transport in man

Question 1

why is there a need for a transport system?

Answer 1

diffusion is inadequate for transport.
- high surface to seas volume ratio
- high distance away

Question 2

what is the need for double circulation

Answer 2

• allows blood entering the lung to be transported at a lower pressure, so that there is more time to by reoxygenated
• allows bloos in the systemic circulation to be pumped at a high pressure so that it can quicky reach all tissues

Question 3

proper terms for RBC, WBC, platelets and plasma

Answer 3

erythrocytes, leucocytes, thrombocytes, plasma

Question 4

structure and function of erythrocyte

Answer 4

1. has haemoglobin: bind reversibly to form oxyhaemoglobin, transport oxygen around the body
2. has no nucleus: increase space for more haemoglobin to be packed, increase the rate of oxygen transported
3. bioncave shape: increase SA to V ratio for quicker diffusion of oxygen
4. elastic and flexible membrane: can change shape to sqeeze in small and narrow capillaries

Question 5

rank the size of the sunstabces in blood from smallest to largest

Answer 5

platelets, red blood cells, white blood cells

Question 6

what is the effect of having sickle cell anaemia

Question 7

what happens during a drop in fitness level?

Question 8

what are the 2 types of white blood cells

Answer 8

phagocytes and lymphocytes

Question 9

what is the function of lymphocytes

Answer 9

product antibodies that:
- neutralise toxins produced by bacteria
- recognise and bind to bacteria, causing them to rupture
- recognise and bind to bacteria, for tagging for phagocytosis by phagocytes
-cause bacteria to clump together, so that they can be easily ingested by phagocytes

Question 10

why the need for phagocytes?

Answer 10

they can carry out phagocytosis on bacteria
they engulf and ingest bacteria
after that they die and form pus

Question 11

what happens when there is tissue rejection?

Answer 11

the immune system recognises the transplant organ as foreign tissue
starts producing antibodies to destroy the transplanted organ (phagocytosis)

Question 12

how to prevent tissue rejection

Answer 12

1. immunosupression
   - be more susceptible to other infections. immune system is comprimised
2. organs transplant from a genetically close donor
   - same person/identical twin CANNOT have tissue rejection

Question 14

which blood groups are universal donors? which blood groups are universal recipient? why?

Answer 14

1. blood group O: they do not have any A or B antigens on the surface of the RBC, cannot recognise and bind to antibodies, hence no agglutination
2. blood group AB: they do not have A or B antibodies in the blood plasma, cannot recognise and bind to antigens so there will be no agglutination

Question 15

importance of blood clots?

Answer 15

1. (entry of stuff IN): prevent the entry of bacteria into the wound
2. (exit of stuff OUT): prevent the excessive loss of blood from the wound

Question 16

when an injury occurs, only a blood clot forms, true/false?

Answer 16

false. both a blood clot and a platelet plug forms (describe platelet plug!!!)

Question 17

process of forming a blood clot

Answer 17

• damages tissue and platelets secrete thrombokinase.
• thrombokinase and calcium ions convert protothrombin (inactive enzyme) ==> thrombin (active enzyme)
• thrombin converts soluble fibrinogen to insoluble fibrin threads
• the fibrin threads form a mesh that traps other blood cells.

Question 18

what does the smooth muscle allow for?

Answer 18

vasocontriction and vasodialation
(decreasing and increasing the size of the lumen)

Question 19

charcateristics of the arteries and reasons

Answer 19

• thick muscular walls: adjusting the lumen size by vasoconstriction/vasodialation ==> control the Bp and blood flow
• elastic fibers: stretch, recoil and dialate==> withstand the high pressure in the vessel so it does not burst

Question 20

where are the location of veins most likely at?

Answer 20

in between large muscles in the body
- bp in the veins is low
- contraction of muscles push against the wall of veins ==> push the blood flow to heart ==> against gravity

Question 21

adaptations of capillaries

Answer 21

• one cell thick endothelium (NOT EPITHELIUM)
• small gaps between the endothelial cells
• large network of capillaries (large SA, lower blood pressure, slower blood flow, more time for diffusion)

Question 22

rank the blood pressure of capillaries, vein, and venule from higest Bp to lowerst Bp

Answer 22

capillaries, venule, vein

Question 23

which arteries are the exceptions of the rule that arteries do not have valves?

Answer 23

pulmonary artery (low o2) and aorta (high o2)

Question 24

function of the chordae tendinae

Answer 24

holds the bicuspid (LEFT) and tricuspid (RIGHT) valve in position, prevents eversion

Question 25

why is the muscles in the walls of the left ventricle thicker than the walla in the right ventricle

Answer 25

• left ventricle forces blood to all parts of the body expcept lungs
• longer distance, higher Bp generated

Question 26

what happens in the coronary heart disease?

Answer 26

there is a buildup of plaque (cholestrol) ==> occusion of coronary arteries
reduced blood supply to the cardiac muscles
a thromosis (blood clot) in the coronary arteries ==> less blood supply for muscles ==> not enough energy for respiration ==> cells die ==> heart cannot pump blood ==> heart attack

Question 27

what are the causes of coronary heart disease

Answer 27

1. high trans fat and saturated fat diet = diet with unsaturated fat
2. sedentary lifetyle = regular exersise strengthens the heart muscle and improves the elasticity of the arterial walls (during exersise, there is a higher bp in the arteries, so the arteries become more elastic + muscular)
3. high stress = reduce stress
4. smoking cigraettes, increasing the inhalation of CO, higher chance of developing blood clots in arteries = quit
5. genetic factors (high bp and cholestrol)