Circulatory System

Question 1

functions of the circulatory system

Answer 1

transportation: respiratory, nutritive, excretory.
regulation: hormonal, homeostasis, temp.
protection: haemostasis, immunity.

Question 2

key functions + components of blood

Answer 2

vehicle for short and long range mass transport or materials for between cells and between cells and external environment.

blood vessel, white blood cells, red blood cells, plasma, platelets.

volume of blood varies with: body size, changes in fluid + electrolyte conc, adipose tissue.

Question 3

composition of blood

Answer 3

consists of formed or cellular elements of blood cells that are suspended in liquid plasma.

plasma - 57%
formed/cellular elements - 45%

Question 4

plasma

Answer 4

55%
straw coloured liquid
~92% of plasma is water and dissolved solutes: specialised proteins, electrolytes (ions), nutrients, hormones and metabolic waste.

Question 5

formed/cellular elements

Answer 5

45%
red blood cells, white blood cells, platelets.

Question 6

erythrocytes (red blood cells)

Answer 6

contain haemoglobin for O2 transport to cells.

120 days in blood stream
smooth, round, biconcave discs - can change shape.
lack nuclei and a lot of other organelles.

Question 7

leukocytes (white blood cells)

Answer 7

main unites of bodys defence system.
transported in blood to sites of injury/invasion by pathogens.

Question 8

thrombocytes (platelets)

Answer 8

haemostasis. arrest of bleeding from injured blood vessels.