A&p Ii: Chapter 22

Front 1

RESPIRATION

Back 1

all events leading to exchange of gasses between atmosphere & cells followed by
cellular use of the gasses

*FIVE EVENTS TIE RESPIRATION AND CIRCULATORY SYSTEM TOGETHER
A. PULMONARY VENTILATION- air in and out of lungs
B. EXTERNAL RESPIRATION- exchange between lungs and blood
C. TRANSPORTATION OF GASSES: O2 and CO2 thru blood
D. INTERNAL RESPIRATION: exchange between blood and tissue cells
E. CELLULAR RESPIRATION: use of O2 by cells and production of CO2

Front 2

RESPIRATORY TRACT ANATOMY

Back 2

UPPER RESPIRATORY TRACT (conducting zone)
1. MOUTH: main entrance/exit for air
2. NOSE: cleans/humidifies/warms air, resonating chamber for speech, olfaction

a. EXTERNAL NOSE
1) EXTERNAL NARES = NOSTRILS = holes
2) PHILTRUM: skin between nostrils
3) ALAE: skin on lateral aspects of nostrils
4) NASAL, FRONTAL, MAXILLARY BONES
5) HYALINE CARTILAGE -> size and shape

Front 3

RESPIRATORY TRACT ANATOMY 2

Back 3

3. PARANASAL SINUSES
*FRONTAL, SPHENOID, ETHMOID, MAXILLARY
*lighten skull, moisten/warm air, produce mucus
*drain into nasal cavity

4. PHARYNX=THROAT: connects mouth/nose to larynx/esophagus
*nasopharynx, oropharynx, laryngopharynx

5. LARYNX=VOICE BOX: attached by ligaments to hyoid bone
a. opening to trachea, contains vocal cords

b. nine pieces of cartilage make up larynx

1) EPIGLOTTIS (1): elastic, closes off larynx during swallowing
2) CRICOID (1) hyaline, most inferior, ring shaped
3) THYROID (1): hyaline, largest = Adams's apple
4) ARYTENOID (2): hyaline, attached to vocal cords
5) CORNICULATE (2): elastic, on top of arytenoids
6) CUNEIFORM (2): elastic, anterior to corniculates at larynx entrance

Front 4

RESPIRATORY TRACT ANATOMY 2 3

Back 4

c. VESTIBULAR FOLDS=FALSE VOCAL CORDS: superior folds

d. VOCAL FOLDS=TRUE VOCAL CORDS: inferior folds contain
VOCAL LIGAMENTS: attach arytenoid to thyroid cart.
*increase tension, change pitch
*increase velocity of air past cords, inc. volume

6. TRACHEA=WINDPIPE: from larynx to chest region
a. pseudostratified columnar ciliated epithelium moves mucus to pharynx

b. TRACHEAL CARTILAGE:"C"-shaped rings hold trachea open

Front 5

. LOWER RESPIRATORY TRACT = BRONCHIAL TREE

Back 5

1. PRIMARY (1o)BRONCHUS: R/L branches of trachea to R/L lungs


2. SECONDARY (2o) BRONCHUS: 1 to each lobe of each lung

a. R LUNG: primary bronchus divides into 3, 2o bronchi
-1 to each: superior, middle, inferior lobes

b. L LUNG: primary bronchus divides into 2, 2o bronchi
-1 to each: superior and inferior lobes

3. TERTIARY (3o) BRONCHUS: 1 to each segment of lung
*last highly cartilage reinforced branches
*last ciliated epithelium
*last mucus producing epithelium

Front 6

. LOWER RESPIRATORY TRACT = BRONCHIAL TREE
2

Back 6

4. BRONCHIOLE: 4mm diameter, profuse branching of 3o bronchi

5. TERMINAL BRONCHIOLE: <.5mm diameter profuse branching of bronchioles

6. RESPIRATORY BRONCHIOLE: branches off terminal bronchioles
*dotted with ALVEOLI (gas exchange sacs)

7. ALVEOLAR DUCTS: off of respiratory bronchioles = "STALK"

8. ALVEOLAR SACS: off of alveolar ducts, opening to 2 or more alveoli
similar look to a "bunch of grapes"

Front 7

. LOWER RESPIRATORY TRACT = BRONCHIAL TREE
2 3

Back 7

ALVEOLUS (ALVEOLI = pl): small sacs = "grape"
a. large surface area for gas exchange with blood
b. surrounded by elastic fibers
c. ALVEOLAR MACROPHAGES: on alveolar surface clean up bacteria
d. RESPIRATORY MEMBRANE: air/blood barrier, gas exchange occurs here
via diffusion: three parts

