Respiratory Respiratory SystemSystem

Chapter 8Chapter 8

Respiratory System Respiratory System FunctionsFunctions

To get oxygen into the red blood To get oxygen into the red blood cellscells

To release carbon dioxide from the To release carbon dioxide from the bloodblood

““pulmonary”- refers to the lungspulmonary”- refers to the lungs

RespirationRespiration Inhalation- air enters nose and mouthInhalation- air enters nose and mouth gains heat and moisture as it enters gains heat and moisture as it enters

the lungsthe lungs filtered by nose hairs and cilia within filtered by nose hairs and cilia within

the trachea to remove contaminantsthe trachea to remove contaminants exhalation- warm air cools as it leaves exhalation- warm air cools as it leaves

the body- condenses on a cold day the body- condenses on a cold day and looks like smokeand looks like smoke

Pathway of airPathway of air Nose- has odor receptors, hairs filter Nose- has odor receptors, hairs filter

air, tear ducts and sinuses drain hereair, tear ducts and sinuses drain here nasopharynx- just above the back of nasopharynx- just above the back of

throatthroat pharynx- connects mouth and nasal pharynx- connects mouth and nasal

passagespassages tonsils- right behind tongue- part of tonsils- right behind tongue- part of

the immune systemthe immune system

Into the windpipeInto the windpipe Glottis- opening from pharynx to tracheaGlottis- opening from pharynx to trachea epiglottis- flap of tissue that covers the epiglottis- flap of tissue that covers the

glottis when you swallow so you don’t glottis when you swallow so you don’t chokechoke

larynx- just below glottis- has vocal cordslarynx- just below glottis- has vocal cords trachea- windpipe- has cartilage rings- trachea- windpipe- has cartilage rings-

prevents collapseprevents collapse bronchi- forks of trachea that leads to the bronchi- forks of trachea that leads to the

lungslungs

The lungsThe lungs Bronchi fork into smaller bronchiolesBronchi fork into smaller bronchioles bronchi and bronchioles are bronchi and bronchioles are

surrounded by smooth muscles- they surrounded by smooth muscles- they can contract and cause asthma- can contract and cause asthma- difficulty breathingdifficulty breathing

end in tiny air sacs called end in tiny air sacs called alveolialveoli Located in the thoracic cavity of the Located in the thoracic cavity of the

upper chestupper chest

AlveoliAlveoli Made of simple squamous epithelium Made of simple squamous epithelium

surrounded by tiny capillariessurrounded by tiny capillaries gas exchange takes place heregas exchange takes place here All these tiny sacs increase surface area All these tiny sacs increase surface area

for gas exchange- lungs have 60mfor gas exchange- lungs have 60m22 of of areaarea

lined with surfactant that prevents lined with surfactant that prevents them from sticking closed by h-bonding them from sticking closed by h-bonding of waterof water

Mechanics of breathingMechanics of breathing The thoracic cavity is sealed so when The thoracic cavity is sealed so when

the the diaphragm musclediaphragm muscle on the bottom on the bottom contracts, the cavity gets biggercontracts, the cavity gets bigger

the vacuum that this creates pulls the vacuum that this creates pulls the lungs open and air rushes isthe lungs open and air rushes is

diaphragm relaxes- lungs expel the diaphragm relaxes- lungs expel the air because they are elasticair because they are elastic

damage to this cavity= lung collapsedamage to this cavity= lung collapse

Other musclesOther muscles External intercostal muscles- expands External intercostal muscles- expands

rib cage to help with inhalationrib cage to help with inhalation internal intercostal muscles- cause rib internal intercostal muscles- cause rib

cage to get smaller= forced exhalationcage to get smaller= forced exhalation contraction of abdominal muscles can contraction of abdominal muscles can

also force more air out of the lungs by also force more air out of the lungs by pushing up against the diaphragm pushing up against the diaphragm

Control of breathingControl of breathing Medulla- control center- generates Medulla- control center- generates

continuous impulses to stimulate continuous impulses to stimulate diaphragmdiaphragm

chemoreceptors sensing carbon chemoreceptors sensing carbon dioxide and acidity in the carotid dioxide and acidity in the carotid (neck) arteries and the aorta can (neck) arteries and the aorta can increase rateincrease rate

Gas exchangeGas exchange Carbon dioxide is carried in blood Carbon dioxide is carried in blood

plasma as bicarbonateplasma as bicarbonate hemoglobin in red blood cells picks hemoglobin in red blood cells picks

up oxygen and changes to up oxygen and changes to oxyhemoglobinoxyhemoglobin

In tissuesIn tissues The oxyhemoglobin drops off oxygenThe oxyhemoglobin drops off oxygen carbon dioxide enters red blood cells carbon dioxide enters red blood cells

and is then converted into and is then converted into bicarbonate and enters the plasmabicarbonate and enters the plasma

