human phys exam 3

Question 1

how many alveoili in pair of lungs

Answer 1

300 million

Question 2

respiratory system

Answer 2

responsible for exchange of gases between external enviornment and cells in body
provides cells in body with oxygen and get rid of CO2

Question 3

exchange of gas proceses

Answer 3

1. ventilation: O2 and O2 from atmosphere to lung (EXCHANGE 1)
2. exchange2: lung to blood
3. transport of O2 and Co2 in blood
4. exchange3: of O2 and Co3 between blood and cells

Question 4

conducting system

Answer 4

air enters upper respiratory tract –> into pharynx –> larynx –> trachea
trachea divides into a pair of primary bronchi

Question 5

pharynx

Answer 5

common passageway for both ingested materials and air

Question 6

trachea

Answer 6

windpipe
flexible tube held by C-shaped rings of cartilage

Question 7

larynx

Answer 7

contains vocal cords
bands of connective tissue that are loosened by actions of muscles to create air when sound passes

Question 8

bronchioles

Answer 8

small collapsible passageways with smooth muscle walls, formed from bronchi
branch until they end at exchange surface (alveoli)
branch more than 20 times –> diamter gets smaller but total cross sectional diameter increases

Question 9

mucus

Answer 9

made by goblet cells interspersed with cilated epithelial cells

Question 10

alveoli

Answer 10

exchange surface of lungs
where O2 and Co2 move between air and blood
make up vast majority of lung tissue

Question 11

type 1 cell alveoli

Answer 11

cover majority of alveolar surface
thin gas exchange cells: close association with pulmonary capillaries
surface is away from the side exposed to lumen
0.2 um thick
diffusional distance ebtween air and blood is less than 1 um
type of epithelial cell

Question 12

type 2 cells alveoli

Answer 12

produce surfactant
surfactant: substance that acts to ease the expansion of lungs during inspiratoin

Question 13

elastin fibers

Answer 13

connective tissue fibers
exist between alveoli
contribute to elastic recoil when lung tissue is stretched

Question 14

pleura

Answer 14

membrane surrounding the lungs
pleural tissue held together with pleural fluid

Question 15

pleural fluid

Answer 15

provides moist slippery surface so that lungs can easily slip along the walls of thorax
fluid holds lungs against thoracid wall

Question 16

pulmonary circulation resistance

Answer 16

resistance is low because:
right ventricle doesn’t contract as powerfully as left ventricle
so low pressure too

Question 17

what happens when low pressure in pulmonary circulation

Answer 17

hydrostatic pressure in lung capillaries is then low
so little fluid leaves circulation in lungs

Question 18

daltons law

Answer 18

total pressure of gases is sum of pressure of individual gases (partial pressure)

Question 19

boyles law

Answer 19

if volume of a container of gas changes, pressure changes in inverse matter

Question 20

2 other gas rules

Answer 20

gases move from high to low pressure
amount of gas dissolved in liquid is determined by partial pressure of gas, solubility of gas, and temperature

Question 21

ventilation

Answer 21

movement of air into and out of lungs

Question 22

ventilation at rest

Answer 22

no air flow in/out of lungs
no pressure gradient
still pressures exerted on lungs

Question 23

lungs at rest

Answer 23

lungs would normally collapse, but there are forces pulling lung walls out
gives them a resting volume (functional residual capacity)

Question 24

intrapleural pressure

Answer 24

neg. intrapleural pressure causes force to keep lungs stretched open at rest since pleural membrane adheres lungs to chest wall

Question 25

breathing equation

Answer 25

F = change in pressure/R

Question 26

inspiration

Answer 26

chest cavity expands diaphragm constricts external intercostal pulls out on ribs transpulmonary pressure increases = lungs expands

Question 27

end of inspiration

Answer 27

inspiratory muscles stop contracting relax lungs passively return to original size because of elastic recoil of lungs

Question 28

intrapulmonary vs intrapleural pressure

Answer 28

intrapulmonary: force exerted by gases within alveoli during respiration intrapleural: force exerted by gases in pleural cavity during respiration

Question 29

intrinsic elastic properties of lungs vs compliance

Answer 29

lungs thicken complains goes down

Question 30

surface tension of lungs and surfactants

Answer 30

surface of alveoli must be kept moist surfactants reduce surface tension not enough surfactant --> too much surface tension --> difficult for lungs to expand during inspiration

Question 31

lung compliance

Answer 31

ability of lung to expand

Question 32

surfactant

Answer 32

decrease surface tension made of phospholipid and protein secreted by type 2 alveoli cells in response to large lung expansion

Question 33

terminal bronchioles

Answer 33

small airways surrounded by smooth muscle that contract/relax

Question 34

normal breathing energy

Answer 34

3% of total energy use high resistance of low compliance: increase amount of energy to breathe

Question 35

tidal volume

Answer 35

volume of gas moving in/out during breathing about 500 ml/breath

Question 36

volume at end of expiration

Answer 36

~2100 ml left in system (functional residual capacity) from that 2100: ~1100 m; gets forced out using expiratory muscles (expiratory reserve volume) ~remaining 100 is residual volume

