Cardiovascular Flashcards
Functions of blood cells
Red blood cells (erythrocytes)
Transports oxygen and haemoglobin around the body
Haemoglobin bonds with oxygen as the blood passes through the lungs
Transports it around the body
Releases it to organs and tissues
Platelets (thrombocytes)
Help prevent abnormal or excessive bleeding
Part of clotting process
Assists in the forming clots by triggering enzyme pathways on exposure to air
Clump together to block holes in blood vessels and are essential to arrest bleeding and repair damaged blood vessels
White blood cells
Defend the body against pathogens
Lymphocytes - two types of cells. B cells can be stimulated to produce and release antibodies. T cells attack virus infected and malignant cells. Creation of memory cells and maintain immunity
Phagocytes - engulfs and digests bacteria, dead cells and tissues
Differences between vein and an artery
Veins have valves/arteries do not
Veins carry low pressure blood/artery carries high
Veins have a large lumen/arteries have small lumen
Veins carry deoxygenated blood (except pulmonary vein)/arteries carry oxygenated blood (except pulmonary artery)
Veins carry blood back to the heart/arteries carry blood away
Veins are less elasticated than arteries
Veins do not have a pulse/arteries do
Structure of arteries arterioles capillaries veins venules
Arteries - walls of arteries smooth muscle fibres. Contract and relax under instructions of sympathetic nervous system
Arterioles - tiny branches of arteries that lead to capillaries. Also under control of sympathetic nervous system. Constrict and dilate to regulate blood flow
Capillaries - tiny and extremely narrow blood vessels. Networks of capillaries present in most organs and tissues of the body. Capillaries supplied with blood by arterioles and drained by venules. One cell thick which allows exchanges of gases and materials of the capillary to surrounding tissue
Veins - walls are layers of tissue that are thinner and less elastic than layers of arteries. Veins have valves that prevent back flow of blood.
Venules - minute vessels that drain blood fro, capillaries into veins. Many venules unit to form vein
What is coronary artery disease
When one or more of coronary arteries become narrowed or blocked by gradual build up of fatty deposits (plagues).
Process known as atherosclerosis and fatty deposits called atheroma
Coronary arteries take blood directly to heart muscle. Narrowing causes a reduction in oxygenated blood flow. Heart is starved of oxygen and can begin to die (infraction)
Causes of CHD
Diet
Avoid diets rich in animal fats and dairy - rise cholesterol level
Poor diet including processed foods will result in lack of vitamins and antioxidants as well as high fats and salt levels
Too much salt in diet - salt should be less than 6g a day.
Alcohol -
