Circulatory System

Question 1

Which blood vessel carries oxygenated blood from the heart to the body?

Answer 1

Aorta

Question 2

Pacemaker cells are found in which chamber of the heart?

Answer 2

the right atrium

Question 3

Which statement is always true regarding arteries?

Answer 3

They carry blood away from the heart

Question 4

Which statements is always true for veins?

Answer 4

They carry blood towards the heart

Question 5

coronary arteries do what?

Answer 5

They supply the heart muscle with oxygenated blood and nutrients.

ensuring it has the energy to pump blood effectively.

Question 6

what is the circulatory system + role?

Answer 6

• example of an organ system
• circulates blood throughout the body
• role is to transport oxygen and nutrients

Question 7

what 3 things does the circulatory system rely on?

Answer 7

blood
blood vessels
the heart

Question 8

why is it called the double circulatory system?

Answer 8

Because there are 2 distinctions loops.

one of them carries deoxygenated blood (body to heart to lungs)

other carries oxygenated blood (lungs to heart to rest of the body)

Question 9

notes 1

Answer 9

atrium = 1
atria = 2

Question 10

notes 2

Answer 10

Artery = deoxygenated
vein = oxygenated

Question 11

What’s the role of a pacemaker?

also how

Answer 11

keeps the heartbeat steady by producing small electrical impulses

which spreads through the muscular walls of the heart causing them to contract

Question 12

Rarely pacemaker don’t properly work sometime so doctors can implant an artificial pacemaker.
Explain how they work and where they are placed

Answer 12

• Its a small device that’s placed just under the skin above the heart.
• it contains a wire that can carry electrical current down to the heart telling it to contract regularl.
• acts like a healthy real one

Question 13

arteries role

Answer 13

Carry blood AWAY from the heart

Remember ‘A for Artery’ and ‘A for Away from the heart’.

Question 14

capillaries role

Answer 14

Capillaries are small blood vessels where
the exchange of oxygen, carbon dioxide, nutrients, and waste between the blood and tissues.

Question 15

vein’s role

Answer 15

Carry blood back to the heart

Question 16

arteries structure (4)

Answer 16

• high pressure
• strong and elastic
• contains muscle and elastic tissues making it thick
• resulting in smaller lumen

Question 17

capillaries

Answer 17

Capillaries are the smallest of the three blood vessels.

The role of capillaries is to exchange nutrients and waste products with the tissues.

Capillary walls are permeable, meaning substances are able to move through them.

Their walls are also only one cell thick which means a short distance for diffusion.

Capillaries carry blood at a low pressure and have a lower rate of flow than arteries.

Question 18

veins

Answer 18

• biggest lumen
• small layer of elastic fibres + smooth muscles
• low pressure so don’t need strong walls
• contains valves - prevent backflow

Question 19

how to calculate the rate of blood flow
e.g.
2,560ml of blood passes through the aorta in 8 minutes. calculate the blood flow through the aorta in ml/min

Answer 19

2,560/8minutes = 320ml/cm

Question 20

what are the nutrients that are exchanged between the blood in the capillaries and the body tissues?

Answer 20

amino acid and glucose

Question 21

which substances are waste products that are exchanged between the blood in the capillaries, and the body tissues?

Answer 21

Carbon dioxide and urea

Question 22

If you consider all the blood vessels inside of a human body, which type of blood vessel accounts for the majority of the cross-sectional area?

Answer 22

Capillaries

Even though individual capillaries have a very small cross-section, there are so many of them that together they have the highest total cross-section.

Question 23

In which order does blood flow through the three types of blood vessels?

Answer 23

Heart ➔ arteries ➔ capillaries ➔ veins ➔ heart

Heart: Blood is pumped from the heart.

Arteries: Oxygenated blood is carried away from the heart to the body (except for the pulmonary artery, which carries deoxygenated blood to the lungs).

Capillaries: Small blood vessels where exchange of oxygen, nutrients, and waste products occurs between the blood and tissues.

Veins: Deoxygenated blood returns to the heart (except for the pulmonary vein, which carries oxygenated blood from the lungs to the heart).

Heart: Blood is pumped out to the body or lungs again.

Question 24

Describe the pathway of blood through the heart:

Answer 24

Deoxygenated blood enters the right atrium via the vena cava.

Blood flows to the right ventricle.

Pumped to the lungs via the pulmonary artery.

Oxygenated blood returns to the left atrium via the pulmonary vein.

Flows to the left ventricle.

Pumped to the body via the aorta.

Vena Cava → Right atrium → valve → Right ventricle → valve → Pulmonary artery → Lungs → Pulmonary veins → Left atrium → valve → Left ventricle → valve → Aorta → Body.