1) alveolar wall: SIMPLE SQUAMOUS EPITHELIUM consisting of type I cells

-dotted with type II cells that produce SURFACTANT (detergent-like
lipoprotein found in alveolar fluid, reduces surface tension, keeps alveoli open)

2) BASAL LAMINA (part of basement membrane)
3) CAPILLARY WALL = endothelium

e. INFANT RESPIRATORY DISTRESS SYNDROME: surfactant not
produced until late gestation. Preemies have low surfactant levels, alveoli
collapse with each exhalation. Lots of energy is expended with each
inhalation to open up alveoli.

Front 8

. LUNGS: LUNG -> LOBES -> SEGMENTS -> LOBULES

Back 8

1. R LUNG: larger, wider, shorter than L lung.
*largest lung for air volume
*three lobes: superior, middle inferior

2. L LUNG: longer, thinner than R lung, holds less air
*two lobes: superior and inferior
*CARDIAC NOTCH: indentation for apex of heart

3. HILUS: medial side of lungs entrance/exit of LUNG ROOT:
a. pulmonary aa and vv b. primary bronchus
c. lymphatic vessels d. nerves

4. APEX: top of lung under clavicle

5. BASE: bottom of lung on diaphragm

6. PLEURA: bilayerd membranous sac around lungs
a. parietal pleura: on thorax wall
b. visceral pleura: on lung surface
c. pleural cavity: between two pleura, contains serous fluid to decrease friction
during inhalation and exhalation

*PLEURISY: inflammation of pleura: either too much/little pleural fluid produced

Front 9

MECHANICS OF PULMONARY VENTILATION (breathing)

Back 9

A. DEFINITIONS
1. INSPIRATION = INHALATION: air into lungs
2. EXPIRATION = EXHALATION: air out of lungs
3. BREATH = one inspiration and expiration event

B. PRESSURES INVOLVED IN PULMONARY VENTILATION

1. ATMOSPHERIC PR. (AP): at sea level = 760 mmHg, fairly constant

2. INTRAALVEOLAR PR. (IAP): pr inside the alveoli. Increases and decreases as you
breathe. Always equalizes with AP. If not inhaling/exhaling, IAP = AP.

3. INTRAPLEURAL PRESSURE (IPP): pleural cavity pr. Incr./decreases as breathe.

4. TRANSPLEURAL PRESSURE (TPP): TPP = IPP - IAP
usually = - 4mmHg, keeps alveoli open.

a. If TPP = 0, lungs collapse: ATELECTASIS

b. PNEUMOTHORAX: increase in air in pleural cavity (ie from a stab wound)
5. IAP and IPP VARY AS:
a. change volume of thoracic cavity
b. muscles contract during breathing movements
c. lungs recoil elastically

Front 10

MECHANICS OF PULMONARY VENTILATION (breathing) 2

Back 10

C. AIR FLOW: movement due to pr. differences between regions (air moves from hi to lo pr.)
BOYLE'S LAW: if temp. is constant, an inc. in pr. causes a decrease in volume
P1 V1 = P2 V2 => 10mmHg x 10ml = 5mmHg x 20ml

D. BREATHING: APPLYING BOYLE'S LAW

1. EUPNEA: resting breathing

2. INSPIRATION = INHALATION: active phase (muscle contractions) during eupnea

a. diaphragm contracts: inc. thorax vol. (when relaxes, dec. volume)

b. external intercostals contract: inc. thorax vol. (relax, dec. vol)

c. as inc. thorax vol., lungs expand to fill space causing an inc. lung vol. and a
dec. in IAP

