topic 3.1.1: exchange surfaces

Question 1

describe the structure and function of cartilage in the mammalian gas exchange system

Answer 1

tracheal rings: keep trachea open

Question 2

describe the distribution and function of ciliated epithelium in the mammalian gas exchange system

Answer 2

found along trachea down to bronchi, has small projections of cilia to sweep

Question 3

describe the distribution and function of goblet cells in the mammalian gas exchange system

Answer 3

scattered throughout ciliated epithelium, produce mucus

Question 4

describe the distribution and function of squamous epithelium in the mammalian gas exchange system

Answer 4

forms alveolar walls, thin and permeable for diffusion

Question 5

describe the distribution and function of smooth muscle in the mammalian gas exchange system

Answer 5

found on walls of bronchi and bronchioles, regulates air flow by dilating and constricting

Question 6

describe the distribution and function of elastic fibres in the mammalian gas exchange system

Answer 6

present in all lung tissues, enable stretching and recoiling

Question 7

define the term tidal volume

Answer 7

vol of air in each breath

Question 8

define the term vital capacity

Answer 8

max vol of air in lungs

Question 9

define the term breathing rate

Answer 9

number of breaths per min

Question 10

define the term oxygen uptake/ consumption

Answer 10

rate of use of oxygen

Question 11

describe the structure of the circulatory system in bony fish

Answer 11

4 pairs of gills, each supported by arch
arch has gill filaments, with lamellae
blood and water flow across gills in countercurrent flow

Question 12

describe the process of ventilation in bony fish

Answer 12

opens mouth and lowers floor of buccal cavity, so water flows in
closes mouth and raises floor of BC, pressure increases
pressure higher in buccal cavity than opercular cavity so water flows over gills
operculum acts as a valve and pump to control water

Question 13

describe the mechanisms of ventilation and gas exchange in insects

Answer 13

gas enters through spiracles, small holes in side, into tracheoles
tracheal fluid at end allows gases to dissolve and diffuse into cells
rhythmic abdominal movements change body vol

Question 14

how would you work out SA:V?

Answer 14

SA/V

Question 15

how does SA:V affect diffusion?

Answer 15

high: large SA so diffusion is fast
low: small SA so diffusion is slow

Question 16

which 3 muscle sets act on the ribs during ventiation?

Answer 16

diaphragm (moves ribcage up and out)
external intercostal (pull ribcage up and out)
internal intercostal (pull ribcage down and in)

Question 17

describe the process of inspiration

Answer 17

ex IMs contract while the int IMs relax, moving the ribcage up and out
vol of the thoracic cavity increases
diaphragm contracts and flattens, further increasing vol of thoracic cavity
lung pressure decreases below atmospheric pressure
air flows into lungs down pressure gradient

Question 18

describe the process of expiration

Answer 18

ex IMs relax while int IMs contract, moving the ribcage down and in
vol of thoracic cavity decreases
diaphragm relaxes and unflattens, further decreasing the volume of thoracic cavity
lung pressure increases above atmospheric pressure
air is forced out of the lungs down pressure gradient