chapter 9 transport in humans Flashcards

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1
Q

what makes up plasma (4)

A
  1. 90% water = acts as a solvent to soluble proteins like fibrinogen, prothrombin and antibodies
  2. Dissolved mineral salts
  3. Food substances like glucose, amino acids, fats and vitamins
  4. Excretory products like urea, uric acid, creatinine, carbon dioxide (present as hydrogencarbonate ions)
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2
Q

function of red blood cells

A
  1. contains haemoglobin: combines reversibly with oxygen
  2. To transport oxygen from lungs to all cells to the body
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3
Q

adaptations of RBCs

A
  1. Has a circular biconcave shape: increase SAVR = contains more haemoglobin = higher rate of absorption and release of oxygen
  2. Does not have a nucleus: increase in space = carry more haemoglobin
  3. Elastic and bellshaped: can squeeze through blood vessels smaller than itself
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4
Q

what are white blood cells (feature + types)

A

feature: able to change its shape and squeeze through the walls of thin blood capillaries into spaces among tissue cells = mobile to fight bacteria
types:
1. lymphocytes: produce antibodies = protect body from disease causing microorganisms
2. phagocytes: able to ingest foreign particles like bacteria

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5
Q

how does agglutination happen

A

happens when plasma contains antibody (in plasma) and antigen (on surface of RBC) of same letter:
antibody a binds to antigen A,
antibody b binds to antigen B

donation: involves only blood (only antigens) - if agglutination occurs it is due to plasma in recipient

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6
Q

features of blood type A

A
  1. can receive A and O
  2. plasma/serum has antibody b
  3. RBC has antigen A
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7
Q

features of blood group B

A
  1. can receive B and O
  2. Plasma has antibody a
  3. RBC has antigen B
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8
Q

features of blood group AB

A
  1. can receive A, B, AB and O (universal acceptor)
  2. Plasma has no antibody
  3. RBC has antigen A and B
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9
Q

features of blood group O

A
  1. can receive O (universal donor)
  2. Plasma has antibody a and b
  3. RBC has no antigen
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10
Q

how does blood clotting occur when there is an open wound (4 steps)

A
  1. Damaged blood vessels release enzyme thrombokinase
  2. stimulates conversion of protein prothrombin into thrombin in presence of calcium ions
  3. Thrombin catalyses conversion of soluble protein fibrinogen to insoluble fibrin threads (will not dissolve in water present in plasma)
  4. Fibrin threads form mesh which trap blood cells and seals wound = microorganisms like bacteria cannot enter
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11
Q

what is phagocytosis

A

definition: process of engulfing/ingesting foreign particles by white blood cells (phagocytes)
process: Phagocyte engulfs bacteria by flowing over them and enclosing them = digests ingested bacteria

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12
Q

how do lymphocytes protect our body (3)

A
  1. Destroying bacteria: attaches to them, causing bacterial surface membrane to rupture
  2. Causing bacteria to clump together = easily ingested by phagocytes
  3. Neutralising harmful substances produced by bacteria
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13
Q

how to reduce risk of rejection in a transplant

A
  1. Tissue match = must be genetically close to the recipient as possible (either from same person or family member)
  2. Use immunosuppressive drugs: inhibit responses of recipient’s immune system = antibodies will not be produced and attack the tissue
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14
Q

what are arteries (function, structure, blood pressure, speed of blood flow)

A

function: Transports blood away from the heart→ carry oxygenated blood (except pulmonary artery)

structure: Thick muscular walls, Small lumen, no valves

BP: high = more blood flowing per unit time in a smaller space

speed of blood flow: fast

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15
Q

adaptations of arteries

A
  1. Thick muscular walls = withstand immense pressure of blood forced out from the heart
  2. Walls with much elastic tissue: able to stretch and recoil under high pressure to push blood along the artery
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16
Q

what are veins (function, structure, blood pressure, speed of blood flow)

A

function: Transport blood towards heart → carry deoxygenated blood (except pulmonary veins)

structure: Large lumen, Thin muscular walls with less elastic tissue, Has semi-lunar valves (open to let blood flow, close to prevent from back flow = usually close after blood has flown so that there will be no backflow)

BP: Low = lumen is larger, more blood flows per unit time in one space

speed: Very slow

17
Q

adaptations of vein

A
  1. Thin muscular walls: Veins transport blood back to the heart = lower blood pressure = walls do not have to withstand the low BP = walls are not so thick and elastic
  2. Valves are present to prevent backflow of blood = blood can flow in one direction (as blood in vein has lower BP, there is less pressure to keep them continuously flowing forward, so it may backflow)
  3. Large lumen provides lower resistance = blood flows back smoothly to heart
18
Q

what are capillaries (function, structure, blood pressure, speed of blood flow)