IAP < AP, air flows from HI pr. to LO pr. until IAP = AP

* if forced inhalation, scalene, sternocleidomastoid, pectoralis minor, &
erector spinae mm. are involved

Front 11

. EXPIRATION = EXHALATION

Back 11

: passive process during eupnea due to muscle
relax., gravity, elastic recoil of lungs
a. as ribs fall & diaphragm relaxes, thorax vol. dec., lung vol. dec. & IAP inc.

b. IAP > AP air is forced out of lungs until IAP = AP

* during forced expiration, active contraction of abdominals, internal
intercostal, latissimus dorsi, & quadratus lumborum mm depress ribs & thorax

Front 12

RESPIRATORY VOLUMES AND PULMONARY FUNCTION TESTS

Back 12

A. RESPIRATORY RATE DURING EUPNEA: 12-15 breaths/minute
*breath = inspiration and expiration

B. volume of air exchanged/breath varies with:
*age *sex *height *physical condition *environ. factors

C. SPIROMETER: measures air in/out


D. SPIROGRAM: graph of air exchange during breathing
1. upward swing = inspiration
2. downward swing = exhalation
3. 4 respiratory volumes and 4 respiratory capacities
4. abnormal or lo values may indicate pulmonary malfunction

E. 4 DISCRETE RESPIRATORY VOLUMES *values are for a 20 yr old male, 155lb.

1. TIDAL VOLUME (TV)= 500ml air inhaled or exhaled with each normal breath

2. INSPIRATORY RESERVE VOLUME (IRV) = 3100ml max. vol. air forcibly
inhaled after a normal tidal inhalation

3. EXPIRATORY RESERVE VOLUME (ERV) = 1200ml max. amount of
air forcibly exhaled after a normal tidal exhalation

4. RESIDUAL VOLUME (RV) = 1200ml amount of air that remains in alveoli and non-
collapsible (PATENT) airways after maximal expiration.

Front 13

RESPIRATORY VOLUMES AND PULMONARY FUNCTION TESTS 2

Back 13

F. FOUR RESPIRATORY CAPACITIES: combination of 2 or more respir. volumes. Give
more information about respiratory status.

1. INSPIRATORY CAPACITY (IC) = TV + IRV = 3600ml
max. amount of air forcefully inspired after normal tidal exhalation

2. FUNCTIONAL RESIDUAL CAPACITY (FRC) = ERV + RV = 2400ml
air remaining in lungs after normal tidal exhalation


3. VITAL CAPACITY (VC) = TV + IRV + ERV = 4800ml max. amount
of exchangeable air with atmosphere in one breath

4. TOTAL LUNG CAPACITY (TLC) = IRV + TV + ERV + RV = 6000ml
maximum amount of air lungs can contain

Front 14

. GAS EXCHANGE AND MORE GAS LAWS

Back 14

A. GENERAL RULES OF THUMB due to passive transport theory

1. gasses move from an area of hi pr. to areas of lo pr.

2. gasses move from areas of hi conc. to areas of lo conc. of that gas

B. GAS LAWS CONTINUED...

1. CHARLES' LAW: if pr is constant, inc. in T -> inc. in Vol
a. hi temp makes molecules move faster, collide more often and expand to fill
more volume
b. gasses enter warm lungs, gas expands, inc. lung vol.

Front 15

. GAS EXCHANGE AND MORE GAS LAWS
2

Back 15

2. DALTON'S LAW OF PARTIAL PRESSURES: each gas in a mixture exerts its own
pr independent of other gasses in mix

a. PARTIAL PRESSURE: pr of one gas in the mixture

b. TOTAL PR: sum of all partial pr of gasses in mix p1 + p2 + p3 +.....

c. if know [gas] in atmosphere, & have total pr. of a mixture, can figure out
partial pr. of each gas in the mixture

atmospheric pressure = 760 mmHg

N2 = 79% of gas volume in atmosphere
pN2 = .79 x 760mmHg = 597mmHg

O2 = 21% -> pO2 = .21 x 760 =160mmHg
CO2 = .04% -> pCO2 = .0004 x 760 =.3mmHg
H2O = .5% -> pH2O = .005 x 760 = 3.8mmHg

d. EACH GAS WILL FOLLOW ITS OWN PRESSURE GRADIENT

e. if you increase total pr. without changing [gasses] in the mixture, all partial pr.
will increase proportionately.

