proteins (lysozymes) that break down the walls of bacteria and are contained insaliva, tears, and other mucusCillia-beat to sweep invaders out of the respiratory tractGastric Juice-kills most microbes that make it to the stomachSymbiotic Bacteria-outcompete harmful bacteria in the gut and vagina

Figure 49-1EyesBlinking wipes tears acrossthe eye. Tears contain theantibacterial enzyme lysozyme.EarsHairs and ear wax trappathogens in the passagewayof the external ear.NoseThe nasal passages are linedwith mucus secretions andhairs that trap pathogens.Digestive tractPathogens are trapped in salivaand mucus, then swallowed.Most are destroyed by the lowpH of the stomach.Airways (lining of trachea)Instead of reaching thelungs, most pathogens aretrapped in mucus and sweptup and out of the airway viathe beating of cilia. CiliatedcellsMucus-secretingcells

Second Line DefensesPhagocytes (WBCs)-engulf pathogens by phagocytosisNeutrophils-most abundant phagocytic cells that engulf pathogensMonocytes-cells that enlarge into macrophages that engulf still more pathogens and cell debris (large numbers of these in the spleen and lymph nodes)NK or natural killer cells-Destroy cells that play host to viruses and bacteria Eosinophils kill multicellular invadersDendritic cells stimulate acquired immunityComplement system-about 30 proteins that function together to stimulate immune response. These attract phagocytes to an infection and help to break open foreign cellsInterferons-proteins produced by infected cells that stimulate neighboring cells to produce proteins to defend against infecting virusesInflammatory Response-pain and swelling at an infection siteMast cells (basophils) in the area burst open and release histamineHistamine cause nearby blood vessels to dilate, biringing more blood to the infection site.(vasodilation)Phagocytes are attracted to that area, and relaease chemical signals that bring more blood to the areaThe complement system reacts

Figure 49-2 Mast cells secrete signals that increaseblood flow.Granulescontain signalingmoleculesNucleusMulti-lobednucleusVesiclescontainingsignalingmoleculesNeutrophils ingest and kill pathogens. Macrophages recruit other cells andingest and kill pathogens.LysosomesdigestbacteriaPseudopodia engulfbacteriaVesiclessecrete cell-killing toxinsNucleus

Figure 49-5Inactive lymphocyteActivated lymphocyteNucleusNucleusLarge amountof rough ER

Figure 49-3THE INFLAMMATORY RESPONSEBlood vesselRed blood cellPlatelet1. Bacteria andother pathogensenter wound.MacrophageMast cell2. Platelets fromblood releaseblood-clottingproteins atwound site.3. Injured tissuesand macrophagesat the site releasechemokines, whichrecruit immunesystem cells to site.Neutrophil4. Mast cells atthe site secretefactors thatconstrict bloodvessel at woundbut dilate bloodvessels nearwound.5. Neutrophilsarrive, beginremovingpathogens byphagocytosis.6. Some newlyarrived leukocytesmature intomacrophagesthat phagocytizepathogens andsecrete keycell-cell signals.MacrophageInitiate tissuerepair

Third line of defense (Acquired Immunity)Up until now, the immune response has been general and not specific to the pathogen.Acquired immunity is built specifically to fight a particular antigen (like a toxin from a bacterium, protein coat of a virus, or a molecule unique to a pathogen)Major histocompatibility complex (MHC) distinguishes between self cells and foreign cellsThis is a collection of glycoproteins on the surfaces of all body cellsThese are made from about 20 genes (50 alleles) and each is unique to each person, so its unlikely youll have the same proteins as someone else

Acquired Immune CellsB Cells-are made and mature in the bone marrow, and respond to antigens. They make antibodies (proteins) against the antigenAntibodies are specific to the antigenThere are 5 classes of antibodies (immunoblobulins), and each is associated with a particular activityEach class of antibodies is Y-shaped with constant regions and variable regions. The variable regions give the antibodies specificity for the antigenPlasma Cells-release antibodies that circulate to an infection siteMemory B Cells-stick around after an infection to make you immune to future attacks from the same strain of the infection

Figure 49-6aB-cell receptorAntigen-binding siteHeavy chainHeavy chainLightchainDisulfide bridgeTransmembrane domainsLight chainsHeavy chainAntigen-bindingsiteAntigen-bindingsiteHeavy chainAntigen-binding site

Figure 49-6-Table 49-2

Acquired Immune Cells cont.T Cells-originate in the bone marrow, but mature in the thymus (a gland, hence the T)MHC markers of the T cells distinguish between self and nonself cellsA host body cell will display self and non-self markers, which the Tcells interpret as nonselfCancer cells are often recognized as nonselfCytotoxic T cells-lyse nonself cells by punctuing themHelper T cells-activate inactive macrophages, stimulate B cell production and stimulate cytotoxic T cellsWhen an antigen binds to T or B cells, they proliferate, which is called clonal selection, since only cells that match the antigen will be cloned

Figure 49-6bT-cell receptorTransmembrane domains Chain ChainAntigen-binding site Chain ChainAntigen-binding site

