Tissue fluid and the lymph systemEdexcel A-Level Biology B: Flashcards

Exam questions on Tissue fluid and the lymph system

1. In a capillary bed, the hydrostatic pressure of the blood is 4.0 kPa at the arteriole end and 1.5 kPa at the venule end. Throughout the capillary, the oncotic pressure of the blood plasma is 3.3 kPa. The hydrostatic pressure and oncotic pressure of the tissue fluid outside the capillary can be ignored.
   Explain why the hydrostatic pressure of the blood is lower at the venule end of the capillary than at the arteriole end.2 marks
2. A child with severe protein deficiency has a swollen abdomen and swollen legs. A blood test shows that the concentration of proteins in the child's blood plasma is much lower than normal.
   Explain how the low concentration of plasma proteins causes the swelling in the child's abdomen and legs.2 marks
3. During cancer surgery, some of the lymph vessels in a woman's armpit were removed. Six months later her arm on that side is swollen, and the swelling does not go down overnight.
   Describe how tissue fluid that is not reabsorbed by the capillaries is returned to the blood.3 marks