Front 16

. GAS EXCHANGE AND MORE GAS LAWS
3

Back 16

HENRY'S LAW: when a mixture of gasses is in contact with a liquid, each gas
dissolves in proportion to its own solubility in that liquid and its own partial pressure

a. increase solubility, increase volume of gas dissolved

b. increase partial pressure of gas, increase volume of gas dissolved

c. increase temperature of gas, decrease solubility, decrease volume of gas
dissolved

d. CO2 is the gas most soluble in plasma, followed by O2 (1/20th of CO2's
solubility) and N2 (1/2 of O2's solubility)

e. SODA EXAMPLE
CO2 in soda is under pressure, Total pressure is high so pCO2 is high

Decrease total pressure (open can) and pCO2 drops, CO2 bubbles out

If keep soda in the refrigerator, increase CO2 solubility, more gas stays
dissolved

Front 17

DEEP SEA DIVER

Back 17

: deep under water, pr = 4x atmospheric pressure. Gasses
are forced into blood and tissues more (are more soluble because partial
pressures are higher) N2 is forced into blood and tissues more
*"RAPTURES OF THE DEEP" become dizzy, giddy
if ascend gradually, decrease total pressure slowly & let gasses bubble out of
tissues and blood gradually

if ascend fast, total pr dec. fast, & pN2 drops fast. N2 bubbles rapidly out of
tissues & blood => "BENDS" pain, seizures, numbness, etc..

Front 18

. EXTERNAL RESPIRATION

Back 18

: gas exchange between lungs and blood (explains what you
already know about movement of oxygen and carbon dioxide!!!)

1. gas diffuses across respiratory membrane: each gas follows its own concentration and
pressure gradient

alveoli deoxygenated blood in pulmonary aa. and capillaries

hi [O2] -> lo [O2]
low [CO2] <- hi [CO2]
pO2 = 104mmHg -> pO2 = 40mmHg
pCO2 = 5mmHg <- pCO2 = 40mmHg

result, CO2 leaves blood and enters alveoli to be exhaled, O2 leaves alveoli and enters
blood to go to tissues

Front 19

INTERNAL RESPIRATION

Back 19

gas exchange between blood and interstitial fluid

1. each gas follows its own concentration gradient and pressure gradient

oxygenated blood interstitial
in capillaries fluid

hi [O2] -> lo [O2]
lo [CO2] <- hi [CO2]
pO2 = 104mmHg -> pO2 = 40mmHg
pCO2 = 5mmHg <- pCO2 = 40mmHg

result: O2 leaves capillaries and enters interstitial fluid to go to tissue cells, CO2 leaves
interstitial fluid to go into caps for removal once reach lungs

Front 20

OXYGEN TRANSPORTATION

Back 20

a. 1.5% of O2 carried in plasma
b. 98.5% of O2 carried by hemoglobin attached to heme: oxyhemoglobin (HbO2)
*DEOXYHEMOGLOBIN = HHb

1) O2 must detach from hemoglobin to get to tissues
2) the affinity of O2 for hemoglobin varies with:
* pO2: decrease pO2, less affinity
* CO2: inc CO2 (dec pH, inc [H+] & acid), less affinity
* temperature: inc T, less affinity

Front 21

CARBON DIOXIDE TRANSPORTATION

Back 21

a. 7-10% dissolved in the plasma
b. 20-30% attached to globin of the Hb = carbaminohemoglobin (HbCO2)
c. 60-70% converted to bicarbonate ions (HCO3-) which travel through the
plasma. The following reaction takes place primarily in the RBC's because they
have the facilitating enzyme

carbonic anhydrase
CO2 + H2O <------------------> H2CO3 <--> H+ + HCO3-

*H2CO3 = carbonic acid, HCO3- = bicarbonate

d. increase in H+ causes a slight change in pH but H+ bind to Hb => HHb

e. CHLORIDE SHIFT: HCO3- will diffuse out of RBC into plasma, and Cl-
enters the cell

f. process is reversed at the lungs; CO2 is released

g. HYPOVENTILATION: slower/shallower respirations cause lower than
normal volume of air inhaled and exhaled per minute (below tidal volume):
inc. CO2 in blood, inc. carbonic acid in blood, blood pH drops

h. HYPERVENTILATION: deeper/faster respirations cause higher than normal
volume of air inhaled and exhaled per minute (greater than TV): dec. CO2 in
blood, dec. carbonic acid in blood, inc. blood pH