Types of Immune ResponseCell-mediated response-Mostly T cells respond to nonself cells via clonal selectionTcells produce cytotoxic TcellsT cells produce helper Tcells that bind to macrophages, which carry nonself markers from the cells theyve encounteredHelper T cells produce interleukins to stimulate proliferation of more T and B cells (these make you achy)Humoral response (antibody-mediated)-response to antigens or pathogens within the lymph.B cells produce plasma cells, which release antibodies for the antigenB cells produce memory cells Macrophages and helper T cells stimulate B cell production

Figure 49-13CELL-MEDIATED RESPONSEHUMORAL RESPONSE1. Cytotoxic T cellmakes contact withvirus-infected cell andreleases granules(black dots).2. Molecules in thegranules induceinfected cell to self-destruct, killing heviral particles inside.Cytotoxic T cellGranulesVirus-infectedhost cellVirus particleUninfectedhost cell1. Antibodies coatfree virus particles.The virus cannot bindto the host cellsplasma membrane.VirusAntibodyAntigen2. The antibody-coatedvirus is recognized,phagocytized, anddestroyed by aneutrophil ormacrophage.Neutrophil

Figure 49-11ANTIGEN PRESENTATIONAntigen fragmentbinding siteMajorhistocompatibility(MHC) proteinDendritic cell Foreign peptideERGolgiapparatus1. Dendritic cellingests peptide.2. Enzyme complexinside cell breakspeptide into pieces.3. Peptide pieces bindto MHC Class I proteininside endoplasmicreticulum.4. The MHC-peptidecomplex is transportedto the cell surface viathe Golgi apparatus.5. The MHC Class Iprotein presents thepeptide on the surfaceof the cell membrane.MHCPiece offoreignpeptideT-CELL ACTIVATION (CD8+ T cells)Dendritic cell1. T-cell receptor bindsto peptide presentedon MHC protein onsurface of dendritic cell.Complex activationprocess begins,involving interactionsamong many proteinson the surfaces of thetwo cells.

MHCAntigenClonal expansionCD8+T cell2. Activated CD8+T cells multiply anddifferentiate. EffectorT cells that result leavelymph node andenter blood.

Cytotoxic T cells

Figure 49-12B-CELL ACTIVATIONForeignpeptideB-cellreceptorsB-cellMHCClass IIprotein1. B cell encounters andbinds to foreign peptidein lymph or blood. Thepeptide is internalized,processed, and presentedon the surface by anMHC Class II protein.2. The MHC-peptidecomplex interacts withcomplementary receptorson a helper T cell,activating it.B cellHelper T cellCytokinesActivation3. Cytokines from theactivated helper T cellactivate the B cell.4. The activated B cellbegins to divide. Somedaughter cellsdifferentiate into plasmacells which producelarge quantities of antibodies.PlasmacellsAntibodiesAntibodies will bind toantigens and markthem for destruction

Fighting InfectionAntibiotics-fight bacteria onlyVaccines-preventative, containing only antigen-portions or dead/weak strains of pathogens in order to stimulate memory cell productionActive immunity (everything weve discussed so far)Passive immunity-when antibodies are given to you. Usually via the placenta or breast milk for babies

Figure 49-14Initial exposure to antigenSecond exposure to antigenPrimary immuneresponseSecondaryimmuneresponseResponseis largerResponseis faster

Immune DisordersAllergies-hypersensitive responses to antigens called allergens. IgE class antibodies are producedAutoimmune Diseases-loss of self-toleranceStress and exertion-exercise improves the immune system, stress supresses itImmunodeficiency DiseasesHIVSevere combined immunodeficiency (SCD)-lymphocytes are rare or absent

Regulation and ControlEndocrine System-is a series of hormone-producing glands throughout the body which are circulated through the blood and influence target cellsThe nervous system also controls the bodys functions

AP-Pertinent Endocrine InfoPosterior Pituitary-stores ADH (antidiuretic hormone) and oxytocin, which are produced in the hypothalamusAnterior Pituitary-produces tropic hormones (hormones that target other glands)Regulated by releasing hormones produced by the hypothalamusPancreasIslets of Langerhans have 2 cell types (producing antagonistic hormones)Alpha cells-secrete glucagon into the blood when blood sugar drops, stimulating the liver to release glucoseBeta cells-secrete insulin, stimulating the liver to take up glucose and convert it to glycogen or fat

Figure 47-3-1HypothalamusGrowth-hormone-releasing hormone:stimulates release of GH from pituitaryglandCorticotropin-releasing hormone (CRH):stimulates release of ACTH from pituitaryglandGonadotropin-releasing hormone:stimulates release of FSH and LH from pituitary glandThyroid-releasing hormone: stimulatesrelease of TSH from thyroid glandAntidiuretic hormone (ADH): promotesreabsorption of H2O by kidneysOxytocin: induces labor and milk releasefrom mammary glands in femalesSteroidsPolypeptidesAmino acid derivatives

