Animal Transport

Question 1

vascular system of earthworms

Answer 1

vascularisation, closed circulatory system and
pumps, carriage of respiratory gases in blood

Question 2

vascular system of insects

Answer 2

open circulatory system, dorsal tube-shaped
heart, lack of respiratory gases in blood

Question 3

vascular system of fish

Answer 3

single circulatory system

Question 4

vascular system of mammals

Answer 4

double circulatory system

Question 5

what is an open circulatory system

Answer 5

Transport medium pumped by the heart is not contained within vessels, but moves freely

Transport fluid comes into direct contact with
the cells

Question 6

what is a closed circulatory system

Answer 6

● Blood pumped by the heart is contained within blood vessels

● Blood does not come into direct contact with the cells

Question 7

advantages of closed circulatory system

Answer 7

● Blood pressure can be maintained
● Blood supply to different organs can vary
● Lower volumes of transport fluid required

Question 8

what is a single circulatory system

Answer 8

● Circulatory system in which the blood travels through the heart once in one circuit
● Blood flows through the heart and is pumped around the body before returning to the heart

Question 9

what is a double circulatory system

Answer 9

● Circulatory system in which the blood flows through the heart twice in two circuits
● Blood is pumped from the heart to the lungs before returning to the heart. It is then pumped around the
body, after which it returns to the heart again

Question 10

What are the benefits of a double circulatory
system?

Answer 10

● Maintains blood pressure around the whole body
● Uptake of oxygen is more efficient
● Delivery of oxygen and nutrients is more efficient
● Blood pressure can differ in pulmonary and systemic circuits

Question 11

Describe the double circulatory system in
humans.

Answer 11

Blood flows through the heart twice in two circuits:
● Pulmonary circuit
● Systemic circuit

Question 12

Name the four chambers of the mammalian heart.

Answer 12

● Left atrium
● Right atrium
● Left ventricle
● Right ventricle

Question 13

Describe the pathway of blood around the body, naming the structures of the heart

Answer 13

Pulmonary vein → Left atrium → Left ventricle → Aorta → Body → Vena cava → Right atrium →Right ventricle → Pulmonary artery → Lungs

Question 14

Where are the atrioventricular valves found and what is their function?

Answer 14

● Found between the atria and ventricles
● Prevent the backflow of blood from the
ventricles into the atria

Question 15

What are the two types of atrioventricular valves?

Answer 15

● Bicuspid (left side)
● Tricuspid (right side)

Question 16

Where are the semilunar valves found and what is their function?

Answer 16

● Found between the ventricles and arteries
● Prevent the backflow of blood from the
arteries into the ventricles

Question 17

Name the five types of blood vessel

Answer 17

● Arteries
● Arterioles
● Capillaries
● Venules
● Veins

Question 18

Describe the pathway of blood through the blood vessels.

Answer 18

heart → arteries → arterioles →
capillaries → venules → veins → heart

Question 19

What is the function of arteries?

Answer 19

Carry blood away from the heart to the
tissues, under high pressure.

Question 20

Relate the structure of arteries to their
function.

Answer 20

Thick, muscular walls to handle high
pressure without tearing. Elastic tissue
allows recoil to prevent pressure surges.
Narrow lumen to maintain pressure.

Question 21

What is the function of veins?

Answer 21

Carry blood towards the heart under low
pressure.

Question 22

Relate the structure of veins to their function.

Answer 22

Thin walls due to lower pressure. Require
valves to ensure blood doesn’t flow
backwards. Have less muscular and elastic
tissue as they don’t have to control blood
flow.

Question 23

What is the function of capillaries?

Answer 23

Form a large network through the tissues
of the body and connect the arterioles to
the venules.

Question 24

Relate the structure of capillaries to their function

Answer 24

● Walls only one cell thick ∴ short diffusion pathway
● Very narrow, so can permeate tissues and red blood cells can lie flat against the wall, reducing the diffusion distance
● Numerous and highly branched, providing a large surface area

Question 25

What is the function of arterioles?

Answer 25

Connect the arteries and the capillaries

Question 26

how many chambers does the heart have

Answer 26

4 chambers
left atrium
right atrium
left ventricle
right ventricle

Question 27

4 valves

Answer 27

tricuspid valve
bicuspid valve
mitral valve
aortic valve

Question 28

What is the function of venules?

Answer 28

Connect the capillaries and the veins.

Question 29

Relate the structure of arterioles and
venules to their function

Answer 29

● Branch off arteries and veins in order to feed blood into capillaries
● Smaller than arteries and veins so that the change in pressure is more gradual as blood flows to the capillaries

Question 30

What is the cardiac cycle?

Answer 30

● The sequence of events involved in one complete contraction and relaxation of the heart
● Three stages: atrial systole, ventricular systole and diastole

Question 31

Describe what happens during ventricular diastole.

Answer 31

The heart is relaxed. Blood enters the atria,
increasing the pressure and pushing open the AV valves. This allows blood to flow into the
ventricles. Pressure in the heart is lower than in the arteries, so SL valves remain closed.

Question 32

Describe what happens during atrial systole.

Answer 32

● The atria contract, pushing any
remaining blood into the ventricles
● AV valves pushed fully open

Question 33

Describe what happens during
ventricular systole

Answer 33

The ventricles contract. The pressure in the
ventricles increases, closing the AV valves
to prevent backflow and opening the SL
valves. Blood flows into the arteries.

Question 34

Why is cardiac muscle described as
myogenic?

Answer 34

It initiates its own contraction without
outside stimulation from nervous
impulses.