Week 5 (Exam 2): Respiratory System & Gas Exchange; Cardiovascular System

Question 1

what do eukaryotic cells use O2 for?

Answer 1

to metabolize organic molecules for ATP production, giving off CO2 as a by-product

Question 2

gas exchange

Answer 2

the transport of gases such as O2 & CO2 between an organism & its environment

Question 3

diffusion

Answer 3

the net movement of molecules from a region of higher concentration —> a region of lower concentration

Question 4

what distances is diffusion ineffective over?

Answer 4

distances over 100 mm

Question 5

what is partial pressure?

Answer 5

the fractional concentration of a gas relative to other gases present multiplied by the total pressure of the gas mixture

Question 6

bulk flow

Answer 6

the physical movement of fluids, either a liquid or gas, as a result of pressure differencs
-ventilation & circulation

Question 7

ventilation

Answer 7

the movement of an animal’s respiratory medium - water or air - past a specialized respiratory surface

Question 8

circulation

Answer 8

the movement of a specialized body fluid in animals that carries oxygen & CO2 & nutrients & waste products through the body

Question 9

circulatory fluid

Answer 9

hemolymph in invertebrates & blood in vertebrates

Question 10

how does resistance affect flow rate?

Answer 10

if resistance doubles, flow rate is halved

Question 11

what is the first step of gas transport & exchange?

Answer 11

ventilation by bulk flow

Question 12

what does ventilation by bulk flow entail?

Answer 12

breathing moves air (containing O2) into the lungs and air (containing CO2) out

Question 13

second step of gas transport & exchange

Answer 13

diffusion across the respiratory surface

Question 14

what does diffusion across the respiratory surface entail?

Answer 14

O2 diffuses from the lung into the blood & CO2 diffuses out of the blood into the lungs

Question 15

what is the third step of gas transport & exchange

Answer 15

circulation by bulk flow

Question 16

what does circulation by bulk flow entail

Answer 16

O2 & CO2 are transported by the circulatory system to & from cells

Question 17

fourth step of gas transport & exchange

Answer 17

diffusion between blood & cells

Question 18

what does diffusion between blood & cells entail

Answer 18

O2 diffuses from the blood into the cells & CO2 diffuses out of the cells into the blood

Question 19

what are lungs

Answer 19

internal organs that perform gas exchange in terrestrial vertebrates

Question 20

what is the trachea

Answer 20

an internal system of tubes that branch from openings along the abdominal surface into smaller airways, directing oxygen to & removing CO2 from respiring tissues

Question 21

lamullae

Answer 21

a thin, sheetlike structure spread along the length of each gill filament

Question 22

capillaries

Answer 22

very small blood vessels

Question 23

how does blood flow through capillaries?

Answer 23

in a direction opposite to the flow of water past the gills
-countercurrent flow

Question 24

spiracles

Answer 24

openings in the exoskeleton on either side of an insect’s abdomen through which gases are exchanged

Question 25

hemoglobin

Answer 25

an iron-containing molecule specialized for oxygen transport

Question 26

what makes up the cellular fraction of blood?

Answer 26

red blood cells with hemoglobin

Question 27

hematocrit

Answer 27

the fraction of red blood cells within the blood of vertebrates

Question 28

solubility

Answer 28

the ability of a substance to dissolve in a solvent

Question 29

how does hemoglobin affect the amount of O2 in the blood?

Answer 29

it increases it by binding to O2 and removing it from solution

Question 30

what are hemoglobins produced by?

Answer 30

red blood cells

Question 31

where do hemoglobins reside?

Answer 31

red blood cells that lack a nucleus

Question 32

path of O2 regarding hemoglobin

Answer 32

O2 diffuses into the blood —> diffuses into the red blood cells —> binds to the heme group in hemoglobin —> removes O2 from solution (keeping the O2 partial pressure of the red blood cell below that of blood plasma —> O2 diffuses into other cells

Question 33

oxygen dissociation curve

Answer 33

the curve that results when blood partial pressure of O2 is plotted against the percentage of O2 bound to hemoglobin -as partial pressure of O2 rises, hemoglobin binds to O2 with increasing binding affinity

Question 34

cooperative binding

Answer 34

the increase in binding affinity with additional binding of oxygen

Question 35

how does oxygen consumption affect the local O2 partial pressure?