Figure 47-3-2Adrenal glandsThyroid glandThyroxine: increases metabolic rateand heart rate; promotes growthKidneysEpinephrine: produces many effectsrelated to short-term stress responseAldosterone: increases reabsorption ofNa+ by kidneysCortisol: produces many effects related toshort-term and long-term stress responsesVitamin D: decreases blood Ca2+Testes (in males)Erythropoietin (EPO): increasessynthesis of red blood cellsTestosterone: regulates developmentand maintenance of secondary sexcharacteristics in males; other effectsSteroidsPolypeptidesAmino acid derivatives

Figure 47-3-3Pituitary glandThyroid-stimulating hormone (TSH):stimulates thyroid gland to secretethyroxineProlactin: stimulates mammary glandgrowth and milk production in femalesFollicle-stimulating hormone (FSH)and luteinizing hormone (LH): involvedin production of sex hormones;regulate menstrual cycle in females Growth hormone (GH): stimulates growthAdrenocorticotropic hormone (ACTH):stimulates adrenal glands to secreteglucocorticoidsSteroidsPolypeptidesAmino acid derivatives

Figure 47-3-4Parathyroid glandsPancreas (islets of Langerhans)Ovaries (in females)Insulin: decreases blood glucoseGlucagon: increases blood glucoseEstradiol: regulates development andmaintenance of secondary sexcharacteristics in females; other effectsProgesterone: prepares uterus for pregnancyParathyroid hormone (PTH): increases blood Ca2+SteroidsPolypeptidesAmino acid derivatives

Figure 47-16The posterior pituitaryThe anterior pituitaryHypothalamusPosteriorpituitaryHypothalamichormonesNeurosecretorycells of thehypothalamusBlood vesselsBlood vesselsNeurosecretorycells of thehypothalamusHypothalamichormonesAnteriorpituitaryPituitaryhormonesHormoneTargetResponseADHOxytocinKidneynephronsMammary glands,uterine musclesAquaporinsactivated; H2O reabsorbedContraction duringlabor; ejection ofmilk during nursingHormoneTargetResponseACTHFollicle-stimulatinghormone (FSH)and luteinizinghormone (LH)AdrenalcortexTestes orovariesProduction of sexhormones; controlof menstrual cycleProduction ofthyroidhormonesGrowthhormone(GH)Prolactin(PRL)Thyroid-stimulatinghormone (TSH)Many tissuesMammaryglandsThyroidMammarygland growth;milk productionGrowthProduction ofglucocorticoids

How hormones workMethod 1: (for steroid hormones)The hormone diffuses through the pm and heads for the nucleus.It binds to a receptor protein in the nucleus, which activates the DNA to turn on a specific geneMethod 2: (for protein hormones)The hormone binds to a receptor on the plasma membrane (receptor-mediated endocytosis), which stimulates a second messenger2nd messengers can be cAMP, which triggers an enzyme that makes cellular changes, or Inositol triphosphate (IP3) that triggers the release of calcium ion from the ER, that triggers enzymes to make cellular changes

Figure 47-18STEROID HORMONE ACTIONHormonereceptorSteroidhormoneHormone-receptorcomplexHormone-responseelementRNApolymeraseDNAmRNANucleusProteinsRibosome3. Hormone-receptorcomplex entersnucleus and bindsto DNA, inducesstart of transcription.1. Steroidhormoneenterstarget cell.2. Hormone bindsto receptor, inducesconformationalchange.4. Many mRNAtranscripts areproduced,amplifyingthe signal.5. Each transcript istranslated many times,further amplifying thesignal.

Figure 47-21MODEL FOR EPINEPHRINE ACTIONEpinephrineReceptor1. Epinephrinebinds to receptorAdenylylcyclase3. Activated adenylyl cyclase catalyzes formation of cAMP2. Activationof G protein4. Activation of cAMP-dependent protein kinase A5. Activation of phosphorylase kinase6. Activation of phosphorylase7. Production of glucose from glycogenTransmission ofmessage fromcell surface

Nerves and ImpulsesA Neuron (nerve cell) consists of a cell body, dendrite(s), and an axonImpulses begin at the dentrites, travels through the cell body, and ends at the axon in a gap called a synapseSynapse is the axon of one nerve and its gap associated with the dendrite of the next nerveTypes of neuronsSensory (afferent)-receive the initial stimulus (retina of eye, skin touch receptors, etc)Motor (efferent)-stimulate effectors (target cells that produce a response (neuro-muscular junctins, sweat gland stimulus, etc)Association (interneurons)-in the spinal cord and brain. These receive sensory info and send impulses to motor neurons, and are known as integrators that evaluate appropriate responses to stimuli

Figure 45-3Information flow through neuronsNucleusDendritesCollectelectricalsignalsCell bodyIntegrates incoming signalsand generates outgoingsignal to axonAxonPasses electrical signalsto dendrites of anothercell or to an effector cellNeurons form networks for information flow

Impulse TransmissionChemical changes across the membranes of neurons transmits the impulse.An unstimulated neuron is polarized-an excess of Na+ is on the outside of the cell, while an excess of K+ is on the outside. Sodium/potassium pumps maintain this polarizationOverall, the inside of the cell is negative b/c of a large number of negatively charged molecules and ions inside the cell. Transmission of a nerve starts with this unstimulated resting potential

Figure 45-4Outside of cellInside of cellMicroelectrode0 mV 65 mV Instrumentrecords voltageacross membraneK channel

Figure 45-5HOW THE SODIUM-POTASSIUM PUMP (Na+/K+-ATPase) WORKSOutsidecellInsidecell1. Three sodium ions(Na+) enter the proteinfrom within the cell.2. ATP phosphorylates the pump.It changes shape and releases3 Na+ to the outside of the cell.3. Two potassium ions(K+) enter the proteinfrom outside the cell.4. The phosphate group drops off the pump. The proteinchanges shape and releases2 K+ to the interior of the cell.

