Exchange in the Capillaries

Question 1

What is blood?

Answer 1

The fluid used to transport materials around the body.

Question 2

What is hydrostatic pressure?

Answer 2

The pressure that a fluid exerts when pushing against the sides of a vessel or container.

Question 3

What is lymph?

Answer 3

The fluid held in the lymphatic system.

Question 4

What is the lymphatic system?

Answer 4

A system of tubes that returns excess tissue fluid to the blood system.

Question 5

What is oncotic pressure?

Answer 5

The pressure created by the osmotic effects of the solutes.

Question 6

What is plasma?

Answer 6

The fluid portion of the blood.

Question 7

What is tissue fluid?

Answer 7

The fluid surrounding the cells and tissues.

Question 8

What does the plasma contain dissolved in it?

Answer 8

Oxygen, carbon dioxide, minerals, glucose, amino acids, hormones and plasma proteins.

Question 9

What are the cells that you would find in the plasma?

Answer 9

Erythrocytes, red blood cells
Leucocytes, various white blood cells
Platelets.

Question 10

How is tissue fluid formed?

Answer 10

By plasma leaking from the capillaries.

Question 11

What does the tissue fluid do?

Answer 11

Supplies cells in the tissue with the oxygen and nutrients that they require.

Question 12

The movement of plasma into tissue fluid is what?

Answer 12

Mass flow.

Question 13

Describe the order of blood vessels through an organ.

Answer 13

Arteries
Arterioles
Capillaries
Venules
Veins

Question 14

At the arterial end of the capillary what is the pressure like?

Answer 14

The hydrostatic pressure is very high.

Question 15

What does the hydrostatic pressure do to the blood plasma?

Answer 15

It pushes it out of the capillaries into the cells of the tissue and turns into tissue fluid.

Question 16

Why are red blood cells not pushed out due to the hydrostatic pressure?

Answer 16

They are to large to pass through the capillary membrane.

Question 17

Why does tissue fluid surround the body cells?

Answer 17

So that the exchange of gases and nutrients can occur across the plasma membrane.

Question 18

Not all tissue re-enters the blood. Where does it go?

Answer 18

Some tissue fluid is directed into another tubular system called the lymphatic system.

Question 19

What does the lymphatic system do?

Answer 19

Drains excess tissue fluid out of the tissue and returns it to the blood system via the subclavian vein in the chest.

Question 20

What is the fluid in the lymphatic system called?

Answer 20

Lymph

Question 21

What does lymph contain more of than tissue fluid?

Answer 21

Lymphocytes as they are produced in the lymph nodes.

Question 22

What are lymph nodes and what are they involved in?

Answer 22

They are swellings found at intervals along the lymphatic system, which have an important role in the immune system.

Question 23

What happens regarding the lymph nodes and capillaries if a tissue is infected?

Answer 23

The capillaries become more leaky and release larger amounts of tissue fluid, which is then directed into the lymphatic system. This helps direct bacteria towards the lymph nodes.

Question 24

The hydrostatic pressure of blood does what?

Answer 24

Pushes fluid out into the tissues.

Question 25

The hydrostatic pressure of the tissue fluid does what?

Answer 25

Tends to push fluid into the capillaries.

Question 26

The oncotic pressure of blood does what?

Answer 26

Tends to pull water back into the blood.

Question 27

What does the oncotic pressure of the tissue fluid do?

Answer 27

Pulls water into the tissue fluid.