BIOLOGY CH.
5
1.
Blood Composition
Adult = 5-6 litres blood in body
Blood consists of:
A liquid part
blood plasma
A solid part
platelets
red blood cells
white blood cells
Blood plasma
7% plasma proteins (fibrinogen)
91% water
2% dissolved compounds
Also carries oxygen, nutrients, carbon dioxide, urea
Red blood cells
- no nucleus
- can pick up oxygen
- last about 4 months then die
White blood cells
- have a nucleus
- protect body
- destroy germs
Platelets
- fragments of cells
- help in clotting blood
2.
Circulation
Blood circulates through body
Pulmonary circulation = right side of the heart pumps blood into lungs and back to
the heart blood becomes oxygenated and gets rid of carbon dioxide
Systemic circulation = left side of heart pumps blood to all organs (-lungs) blood
loses oxygen and nutrients waste products are picked up
Here is the whole cycle (not totally sure about this):
Left ventricle aorta organs superior/inferior vena cava right atrium right
ventricle pulmonary artery lungs pulmonary veins left atrium
(ik heb een ezelsbruggetje, maar ik weet niet of die voor jullie werkt: aorta goes to
organs)
3.
The Heart
(learn all parts of heart)
About 70 beats per minute
On the outside:
- coronary artery = oxygen + nutrients to the heart
- coronary vein = carbon dioxide + waste products away from the heart
4.
Blood Vessels
Arteries
- thick walled and elastic
- contract and bounce back, pushing the blood further and creating a pulse
- run away from heart
- high pressure
- deep in body
Capillaries
- wall = one cell layer thick
- branch from arteries
- supply organs from nutrients and oxygen
Veins
- bring blood back to the heart
- low pressure
- have valves
- less deep in body
- thin walls
5.
Cardiovascular Diseases
Low blood pressure
- symptoms = dizzy, fainting
High blood pressure
- Cause = obesity, alcohol, can run in family
- Can be reduced by living healthier
Atherosclerosis
- Disease in vessels
- inner lining of vessel is filled with plaque
- may block blood flow which can cause heart attack
- surgeon can make bypass grafts (extra vessels) to make the bloodstream flow
- atherosclerosis can be taken away with balloon catherisation a small balloon is
---[blown up inside the vessel pushes away the plaque
6.
Tissue Fluid and Lymph
Tissue fluid = the liquid that is forced out of the blood so that it can reach the cells
= contains oxygen, dissolved food and nutrients
= part of it passes back into the vessel
Lymphatic vessels take up part of tissue fluid
liquid inside = lymph
Lymph = contains white blood cells and dissolved substances
Lymphatic vessels join up into lymphatic duct and thoracic duct
Lymphatic nodes = purify lymph
7.
Excretory System
(learn parts of excretory system)
Two kidneys = supplied by renal arteries
= contain deoxygenated blood
= clean blood cleaned blood it taken away by renal veins
Kidneys take out waste products, water, salts, and harmful substances
All removed substances = urine
Urine goes through ureters to bladder passes out of body through urethra
8.
Antibodies
White blood cells can kill certain bacteria by surrounding them
Antigen = a foreign body entering your body
Micro-organisms (a.k.a. pathogens, germs) cause diseases
White blood cells produce antibodies
Antibodies stick to the pathogen this inactivates the pathogen
Natural immunity = after youve been ill the white blood cells remember how to
make certain antibodies
Artificial immunity = you get a vaccination with a mild form of a disease your body
creates antibodies body remembers how to make antibodies
9.
Blood Clotting
When blood touches air it clots
A blood clot is created like this:
A vessel is open/blood streams out of the body platelets become sticky and get
stuck to the vessel wall form clot fibrinogen = turned into fibrin fibrin creates
fibres, which trap red blood cells bleeding is stopped
Haemophilia = disease blood doesnt clot
10.
Blood groups and blood transfusions
(learn fig. 56)
Blood transfusion = receiving blood from a donor
When e.g. antigen A comes together with anti-A sticks together
^^ same goes for blood group B