Answer 35

reduces it in the cell & surrounding tissues to 40 mmHg or less

Question 36

myoglobin

Answer 36

a monomer that contains 1 heme group

Question 37

which molecule has a greater affinity for O2: myoglobin or hemoglobin?

Answer 37

myoglobin

Question 38

which kinds of cells store large amounts of myoglobin?

Answer 38

red muscle cells that depend on aerobic respiration to produce ATP

Question 39

open circulatory systems

Answer 39

circulating fluid is contained within the body cavity -have channel-like routes that direct where the fluid moves

Question 40

closed circulatory system

Answer 40

made up of set of internal vessels & a heart that pumps blood to different body regions -delivers O2 at high rates

Question 41

how does increased blood pressure affect rate of blood flow?

Answer 41

increases it

Question 42

how does increased resistance affect rate of blood flow?

Answer 42

decreases it

Question 43

arteries

Answer 43

large, high-pressure vessels that move blood flow away from the heart & toward tissues

Question 44

veins

Answer 44

large, low-pressure vessels that returns blood to the heart

Question 45

arterioles

Answer 45

small branches of an artery

Question 46

capillaries

Answer 46

very small blood vessels arranged in finely branched networks connecting arterioles to venules, where gases, nutrients, & waste products are exchanged by diffusion w/ surrounding tissues

Question 47

venae cavae

Answer 47

two large veins in the vertebrate body that drain blood from the head and body into the heart

Question 48

lymphatic system

Answer 48

a network of vessels distributed through the vertebrate body with important functions in the immune system

Question 49

lymph

Answer 49

the fluid in the vertebrate lymphatic system in which T and B cells circulate

Question 50

lymphatic vessels

Answer 50

merge with larger thin-walled vessels, drain the lymph into lymphatic ducts, and empty into the venous system leading to the heart

Question 51

which gland releases what in response to dehydration?

Answer 51

posterior pituitary gland; ADH

Question 52

what effect does ADH have on arteries?

Answer 52

causes them to constrict

Question 53

what happens if blood pressure drops?

Answer 53

arterioles supplying the limbs maintain blood pressure to the heart, brain, and kidneys by stimulating the smooth muscle to contract

Question 54

what happens if blood pressure is high?

Answer 54

sympathetic neurons synapsing on the smooth muscles are inhibited

Question 55

vasoconstriction

Answer 55

the narrowing of a blood vessel by the contraction of smooth vessel, which in turn increases resistance and decreases blood flow

Question 56

vasodilation

Answer 56

the widening of a blood vessel by the relaxation of smooth muscle, which in turn decreases resistance and increases blood flow

Question 57

pulmonary circulation

Answer 57

circulation of the blood to the lungs

Question 58

systematic circulation

Answer 58

circulation of the blood to the body

Question 59

what adaptation made double circulation possible?

Answer 59

4-chambered hearts

Question 60

how many chambers do fish hearts have?

Answer 60

2 chambers

Question 61

atrium function

Answer 61

receives blood

Question 62

ventricle function

Answer 62

pump blood

Question 63

where does deoxygenated blood flow to in a fish?

Answer 63

atrium

Question 64

where does blood from the atrium flow to in a fish?

Answer 64

ventricle

Question 65

where does deoxygenated blood from the ventricle flow to in a fish?

Answer 65

main artery

Question 66

where does blood from the main artery flow to in a fish?

Answer 66

the gills

Question 67

where does blood from the gills flow to in a fish?

