Transport in Humans Flashcards

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1
Q

features of unicellular organisms

A

-ToS through diffusion, osmosis and active transport
-Slow process

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2
Q

features of multicellular organisms

A

-ToS through transport systems
-xylem phloem
-blood and lymphatic system
-more efficient than diffusion to sustain life of organism

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3
Q

direction of blood

A

Heart Aorta/Arteries Arteriols CapillaryCells Venules Vein/Vena cava

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4
Q

function of heart

A

-muscular pump keeps blood circulating around body
-fills up with blood when relaxes
-squeeze out blood with great force when contracts

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5
Q

arteries

A

carry blood away from heart, aorta is largest leaving left side of heart

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6
Q

features of blood capillaries

A

-microscopic; found within cells; walls are made up of single layer of flattened epithelial that are partially permeable
-branch out to increase SA:V, for increase rate of EoS between blood and tissue cells
-total cross sectional area increase, lower blood pressure, slower blood flow, more time for EoS

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7
Q

blood capillaries unity

A

capillaries unit the form small veins called venules which join together to form bigger veins that carry blood to the heart

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7
Q

function of pulmonary circuit

A

transport deoxygenated blood from the heart to the lungs for gas exchange and transport the oxygenated blood back to the left side of the heart

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8
Q

function of systemic circuit

A

transport oxygenated blood from the heart to the rest of the body except and lungs and transport deoxygenated blood from the body back to the right side of the heart through the vena cava

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9
Q

advantages of double circulation

A

-blood enter the lungs at lower pressure due to thinner wall, blood flows through lungs slower, more time for oxygen to be absorbed into the blood before it returns to the heart
-LV pumps blood at a high pressure throughout the body so that oxygenated blood is sent to body tissues more quickly, maintain high metabolic rate in mammals
-oxy and deoxy blood don’t mix

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10
Q

function of pericardium

A

surrounds the heart and is made up of two layers of membrane, inner layer is in contact with the tissues making up the heart and fluid between membrane reduce friction when the heart beats

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11
Q

why do atria have thin muscular walls

A

they only force blood into the ventricles, does not require high blood pressure

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12
Q

why do ventricles have thick muscular walls

A

they pump blood away from the heart, requires high blood pressure

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13
Q

why does RV have thinner wall than LV

A

RV requires a lower blood pressure as it only pumps blood to the lungs which is close to the heart

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14
Q

function of median septum

A

muscular wall between right and left side of heart, prevent mixing of oxygen and deoxygenated blood

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15
Q

when do atrioventricular valves open and close

A

-pressure in atrium higher than pressure in ventricle
-vice versa, prevent back flow of blood into atria
points downwards to permit easy flow into ventricles

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16
Q

what are chordae teninae

A

attach ventricle flaps to ventricle walls

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17
Q

features of semilunar valves

A

-found in aorta and pulmonary artery
-ensures blood flows in correct direction instead of back to ventricles

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18
Q

features of coronary arteries

A

two small ones emerge in the aorta that provide the heart with nutrients and oxygen, vein remove CO2 and waste products, blood is returned to coronary sinus which in turns opens into the right atrium,

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19
Q

what is arteriosclerosis

A

degeneration changes in the artery making them less elastic

20
Q

what is atherosclerosis

A

-deposition of plaque on walls, a specific form of arteriosclerosis
-blood supply to the heart is greatly reduced due the blockage of coronary arteries, can lead to heart attack

21
Q

how does atherosclerosis occur

A

-fatty substances deposited into inner surface of coronary arteries
-lumen narrows and blood pressure increase
-inner surface of artery becomes a rough surface which may result in blood clots being trapped in the artery
-blood flow in the artery may reduce resulting in an insufficient amount of oxygen and nutrient to heart muscles
-tissues die

22
Q

recite the cardiac cycle

A

-RA receive blood from vena cava while LA receive blood from pulmonary vein
-RA contracts forcing blood into RV
-increase in blood pressure forces the tricuspid and bicuspid valve to close to prevent back flow of blood, produce “lub” sound
-Short while, RV contracts and RA relax and blood flows to pulmonary artery
-ventricles then relax
-drop in pressure causes semi lunar valves in both arches to close causing a “dub” sound, preventing back flow of blood
-drop in pressure also causes tricuspid and bicuspid valve to open
-cycle repeats

23
Q

when is the “lub” sound formed

A

when the atrioventricular valves close due to increase in blood pressure

24
Q

when do semi lunar valves open and close

A

-when the pressure in the LA is higher than the pressure in the aorta
-closes when LV starts to relax

25
Q

when does bicuspid valve open and close

A

-opens when ventricular pressure is lower than atrial pressure
-closes vice versa

