B3.2.11 (HL)—Tissue fluid in capillaries
Tissue fluid forms when capillary hydrostatic pressure forces plasma out, while plasma proteins help draw fluid back near venule ends.
- Syllabus
- First assessment 2025
- Objective
- B3.2.11
- Level
- HL
Concept essentials
- Hydrostatic pressure at arteriole ends forces plasma fluid out of capillaries.
- Plasma proteins remain in blood and create osmotic pull back into capillaries.
- Lower pressure near venule ends allows most tissue fluid to re-enter blood.
- Excess tissue fluid is drained into the lymphatic system.
ConceptIB Biology HL