Circulatory System

Question 0

Components of blood:

Plasma

Answer 0

55% blood volume
91% water
Dissolved substances:
Nutrients- glucose, amino acids, lipid
Gases- O2, CO2
Wastes- urea
Hormones/proteins

Question 1

Function of the blood

Answer 1

Transport O2 & nutrients to cell
Transport CO2 & wastes away from cell
Transport hormones to cells
Maintain body temp
Maintain pH of body fluids
Maintain water and ion content of body fluids
Protect against disease-causing organisms

Question 2

Components of blood:

Leucocytes WBC

Answer 2

1% blood volume
Kill foreign matter- remove dead/injured cells
Last few days
Granulocyte- nucleus- granular cytoplasm
Monocyte- nucleus- agranular cytoplasm

Question 3

Components of blood:

Erythrocytes RBC

Answer 3

45% blood volume
No nucleus- room for haemoglobin & O2
Bi concave discs- increase S.A
Last 120 days
Produced in red bone marrow

Question 4

Components of blood:

Thrombocytes - platelets

Answer 4

Prevent blood clotting
No nucleus
Last 7 days
Produced in bone marrow

Question 5

Process of O2 and CO2 around body

Answer 5

O2: 3% dissolved in plasma
       97% as oxyahaemoglobin 
       - alveoli to body tissue cell
CO2: 8% dissolved in plasma
          22% as carbaminohaemoglobin 
          70% as bicarbonate ions

Question 6

Transport of nutrients and wastes

Answer 6

1. Plasma moves from capillary to tissue fluid
   
   • change in size of capillary- big-small
   • plasma is forced out (not all)
2. O2/ glucose move into tissue fluid/into cell by diffusion-conc. Grad. By respiration
3. CO2/ urea move out of tissue fluid/out of cell by diffusion- conc. Grad. By respiration
4. Tissue fluid moves back into capillary
   
   • change in size of capillary- small-big by osmosis
   • lower pressure/ increase in osmotic pressure
5. Excess fluid moves into lymphatic system
   
   • lymph vessel has larger S.A for excess fluid
   • walls of capillary- more permeable-excess fluid moves in easier
6. Tissue fluid now called lymph

Question 7

Main components of circulatory system

Answer 7

Blood
Heart
Blood vessels

Question 8

Define diastole and systole and vasoconstriction and vasodilation

Answer 8

Diastole: relaxation phase(filling)
Systole: contraction phase
Vasoconstriction: contraction of blood vessel- reduce diameter of blood vessel- reduce blood flow
Vasodilation: muscle relaxes- increase blood flow

Question 9

Describe the cardiac cycle

Answer 9

1. Atria and ventricles both in diastole:
   
   • atria and ventricles fill with blood as valves open
2. Atria systole:
   
   • atria contracts & forces blood into ventricles
   • semi-lunar valves close
   • bi/tricuspid valves open
3. Ventricle systole:
   
   • ventricle contracts & forces blood out of heart into arteries
   • semi-lunar valves open
   • bi/tricuspid valves close to prevent back flow

Question 10

Describe cardiac output

• Factors affecting
• formula
• how increased and decreased
• When exercising

Answer 10

Factors affecting:
Heart rate- beats per minute
Stroke volume- amount of blood released from heart each beat
Formula- stroke volume x heart rate = cardiac output
Increased by: increased stroke volume/heart rate
Decreased by: decreased stroke volume/heart rate
When exercising: muscles that contract need more blood-more nutrients and O2
Remove CO2 and heat produced

Question 11

Types of blood vessels

Answer 11

Arteries: move blood away from heart
Thick, muscular, elastic walls
Veins: moves blood to heart
Thin, no elastic, no muscle walls
Capillaries: carries blood between cells
One cell thick, easy exchange of O2 & CO2