Cardiovascular Physiology Part F: Capillary Exchange

Question 1

Where does capillary exchange take place?

Answer 1

between blood and ISF

Question 2

Solutes enter and leave capillaries by:

Answer 2

1. Diffusion
2. Vesicular transport
3. Mediated transport

Question 3

Major route that solutes enter and leave capillaries

• CO2, O2, ions, aa, glucose, hormones etc
• usually between endothelial cells

Answer 3

Diffusion

Question 4

Solutes enter and leave capillaries by:
Vesicular Transport
occurs via…..

Answer 4

Transcytosis- endocytosis from blood into endothelial cell, then exocytosis from endothelial cell into ISF

Question 5

H2O enters (absorption) or leaves (filtration) capillaries by:

Answer 5

1. Osmosis

2. Bulk Flow

Question 6

4 Pressures involved in bulk flow

Answer 6

1. blood hydrostatic P (BHP) = blood pressure
2. blood osmotic P (BOP) – mainly due to plasma proteins
3. ISF hydrostatic pressure (IFHP) = 0 mmHg
4. ISF osmotic pressure (IFOP) – mainly due to ISF proteins
   (*look at diagram in notes)

Question 7

Net Filtration Pressure Equation

Answer 7

NFP = (BHP + IFOP) - (BOP - IFHP)

promote filtration oppose filtration

Question 8

Edema

Answer 8

accumulation of fluid in the tissue causing swelling

Question 9

Edema can be due to

Answer 9

1. High blood pressure (⇑ BHP)
2. leakage of plasma proteins into ISF ⇒ inflammation (⇑ IFOP)
3. ⇓ plasma proteins (malnutrition, burns) (⇓ BOP)
4. obstruction of lymph vessels - elephantiasis, surgery