3.1 exchange surfaces

Question 1

what is ventilation?

Answer 1

the refreshing of air in the lungs so there is a higher oxygen concentration in the blood, and a lower carbon dioxide concentration

Question 2

what are intercostal muscles?

Answer 2

the muscles between the ribs, the contraction of the external intercostal muscles raises the ribcage

Question 3

what are the alveoli?

Answer 3

the folds of the lung epithelium, where gas exchange takes place in the lungs

Question 4

what are the bronchi and bronchioles?

Answer 4

smaller airways leading to the lungs

Question 5

what is the diaphragm?

Answer 5

a layer of muscle beneath the lungs

Question 6

what is the trachea?

Answer 6

the main airway leading from the back of the mouth to the lungs

Question 7

what are the feature of a good exchange surface?

Answer 7

• large surface area
• thin barrier
• good blood supply

Question 8

what are the airway requirements?

Answer 8

• LARGE enough for sufficient flow without obstruction
• DIVIDE INTO SMALLER AIRWAYS
• STRONG to prevent collapsing
• FLEXIBLE to allow movement
• be able to STRETCH and RECOIL

Question 9

What are goblet cells?

Answer 9

cells that secrete mucus

Question 10

what is smooth muscle?

Answer 10

involuntary muscle that contracts without the need for conscious thought

Question 11

what are elastic fibres?

Answer 11

protein fibres that can deform and recoil to their original size

Question 12

what are ciliated epithelium?

Answer 12

a layer of cells with hair-like extensions called cilia

Question 13

what are organelles?

Answer 13

the small structures within cells, each with a specific function

Question 14

what is surface area to volume ration?

Answer 14

a calculation used by biologists to define the limits on size of an organism

Question 15

what are 3 main factors that affect the need for an exchange surface?

Answer 15

• size
• level of activity
• SA:V

Question 16

what is cartilage?

Answer 16

a form of connective tissue

Question 17

what are some precautions when using a spirometer?

Answer 17

• sterile equipment
• enough oxygen
• fresh supply of soda lime
• constant temperature
• equipment that is functioning properly

Question 18

what is respiratory minute volume?

Answer 18

the volume of air inhaled or exhaled from a persons lungs in one minute

tidal volume X breathing rate

Question 19

what is dead space?

Answer 19

the air in the bronchioles, bronchi and trachea

Question 20

whatt is vital capacity?

Answer 20

the greatest volume of air that can be expelled from the lungs after one breath

Question 21

what is a spirometer?

Answer 21

a device that can measure the movement of air into and out of the lungs

Question 22

what is tidal volume?

Answer 22

the volume of air inhaled or exhaled in one breath

Question 23

what is oxygen uptake?

Answer 23

the volume of oxygen absorbed by the lungs in one minute

Question 24

what is breathing rate?

Answer 24

the number of breaths per minute

Question 25

what structures are in the trachea?

Answer 25

• large C-shaped cartilage
• smooth muscle
• elastic fibres
• goblet cells
• ciliated epithelium

Question 26

what structures are in the bronchi?

Answer 26

• smaller, less regular cartilage
• smooth muscle
• elastic fibres
• goblet cells
• ciliated epithelium

Question 27

what are the structures in the alveoli?

Answer 27

• elastic fibres

Question 28

what are the structures in the bronchioles?

Answer 28

• elastic fibres
• ciliated epithelium
• smooth muscle
• some cartilage

Question 29

what are some features of the alveoli?

Answer 29

• moist alveolar surface
• large surface area
• thin wall

Question 30

what is the process of ventilation in bony fish?

Answer 30

1. mouth opens, operculum closes
2. buccul cavity floor is lowered
3. volume increases, pressure decreases in buccal cavity
4. water rushes into mouth
5. opercular cavity expands
6. buccul cavity floor is raised
7. water moves from buccul cavity over the gills into opercular cavity
8. mouth closes, operculum opens
9. the sides of the opercular cavity move inwards, pressure increases
10. water rushes out of the fish through the operculum.

Question 31

what is countercurrent flow?

Answer 31

the flow of blood through the capillaries in the opposite direction to the flow of water

Question 32

why is countercurrent flow important?

Answer 32

it maintains an oxygen conentration gradient

Question 33

what is the process of ventilation in insects?

Answer 33

1. air enters via the spiracles
2. air is transported through the tracheae
3. the tracheae divides into tracheoles
4. the ends of the tracheoles are filled with fluid

more oxygen can be absorbed when the insect is active as the tracheal fluid withdraws to allow a larger surface area for diffusion

Question 34

how do flight muscles help with ventilation in insects?

Answer 34

specialised air sacs in the trachae are squeezed

Question 35

how does wing movements help with ventilation in insects?

Answer 35

alters the volume and pressure of the thorax

Question 36

how do specialised breathing movements help with ventilation in locusts?

Answer 36

the abdomen expands so the spiracles at the front open and air enters then leaves from the spriacles at the back

Question 37

what type of circulatory system do insects have?

Answer 37

open circulatory system