1. What is CVD

Question 1

What is a mass flow system?

Answer 1

the transport of substances in the flow of a fluid e.g the circulatory system

Question 2

Why do animals have a heart and circulatory system?

Answer 2

For mass transport to overcome limitations of diffusion in meeting the requirements of the organism.

Question 3

Which type of blood enters the right side of the heart?

Answer 3

Deoxygenated

Question 4

Which type of blood enters the left side of the heart?

Answer 4

Oxygenated

Question 5

Describe the blood flow sequence through the heart.

Answer 5

vena cava (from body), right atrium, AV valves, right ventricle, semi-lunar valve, pulmonary artery (to lungs)
pulmonary vein (from lungs), left atrium, AV valves, left ventricle, semi-lunar valve, aorta (to body)

Question 6

What is an implication of a faulty heart valve?

Answer 6

leakage

Question 7

Cardiac muscle contract myogenically. What is meant by myogenic?

Answer 7

The contraction is automatic with no nerve impulse required

Question 8

Describe the order of the cardiac cycle

Answer 8

Atrial systole, ventricular systole, diastole

Question 9

Describe atrial systole

Answer 9

Blood under low pressure flows into both atria.
As they fill the pressure on AV valves increases.
Blood forces the valves open and leaks into ventricles.
Atria contract forcing remaining blood out.

Question 10

Describe ventricular systole

Answer 10

Ventricles contract from the base upwards increasing pressure.
AV valves are forced shut due to the pressure on them to prevent back flow and blood is forced out into the arteries.

Question 11

Describe diastole

Answer 11

Atria and ventricles relax lowering the pressure in atria and ventricles.
The semi-lunar valves close to prevent back flow
The coronary arteries fill
Low pressure in atria helps draw blood back to the heart.

Question 12

How is a heartbeat initiated?

Answer 12

SAN/pacemaker (located in the right atrium) starts waves of depolarisation, causing a contraction.
The waves spread and are prevented from reaching ventricles by a band of fibres with high electrical resistance.
The AVN in the septum conducts waves through the ventricles shortly after atria contraction.
The waves are passed onto the purkyne fibres.
The ventricles then contract from the base upwards

Question 13

Why is waters solvent properties a benefit?

Answer 13

Allow chemicals to dissolve easily so biochemical reactions can occur in the cytoplasm

Question 14

Why do ionic molecules dissolve easily in water?

Answer 14

When broken apart the ions are attracted to the oppositely charged water molecule part

Question 15

Polar molecules that also easily dissolve in water are said to be..

Answer 15

hydrophillic

Question 16

Name a non-polar, hydrophobic substance.

Answer 16

Lipids

Question 17

Why is waters high SHC a benefit for organisms?

Answer 17

It warms up and cools down slowly so organisms can maintain a steady temperature even when the ambient temperature is constantly changing

Question 18

Describe and explain the structure of an artery.

Answer 18

Narrow lumen
thick walls- withstand pressure
middle coat with lots of collagen and elastic tissue- for elastic recoil to minimise damage
no valves

Question 19

Describe and explain the structure of a vein.

Answer 19

wide lumen
thinner walls
less collagen and elastic tissue
valves- pressure is low so prevents back flow

Question 20

What is assisted flow in the veins?

Answer 20

Pressure in the veins is low so the flow is helped by the contraction of skeletal muscles.

Question 21

Describe and explain the structure of a capillary.

Answer 21

One cell thick cell walls to allow for easy diffusion.
Blood pressure is low to assist with diffusion
no valves