Upload
uconn-stamford
View
119
Download
1
Tags:
Embed Size (px)
Citation preview
© 2010 Pearson Education, Inc.
THE STRUCTURAL ORGANIZATION OF ANIMALS
• Life is characterized by a hierarchy of organization.
• In animals:
– Individual cells are grouped into tissues
– Tissues combine to form organs
– Organs are organized into organ systems
– Organ systems make up the entire organism
Cellular level:Muscle cell
Figure 21.1-1
Cellular level:Muscle cell
Tissue level:Cardiac muscle
Figure 21.1-2
Cellular level:Muscle cell
Tissue level:Cardiac muscle
Organ level:Heart
Figure 21.1-3
Cellular level:Muscle cell
Tissue level:Cardiac muscle
Organ level:Heart
Organ system level:Circulatory system Organism level: Multiple
organ systemsfunctioning together
Figure 21.1-5
© 2010 Pearson Education, Inc.
Cell
Level Description
The basic unit ofall living organisms
Muscle cell
Example
HIERARCHICAL ORGANIZATION OF ANIMALS
Figure 21.UN01a
© 2010 Pearson Education, Inc.
Level Description Example
HIERARCHICAL ORGANIZATION OF ANIMALS
Tissue A collection of similarcells that performa specific function
Cardiac muscle
Figure 21.UN01b
© 2010 Pearson Education, Inc.
Level Description Example
HIERARCHICAL ORGANIZATION OF ANIMALS
Organ Multiple tissuesforming a structurethat performs a specific function
Heart
Figure 21.UN01c
© 2010 Pearson Education, Inc.
Level Description Example
HIERARCHICAL ORGANIZATION OF ANIMALS
Organsystem
A team of organs thatwork together
Circulatorysystem
Figure 21.UN01d
© 2010 Pearson Education, Inc.
Level Description Example
HIERARCHICAL ORGANIZATION OF ANIMALS
Organism A living being, whichdepends on thecoordination of allstructural levels forhomeostasis andsurvival Person
Figure 21.UN01e
© 2010 Pearson Education, Inc.
Cell
Level
Tissue
Organ
Organ system
Organism
Description
The basic unit ofall living organisms
A collection of similarcells that performa specific function
Multiple tissuesforming a structurethat performs a specific function
A team of organs thatwork together
A living being, whichdepends on the coordinationof all structural levels forhomeostasis and survival
Muscle cell
Example
Cardiac muscle
Heart
Circulatory system
Person
HIERARCHICAL ORGANIZATION OF ANIMALS
Figure 21.UN01
© 2010 Pearson Education, Inc.
Form Fits Function
• Analyzing a biological structure gives us clues about:
– What it does
– How it works
© 2010 Pearson Education, Inc.
• Biologists distinguish anatomy from physiology.
– Anatomy is the study of the structure of an organism.
– Physiology is the study of the function of an organism’s structural equipment.
© 2010 Pearson Education, Inc.
Tissues
• In most multicellular animals, cells are grouped into tissues.
– A tissue is an integrated group of similar cells that perform a specific function.
– Animals have four main categories of tissue.
© 2010 Pearson Education, Inc.
Epithelial Tissue
• Epithelial tissue, also known as epithelium:
– Covers the surface of the body
– Lines organs and cavities within the body
Some examples of organslined with epithelial tissue:
Heart
Lung
Stomach
Small intestine
Large intestine
Urinary bladder
Figure 21.3a
Epithelial tissue lining esophagusFigure 21.3b
Epithelial tissue lining small intestineFigure 21.3c
© 2010 Pearson Education, Inc.
• Cells of epithelial tissues:
– Are bound tightly together
– Form a protective barrier
– Fall off and are continuously renewed
© 2010 Pearson Education, Inc.
Connective Tissue
• Connective tissues have a sparse population of cells in an extracellular matrix consisting of a web of protein fibers within a uniform foundation that may be liquid, jellylike, or solid.
• The structure of connective tissue is correlated with its function: to bind and support other tissues.
(a) Loose connective tissue(under the skin)
(b) Adipose tissue
(c) Blood
(d) Fibrous connective tissue(forming a tendon)
(e) Cartilage (at the end of a bone)(f) Bone
Cell
Cells
Matrix
Plasma
Matrix
Cells
Collagenfiber
Fatdroplets
White bloodcells
Red bloodcell
Cellnucleus
Collagenfibers
Figure 21.4
© 2010 Pearson Education, Inc.
• Loose connective tissue:
– Is the most widespread connective tissue
– Binds epithelia to underlying tissues
– Holds organs in place
(a) Loose connective tissue(under the skin)
Cell
Collagen fiber
Figure 21.4a
© 2010 Pearson Education, Inc.
• Adipose tissue:
– Stores fat
– Stockpiles energy
– Pads and insulates the body
(b) Adipose tissue
Fatdroplets
Figure 21.4b
© 2010 Pearson Education, Inc.
• Blood:
– Is a connective tissue with a matrix of liquid
– Contains red and white blood cells suspended in plasma
(c) Blood
Plasma
White blood cells
Red blood cell
Figure 21.4c
© 2010 Pearson Education, Inc.