Propagating the ImpulseIn response to a stimulus, gated ion channels open an allow Na+ to rush into the cell, meaning that the cell depolarizes.If the impulse is strong enough to get above the threshold level, more ion channels open, causing action potential (complete depolarization), which stimulates neighboring channels to openIn response, other channels open to allow K+ outside of the cell to repolarize the cellThis results in hyperpolarization b/c more K+ moves out than is needed to establish repolarization

Figure 45-61. Depolarization phase2. Repolarization phase3. Hyperpolarization phaseResting potentialThreshold potential

Figure 45-11PROPAGATION OF ACTION POTENTIALAction potential spreads as a wave of depolarization.NeuronAxon1. Na+ enters axon.2. Charge spreads;membranedownstreamdepolarizes.Depolarization atnext ion channel3. Voltage-gatedchannel opens inresponse todepolarization.NeuronElectrodeAElectrodeBElectrodeCABC

Refractory PeriodThe neuron cannot now respond to a new stimulus b/c K+ and Na+ are on the wrong sides of the membraneSodium/Potassium pumps must now reestablish resting potential so that the neuron can react to a new stimulus

MyelinzationSome neurons are myelinized (covered with a sheath of Schwann cells), which insulate the nerves impulseBreaks in this sheath are called nodes of Ranvier. Impulses jump from node to node (saltatory conduction)

Figure 45-12aAction potentials jump down axon.Nodes of RanvierSchwann cells (glia)wrap around axon,forming myelin sheathAxonSchwann cell membranewrapped around axonAction potential jumpsfrom node to node

Figure 45-12bWHY ACTION POTENTIALS JUMP DOWN MYELINATED AXONSSchwann cellNode ofRanvier3. In this way, electricalsignals continue to jumpdown the axon much fasterthan they can move downan unmyelinated cell.1. As charge spreads downan axon, myelination (viaSchwann cells) preventsions from leaking out acrossthe plasma membrane.2. Charge spreadsunimpeded until it reachesan unmyelinated section ofthe axon, called the nodeof Ranvier, which is packedwith Na+ channels.

At the SynapseThe impules reaches a presynaptic dead-end, but still needs to be carried to the postsynaptic cellChemicals are needed to bridge that gap and transmit information between these cells Calcium gates open, letting Ca+2 ion into the presynaptic cellSynaptic vessicles on the presynaptic cell release neurotransmitter substancesNeurotransmitters bind with postsynaptic cell receptorsIf its Na+ gates are open, the membrane depolarizes, resulting in excitatory postsynaptic potential (EPSP)If its Na+ gates are closed, the membrane becomes hyperpolarized and results in inhibitory postsynaptic potential (IPSP)Neurotransmitters are degraded and recycled by enzymes in the synaptic cleft and picked up by the presynaptic cell to be re-used

Figure 45-14SynapticvesiclesSynapseEnd of axonDendrite

Figure 45-15PresynapticneuronPostsynapticneuronACTION POTENTIAL TRIGGERS RELEASE OF NEUROTRANSMITTERNa+ and K+channelsPresynapticmembrane(axon)Postsynapticmembrane(dendrite orcell body)SynapticcleftActionpotentials1. Action potential arrives;triggers entry of Ca2+.2. In response to Ca2+, synapticvesicles fuse with presynapticmembrane, then releaseneurotransmitter.3. Ion channels open whenneurotransmitter binds; ionflows cause change inpostsynaptic cell potential.4. Ion channels will close asneurotransmitter is brokendown or taken back up bypresynaptic cell (not shown).

Figure 45-15-Table 45-2

The Nervous SystemIn primative organisms, there is a primitave nervous system, often with no centralized control center (esp with radially symmetric animals)With bilateral symmetry and cephalization, nervous systems became ladder-like and ganglia began taking on a primitive brain-like functionWith vertebrates, there is 1 major nerve bundle and a brain.

