AOS 2: Cardiorespiratory system

Question 1

Cardiovascular system function

Answer 1

• Circulate blood to all parts of the body
• Transport water, oxygen and nutrients to the cells
• Transport wastes, including carbon dioxide, away from the cells
• Maintain correct body temperature
• Fight disease through white blood cells and antibodies in the blood

Question 2

The heart

Answer 2

The heart is responsible for the movement of blood around the body, functioning as two pumps

Question 3

Right side of heart

Answer 3

The right side deals with deoxygenated blood

Question 4

Left side of heart

Answer 4

The left side deals with oxygenated blood

Question 5

Chambers

Answer 5

The heart has four chambers- two atria and two ventricles.
- The Atria are the upper chambers that receive blood
- The Ventricles are the lower chambers that pump blood

Question 6

Function of heart

Answer 6

The heart works by the continual contraction and relaxation of the atria and ventricles.

Question 7

Systole

Answer 7

When the heart contracts, it forces blood out of the ventricles and into the arteries

Question 8

Diastole

Answer 8

When the heart relaxes, it fills with blood from the veins.

Question 9

Cardiac cycle

Answer 9

The cardiac cycle is made up of two main phases:
1. The atria contracting (systole) while the ventricles relax (diastole)
2. The ventricles contracting (systole) while the atria relax (diastole)

Question 10

Blood vessels

Answer 10

The cardiovascular system has three types of blood vessels that control the direction and volume of the blood flow around the body

Question 11

Arteries

Answer 11

Carry oxygenated blood and nutrients from the heart to the body tissue.

Question 12

Artery structure

Answer 12

• thick, elastic, muscular walls to withstand high blood pressures
• Walls contract and relax to move blood throughout the body
• Decrease in size and become arterioles as the network of blood vessels works its way into the depths of the body

Question 13

Capillaries

Answer 13

In close proximity to all tissues for gas, nutrient and waste exchange

Question 14

Capillary structure

Answer 14

• Smallest and most abundant blood vessel
• Walls are extremely thin to assist with diffusion

Question 15

Vein

Answer 15

Carries mainly deoxygenated blood back to the heart

Question 16

Vein structure

Answer 16

• thin, less elastic walls as blood pressure is low
• Contain one-way valves to ensure blood flows back to the heart
• Surrounding muscles act as a “pump” to move blood against gravity and back to the heart

Question 17

Pulmonary circulation

Answer 17

The movement of blood from the heart, to the lungs, and back again.

Question 18

Systemic circulation

Answer 18

The movement of blood from the heart, to the tissue, and back again.

Question 19

The blood

Answer 19

The blood is the transport medium for dissolved gases, nutrients, hormones and waste products.

Blood consists of:
- Plasma
- Red blood cells
- White blood cells
- Platelets

Question 20

Plasma

Answer 20

• The fluid component of blood
• Carries blood cells and transports nutrients and waste
• Plasma makes up about 55% of total blood volume

Question 21

Red blood cells

Answer 21

• Transport oxygen to the muscles
• Contain haemoglobin
  Produced in the bone marrow.

Question 22

White blood cells

Answer 22

• Fight disease-causing organisms
• while blood cells make up about 45%

Question 23

Platelets

Answer 23

• Cause blood to clot when a blood vessel is damaged
• Produced in the bone marrow

Question 24

Cardiovascular responses to exercise

Answer 24

A number of changes occur within the cardiovascular system when exercise begins. These changes allow the body to meet the demands of exercise.

Question 25

Immediate, short-term responses

Answer 25

Acute responses to exercise. They revolve around the increased demand for oxygen and fuels at the working muscles.

Question 26

Increased heart rate

Answer 26

Heart rate quickly increases above resting levels at the onset of exercise.

Heart rate generally increases linearly as exercise intensity increases.

Heart rate will plateau at submaximal intensities or when maximal HR is reached.

Question 27

Increased stroke volume

Answer 27

Stroke volume increases with exercise intensity, but only to a certain point.

Stroke volume plateaus at approximately 60% of an individual’s maximal exercise capacity.

Question 28

Increased cardiac output

Answer 28

Cardiac output is a product of heart rate and stroke volume (HR x SV = Q).

Cardiac output increases with exercise intensity as a result of increases in heart rate and stroke volume.

Question 29

HR X SV = Q

Answer 29

Cardiac output is directly affected by the responses of heart rate and stroke volume to the increased demand for oxygen and fuel at the muscle.