26
Q

how often is signal from SA node sent out

A

every 0.8 seconds for a person with a resting heartbeat of 72 beats a minute

27
Q

how does the SA node work

A

-pacemaker generates wave of signals to contract
-signals delayed at AV notes
-signals pass the heart apex
-signals spread throughout ventricles

28
Q

how does exercise influence the pacemaker

A

-more oxygen required for cell respiration
-carbon dioxide needs to be removed in bloodstream
-medulla chemically senses increase in CO2 and sends signals to cardiac nerve to increase heart rate
-signal is sent to SA node

29
Q

how does adrenaline influence pacemaker

A

-excitements causes adrenal glands to secrete more adrenaline into bloodstream
-causes the SA node to “fire” which increases heart rate

30
Q

features of artery

A

-receive blood from heart and carry it away from heart
-elasticity enables the wall to stretch and recoil back to help push the blood in spurts
-muscles to bring about constriction and dilation of artery
-no valves
-oxygenated blood except pulmonary artery

31
Q

features of vein

A

-carry blood to heart
-thin, less muscular and less elastic walls due to lower venous pressure as blood flow is assisted by skeletal system
-large lumen
-semi lunar valves present
-deoxygenated blood

32
Q

how is tissue fluid formed

A

-phagocytic WBC squeeze through walls of the capillaries in to the tissue fluid
-oxygen and dissolved food substances diffuse from the blood into the tissue fluids and into the cells and vice versa

33
Q

components of plasma

A

-pale yellow liquid
-90% water
-10% transported dissolved substances
-excretory products, hormones, food substances, dissolved mineral salts, soluble proteins

34
Q

adaptations of RBC

A

-circular biconcave shape to increase SA:V ratio for faster rate of release and absorption of oxygen
-elastic in order to change into bell shape to fit through capillaries
-no nucleus for more haemoglobin to fit

35
Q

what happens to worn out RBC

A

-worn out RBCs are destroyed in the spleen and the released haemoglobin is transported to the liver to be broken down

36
Q

do natural antibodies react with antigens from RBC

A

no, but they may react with the antigens in the RBCs of another person which can cause clumping of RBCs

37
Q

why is blood type O a universal donor

A

-recipient’s antibodies will not agglutinate with the donors RBC as they do not have antigens
-donor’s antibodies a and b will be so diluted in recipients blood that it does not have any effects on recipients RBC

38
Q

why can a blood type A receive type A blood

A

anti B antibodies do not combine with the type A antigens on the donor’s RBC

39
Q

features of WBC

A

-produced by stem cells in bone marrow
-contains nucleus
-can move, change shape and squeeze through blood capillaries into tissue fluid
-irregular shape
-colourless

40
Q

what produces antibodies and how does it act

A

-produced by lymphocytes
-destroys bacteria by rupturing its surface membrane
-clumping bacteria together so it can be easily engulfed by phagocytes
-neutralise the toxins in produced by bacteria

41
Q

function of phagocytes

A

approach and ingest foreign particles and digest them intracellularly

42
Q

how is pus formed

A

in the process of phagocytes fighting bacteria, some phagocytes die and together with bacteria form pus

43
Q

describe the process of blood clotting

A

when a blood vessel is damaged, damaged tissues and platelets release thrombokinase that converts the soluble protein prothrombin into thrombin in the presence of calcium ions, thrombin catalyses the conversion of fibrinogen into fibrin, insoluble fibrin threads forms a net like structure, RBC trapped in fibrin form blood clot

44
Q

what is haemophilia

A

hereditary disease, normal blood clotting mechanism is damaged, where even a slight injury can cause person to bleed to death

45
Q

describe the process of immunisation/vaccination

A

inducing antibody production directly into humans by injecting a dead or weakened form of the pathogen to stimulate the immune system to produce antibodies against the pathogen

46
Q

why do some tissue transplant not work and the prevention for this

A

-immune system may consider transplanted tissue as a foreign body and reject it, causing lymphocytes to produce antibodies that destroy it
-genetic match for organ or tissue
-immuno-suppressive drug for rest of life
-x ray radiation of bone marrow or lymphatic system

47
Q

what is the fluid surround cells/ in blood/ lymphatic system called

A

-tissue fluid
-plasma
-lymph

48
Q

function of lymphatic system

A

-return excess interstitial fluid into blood circulation
-return plasma protein to maintain a low interstitial fluid protein concentration and maintain osmotic pressure gradient across capillary membrane
-transport waste from tissue cells
-acts as filters and traps for bacteria
-role in absorption and transportation of fat from small intestine