The Vertebrate Nervous systemReflex-see following diagramCNS (Central Nervous System)-Brain, spinal cordPNS (Peripheral Nervous System)-sensory neurons that transmit impulses to the CNS, and back to effectorsMotor neurons within the PNS:Somatic Nervous system-directs skeletal musclesAutonomic Nervous system-directs organ activities and involuntary muscles (2 divisions);Sympathetic nervous system-Prepare the body for action (increasing heart rate, release of sugar, i.e. fight or flight)Parasympathetic nervous system-tranquil functions like saliva or digestive enzyme release

Figure 45-1The brain integrates sensory information and sends signalsto effector cells.When reflexes occur, sensory information bypasses thebrain.Sensory neuronSensory receptorCNS (brain spinal cord)InterneuronMotor neuron(part of PNS)Effector cellsSensoryreceptorMotor neuronEffector cellsSensory neuronSpinal cordInterneuron

Figure 45-18Central nervous system (CNS)Information processingPeripheral nervous system (PNS)Sensoryinformationtravels inafferent divisionMost informationtravels inefferent division,which includesSomaticnervoussystemAutonomicnervous systemParasympatheticdivisionSympatheticdivision

Figure 45-19PARASYMPATHETIC NERVESRest and digestSYMPATHETIC NERVESFight or flightConstrict pupilsStimulate salivaSlow heartbeatConstrict airwaysStimulate activityof stomachInhibit release ofglucose; stimulategallbladderStimulate activityof intestinesContract bladderPromote erectionof genitalsSacralnervesLumbarnervesThoracicnervesCervicalnervesCranialnervesDilate pupilsInhibit salivationIncrease heartbeatRelax airwaysInhibit activityof stomachStimulate releaseof glucose; inhibitgallbladderInhibit activityof intestinesRelax bladderPromoteejaculation andvaginal contractionSecreteepinephrine andnorepinephrine(hormones thatstimulate activity;see Chapter 47)Sympathetic chain:bundles of nervesthat synapse withnerves from spinalcord, then sendprojections to organs

Sensation and PerceptionThe Brain has different regions for processing different information, but the cerebral cortex (outside) of the brain processes most informationVarious organs function to allow the organism to get information about the outside world.

Figure 45-20The brain is made up of four distinct structures.Inside viewDiencephalonInformationrelay and controlof homeostasisBrain stem Information relayand center of autonomic controlfor heart, lungs, digestive systemCerebrumConsciousthought,memoryCerebellumCoordinationof complexmotor patterns The cerebrum has two hemispheres, each of whichhas four lobes.Rear viewLeft cerebralhemisphereRight cerebralhemisphereCorpus callosum:neurons that connectthe two hemispheresInside viewFrontal lobeParietal lobeOccipital lobeTemporal lobeCorpus callosum

Figure 45-21Top view of cerebrumMotor functions(right side of body)Hearing (right ear)Language andmath computationSight(right visual field)LefthemisphereRighthemisphereTop viewCorpus callosumMotor functions(left side of body)Sense of touchand of temperature(left side of body)Hearing (left ear)Spatialvisualizationand analysisSight(left visual field) Cross section through area responsible for sense of touchand of temperatureLefthemisphereIntra-abdominalTongueTeethJaw LipsNoseEyeThumbFingersHandArmHeadTrunkHipLegGenitalsSense of touchand of temperature(right side of body)

Figure 46-4Outer earMiddle earInner earAuditory neurons (to brain)CochleaEar ossiclesEar canalSound waves (in air)Tympanic membrane (eardrum)Middle ear cavityCochleaStapesSound waves (in fluid)Oval window

Figure 46-5CochleaAuditory nerveNeurons (to auditory nerve)Three fluid- filled chambersTectorial membraneHair cellsTectorial membraneStereociliaOuter hair cellsAxons of sensory neurons Inner hair cellsBasilar membraneThe middle chamber of the fluid-filled cochlea contains hair cells.Hair cells are sandwiched between membranes.

Figure 46-8The structure of the vertebrate eye.In the retina, cells are arranged in layers.Ganglion cellsConnecting neuronsPhotoreceptor cellsPigmented epitheliumRetinaDirection of lightFoveaOptic nerve (to brain)ScleraIrisPupilCorneaLensAxons to optic nerve

Figure 46-14What we see in the light (the top compartment in the white box contains a lightbulb wrapped in dark cloth)What pit vipers see in the darkPit vipers can detect infrared radiation.Warm animals emit much more infrared radiation than their surroundings do.Pits

Figure 46-15Taste budPoreTaste cells (salt, acid, sweet, bitter, meaty, etc.)Afferent neuron (to brain)

Figure 46-16BrainNasal cavityOdor moleculesGlomeruliAction potentialsOlfactory bulb of brainBoneOlfactory receptor neuronMucus

Muscles3 types: skeletal, cardiac, and smoothSkeletal muscle consists of muscle fibersSarcolemma-plasma membrane of the muscle cell has many transverse tubules (T tubules) or invaginationsSarcoplasm-cytoplasm of the muscle cell has a strong sarcoplasmic reticulumCells are multinucleate and the nuclei migrate outwardFilled with myofibrils, consisting of:Thin filaments-actin (globular protein) in a double helix, and troponin and tropomyosin that cover binding sites on the actinThick filaments-myosin (filamentous protein) with a protruding head

Figure 46-24-Table_46-1

Figure 46-19SarcomereMyofibrilDark bandLight bandRelaxedContractedMuscle tissueBundle of muscle fibers (many cells)MusclesMuscle fiber (one cell) contains many myofibrils

Figure 46-20MyofibrilRelaxedContractedThin filament (actin)Thick filament (myosin)Z diskAACCDDBB

Muscle ContractionIs described as a sliding filament modelATP binds to the myosin head, forming ADP+PCalcium ion binds to troponin, which shifts the tropomysin, exposing the binding sites on the actin filamentsMyosin heads bind to actin at the binding sites, releasing the ADP+P. This pulls the actin toward the center of the sarcomere, causing the muscle fiber to contractAddition of new ATP unbinds the cross-brige between actin and myosin, and the muscle goes back to its unattached positionGiven all of this, why rigor mortis?

