7.6 - Tissue Fluid And Its Formation

Question 1

What does tissue fluid contain?

Answer 1

Glucose, amino acids, fatty acids, ions in a solution and oxygen

Question 2

What does tissue fluid get back in return from supplying the tissues?

Answer 2

Carbon dioxide and wast materials

Question 3

What is tissue fluid formed from?

Answer 3

Blood plasma

Question 4

What is the composistion of blood plamsa controlled by?

Answer 4

Various homeostatic systems

Question 5

The pressure created by the pumping of the heart is called what?

Answer 5

Hydrostatic pressure

Question 6

What causes the tissue fluid out of the blood plasma?

Answer 6

Hydrostatic pressure

Question 7

What causes the outward pressure of tissue fluid

Answer 7

1. Hydrostatic pressure of the tissue fluid outside the capillaries, which resists outward movement of liquid
2. The lower water potential of the blood, due to the plasma proteins, that causes water to move back into the blood within the capillaries

Question 8

The hydrostatic pressure is only enough to force small molecules out of the capillaries leaving what behind because they are too big to cross the membrane?

Answer 8

All cells and proteins

Question 9

What is the name of the filtration that is under pressure?

Answer 9

Ultrafiltration

Question 10

Most tissue fluid returns back to the blood plasma directly vis what?

Answer 10

Capillaries

Question 11

What are the 5 stages of tissue fluid returning back to the blood plasma?

Answer 11

1. The loss of the tissue fluid from the capillaries reduces the hydrostatic pressure inside them
2. As a result, by the time the blood has reached the venous end of the capillary network its hydrostatic pressure is usually lower than that of the tissue fluid outside them
3. Therefore tissue fluid is forced back into the capillaries by the higher hydrostatic pressure outside them
4. In addition, the plasma has lost water and still contains proteins. It therfore has a lower wtaer potential than the tissue fluid
5. As a result, water leaves the tissue by osmosis down a water potential gradient

Question 12

Not all the tissue fluid can return via the capillaries the rest is carried back via what?

Answer 12

The lymphatic system

Question 13

What is the lymphatic system?

Answer 13

A system of vessels that begin in the tissues, initially they resemble capillaries (except they have dead ends), but they gradually merge into larger vessels that form a network throughout the body.

Question 14

How does the lymphatic system return tissue fluid into the bloodstream?

Answer 14

The larger vessels drain their contents back into the bloodstream via two duct that join close to the heart

Question 15

The contents of the lymphatic system are not moved by the pumping of the heart instead they are moved by what?

Answer 15

• hydrostatic pressure of the tissue fluid that has left the capillaries
• contraction of body muscles that squeeze the lymph vessels

Question 16

How do the lymph vessels ensure that the fluid inside them moves away from the tissues in the direction of the heart

Answer 16

Valves