3.1.1 exchange surfaces

Question 1

what is a specialised exchange surface

Answer 1

adapted to maximise the rate of diffusion across it

Question 2

what type of organisms need specialised exchange surfaces

Answer 2

multicellular that have small SA:volume ratios
long diffusion rates
high metabolic rates

Question 3

Ficks law

Answer 3

( SA x concentration difference) / diffusion distance

Question 4

what conditions for diffusion rate to be maximium

Answer 4

large surface area
large concentration gradient
short diffusion difference

Question 5

how does large surface area increase rate of diffusion

Answer 5

increase area over which diffusion can occur

Question 6

how does thin feature of the organism increase rate of diffusion

Answer 6

keeps diffusion distance short

Question 7

how does good blood supply increase rate of diffusion

Answer 7

maintains steep concentration gradient of repiratory gases

Question 8

how does well ventilated increase rate of diffusion

Answer 8

maintains steep concentration gradient of repiratory gases

Question 9

what is gas exchange

Answer 9

swapping CO2 for O2 by diffusion

Question 10

function of trachea

Answer 10

non-collapsible tube through which air is drawn into the lungs

Question 11

function of alveoli

Answer 11

microscopic air sacs adapted for gas exchange

Question 12

function of bronchus

Answer 12

flexible tubes which deliver air from trachea to bronchioles

Question 13

function of pleural membrane

Answer 13

double membrane that surrounds lungs and protects them from friction during breathing

Question 14

function of diaphragm

Answer 14

flexible sheet of muscle involved in ventiallation

Question 15

function of bronchioles

Answer 15

flexible,narrow tubes which deliver air to the alveoli

Question 16

function of intercoastal muscles

Answer 16

muscles between ribs involved in ventilation

Question 17

function of ciliated cells

Answer 17

sweep mucus out trachea

Question 18

function of goblet cells

Answer 18

produce mucus

Question 19

function of smooth muscle cells

Answer 19

constrict bronchioles

Question 20

function of squamous epithelium cells

Answer 20

short diffusion distance

Question 21

why is ventilation of the lungs important

Answer 21

increase the concentration gradient and pressure

Question 22

what happens during inspiration

Answer 22

diaphragm contracts,flattens and lowers
external intercoastal muscles contract to move ribs up
volume of chest cavity increases
lower pressure in chest cavity
air is drawn into lungs
lungs swell

Question 23

what happens during expiration

Answer 23

diaphragm relaxes to dome shape
external intercoastal muscles relax to move ribs down
volume of chest cavity decreases greater than atmosphere pressure in chest cavity
air moves out of lungs
lungs shrink

Question 24

what is forced expiration

Answer 24

requires energy to forcablly push ribs down hard and fast to expel air quickly
occurs during exercise

Question 25

closed circulatory system

Answer 25

blood is enchased in vessels
high pressure so blood flows quickly

Question 26

where are single closed circulatory systems found

Answer 26

fish and annelid worms

Question 27

key features of single closed circulatory system

Answer 27

blood passes through 2 sets of cappillaries
low pressure
flows through heart once
slow flow

Question 28

key features of double closed circulatory system

Answer 28

travels through heart twice
1 capillary network
high pressure
fast blood flow

Question 29

where is double closed circulatory system found

Answer 29

birds and most mammals

Question 30

where is open circulatory system found

Answer 30

invertebrate

Question 31

key features of open ciirculatory system

Answer 31

split by membrane
hemolymph

Question 32

what does open circulatory system transport

Answer 32

food,cells in defence against disease
nitrogenous waste products

Question 33

function of heart

Answer 33

generate blood vessels

Question 34

function of blood vessels

Answer 34

maintain and regulate pressure

Question 35

function of pulmonary capillary bed

Answer 35

exchange surfaces - O2 into blood
- CO2 into lungs

Question 36

function of systemic capillary beds

Answer 36

exchange surfaces - O2 into cells
- CO2 into blood