Term

Explain the difference between open and closed circulatory systems + single/double.

Definition

open system: blood is not confined to blood vessels and comes into direct contact with tissues and cells closed system: blood confined within blood vessels - single: blood passes through the heart once during each circulation - double: blood passes through the heart twice during each circulation

Term

Name the different types of blood vessels and their adaptations and function.

Definition

arteries: - carry oxygenated blood away from the heart - thick muscular wall allows it to withstand high pressure - elastic tissue stretches and recoils to smoothen pressure fluctuations arterioles: - link the arteries and the capillaries - controls blood flow to tissues by using its smooth muscle in its walls to do vasodilation/constriction capillaries: - link the arterioles to the venules - oxygen leaves blood through capillary walls - one cell thick endothelium for hort diffusion distance - very narrow lumen which slows blood flow venules: - link the capillaries with the veins - thin walls for short diffusion distance veins: - carry deoxygenated blood to the heart (except pulmonary vein) - thin walls - valves prevent backflow of blood

Term

Explain the process of tissue fluid formation.

Definition

- blood enters capillary from arterioles at high pressure - this increases hydrostatic pressure in capillary walls - the pressure forces water and small solutes out of the capillary walls, forming tissue fluid - solutes in the blood increase oncotic pressure in the blood, causing some of the water to move back into the blood via osmosis - hydrostatic pressure is lower at venule end - this causes water to move back into the capillaries through osmosis due to the oncotic pressure in the blood - extra tissue fluid drains into the lymphatic system