exchange surfaces

Question 1

what does a peak flow meter do

Answer 1

measures the rate at which ir can be expelled from the lungs

Question 2

how does a vitalograph work

Answer 2

patient breathes out as quickly as they can

Question 3

what is a spirometer

Answer 3

used to measure different aspects of lung volume

Question 4

define tidal volume

Answer 4

volume of air that moves into and out the lungs at rest

Question 5

define vital capacity

Answer 5

volume of air breathed in when the strongest possible exhalation is followed by the deepest intake of breath

Question 6

define inspiratory reserve volume

Answer 6

maximum volume of air you can breathe in over and above a normal inhalation

Question 7

define expiratory reserve volume

Answer 7

extra amount of air you can force out

Question 8

define residual volume

Answer 8

volume of air left in the lungs when you’ve exhaled as hard as possible

can’t be measured directly

Question 9

define total lung capacity

Answer 9

sum of vital capacity and the residual volume

Question 10

how do we find the ventilation rate

Answer 10

tidal volume x breathing rate

Question 11

what stops gaseous exchange in insects

Answer 11

their exoskeleton

Question 12

where are spiracles

Answer 12

along the thorax and abdomen

Question 13

how can water loss be minimised in insect tracheal system

Answer 13

closed spiracles using sphincters

Question 14

what lines the trachea

why

Answer 14

chitin

keeps them open if bent or pressed

impermeable so gaseous exchange doesn’t take place here

Question 15

what’s towards the end of tracheoles

Answer 15

tracheal fluid

limits the penetration of air for diffusion

Question 16

how does less moisture affect the tracheal system in insects

Answer 16

exposes more surface area for gaseous exchange

Question 17

describe the mechanisms of mechanical ventilation of the tracheal system

Answer 17

air is actively pumped into the system by muscular pumping movements of the thorax and/or abdomen

these movements change the volume of the body which changes the pressure

Question 18

describe collapsible enlarged trachea or air sacs

Answer 18

act as air reservoirs

used to increase the amount of air moved through the gas exchange system

Question 19

how are gills adapted to be an efficient gaseous exchange system

Answer 19

large SA

good blood supply

thin layers

Question 20

what is the operculum

Answer 20

covers the gills

Question 21

what does a the efferent blood vessel do

Answer 21

carries blood leaving gills in the opposite direction of water

maintains a steep conc gradient

Question 22

describe the processes of water moving into the fish

Answer 22

mouth opens and floor of buccal cavity lowers

increases the vol (decrease pressure)
so water moves into the b. cavity

the opercular valve shuts and the opercular cavity expends (lowers the pressure)

floor of buccal cavity moves up so water moves over the gills

the mouth closes and the operculum opens and the sides of the opercular cavity move inward
(increases the pressure)

forcing water out the gills
the floor of the buccal cavity moves steadily up to maintain flow of water

Question 23

what are features of efficient gaseous exchange in water

Answer 23

tips of adjacent gill filaments overlap
which increases the resistance to water flow, so more time for g. exchange

blood and water flow in opposite directions (countercurrent) (maintain steep conc gradient)

Question 24

what is the open body cavity called

what is low here

Answer 24

haemocoel

low pressure

Question 25

what is insect blood called what does it carry

Answer 25

haemolymph transports food and nitrogenous waste products

Question 26

what is the heart's structure in an insects

Answer 26

extends along the length of the thorax and abdomen

Question 27

what is a downside to the open circulatory system in insects

Answer 27

steep diffusion rates can't be maintained amount of haemolymph flowing cannot be varied to meet changing demands

Question 28

describe a single circulatory system

Answer 28

blood travels once through the heart for each complete circulation

Question 29

what is a downside to single closed circulatory system

Answer 29

blood passes through two sets of capillaries before returning to the heart after the second, blood pressure drops so blood returns to the heart slowly

Question 30

describe a double circulatory system

Answer 30

blood travels to twice through the heart for each circuit of the body

Question 31

describe the proportion of elastin, smooth muscle and collagen in arteries

Answer 31

lots of elastin and smooth muscle less collagen

Question 32

describe the proportion of elastin, smooth muscle and collagen in veins

Answer 32

more collagen, then muscle then elastin these proportions decrease as you go further away from the heart

Question 33

how do substances in the plasma pass through capillary walls

Answer 33

through fenestrationsn

Question 34

define oncotic pressure what is its value

Answer 34

tendency of water to move into the blood -3.3 kPa

Question 35

at the arterial end of the capillary, what is present and what is its value

Answer 35

hydrostatic pressure 4.6 kPa

Question 36

what is higher at the arterial end what does this result in

Answer 36

hydrostatic pressure is higher than oncotic pressure so fluid is squeezed out the capillaries

Question 37

what happens as the venous end

Answer 37

hydrostatic press down to ~2.3 kPa as fluid has moved out and pulse is lost oncotic pressure is still -3.3 kPa so it is stronger than hydrostatic pressure so water moves into capillaries by osmosis

Question 38

what happens to the 10% of tissue fluid that doesn't return to capillaries

Answer 38

becomes lymph contains fatty acids the fluid is transported by squeezing of the body muscles has valves eventually lymph returns to the blood flowing into the right and left subclavian veins

Question 39

what happens in lymph nodes

Answer 39

lymphocytes build up which pass into the blood lymph nodes intercept bacteria and other debris enlarged lymph nodes are a sign the body is fighting off an invading pathogens

Question 40

what are adaptations of the nasal cavity

Answer 40

hairy lining - traps pathogens trapped in mucus moist lining - increases humidity high surface area with good blood supply - warms air to body temperature

Question 41

what are adaptations of the trachea

Answer 41

incomplete rings of strong and flexible cartilage - stops trachea from collapsing lined with cillia with goblet cells

Question 42

what are adaptations of bronchioles

Answer 42

no cartilage -- smooth muscle contract and constrict to change volume of air reaching lungs thin layer of flat epithelium making gas exchange possible

Question 43

what are adaptations of alveoli

Answer 43

layer of flattened epithelial cells some collagen, elastic fibres allows stretching as air drawing in and then recoil to squeeze air out

Question 44

what does elastic fibres do

Answer 44

composed of elastin and stretch and recoil, providing flexibility

Question 45

what do smooth muscle do

Answer 45

contracts + constriccts to change size of lumen

Question 46

what do collagen do

Answer 46

provide structural support and maintain shape of vessel

Question 47

what do arterioles have a higher and lower proportion of

Answer 47

high smooth muscle and lower elastin prevent blood flowing into capillary bed

Question 48

what is an adaptation of capillaries

Answer 48

cross sectional area is higher than arteriole supplying them so a low rate of flow gives more time for exchange of materials by diffusion

Question 49

what is composition of veins

Answer 49

mostly collagen, less smooth muscle and very little elastic fibres

Question 50

what are adaptations of venules

Answer 50

bigger veins run between bigger muscles when muscle contract they squeeze veins, forcing blood quicker to the heart breathing movement of chest acts as a pump the changes in pressure in the blood in the veins of the chest and abdomen toward the heart