• Fibrous connective tissue:
– Has a dense matrix of collagen
– Forms tendons and ligaments
(d) Fibrous connective tissue(forming a tendon)
Cell nucleus
Collagen fibers
Figure 21.4d
© 2010 Pearson Education, Inc.
• Cartilage:
– Has a strong but rubbery matrix
– Functions as a flexible, boneless skeleton
– Forms the shock-absorbing pads that cushion the vertebrae of the spinal column
(e) Cartilage (at the end of a bone)
Matrix
Cells
Figure 21.4e
© 2010 Pearson Education, Inc.
• Bone:
– Is a rigid connective tissue
– Has a matrix of collagen fibers hardened with deposits of calcium salts
(f) Bone
Cells
Matrix
Figure 21.4f
© 2010 Pearson Education, Inc.
Muscle Tissue
• Muscle tissue:
– Consists of bundles of long, thin, cylindrical cells called muscle fibers
– Has specialized proteins that contract when stimulated by a nerve
(a) Skeletal muscle(short segments ofseveral muscle fibers)
(b) Cardiac muscle
Unit ofmusclecontraction
Musclefiber(cell)
Musclefiber
Junction betweentwo cells
(c) Smooth muscle
Nucleus
Nucleus
Muscle fiber
Nuclei
Figure 21.5
(a) Skeletal muscle(short segments ofseveral muscle fibers)
Unit ofmusclecontraction
Muscle fiber(cell)
Nuclei
Figure 21.5a
(b) Cardiac muscle
Musclefiber
Junction between two cells
Nucleus
Figure 21.5b
(c) Smooth muscle
Muscle fiber
Nucleus
Figure 21.5c
© 2010 Pearson Education, Inc.
• Skeletal muscle is:
– Attached to bones by tendons
– Responsible for voluntary movements
– Striated because the contractile apparatus forms a banded pattern in each cell or fiber
© 2010 Pearson Education, Inc.
• Cardiac muscle is:
– Composed of cells that are branched and striated
– Found only in heart tissue
– Responsible for the contraction of the heart
© 2010 Pearson Education, Inc.
• Smooth muscle is:
– Named for its lack of obvious striations
– Found in the walls of various organs
– Involuntary
© 2010 Pearson Education, Inc.
Nervous Tissue
• Nervous tissue:
– Makes communication of sensory information possible
– Is found in the brain and spinal cord
– Consists of a network of neurons
Brain
Nerve
Spinal cord
Figure 21.6a
Signal-receivingextensions Cell body
Signal-transmittingextensions
LM
Figure 21.6b
© 2010 Pearson Education, Inc.
Organs and Organ Systems
• An organ consists of two or more tissues packaged into one working unit that performs a specific function.
• Examples include the heart, liver, stomach, brain, and lungs.
© 2010 Pearson Education, Inc.
• Organ systems:
– Are teams of organs that work together
– Perform vital body functions
Blast Animation: Anatomy of the Kidney
Skeletal system:supports body andanchors muscles
Cartilage
Bone
Figure 21.8a
Circulatory system:transports substancesthroughout body
Blood vessels
Heart
Figure 21.8b
Respiratory system:
exchanges O2 and
CO2 between blood
and air
Nasal cavity
Bronchus
Pharynx
Trachea
Larynx
Lung
Figure 21.8c
Digestive system:breaks down foodand absorbsnutrients
Large intestine
Small intestine
Esophagus
Stomach
Liver
Mouth
Anus
Figure 21.8e
Muscular system:moves body
Skeletal muscles
Figure 21.8d
Urinary system:rids body ofcertain wastes
Urinary bladder
Urethra
Ureter
Kidney
Figure 21.8f
Reproductive system:produces gametesand offspring
Seminal vesicles
Prostate gland
Vas deferens
Urethra
Oviduct
Vagina
Uterus
Ovary Penis
Testis
Figure 21.8h
Lymphatic andimmune system:defends againstdisease
Lymphaticvessels
Lymphnodes
Thymus
Spleen
Figure 21.8j
Sense organ(ear)
Nervous system:processes sensoryinformationand controlsresponses Spinal cord
Nerves
Brain
Figure 21.8k
© 2010 Pearson Education, Inc.
EXCHANGES WITH THE EXTERNAL ENVIRONMENT
• Every organism is an open system, continuously exchanging chemicals and energy with its surroundings to survive.
© 2010 Pearson Education, Inc.
• An animal’s size and shape affect how it exchanges energy and materials with its surroundings.
• All living cells must be bathed in a watery solution so that exchange of materials can occur.
© 2010 Pearson Education, Inc.
• Animals use three organ systems to exchange materials with the external environment:
– Digestive
– Respiratory
– Urinary
• The circulatory system transports materials inside the body from these exchange surfaces.
Unabsorbed matter (feces) Metabolic waste products (such as urine)
External environment
RespiratorysystemDigestive
system
Urinarysystem
Circulatorysystem
Interstitialfluid
Nutrients
Body cells
Animal
Mouth Food
Anus
Heart
Blood
CO2O2
Figure 21.11
© 2010 Pearson Education, Inc.