A

function: Involved in exchange of substances
structure: One cell thick wall, no muscular or elastic tissue, Large lumen

BP: low
speed: slow

19
Q

adaptations of capillaries (one capillary and capillarIES)

A

One capillary:
1. one-cell thick wall = shorter diffusion distance which increases rate of diffusion;
2. large lumen relative to diameter = reduce pressure of blood flowing from arteriole end to venule end = allow more time for exchange of materials;
Capillaries
3. extensive network = to increase (cross-sectional) surface area = increased exchange of materials (more blood flows through more capillaries)

20
Q

how does exchange of substances occur in capillaries (5 steps)

A
  1. happens between blood capillary, tissue fluid (carries substances in solution between tissue cells and blood capillaries) and tissue cells
  2. blood flow towards right: oxygen gets released from oxyhaemoglobin, dissolved food substances diffuse out of RBC - out of blood capillary - into tissue fluid - into cells
  3. RBCs may become bell shaped: increase surface area to speed up absorption/release of oxygen
  4. rate of blood flow decreases = more time for exchange of materials between blood and tissue cells
  5. waste products diffuse out of cells = into tissue fluid = diffuse through capillary walls into RBCs
21
Q

what happens during atrial diastole (relaxation)

A
  1. deoxy blood flows into right atrium (RA) via vena cava
  2. oxy blood flows into left atrium (LA) via pulmonary vein (PA)
  3. pressure in atria increases but does not exceed pressure in ventricles
  4. valves are still closed due to pressure
  5. ventricles start to contract
22
Q

what happens during atrial systole (contraction)

A
  1. pressure in atria increases, exceeds pressure in ventricles
  2. bicuspid and tricuspid valves open
  3. deoxy blood flows from RA through tricuspid valve (TV) into right ventricle (RV)
  4. oxy blood flows from LA through bicuspid valve (BV) into left ventricle (LV)
23
Q

what happens during ventricular systole

A
  1. pressure in ventricles increases, exceeds pressure in aorta and pulmonary artery (PA)
  2. semi lunar valves (SLV) open
  3. deoxy blood flows out of RV through SLV into PA
  4. oxy blood flows out of LV through SLV into aorta
  5. pressure in ventricles exceeds pressure in atria
  6. BV and TV close before blood starts to flow into aorta/PA (shld close before blood starts to flow, to prevent backflow back from ventricles into atria)
24
Q

what happens during ventricular diastole

A
  1. pressure of ventricles decrease
  2. semi lunar valves close after all blood in ventricles have been emptied out (now all valves are closed)
  3. artrial diastole starts
25
Q

how is the lub sound produced

A

when pressure in ventricles exceeds pressure in atria, and BV/TV close

26
Q

how is dub sound produced

A

when pressure in aorta/PA exceeds pressure in ventricles and semi lunar valves close (ventricular diastole)

27
Q

why do left and right atria have the lowest thickness

A

left and right atria have the lowest thickness: only force blood a short distance to the ventricles = does not need to withstand high pressure

28
Q

why is left ventricle the thickest

A

→Left ventricle has a thicker muscular wall compared to right ventricle: LV pumps blood around the body = has to withstand higher pressure than that in right ventricle

→ LV is thicker than RV: more force is exerted when thicker wall of LV contracts to force blood out = higher BP in LV

29
Q

why is right ventricle not as thick as left ventricle

A

→ Right ventricle has a thinner muscular wall to LV: need to withstand lower pressure than that in LV = only needs to pump blood a short distance = to lungs located close to the heart

30
Q

what does coronary heart disease affect

A

→affects coronary arteries: lie on outside of heart and carry blood to muscles in the walls of heart

31
Q

what does coronary heart disease cause (cause + effect on cells)

A

causes atherosclerosis: fats and cholesterol deposits on inner wall of arteries harden to form a plaque = narrows lumen of artery = affected artery develops rough inner surface = increases the risk of a blood clot being trapped in artery = cuts off supply of blood and oxygen to the heart muscles

effect: cells/part of heart tissue within the affected part die/get damaged = heart cannot function anymore = heart attack

32
Q

how can coronary heart disease be prevented (3)

A
  1. Stop smoking: reduces the intake on nicotine and carbon monoxide = decreases risk of deposition of fats on inner lining of arteries;
  2. Regular physical exercise: strengthens the heart and maintains elasticity of the arterial walls
  3. Substituting animal fats in diet with polyunsaturated plants fats: these fats do not stick to the inner surface of arteries