(5) Blood and circulation

Question 1

(In mammals) what does blood transport?

Answer 1

• Oxygen to organs that need it.
• Carbon dioxide away from organs.
• Nutrients to the parts the need it.
• Urea from the liver to the kidneys.
• Hormones and antibodies.

Question 2

How do single celled organisms obtain oxygen?

Answer 2

By diffusion through the surface membrane of the cell.

Question 3

What are the two types of circulatory systems?

Answer 3

• Single circulatory system

- Double circulatory system

Question 4

What is the difference between a single and double circulatory system?

Answer 4

In a single circulatory system the blood is pumped from the heart directly to the rest of the body. Whereas in a double circulatory system the blood is pumped from the heart to the gas exchange organ, back to the heart and then to the rest of the body.

Question 5

What are the two parts to a double circulatory system?

Answer 5

1) Pulmonary circulation

2) Systemic circulation

Question 6

What divides the left and right side of the heart?

Answer 6

The septum

Question 7

What does the right and left ventricle do?

Answer 7

The left one pumps blood to the rest of the body, while the right one pumps blood to the lungs.

Question 8

Why are there valves in the heart?

Answer 8

To ensure the blood only flows in one direction.

Question 9

What is special about cardiac muscle?

Answer 9

It doesn’t get fatigued.

Question 10

What is the coronary circulation?

Answer 10

It is the heart’s own blood supply.

Question 11

What hormone triggers the fight or flight response?

Answer 11

Adrenaline

Question 12

What part of the brain controls the heart rate?

Answer 12

The medulla

Question 13

What do arteries do?

Answer 13

They carry blood from the heart to the organs of the body.

Question 14

What do veins do?

Answer 14

They carry blood from the organs back to the heart. (They have a much lower blood pressure than the arteries)

Question 15

What do capillaries do?

Answer 15

They carry blood through organs, and bring it close to all cells in the organ. It’s walls are one cell thicc to allow for diffusion of nutrients.

Question 16

What is plasma?

Answer 16

It is the liquid part of blood. It carries all the components of blood around the body.

Question 17

What is RBC?

Answer 17

It is the part of blood that gives its red colour. It is responsible for carrying oxygen throughout the body.

Question 18

What are lymphocytes?

Answer 18

They are a type of WBC, they produce antibodies to destroy microrganisms.

Question 19

What are phagocytes?

Answer 19

They are a type of WBC, they digest and destroy bacteria.

Question 20

What are platelets?

Answer 20

They release chemicals to make blood clot.

Question 21

Do RBC have a nucleus?

Answer 21

No, they need the extra space for hemoglobin.

Question 22

What are antigens?

Answer 22

They are markers on a bacteria and viruses that antibodies use to recognize foreign objects.

Question 23

How do antibodies destroy pathogens?

Answer 23

• Causing them to stick together, so phagocytes can easily ingest them.
• Acting as a label, so it is more easily recognized by a phagocyte.
• Causing bacteria cells to burst open.

Question 24

What is immunity?

Answer 24

It’s when the memory lymphocytes quickly identify a pathogen it previously dealt with and and produces antibodies to immediately deal with it.

Question 25

What are platelets?

Answer 25

They are fragments of large cells made in the bone marrow.

Question 26

How do platelets form a scab?

Answer 26

When they are exposed to air from cut skin, they produce a chemical that causes fibrinogen to change into fibrin. This traps RBC and creates a scab.