REGULATING THE INTERNAL ENVIRONMENT
• Every living organism has the ability to respond to its environment.
© 2010 Pearson Education, Inc.
Homeostasis
• Homeostasis is the body’s tendency to maintain relatively steady conditions in the internal environment when the external environment changes.
Externalenvironment
Large externalchanges
Animal’s internalenvironment
Homeostaticmechanisms
Small internalchanges
Figure 21.12
© 2010 Pearson Education, Inc.
Negative and Positive Feedback
• Most mechanisms of homeostasis depend on a common principle called negative feedback, in which the results of a process inhibit that same process, such as a thermostat that turns off a heater when room temperature rises to the set point.
Animation: Positive Feedback
Animation: Negative Feedback
Thermostat(control center)turns heater off
Set point:Room temperature20C (68F)
Roomtemperaturedrops
Response:Heatingstops
Stimulus:Room temperatureis above set point
Figure 21.13a
Thermostat(control center)turns heater on
Set point:Room temperature20C (68F)
Roomtemperaturerises
Response:Heatingstarts
Stimulus:Room temperatureis below set point
Figure 21.13b
© 2010 Pearson Education, Inc.
• Less common is positive feedback in which the results of a process intensify that same process, such as uterine contractions during childbirth.
© 2010 Pearson Education, Inc.
• Humans have homeostatic mechanisms that aid in thermoregulation, which:
– Cool or
– Heat the body
Blast Animation: Negative Feedback: Body Temperature
Bodytemperaturedrops
Set point:Body temperature near 37C (98.6F)
Stimulus:Body temperatureis above set point
Control centerin brain activatescooling mechanisms
Response:1. Blood vessels dilate2. Sweat is produced
Sweatgland
Skin
Figure 21.14a
Set point:Body temperature near 37C (98.6F)
Bodytemperaturerises
Stimulus:Body temperatureis below set point
Control centerin brain activateswarming mechanisms
Response:1. Blood vessels constrict2. Muscles shiver3. Metabolic rate increases
Skin
Figure 21.14b
© 2010 Pearson Education, Inc.
• Fever:
– Is an abnormally high internal body temperature
– Usually indicates an ongoing fight against infection
© 2010 Pearson Education, Inc.
Osmoregulation
• Living cells depend on a precise balance of:
– Water
– Solutes
• Osmoregulation is the control of the gain or loss of:
– Water
– Dissolved solutes, such as salt
© 2010 Pearson Education, Inc.
Homeostasis in the Urinary System
• The urinary system:
– Plays a central role in homeostasis
– Forms and excretes urine
– Regulates the amount of water and solutes in body fluids
© 2010 Pearson Education, Inc.
• In humans, the two kidneys:
– Are the main processing centers
– Contain many fine tubes called tubules
– Include an intricate network of capillaries
© 2010 Pearson Education, Inc.
• As blood circulates through the kidneys:
– A fraction of it is filtered
– Plasma enters the kidney tubules, forming filtrate
• Filtrate contains:
– Valuable substances that need to be reclaimed (such as water and glucose)
– Substances to be eliminated, such as urea
© 2010 Pearson Education, Inc.
• The human urinary system includes:
– The kidneys
– Nephrons, the functional units of the kidney
– The urinary bladder, where urine is stored
Animation: Nephron Introduction
Renal artery (red) andrenal vein (blue)
(a) Urinary system
Kidney
Ureter
Urinarybladder
Urethra
Figure 21.17a
(b) Kidney
Ureter
Nephron
Figure 21.17b
© 2010 Pearson Education, Inc.
• Nephrons:
– Carry out the functions of the urinary system
– Consist of a tubule and its associated vessels
– Number more than a million in a kidney
(c) A nephron and collecting duct
Branch ofrenal artery
Branch ofrenal vein Collecting
duct
Filter Tubule
To ureter
Figure 21.17c
© 2010 Pearson Education, Inc.
• Nephrons perform four key functions:
– Filtration, forcing water and other small molecules from the blood to form filtrate
– Reabsorption of water and valuable solutes back into the blood
– Secretion of certain substances, such as ions and drugs, into the filtrate
– Excretion of urine from the kidneys
Filtration Reabsorption Secretion
Renal artery
Renal vein
Capillaries
Tubule
Urine
Filtrate
Excretion
Figure 21.18
© 2010 Pearson Education, Inc.
• Hormonal control of the nephrons allows the body to control its internal concentration of:
– Water
– Dissolved molecules
© 2010 Pearson Education, Inc.
• Kidney failure can be caused by:
– Injury
– Illness
– Prolonged use of pain relievers, alcohol, or other drugs
• One option for treatment of kidney failure is dialysis, filtration of blood by a machine.
Used dialyzingsolution (withurea andexcess salts)
Line fromapparatusto vein
Fresh dialyzingsolution
Dialyzingsolution
Line from arteryto apparatus
Tubing made of aselectively permeable membrane
Pump
Figure 21.19