components of blood
The substances that plasma transports
Blood cells, nutrients(dissolved food molecules), excretory products(urea, CO2), hormones(from endocrine glands)
The antibodies that each blood group has.
A: antibody b
B: antibody a
AB: no antibodies
O: antibody a and b
Name all the blood vessels in descending order of blood pressure present.
Aorta → Arteries → Arterioles → Capillaries → Venules → Veins → Vena Cava
Systole occurs when…
Diastole occurs when…
The ventricular or atrial muscles contract.
The ventricular or atrial muscles relax.
Blockage of coronary arteries(lie outside the heart, branching from the aorta)
Greatly reduced blood supply> heart attack
The definition of phagocytosis.
The process by which a white blood cell engulfs and ingests foreign particles such as bacteria.
Define agglutination.
The formation of clumps of proteinaceous particles like red blood cells and bacteria, in antibody-antigen reactions.
Compare the characteristics and functions of veins and arteries.
Since the arteries need to withstand the high pressure of the blood forced out of the heart, and allow blood to flow fast, the walls are thick, muscular and elastic.
The elasticity enables the artery wall to stretch and recoil, to push the blood in spurts along the artery. (gives rise to pulse)
However, blood is transported(towards the heart) at a much lower pressure in the veins, and blood flows more slowly and smoothly in the veins. Hence, the walls are comparatively less muscular and less elastic, thinner and smaller. Additionally, valves and a large lumen( offers less resistance to blood flow)are present.
The median septum prevents
the mixing of deoxygenated blood in the right side with the oxygenated blood in the left side.
mixing= reduce the amount of oxygen carried to the rest of the body
During a heart attack, …
blood flow(supply) to a particular part of the heart may be blocked. Since the part cannot receive sufficient oxygen/ nutrients, the region of the heart muscle dies.
Such extensive heart damage can be fatal as the heart is no longer able to pump blood to various parts of the body.
All functions of antibodies produced by lymphocytes
Recognise pathogens/ foreign particles; destroy disease-causing organisms such as bacteria and viruses; cause bacteria to clump together for easy ingestion by phagocyte; neutralise the toxins caused by bacteria
Clumping occurs in Blood Group B when the donor has a blood group of…
A and AB
List either
a) the main arteries of the body and the organ blood flows to
b) the main veins of the body and the organ blood is transported from/to
a) pulmonary arteries(RV)> lungs; aorta(LV)> all; hepatic artery>liver; artery to stomach and intestines; renal arteries> kidneys
b) pulmonary veins(LA)> heart; superior vena ceva> heart(RA) ; inferior vena ceva> heart(RA); renal vein(kidneys); hepatic vein(liver); hepatic portal vein> liver
During atrial sytole, …
blood flow, pressure and sound produced(if any)
The ventricular muscles contract, causing a rise in pressure in the ventricles. The rise in pressure causes the bicuspid and the tricuspid valves to close to prevent the backflow of blood into the atria. This produces a loud ‘lub’ sound. The semi-lunar valves open and blood flows from the RV into the PA and LV into Aorta respectively.
Causes of Coronary heart disease
Atherosclerosis
Fatty deposits(eg:cholesterol and saturated fats) collecting on the inner surface of coronary arteries narrowing lumen space.
The way in which blood clots.
Thrombin in platelets convert the soluble protein fibrinogen to insoluble threads of fibrin.
Fibrin threads entangle blood cells and the whole mass forms a clot or a scab.
The clot seals the wound, preventing entry of microorganisms and excessive blood loss.
The reason why blood O can be transfused to a recipient of any blood type.
The red blood cells(RBC) of group O blood do not have antigens A and B. Hence, when group O RBC are transfused into a person of blood group (-), the recipient’s antibodies will not agglutinate with the donor’s (O) RBC.
no antigens> recipients antibodies X attack RBC> no agglutination> universal donor
Where waste substances are transferred from and their destination. ( tissue fluid/capillaries)
Metabolic( or excretory) waste products diffuse from the cells into the tissue fluid. They are then transferred through the blood capillary walls into the blood. The blood transports these waste products to the secretory organs for removal.
During atrial diastole and ventricular diastole,
The ventricular muscles relax. The fall in pressure causes the semi-lunar valves to close, to prevent the backflow of blood from the PA and aorta back into the ventricles. This produces a soft ’dub’ sound. Slow release of blood out of aorta.
Smoking increases the risk of heart disease because …
Sedentary lifestyle increase the risk of coronary heart disease since…
Nicotine in cigarettes increase blood pressure and the risk of blood clotting in arteries.
Lack of exercise and being inactive lead to the build-up of fatty deposits that block arteries.
With your knowledge of white blood cells and organ transplant, explain and describe tissue and immune system rejection in the recipient’s body.
Any organ from another person may be treated as a foreign body by the recipient’s immune system. The recipient’s white blood cells may respond by producing antibodies to destroy the transplanted organ.
If the tissues of the donor and recipient are not genetically similar, and no drugs, which inhibit the responses of the recipient’s immune system are used, the transplanted organ could be destroyed by antibodies.
The reason why blood group AB are universal recipients.
Group AB’s blood does not have antibody a or b. There are no antibodies present that will attack the antigens on the donor’s red blood cells. When blood of any blood group is transfused, no agglutination will occur with the donor’s red blood cells. Hence…
Describe the relationship between the dilation and contraction of the artery and the size of the lumen.
When an artery constricts, its lumen becomes narrower and less blood flows through it per unit time.
When an artery dilates, its lumen becomes wider and more blood flows through it per unit time.
Describe the pressure changes in the heart in one heartbeat.
1. Atrial systole> both ventricular and atrial pressure increase
2. Ventricular systole + Atrial diastole> ventricular pressure rises
3. Ventricular diastole and Atrial diastole> pressure drops
We can reduce the risk of getting coronary heart disease through…
Maintaining a healthy diet
Smoking cessation
Regular physical exercise: strengthens heart and maintains elasticity of arterial walls.