Question 37

vital capacity

Answer 37

total maximal volume we can move in and out of lungs

Question 38

forced expiratory volume (FEV)

Answer 38

volume that can be expired in 1 second typically ~8-% of total

Question 39

minute ventilation

Answer 39

tidal volume + breathing rate ml/min

Question 40

alveolar ventilation

Answer 40

amount of fresh air brought into alveoli/minute not the same as inspiration/expiration because of dead volume dead space is ~150 ml, so normal tidal volume of 500 is only 350ml of new air (tidal volume-dead space) X breathing frequency

Question 41

bicarb equation

Answer 41

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

Question 42

upper region of respiratory system

Answer 42

pharynx vocal cords nasal cavity esophagus tongue larynx

Question 43

lower region of respiratory system

Answer 43

right lung right bronchus diaphragm lefft lung left bronchus

Question 44

muscles of active expiration

Answer 44

internal intercostal muscles abdominal muscles

Question 45

accessory muscles of inspiration

Answer 45

sternocleidomastoid scalenu

Question 46

major muscles of inspiration

Answer 46

diaphragm

Question 47

respiratory muscles

Answer 47

voluntary skeletal muscless

Question 48

transmural pressure gradient across lung wall

Answer 48

= intra-alveolar pressure minus intrapleural pressure

Question 49

transmural pressure gradietn across thoracid wall

Answer 49

= atmospheric pressure minus intrapleural pressure

Question 50

expiration

Answer 50

passive: elastic recoil, relaxation of external intercostal and diaphragm active: contraction of internal intercostal and abdominal muscles

Question 51

alveoli and surfactant

Answer 51

in lungs, smaller alveoli have more surfactant equalizes pressure between large and small alveoli

Question 52

hypoxia

Answer 52

state of too little oxygen

Question 53

gypercapnia

Answer 53

elevated concentrations of carbon dioxide

Question 54

autoregulation in alveoli

Answer 54

blood flow to individual alveoli is matched to ventilation

Question 55

repiratory quotient

Answer 55

each o2 consumed is about 0.8 Co2 @rest: 250 ml O2 = 200 ml CO2

Question 56

repiratory quotient

Answer 56

each o2 consumed is about 0.8 Co2 @rest: 250 ml O2 = 200 ml CO2

Question 57

normal alveolary ventilation

Answer 57

4200 ml O2 conc. of air is 21% alveoli are being ventilated with 840 ml of O2 per min.

Question 58

movement of O2 and CO2

Answer 58

simple diffusion rate of diffusion is proportional to: conc. gradient and surface area inversely poportional to: thickness of surface diffusion is rapid over short distances

Question 59

atmopsheric pressure of oxygen

Answer 59

160 mm HG at normal alveolar venitlation: alveolar p02 is 100 instead of 160 why difference? dead volume O2 diffused out of alveoli into lood quick

Question 60

o2 exchange between alveoli and blood

Answer 60

diffusion is critical to respiration equilibrium is reached between alveoli and capilaries after only 1/3 of way through capilarries

Question 61

O2 IN blood

Answer 61

poorly solube only 3 ml can dissolve in a liter of blood

Question 62

liter of arterial blood

Answer 62

contains 200ml of O2 because hemoglin binds to O2

Question 63

hemoglobin in blood

Answer 63

normal conc. is 150g/liter each gram of Hb can binds with 1.34 ml of O2 --> increases capacity of O2 in blood nearly all of O2 in blood is noramlly bound to Hb

Question 64

Hb O2

Answer 64

Hb + O2 <--> HbO2 readily reversible fast reaction cooperative interaction among 4 subunits creates sigmoid shape of binding curve

Question 65

hemoglobin

Answer 65

iron containing protein each molecule has 4 similar iron containing subunits that can each bind to one molecule of O2 each subunitc an be oxygenated or deoxygenated

Question 66

hemoglobin saturation

Answer 66

%of subunits in oxygenated form

Question 67

diphosphoglycerate (DPS)

Answer 67

produced as a result of glycolysis in red blood cells shifts curve to right red blood cells make more DPS

Question 68

CO2 transport

Answer 68

CO2 more soluble than O2, but still not transported as free soluble gas some bind to amino acids, other binds to Hb CO2 binds to deoxygenated Hb better than oxygenated Hb

Question 69

CO2 to bicarbonate

Answer 69

most entering CO2 is converted to bicarbonate by carbonic anhydrase

Question 70

carbonic annhydrase enzyme

Answer 70

found in RBC makes carbonic acid disscoiates into bicarbonate and H+

Question 71

hyperventilation

Answer 71

caused by increase of CO2 which causes increase in circulating H+

Question 72

breakdown of CO2

Answer 72

body makes about 200 ml CO2/min 7%: circulates free in blood 23%: binds to Hb 70% converted to bicarbonate in RBC, then transported out in exchange for Cl-

Question 73

at level of tissue

Answer 73

O2 is diffusing out of plasma into tissue --> causes p02 to decrease more O2 dissociates from Hb--> making it available to diffuse into tissue CO2 diffuses out of of tissue into plasma

Question 74

at level of alveoli

Answer 74

partial pressure of O2 and CO2 reverse processes O2 diffuses into plasma CO2 diffuses out of plasma