Figure 46-22CHANGES IN THE CONFORMATION OF THE MYOSIN HEAD PRODUCE MOVEMENT.1. ATP bound to myosin head. Head releases from thin filament.2. ATP hydrolized. Head pivots, binds to new actin subunit.3. Pi released. Head pivots, moves filament (power stroke).4. ADP released. Cycle is ready to repeat.Myosin head of thick filamentActin in thin filament

Figure 46-23Tropomyosin and troponin work together to block the myosin binding sites on actin.Myosin headTroponinTropomyosinActinMyosin binding sites blockedCalcium ionsMyosin binding sitesWhen a calcium ion binds to troponin, the troponin-tropomyosin complex moves, exposing myosin binding sites.Myosin binding site exposed to myosin headCalcium ionTroponin-tropomyosin complex, moved

Neuromuscular JunctionsThis occurs when the end of an axon synapes with a muscle.Action potential releases acetylcholineThis generates action potential on the sarcolemma and T tubulesSarcoplasmic reticulum releases Calcium ionActin/Myosin cross bridges form

Figure 46-24HOW DO ACTION POTENTIALS TRIGGER MUSCLE CONTRACTION?Motor neuronMuscle cellMotor neuronAction potentialAChACh receptorAction potentialsThick filaments (myosin)Thin filaments (actin)Ca2+ ions1. Action potential arrives; acetylcholine (Ach) is released.2. ACh binds to ACh receptors on the muscle cell, triggering depolari-zation that leads to action potential.3. Action potentials propagate across muscle cells plasma membrane and into interior of cell via T tubules.4. Proteins in T tubules open Ca2+ channels in sarcoplasmic reticulum.5. Ca2+ is released from sarcoplasmic reticulum. Sarcomeres contract when troponin and tropomyosin move in response to Ca2+ and expose actin binding sites in the thin filaments (see Figure 46.23).

Reproduction While some animals are capable of asexual reproduction (budding, parthenogenesis), most reproduce sexuallyHumans, as well as some other animals have both primary and secondary sex characteristicsPrimary sex characteristics=structures directly involve with sexual reproductionSecondary sex characteristcs=structures that distinguish male from female, but arent involved in reproduction directly

Human Reproductive AnatomyFemaleOvaries-produce eggs and hormonesOviducts (fallopian tubes)-carry eggs to uterusUterus-muscular organ for implantation and development of young. Neck of the uterus is a muscular structure called the cervixVagina-tube-like structure leading out of the body from the uterusMaleTestis-produce sperm and are made of seminiferous tubules and interstitial (stem) cells. These hang below the body in the scrotum b/c sperm are best produced about 2 degrees below body tempEpididymis-coiled tube attached to each testis where sperm matureVas deferens-tube that transfers sperm from epiddiymis to urethraSeminal vesicles-glands that secrete mucus that mixes with the sperm to make semen. Mucus contains fructose to give the sperm energy and prostaglandins that stimulate uterine contractions Prostate gland-secretes an alkaline fluid into the semen which helps to neutralize vaginal acidity as well as any acidity from leftover urine in the urethraBulbourethral (Cowpers) glands-secrete fluid into the urethra for lubricationPenis-transport structure for semen

Figure 48-9Side viewFront viewVaginaCervixUterusOpening of vaginaOpening of urethraLabium majusLabium minusClitorisUrinary bladderUrethraOviductOvaryOviductOvaryVaginaCervixUterus

Figure 48-7Side viewFront viewVas deferensBulbourethral glandProstate glandEjaculatory ductSeminal vesicleVas deferensScrotumTestisEpididymisUrinary bladderVas deferensScrotumTestisEpididymisBulbourethral glandProstate glandSeminal vesicleErectile tissue ofpenisUrethra Prepuce (foreskin)Urinary bladderErectile tissue of penisUrethra

Figure 48-7-Table 48-1

Gametogenesis in MalesSpermatogenesis-begins at puberty and ends at death. Spermatogonia divide mitotically to make primary spermatocytes, which go through meiosis. Cells produced by Meiosis I are called secondary spermatocytes. Cells produced by meiosis II are called spermatids.Sertoli cells in the seminiferous tubules nourish the spermatids as they mature. They finish maturing into sperm in the epididymis where theyre stored until used.Sperm contain a head region, containing the nucleus and acrosome (with enzymes), the midpiece, containing mitochondria to power the tail, and the tail

