3.1 exchange surfaces

Question 1

What is the role of surfactant in the lungs

Answer 1

maintain surface tension so the alveoli does not get too over stretched

Question 2

Why is a baby’s first breath difficult

Answer 2

large change in atmospheric pressure as the lungs are filled with fluid

Question 3

What happens to the diaphragm during inspiration

Answer 3

contraction

Question 4

What happens to the diaphragm during expiration

Answer 4

relaxation

Question 5

What happens to the external intercostal muscles during inspiration

Answer 5

contract

Question 6

What happens to the internal intercostal muscles during inspiration

Answer 6

relax

Question 7

What happens to the external intercostal muscles during expiration

Answer 7

relax

Question 8

What happens to the internal intercostal muscles during expiration

Answer 8

contract

Question 9

What happens to the rib cage during inspiration

Answer 9

up and out

Question 10

What happens to the rib cage during expiration

Answer 10

down and in

Question 11

What happens to the thoraic volume during inspiration

Answer 11

increases

Question 12

What happens to the thoraic volume during expiration

Answer 12

decreases

Question 13

What happens to the intrapulmonary pressure during inspiration

Answer 13

decreases

Question 14

What happens to the intrapulmonary pressure during expiration

Answer 14

increases

Question 15

What happens to the air movement during inspiration

Answer 15

pressure falls below atmospheric pressure so air is drawn inside

Question 16

What happens to the air movement during expiration

Answer 16

pressure goes above the atmospheric pressure so air moves out

Question 17

What structures does a trachea contain

Answer 17

• cartilage
• smooth muscle
• elastic fibres
• ciliated epithelium
• goblet cells
• mucous glands

Question 18

What structures does the bronchi contain

Answer 18

• cartilage
• smooth muscle
• elastic fibres
• ciliated epithelium
• goblet cells
• mucous glands

Question 19

What structures does the larger bronchioles contain

Answer 19

• smooth muscle
• elastic fibres
• ciliated epithelium
• goblet cells

Question 20

What structures does the smaller bronchioles contian

Answer 20

• smooth muscle
• elastic fibres

Question 21

What structures does the smallest bronchioles contain

Answer 21

elastic fibres

Question 22

What structures does the alevoli contain

Answer 22

elastic fibres

Question 23

Function of cartilage

Answer 23

to support the trachae and ensure airway is open

Question 24

Function of the ciliated epithelium

Answer 24

cilia on the surface which sweep mucus, dust and bacteria upwards

Question 25

Function of goblet cells

Answer 25

secrete mucus

Question 26

Function of smooth muscle

Answer 26

adjust size of airways

Question 27

Function of squamous epithelium

Answer 27

short diffusion pathway for rapid gaseous exchange

Question 28

Function of elastic tissue

Answer 28

recoil

Question 29

Define alveolar air

Answer 29

air located in the alveoli that takes part in gaseous exchange

Question 30

Define tidal volume

Answer 30

volume of air that moves in and out of the lungs with each breath at rest

Question 31

Define residual volume

Answer 31

volume of air that is left in the lungs after maximum exhilation

Question 32

Define vital capacity

Answer 32

volume of air that can be breathed in after maximum exhilation

Question 33

Define dead space air

Answer 33

volume of ventilated air that isn't participating in gaseous exchange

Question 34

Define inspiratory reserve volume

Answer 34

maximum volume of air you can breathe in after normal inhilation

Question 35

Define expiratory reserve volume

Answer 35

maximum volume of air that can be exhaled after normal exhilation

Question 36

Define total lung capacity

Answer 36

vital capacity + residual volume

Question 37

What is the counter current system in fish

Answer 37

* opposite directional flow of water and blood * maintains concentration gradient in the capillary

Question 38

What is the ventilation mechanism in fish

Answer 38

* when the fish open their mouths the lower the floor of the buccal cavity * volume inside the buccal cavity increases so there is a decrease in pressure inside * the pressure is higher outside than inside so water flows in * the fish then raises the floor of the buccal cavity increasing the pressure * water flows outwards to the gill cavity * as water pressure builds in the gill cavity the operculum forces open and water exits the fish

Question 39

What is the ventilation mechanism in insects

Answer 39

* very active, flying insects need more oxygen * they create mass flow by closing the spiracles and using abdominal muscles to create a pumping movement

Question 40

Structure to function of the alveoli

Answer 40

* small = large SA:V ratio * constant blood flow = step concentration gradient * 1 cell thick = shorter diffusion distance * large number = increases SA * contains surfactant = maintains surface tension * contains elastin = allows recoil