Lymphatic system

Question 1

Tissue fluid

Answer 1

Formed by blood plasma leaking from the capillaries. Surrounds the cells and provides them oxygen and nutrients

Question 2

What is lymph

Answer 2

Excess fluid not passed back into the capillaries drained back into the lymphatic system. Colourless/pale yellow fluid.

Question 3

Tissue fluid formation

Answer 3

1. Hydrostatic pressure higher in arteriole end of capillary than in tissue fluid
2. Difference in pressure forces fluid containing small moleculoes out of the blood through capillary walls. This forms tissue fluid
3. Red blood cells, platelets and plasma proteins remain in the blood
4. Exchange between tissue fluid and cells by diffusion. Oxygen and nutrients enter the cell and other waste leaves the cell into tissue fluid
5. As fluid leaves capillaries, hydrostatic pressure is reduced. Pressure at venous end much lower
6. Water leaves capillary but plasma proteins cant leave, lowers water potential of blood. Water potential in the capillaries lower than in the tissue fluid at venule end. Osmotic pressure higher at venule end than hydrostatic pressure. Water moves by osmosis into the capillaries carrying waste
7. Excess tissue fluid collected into lymph system ans returned to circulatory system.

Question 4

Summary

Answer 4

High hydrostatic pressure at arteriole end forces fluid out of the capillaries but plasma proteins remain inside. Lowers water potential & hydrostatic pressure of the blood. Hydrostatic pressure lower and water potential in tissue fluid is higher in the venule end so water returns to the capillaries by osmosis. Excess back to lymph system.