Figure 48-3SpermatogenesisMitosis anddifferentiationSpermatogonium (2n)Primary spermatocyte (2n)(May divide by mitosis toform more spermatogonia)Secondaryspermatocyte (n)Meiosis IMeiosis IISpermatids (n)Mature spermcells (n)OogenesisMeiosis IMeiosis IIMitosis anddifferentiationOogonium (2n)Primary oocyte (2n)Secondary oocyte polar body (n)Ootid polar body (n)Mature egg cell (ovum) (n)

Figure 22-2AcrosomeHeadFlagellumNucleusCentriolePlasmamembraneVacuole(not presentin all sperm)MitochondriaNeckMidpieceTail

Gametogenesis in FemalesOogenesis-begins during embryonic development with oogonia that divide mitotically to make primary oocytes.Primary oocytes will undergo meiosis, however the timing is different than that of the male. Before birth, these proceed only to Prophase I until the female hits puberty.At puberty, once per month, 1 primary oocyte will proceed through meiosis I within a group of cells called a follicle, that nourishes and protects the cell. At the end of Mieosis I, cytoplasmic division is uneven, resulting in 1 secondary oocyte and 1 polar body. This polar body may go through meiosis II, but eventually disintegrates and is not used. The secondary oocyte is what is ovulated when the folicle breaks open on the wall of the ovary If it is fertilized as it proceeds down the fallopian tube, it undergoes Meiosis II, but again, cytoplasmic division is uneven so only one mature ovum is produced

Hormonal Control of ReproductionThe female reproductive cycle is characterized by 2 separate cycles, since the body needs to prepare both the egg and the uterus for implantationThe hypothalamus releases gonadotropin releasing hormone (GnRH), because of low levels of estrogen and progesterone in the blood, which stiumlates the anterior pitutary to release follicle stimulating hormone (FSH) and luteinizing hormone (LH) The ovarian cycleThe follicular phase-development of the egg and estrogen secretion from the follicleOvulation-midcycle release of the egg b/c of positive feedback from the quick release of LHLuteal phase-secretion of estrogen and progesterone from the corpus luteum after ovulation and the corpus luteum thickensThe menstrual cycleEndometrium thickens as a result of the estrogen and progesterone from the luteal phaseHigh levels of estrogen and progesterone cause negative feedback of the hypothalamus and anterior pituitary which stops producing FSH and LHThe endometrium disintegrates, causing the flow phase(menstrual cycle)If an embryo were to have implanted, it would secrete human chorionic gonadotropin (HCG), which would sustain the corpus luteum, which would continue to secrete estrogen and progesterone (pregnancy tests detect HCG). Later, the placenta would produce progesterone.

Figure 48-12FolliclecellsOocytes1. Formation of primaryoocytes within follicles5. Degeneration ofcorpus luteum3. Maturation offollicleSecondary oocyteto oviduct4. Ovulation2. Follicle growth

Figure 48-13Menstrual(uterine)cycleOvulationPituitaryhormonecycle OvarianhormonecycleOvariancycleFollicle growthFOLLICULAR PHASECorpus luteum degenerationLUTEAL PHASEEstradiolProgesteroneMenstruationFSHLHHormone levelsHormone levelsThickness ofuterine liningDays07142128

Figure 48-14OvulationFollicle growthFOLLICULAR PHASECorpus luteum degenerationLUTEAL PHASEEstradiolProgesteroneOvarian hormones andpituitary hormones exertfeedback on each otherNegative feedbackon LHPositive feedbackon LHNegative feedbackon LH,FSHFollicles andcorpus luteumsecretehormones

Hormones in the male cycleThe same hormones that regulate the female cycle also regulate the male.Again, as the hypothalamus releases GnRH, the anterior pituitary releases FSH and LH (which stimulates the interstitial cells in males, so its called ICSH in males)Interstitial cells release testosterone and other androgens, which cause the Sertoli cells to nourish the sperm cells. Hormone and gamete production are relatively stable throughout the cycle

DevelopmentIn some animals, theres metamorphosis (insects have complete or incomplete), amphibians have a different form where they re-appropriate the energy and cells from a tail to the legsIn humans, development continues from fertilization until birth, and the infant resembles the adult

FertilizationOccurs when the sperm penetrates the plasma membrane of the secondary oocyte.Recognition-sperm secretes a protein that binds with receptor molecules in the zona pellucida (surrounding the plasma membrane of the oocyte)Penetration-the plasma membrane of the gametes fuse so that the sperm nucleus can enter the oocyteA fertilization membrane forms-blocking any other sperm from entering the oocyteThe secondary oocyte completes meiosis II-the polar body is dischargedNuclear fusion/replication-the gamete nuclei fuse resulting in a diploid zygote nucleus

Figure 22-1Haploid (n)Diploid (2n)SpermEggFertilizedeggBlastulaGastrulaAdultNewbornFirst trimesterSecond trimesterEarly first trimesterCLEAVAGEFERTILIZATION

Figure 22-9FertilizationDay 0Fallopian tubeDay 1Day 2Day 3Day 4Day 5BlastocystOvulationOvaryUterusPrecursorto placentaTrophoblastDays 710: Implantation in uterine wallInnercellmassDay 6

