transport in humans

Question 1

what is the primary function of red blood cells?

Answer 1

it transports oxygens from the lungs to respiring cells

Question 2

what are the features of the rbc and how it aids function?

Answer 2

-biconcave shape=greater surface area to volume ratio for an increased rate of diffusion of oxygen into and out of the cell
-contains haemoglobin=haemoglobin binds reversibly to oxyegn
-lacking most organelles=more space to pack more haemoglobin in the cell&no mitochondria to use up oxygen

Question 3

what is the primary function of a white blood cell?

Answer 3

protect body from diseases and infections

Question 4

what are the features of the wbc and how it aids function?

Answer 4

-irregularly shaped=allows the cell to squeeze through gaps in the capillary endothelium
-less numerous than rbc=increases in numbers when fighting pathogens

Question 5

what is the function of phagocytes?

Answer 5

ingest foreign matter like bacteria and viruses

Question 6

what is the function of lymphocytes?

Answer 6

produce antibodies that bind to and neutralise toxins

Question 7

what are wbcs responsible for as well?

Answer 7

they are responsible for organ rejections after transplants
wbc can detect and destroy all foreign substances, they may recognise the cells of the newly transplanted organ as foreign and begin destruction process to get rid of all foreign substances from the body

Question 8

how to avoid tissue rejection?

Answer 8

tissue matching using blood types and many genetic markers
or
use patients own stem cells and genetically engineer them to develop into the organ required

Question 9

what is the primary function of platelets?

Answer 9

initiate the blood clotting process
-prevent excessive blood loss
-prevent entry of pathogens

Question 10

what are the feature(s) of platelets?

Answer 10

small fragments of cytoplasm

Question 11

what are the steps in the blood clotting process?

Answer 11

-platelets and damaged tissues release enzymes
-enzymes convert soluble fibrinogen into insoluble fibrin strands
-fibrin strands form a mesh over the wound to trap rbc and form a clot

Question 12

what is the primary function of plasma?

Answer 12

medium for transport

Question 13

what are the features of plasma

Answer 13

pale yellow fluid that is 95% water

Question 14

what are the substances transported? (plasma)

Answer 14

useful:
-nutrients(glucose, amino acids)
-vitamins(A-E, K)
-hormones(testosterone, oestrogen, insulin)
-proteins (albumin, antibodies, enzymes)
-ions (calcium, iron, sodium)
not useful:
-urea
-co2

Question 15

what do blood vessels in the body form?

Answer 15

a continuous network of tubes for blood to flow to and from the various organs

Question 16

what do the arteries do?

Answer 16

they transport blood away from the heart

Question 17

what do veins do?

Answer 17

they transport blood towards the heart

Question 18

what do capillaries do?

Answer 18

they allow substances to be exchanged between blood and body cells

Question 19

what is the vessel wall, lumen diameter, vessel diameter, presence of valves in the arteries?

Answer 19

thick and elastic muscular wall, narrow, large, absent

Question 20

what is the vessel wall, lumen diameter, vessel diameter, presence of valves in the veins?

Answer 20

thin muscular wall, wide, large, present

Question 21

what is the vessel wall, lumen diameter, vessel diameter, presence of valves in the capillaries?

Answer 21

one-cell thick endothelium, very narrow, very small. absent

Question 22

what is the direction of flow, oxygen content, carbon dioxide content, blood pressure and speed for arteries?

Answer 22

away from heart, high except for pulmonary artery. opposite of oxygen content, very high

Question 23

what is the direction of flow, oxygen content, carbon dioxide content, blood pressure and speed for veins?

Answer 23

towards heart, lower except for pulmonary vein, opposite of oxygen content, low

Question 24

what is the direction of flow, oxygen content, carbon dioxide content, blood pressure and speed for capillaries?

Answer 24

through the organ, variable, opposite of oxygen content, low

Question 25

liver to the heart?

Answer 25

hepatic

Question 26

lungs to the heart?

Answer 26

pulmonary

Question 27

kidneys to the heart?

Answer 27

renal

Question 28

what does the pulmonary circulation do?

Answer 28

they ensure that blood is constantly refreshed with oxygen and prevents build-up of co2 which is toxic at high concentrations

Question 29

what does the systemic circulation do?

Answer 29

they ensure that body cells receive enough oxygen as quickly as possible, as well as remove metabolic waste from the organs to be excreted

Question 30

what is the feature of the atrial wall and its function?

Answer 30

atrial walls are thinner and less muscular than ventricular walls f: atria only need to pump blood to adjacent ventricles while ventricles pump blood out of the heart

Question 31

what is the feature of the ventricular walls and its function?

Answer 31

left ventricular wall is thicker and more muscular than the right ventricular wall f: left ventricular needs to force blood out at higher pressure over a greater distance to all parts of the body while the right ventricle only needs to pump blood to the nearer lungs

Question 32

what is the feature of the septum and its function?

Answer 32

septum prevents mixing of blood from across chambers f: ensures that oxygenated blood in the left ventricle does not mix with deoxygenated blood in the right ventricle, which would result in less oxygen transported to body cells

Question 33

how long does a typical cardiac cycle last for?

Answer 33

600 milliseconds

Question 34

what happens when the muscles of a chamber contract?

Answer 34

pressure of the chamber increases (vice versa)

Question 35

how does blood flow?

Answer 35

from a region of higher pressure to lower pressure

Question 36

why do valves function?

Answer 36

to prevent excessive backflow of blood by snapping shut

Question 37

what is the name of the heart's set of blood vessels?

Answer 37

coronary circulation

Question 38

what do the coronary arteries do?

Answer 38

they branch off from the aorta to supply the heart muscles with oxygenated blood

Question 39

what happens when the coronary arteries become blocked/narrow?

Answer 39

the heart muscles receive less oxygenated blood and may die, resulting in a heart attack

Question 40

what are the factors that increase the chances of a person suffering from coronary heart diseases?

Answer 40

-unhealthy/unbalanced diet -excessive stress -smoking

Question 41

what is a rising cause of coronary heart disease?

Answer 41

frequent consumption of foods high in fat and cholesterol is a rising cause of coronary heart disease. the excess fat and cholesterol accumulate in the bloodstream and may deposit on the inner walls of the coronary arteries the lumen of the arteries narrow and eventually become entirely blocked, cutting off blood supply to the heart muscles without glucose and oxygen to respire and release energy, the muscles cannot contract for the heart to pump blood , resulting in a heart attack

Question 42

how to prevent coronary heart diseases?

Answer 42

leading a healthy and active lifestyle -healthy and balanced diet (low in saturated fat and cholesterol) -frequent exercise (maintain healthy levels of fat in the body) -not smoking (first, second, third hand-smoke are all damaging when inhaled)