Upper Respiratory Upper Respiratory InfectionsInfections

Sinusitis- infection of the sinuses- Sinusitis- infection of the sinuses- hollow areas of the skullhollow areas of the skull

clogged drainsclogged drains pain increases as you lean forwardpain increases as you lean forward Treated with spray decongestants, Treated with spray decongestants,

hot shower hot shower

Otitis mediaOtitis media Bacterial infection of middle earBacterial infection of middle ear bacteria get in through auditory bacteria get in through auditory

tubetube Treatment= antibioticsTreatment= antibiotics tubes sometimes are inserted to tubes sometimes are inserted to

drain fluiddrain fluid

TonsilitusTonsilitus Tonsils become inflamed and Tonsils become inflamed and

enlargedenlarged Tonsils normally fight pathogensTonsils normally fight pathogens If severely swollen, they can If severely swollen, they can

interfere with breathing so they are interfere with breathing so they are sometimes removedsometimes removed

immune system is impaired if immune system is impaired if removedremoved

laryngitislaryngitis Infection of larynxInfection of larynx Causes hoarsenessCauses hoarseness

Lower respiratory Lower respiratory diseasesdiseases

Acute bronchitus- a bacterial infection of Acute bronchitus- a bacterial infection of the bronchi after a viral Upper the bronchi after a viral Upper respiratory infectionrespiratory infection

dry cough becomes a deep cough that dry cough becomes a deep cough that expectorates mucus and pusexpectorates mucus and pus

pneumonia- viral or bacterial infection of pneumonia- viral or bacterial infection of part of the lungs- alveoli fill with fluidpart of the lungs- alveoli fill with fluid

usually occurs after the fluusually occurs after the flu fever, headache, chest painfever, headache, chest pain

More Lower Resp. More Lower Resp. InfectionsInfections

Pulmonary tuberculosis- bacterialPulmonary tuberculosis- bacterial Bacteria are encased by lung cells- Bacteria are encased by lung cells-

called tuberculescalled tubercules skin test reveals exposureskin test reveals exposure some people can recover naturallysome people can recover naturally sanatoriums- quarantine areassanatoriums- quarantine areas Treatment= antibiotics- but now Treatment= antibiotics- but now

some strains are partially resistantsome strains are partially resistant

Other lung disordersOther lung disorders Pulmonary fibrosis- the inhalation of Pulmonary fibrosis- the inhalation of

dust and fibers such as asbestos dust and fibers such as asbestos causes fibrous connective tissue to causes fibrous connective tissue to build up in the alveolibuild up in the alveoli

the elasticity of the lungs is reduced the elasticity of the lungs is reduced and they cannot inflate properlyand they cannot inflate properly

poor respiration poor respiration

Chronic bronchitusChronic bronchitus Airways are inflamed and filled with Airways are inflamed and filled with

mucusmucus cilia have been lostcilia have been lost more prone to infectionmore prone to infection caused by smoking and exposure to caused by smoking and exposure to

pollutantspollutants

EmphysemaEmphysema Alveoli are stretched out and damaged Alveoli are stretched out and damaged

so that less surface area is available for so that less surface area is available for gas exchangegas exchange

chronicchronic lungs aren’t as elastic and don’t exhale lungs aren’t as elastic and don’t exhale

all the air present- inefficient because all the air present- inefficient because lots of stale air remains in the lungslots of stale air remains in the lungs

supplemental oxygen is sometimes supplemental oxygen is sometimes needed needed

AsthmaAsthma Wheezing, breathlessness and coughingWheezing, breathlessness and coughing affects bronchi and bronchiolesaffects bronchi and bronchioles when airways are exposed to an when airways are exposed to an

irritant, the smooth muscle spasms and irritant, the smooth muscle spasms and constricts themconstricts them

triggered by immune systemtriggered by immune system Treatment- inhalers to stop spasms and Treatment- inhalers to stop spasms and

dilate airwaysdilate airways

Lung cancerLung cancer Steps- caused by smoking and other Steps- caused by smoking and other

chemicals- 1. thickening of cells in chemicals- 1. thickening of cells in airway, 2. cilia are lost, 3. nucleus airway, 2. cilia are lost, 3. nucleus becomes abnormal (damaged DNA), 3. becomes abnormal (damaged DNA), 3. cancerous cells break free and spread cancerous cells break free and spread to other parts of the bodyto other parts of the body

surgery can remove the affected part of surgery can remove the affected part of the lung if it the cancer hasn’t spreadthe lung if it the cancer hasn’t spread

also caused by second hand smokealso caused by second hand smoke