Figure 22-7A WAVE OF Ca2+ SPREADS FROM THE SITE OF SPERM ENTRY.THE FERTILIZATION ENVELOPE LIFTS AND BLOCKS EXCESS SPERM.ExcessspermSperm entersegg hereSperm entersegg here1. Egg is covered with sperm.One sperm enters.2. Fertilization envelopebegins to lift and clear awayexcess sperm.3. Fertilization envelope expandsacross egg. When complete, allexcess sperm are cleared away.FertilizationenvelopeA wave ofcalcium ionsstarts at the point of spermentry andpropagatesacross the eggCa2+Ca2+

CleavageThis is where the zygote begins to divide mitotically, rapidly, dividing up the cytoplasm from the zygote amongst the daughter cellsPolarity-the egg has an upper animal pole and a lower vegetal pole. Cells at the vegetal pole form the yolkCleavage type-early cleavages are polar, dividing the egg into segments (like and orange). Later, the cleavages become parallel with the equator (equatorial cleavage)Recall that protostomes exhibit spiral cleavage(determinate), while deuterostomes exhibit radial cleavage (indeterminate)Indeterminate cleavage happens when a cell is formed that can complete its normal development if separated from the embryoDeterminate cleavage happens when a cell is formed that cannot complete development on its own, but is instead a part of a developing tissue

Figure 22-8-1Radial cleavage: Cells divide at right angles to each other.Spiral cleavage: Cells divide at oblique angles to each other.

Development continues. . . As cleavage continues, a solid ball of cells called a morula is formed.After the morula phase, as cells continue to divide, the result is a hollow ball of cells called a blastulaGastrulation follows (weve discussed this), forming the germ layers, archenteron (primordial gut) and blastopore

OrganogenesisRecall that the 3 tissue layers give rise to distinct organs and organ systemsThe Notochord in chordates forms along the dorsal surface of the mesoderm. If the chordate is a vertebrate, the vertebrae will form from nearby cells in the mesodermThe Neural tube forms in the ectoderm layer above the notochord from a layer of cells called the neural plate. The plate indents, forming the neural groove, which rolls up into the neural tube, which will develop into the CNS. Some cells roll off the top of the neural tube to form the neural crest, which will form many of the components of the head (teeth, bones, muscles, pigment cell of the skin, nerves)

Figure 22-10Ectoderm-derived Nervous system Cornea and lens of eye Epidermis of skin Epithelial lining of mouth and rectumMesoderm-derived Skeletal system Circulatory system Lymphatic system Muscular system Excretory system Reproductive system Dermis of skin Lining of body cavityEndoderm-derived Epithelial lining of: digestive tract respiratory tract reproductive tract urinary tractLiverPancreasThyroidParathyroidsThymus

Figure 22-131. Notochord formsfrom mesoderm cellssoon after gastrulationis complete. NotochordStart of gutEctodermMesodermEndodermDorsalVentralSignalingmoleculesNeural tubeFORMATION OF NEURAL TUBE2. Signals from cells in andnear the notochord induceinward folding of the ectoderm.3. Formation of neuraltube is complete. Cells of notochord are fated to die.

Extraembryonic membrane development (Amniotes)These develop outside of the embryo in birds, reptiles, and humansChorion-outer membrane that in egg-layers is for gas exchange. This implants into the endometrium and later forms the placenta in humansAllantois-this is a sac that buds from the archenteron. It encircles the embryo forming a layer below the chorion. In birds and reptiles, it stores wastes, and then fuses with the chorion for gas exchange. In mammals, this transports waste to the placenta, and finally forms the umbilical cordAmnion-encloses the amniotic cavity (fluid-filled) to cushion and protect the embryoYolk sac-in birds and reptiles, this is a food store for the embryo. In the placentals, the sac is empty b/c the embryo gets nourishment through the placenta

Variations on embryonic developmentThe stages described are general deuterostome stages. There are some specific differences between organisms.FrogsGray crescent forms b/c of the reorganization of the cytoplasm of the zygotes cellsDuring gastrulation, a dorsal lip is formed when cells migrate over the top edge of the blastopore, over a region that was formerly the gray crescentYolk material is more extensiveBirdsBlastodisc-cleavage in the blastula forms a flattened disc-shaped region that sits on top of the yolkPrimitive streak-the blastopore is line-shaped, rather than round HumansBlastocyst consists of 2 parts, the trophoblast and embryonic discTrophoblast-outer ring of cells that is embedded in the endometrium and that produces the HCG, which maintains the corpus luteum. This later forms the chorion and placentaEmbryonic disc- is the inner cell mass (ICM) within the cavity formed by the trophoblast. This is like the blastodisc of birds, and forms a primitive streak

Factors Influencing DevelopmentWhat causes cells to differentiate along different lines?Egg cytoplasm-unequal distribution forms polar bodies and oocytes, it also forms the gray crescent in frogs, and causes poles in embryosEmbryonic induction-occurs where one cell group influences the development of its neighboring cells (these are called organizers) Ex: notochord cells, dorsal lip cellsHomeotic (Hox) genes-These turn on and off genes that affect development. Recall that these tell the embryo where each segment of the body is

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