3.2.3- Exchange At The Capillaries

Question 1

What is hydrostatic pressure?

Answer 1

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

Question 2

What is the ‘lymph’?

Answer 2

The fluid held in the lymphatic system, which is a systemic tubes that returns excess tissue fluid to the blood system.

Question 3

What is oncotic pressure?

Answer 3

The pressure created by the osmotic effect of the solutes.

Question 4

What is plasma?

Answer 4

The fluid portion of the blood.

Question 5

What is tissue fluid?

Answer 5

The fluid that surrounds the cells and tissues. Formed by plasma leaking out of the capillaries.

Question 6

What is the blood made up of.

Answer 6

Plasma with many dissolved substances like CO, Oxygen, amino acids and glucose, as well ad erythrocytes, leucocytes (WBCs) and platelets.

Question 7

By what process does plasma leak out of the capillaries to make tissue fluid?

Answer 7

MASS MOVEMENT.

Question 8

Describe what. Is taken with the plasma and what is left when tissue fluid leaks out of the capillaries and why.

Answer 8

All of the dissolved substances are carried- larger things like WBC’s and erythrocytes are left as they were too big to move through the capillary walls.

Question 9

Lost the five blood vessel types in order of how they’re connected and flow.

Answer 9

Artery's
Arterioles
Capillaries
Venules
Veins

Question 10

Blood flowing into an organ or tissue is carried within _________.

Answer 10

Capillaries.

Question 11

At the ________ end of the capillary there is a high hydrostatic pressure that can result in the plasma being pushed out.

Answer 11

Arterial.

Question 12

Explain why the tissue fluid surrounds cells.

Answer 12

To allow exchange of gases and nutrients to occur across the plasma membrane.

Question 13

What exchange of materials takes place between cells and tissue fluid and by what processes?

Answer 13

Oxygen and nutrients leave the tissue fluid into the cells and waste products leave the cells into the tissue fluid. This is by diffusion, facilitated diffusion and active uptake.

Question 14

Compare the blood pressure at the different ends of the capillary and what affect this will have.

Answer 14

Lower blood pressure at the venous end than the arterial end. This means at the arterial end, plasma will be pushed out and at the venous end, tissue fluid will be pushed back in by mass movement whilst carrying waste substances.

Question 15

Explain what happens to excess tissue fluid that doesn’t reenter the blood.

Answer 15

Some is directed to the lymphatic system that drains excess tissue fluid out of the tissue fluid and returns it to the blood system in subclavian chest. The fluid in the lymphatic system is called lymph and is similar to tissue fluid- it just contains more lymphocytes produced by the lymph nodes.

Question 16

Explain what happens when a tissue is infected.

Answer 16

Capillaries become more leaky so more tissue fluid is directed into the lymphatic system. This will direct the bacteria towards the lymph system, which is where lymphocytes are produced.

Question 17

Where is the net movement of fluid at the venous end of the capillary?

Answer 17

Into the capillary.

Question 18

Where is the net movement of fluid at the arterial end of the capillary?

Answer 18

Out of the capillary.

Question 19

What two things influence the movement of liquid in capillaries?

Answer 19

Oncotic pressure and hydrostatic pressure.

Question 20

The hydrostatic pressure of the blood tends to…

Answer 20

Push fluid out of the capillary to the tissues.

Question 21

The hydrostatic pressure of the tissue fluid tends to do what?

Answer 21

Push fluid into the capillaries.

Question 22

The oncotic pressure of the blood tends to do what?

Answer 22

Pull water back into the blood.

Question 23

The oncotic pressure of the tissue fluid…

Answer 23

Pulls water back into the tissue fluid.

Question 24

At both the arterial and venous end of the capillary, what direction is the oncotic pressure going in?

Answer 24

From the tissue fluid and into the capillary.

Question 25

Where in the capillary is the hydrostatic pressure of the blood inside the capillary more dominant?

Answer 25

The arterial end.

Question 26

Explain what the hydrostatic and oncotic pressures are like at the artery and and of the capillary and what effect this will have on the net movement of fluid.

Answer 26

Hydrostatic pressure of blood higher- pushing outwards of the capillary. Oncotic pressure pushing fluid into the capillary. Net movement of liquid is out of the capillary and towards the tissues.

Question 27

Define what the blood is.

Answer 27

The fluid used to transport materials around the body.