Circulatory System

Question 1

What are the parts of the circulatory system?

Answer 1

Lungs
Heart
Mouth
Blood
Blood vessels

Question 2

Why is the body’s transport system called the circulatory system?

Answer 2

It transports gases around the body.

Question 3

What 2 gases are transported around the body?

Answer 3

Carbon dioxide and oxygen

Question 4

What type of blood does the left side of the heart carry?

Answer 4

Oxygen-rich blood

Question 5

Wha type of blood does the right side of the heart carry?

Answer 5

Oxygen-poor blood

Question 6

What gas is picked up by the blood from the body’s cells?

Answer 6

Carbon dioxide

Question 7

Where is the oxygen-poor blood sent?

Answer 7

To the lungs

Question 8

How does blood circulate around the body? Start with the left side of the heart.

Answer 8

The blood flows from the left side of the heart to the body’s cells.
From the body’s cells the blood is transported into the right side of the heart.
From the right side of the heart, the blood is transported to the lungs.
From the lungs the blood is transported back into the left side of the heart and the cycle starts again.

Question 9

What are the 4 sections of the heart?

Answer 9

Left ventricle
Right ventricle
Left atrium
Right atrium

Question 10

What is the atria (atrium) job?

Answer 10

Collects blood into the heart

Question 11

What is the ventricle’s job?

Answer 11

Pump blood out of the heart

Question 12

What are the 2 jobs of the heart?

Answer 12

Take oxygen-rich blood to the body’s cells for respiration

Transport carbon dioxide out of the body via exhaling

Question 13

Name the four valves of the heart.

Answer 13

Left semilunar valve
Right semilunar valve
Tricuspid valve
Mitral valve

Question 14

Which vein/artery transports oxygenated blood to the body’s cells?

Answer 14

Aorta

Question 15

Which vein/artery transports carbon dioxide-rich blood from the body’s cells to the heart?

Answer 15

Right Pulmonary Vein

Question 16

Which vein/artery transports carbon dioxide-rich blood from the heart to the lungs?

Answer 16

Right Pulmonary Artery

Question 17

Which vein/artery transports oxygenated blood from the lungs to the heart?

Answer 17

Left Pulmonary vein

Question 18

Describe a heartbeat.

Answer 18

A heartbeat begins with all muscles contracted and the valves closed.
Blood flows into the 2 atria and both sides fill up with blood.
The atria contract and the blood is squeezed which causes the valves leading to the ventricles to open.
Blood then flows from the atria into the ventricles.
The valves between the atria and ventricles close to prevent any backflow.
Almost immediately, the ventricles contract and the blood is squeezed again, this time forcing the valves leading out of the heart to open.
Blood is pumped out of the heart.
Once the ventricles are empty, the atria refill with blood and the heartbeat sequence starts again.

Question 19

What is the job of an artery?

Answer 19

Carries oxygenated blood away from the heart.

Question 20

What is the job of a vein?

Answer 20

Carries deoxygenated blood to the heart.

Question 21

What are the jobs of a capillary?

Answer 21

Carries blood to and from the body’s cells and exchanges substances between the blood and the surrounding body cells by the process of diffusion.

Question 22

At what pressure (high/low) is the blood pumped in an artery?

Answer 22

High

Question 23

At what pressure (high/low) is the blood pumped in a vein?

Answer 23

Low

Question 24

Describe the cross-section of an artery.

Answer 24

Thick outer wall
Thick inner layer of muscle and elastic fibres
Narrow central tube

Question 25

Describe the cross-section of a vein.

Answer 25

Thin outer wall Thin inner layer of muscle and elastic fibres Wide central tube

Question 26

What is in the veins that helps prevent backflow?

Answer 26

Valves.

Question 27

Why do veins have valves?

Answer 27

To prevent the possible backflow of blood

Question 28

What else does a vein have that helps squeeze blood back to the heart, besides valves?

Answer 28

The veins are surrounded by muscles that when one moves, the muscles contract and force the blood to the heart.

Question 29

Describe the cross-section of a capillary.

Answer 29

Very thin wall made of a single layer of cells | Narrow central tube

Question 30

What percentage of blood is plasma?

Answer 30

55%

Question 31

What percentage of blood is blood cells?

Answer 31

45%

Question 32

What are the 4 components of blood?

Answer 32

Plasma Red blood cells White blood cells Platelets

Question 33

Define plasma

Answer 33

Blood fluid that surrounds body cells and carries them along as it flows through blood vessels. Mostly made of water. Contains waste substances as well as useful products.

Question 34

What do red blood cells do?

Answer 34

They transport oxygen from the lungs to the body’s cells.

Question 35

Give 5 facts about the red blood cell and describe each.

Answer 35

Large surface area compared to volume: o2 is kept close to the surface and can be released quickly. Disc-shaped and flexible: Cell can travel easily through narrow blood vessels. No nucleus: More room for haemoglobin and so more o2 can be carried. Larger diameter than capillaries: Cell is forced to slow down, therefore gas exchange will definitely happen. Contains haemoglobin: Carries o2 picked up in the lungs and released to the body’s cells.

Question 36

What does a white blood cell do?

Answer 36

Protect the body from disease by fighting invading microbes that cause infections.

Question 37

Name 2 ways that white blood cells fight off diseases.

Answer 37

Some fight against infection by surrounding invading microbes and then digesting them. Others produce antibodies or antitoxins to fight against infection.

Question 38

What are platelets for?

Answer 38

They help with blood clots. They are cell fragments that have broken off of larger cells.