7.3 Circulatory system of a mammal

Question 1

What 2 factors determines whether or not a specialised transport medium is required?

Answer 1

1. the SA:V ratio

2. how active the organism is

Question 2

Define closed (circulatory system)

Answer 2

The blood remains within the blood vessels

Question 3

Define double circulatory system

Answer 3

the blood passes through the heart twice in each circuit. There is 1 circuit which delivers blood to the lungs and another circuit which delivers blood to the rest of the body.

Question 4

Why do mammals need a double circulatory system?

Answer 4

To manage pressure of blood flow (different parts of the body require blood at different pressures)

Question 5

What pressure is required at the lungs (pulmonary circuit) and why?

Answer 5

The blood flows through the lungs at a lower pressure.

This prevents damage to the capillaries in the alveoli and also reduces the speed at which the blood flows, enabling more time for gas exchange

Question 6

What pressure of blood is required for the rest of the body and why?

Answer 6

Higher pressure

To make sure the blood is moving at a faster speed and can/will reach every single respiring cell (so they can respire aerobically)

Question 7

What are the 4 coronary arteries/blood vessels attached to the heart?

Answer 7

1. vena cava
2. aorta
3. pulmonary artery
4. pulmonary vein

Question 8

What are the 2 coronary arteries/blood vessels attached to the lungs?

Answer 8

1. pulmonary vein

2. pulmonary artery

Question 9

What are the 2 coronary arteries/blood vessels attached to the kidneys?

Answer 9

1. renal artery

2. renal vein

Question 10

Explain the transport of oxygen through the body, lungs and heart

Answer 10

Oxygenated blood in kidney (via renal artery)

Deoxygenated blood out kidney (via renal vein) and goes in to the heart (via vena cava)

Deoxygenated blood goes in RIGHT atrium to RIGHT ventricle then to the LUNGS (via pulmonary artery)

Deoxygenated blood in lungs
Oxygenated blood out lungs back to the heart (via pulmonary vein)

Oxygenated blood enters LEFT atrium then LEFT ventricle and finally pushed out to rest of the body via AORTA.

Question 11

What are 7 common features of transport systems?

Answer 11

1. a suitable medium in which to carry materials
2. a form of mass transport in which the transport medium is moved around in bulk over large distances
3. a closed system of tubular vessels that contains the transport medium and forms a branching network to distribute it to all parts of the organism
4. a mechanism for moving the transport medium within vessels (requires a pressure difference between 1 part of the system and another)
5. a mechanism to maintain the masss flow movement in 1 direction e.g valves
6. means of controlling the flow of the transport medium to suit the changing needs of different parts of the organism
7. mechanism for the mass flow of water or gases

Question 12

What are the 2 main ways organisms transport medium?

Answer 12

a. animals use msucular contraction either of the body muscles or of a specialised pumping organ e.g heart
b. plants rely on natural, passive processes e.g evaporation of water

Question 13

Define metabolism

Answer 13

all the chemical processes that take place in living organisms