Front 22

RESPIRATORY CENTER OF THE BRAIN (in brainstem)

Back 22

1. MEDULLARY RHYTHMICITY AREA: sets rhythm of respiration

a. INSPIRATORY AREA: autorhythmic area sends signal to contract
diaphragm and external intercostals

b. EXPIRATORY AREA: inactive during quiet breathing, stimulated by
inspiratory area during hard/fast ventilation. Stimulates internal intercostals,
abdominals to contract.

2. PNEUMOTAXIC AREA (PONS):
a. coordinates transition between inspir. and expir.

b. inhibits inspiratory area to prevent overinflation

INFLATION REFLEX: HERING-BREUER REFLEX stretch
receptors in the lungs send signals to respiratory control centers to stop
inhalation/begin exhalation to prevent over stretching of lungs

3. APNEUSTIC AREA (PONS):
a. coordinates transition between insp. and expir.

b. prolongs inspiration and inhibits expiration

c. overridden by the pneumotaxic area

Front 23

RESPIRATORY CENTER OF THE BRAIN (in brainstem) 2

Back 23

B. PULMONARY IRRITANTS: stimulate receptors in lungs, signals respiratory control centers
*stop breathing APNEA
*cough, sneeze, constriction of airways

C. THOUGHT PROCESSES: voluntarily change rr

D. MEDULLA CHEMICAL REGULATION:

1. chemoreceptors in the medulla are sensitive to pCO2

2. HYPERCAPNIA: excess pCO2 in arterial blood
-stimulates medulla to become more active, increase RR
and depth causing HYPERVENTILATION (inc. O2, dec. CO2)

3. HYPOCAPNIA: low pCO2 levels in arterial blood
-no stimulus to inspiratory center, rr set by autorhythmic cells causing slower,
shallower breathing: HYPOVENTILATION (dec. O2, inc. CO2)

Front 24

RESPIRATORY CENTER OF THE BRAIN (in brainstem) 3

Back 24

E. CAROTID AND AORTIC BODIES: CHEMORECEPTORS

1. sensitive to lg changes in pO2 in arteries (normal = 104mmHg)

2. if pO2 below 50mmHg -> stimulate receptors -> stimulates
inspiratory center -> increases RR -> increase pO2

3. if pO2 far below 50 mmHg = HYPOXIA

receptors do not respond well -> few impulses to respiratory center -> breathing slows/stops

F. PROPRIOCEPTORS (sense movement at joints): stimulate an increase in rate and depth of
respiration before there is a chemical need!

G. CAROTID & AORTIC SINUS (barroreceptors involved in BP regulation)
inc. BP -> medulla -> dec. HR and RR and BP

H. BODY TEMPERATURE: increase temp, inc. rr and vice versa
jump into cold temp: APNEA

I. PAIN: sudden severe pain -> APNEA prolonged pain -> inc. rr

J. STRETCHING ANAL SPHINCTER -> increases rr

Front 25

RESPIRATORY CONT.

Back 25

b. NASAL CAVITY: INTERNAL NOSE
1) NASAL SEPTUM: divides cavity into l and r halves
-hyaline cart, vomer, ethmoid
2) INTERNAL NARES: holes leading to nasopharynx
3) SPHENOID, ETHMOID, MAXILLA, PALATINE BONES
4) VESTIBULE: cavity superior to nostrils
5) VIBRISSAE: nose hairs, filter air
6) NASAL EPITHELIUM: goblet cells, oil/sweat glands warm/filter air,
cilia move mucus to throat
6) NASAL CONCHAE: superior, middle & inferior create air turbulence