B9 transport in animals

Question 1

describe the circulatory system

Answer 1

• system of blood vessels
• with a pump and valves
• to ensure one-way flow of blood

Question 2

describe the single circulation of a fish

Answer 2

• blood flows from heart to gills for oxygenation
• from gills to rest of body
• single circulation: blood glows thru heart only once

Question 3

describe the double circulation of a mammal

Answer 3

blood follows two circuits
- pulmonary: blood flows from heart to lungs for oxygenation then back to heart
- systemic: blood flows from heart to other parts of body then back to heart

Question 4

advantages of double circulation

Answer 4

higher blood pressure:
- o2 and glucose supplied rapidly to cells, co2 and water removed quickly from them
- blood can be supplied to distant parts of large animals

Question 5

how is the activity of the heart monitored

Answer 5

• ECG (electrocardiogram)
• pulse rate
• listening to sounds of valves closing

Question 6

do veins have a pulse? why

Answer 6

• no
• their walls do not expand/contract

Question 7

stages of heartbeat

Question 8

effect of exercise on hr and why

Answer 8

• hr increases with exercise
• increased energy from aerobic respiration needed by muscle cells
• more glucose and oxygen must be supplied by blood to respiring cells, increase rate at which co2 and water (waste products) removed

Question 9

describe coronary heart disease

Answer 9

• blockage of coronary arteries
• unable to supply oxygen rich blood to heart muscles
• cardiac muscles cannot produce enough energy for contraction

Question 10

risk factors for CHD

Answer 10

• diet
• lack of exercise
• stress
• smoking
• genetic predisposition
• age
• sex

Question 11

explain how to prevent CHD

Answer 11

balanced diet
- consume all nutrients needed by body in correct amounts to maintain health
- wide variety of food, eat less animal fat
exercise
- prevent excessive weight gain
- decrease bp
- reduce stress

Question 12

structure of arteries

Answer 12

• thick, muscular wall
• narrow lumen

Question 13

structure of veins

Answer 13

• thin wall
• wide lumen
• valves

Question 14

structure of capillaries

Answer 14

• one cell thick wall
• tiny lumen

Question 15

relate structure of arteries to pressure of blood transported

Answer 15

• elastic tissues make flow of blood smoother
• thick walls to withstand high bp
• narrow lumen to maintain high bp

Question 16

relate structure of veins to pressure of blood transported

Answer 16

• large lumen, thin walls due to low bp
• wide lumen reduces resistance to blood
• veins to prevent backflow

Question 17

explain how structure of capillaries related to functions

Answer 17

• thin wall for short diffusion distance

Question 18

function of capillaries

Answer 18

allow exchange of materials between blood and body cells

Question 19

Answer 19

Question 20

Answer 20

Question 21

components of blood

Answer 21

• red blood cells
• white blood cells
• platelets
• plasma

Question 22

function of red blood cells

Answer 22

• transporting oxygen
• haemoglobin (protein) combines with oxygen

Question 23

function of white blood cells

Answer 23

• ingest and destroy pathogens (phagocytosis)
• production of antibodies

Question 24

function of platelets

Answer 24

• clotting of blood

Question 25

function of plasma

Answer 25

transport of
- blood cells
- ions
- nutrients
- urea
- hormones
- co2

Question 26

Answer 26

Question 27

function of lymphocytes

Answer 27

antibody production

Question 28

function of phagocytes

Answer 28

engulfing pathogens by phagocytosis

Question 29

role of blood clotting

Answer 29

• prevent blood loss
• prevent entry of pathogens