Answer 67

the aorta

Question 68

aorta

Answer 68

a large artery through which oxygenated blood flows from the left ventricle of the heart to the head and body

Question 69

how many chambers does an amphibian and reptile heart have?

Answer 69

3-chambers

Question 70

t/f: in mammals, bulk flow only refers to the movement of oxygen (either into or out of the lungs and within the bloodstream).

Answer 70

false, bulk flow also refers to the movement of carbon dioxide

Question 71

we breathe more quickly and deeply when we exercise. why does this make sense?

Answer 71

-we produce more co2 and increased ventilation is necessary to rid ourselves of co2 -we use more ATP and additional o2 is necessary to generate sufficient ATP

Question 72

what increases the amount of oxygen that fish can extract from the surrounding seawater?

Answer 72

-gills with a large surface area -ventilation of the gills with the aid of an operculum -countercurrent exchange -very thin lamellae

Question 73

what are desirable characteristics for a gas exchange surface?

Answer 73

large surface area and small thickness

Question 74

imagine that someone suffers a horseback riding injury and one of their ribs punctures the diaphragm. how will this injury affect the person’s breathing?

Answer 74

the injury will make it more difficult to increase negative air pressure in their chest cavity, making inhalation more difficult

Question 75

does unidirectional airflow or tidal breathing maintain a larger concentration gradient for diffusion?

Answer 75

unidirectional flow

Question 76

do birds receive fresh air only during inhalation?

Answer 76

no

Question 77

what is tidal ventilation?

Answer 77

air moves into the lungs during inhalation and moves out of the lungs during exhalation

Question 78

what percent of oxygen in the air is typically extracted by the mammalian lung when an animal is resting?

Answer 78

less than 25%

Question 79

t/f: if a hemoglobin molecule comes into close contact with a respiring cell, the presence of CO2 in the environment will cause hemoglobin to bind to more oxygen molecules (if is not already bound to four)

Answer 79

false

Question 80

what does a shift to the right in the hemoglobin dissociation curve mean?

Answer 80

the affinity of hemoglobin for O2 has decreased

Question 81

how do the partial pressures of O2 in the lung, blood cells, and blood plasma compare?

Answer 81

pO2 red blood cell < pO2 blood plasma < pO2 lung

Question 82

insects possess ___ circulatory systems

Answer 82

open

Question 83

what function do collagen and elastin have in arteries?

Answer 83

they provide elastic rebound of the arterial wall to help smooth out blood flow

Question 84

in the disease elephantiasis, lymph vessels become blocked because of infection with parasitic worms. which process would be impacted by this disease?

Answer 84

the return of interstitial fluid to the bloodstream

Question 85

as fluid moves through a vessel, which factors determine the flow resistance?

Answer 85

-the radius of the vessel -the length of the vessel -the viscosity of the fluid

Question 86

diffusion of materials between the blood and body tissues occurs at which of the blood vessels?

Answer 86

capillaries

Question 87

what event occurs during systole?

Answer 87

both ventricles contract

Question 88

atrioventricular valves separate:

Answer 88

the left atrium from the left ventricle and the right atrium from the right ventricle

Question 89

in which of the heart chambers would deoxygenated blood be found?

Answer 89

right atrium and right ventricle

Question 90

why is the muscular wall of the left ventricle thicker than that of the right ventricle?

Answer 90

the left ventricle must contract with more force in order to send blood to the body’s extremities

Question 91

the initiation of the mammalian heart contraction takes place at the:

Answer 91

SA node

Question 92

what event are the following associated with: depolarization, contraction, increased pressure, emptying

Answer 92

systole

Question 93

what event are the following associated with: repolarization, relaxation, decreased pressure, filling

Answer 93

diastole

Question 94

where does the blood in the right side of the heart come from?

Answer 94

the body

Question 95

where does the blood in the right side of the heart go to?

Answer 95

the lungs

Question 96

where does the blood on the left side of the heart come from?

Answer 96

the lungs

Question 97

where does the blood on the left side of the heart go to?

Answer 97

the body