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b1 Flashcards

1
Q

describe function of bicuspid valve

A

its on the left side of the heart and allows blood to flow from ventricle to aorta and preventa blood flowing backwords

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2
Q

describe how electrical impulses spread from sinoatrial node to ventricles

A

wave of depolarization from sinoatrial ndoe spreads over atria causing atria to contract. electrical impulses pass down septum through bundle of his to apex bottom of ventricles. wave of depo spreads up through ventricle walls.

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3
Q

explain how caffeine changes the cardiac output of the daphnia

A

caffeine increases cardiac output as heartrate is increasing therefore there is an increase in heartbeats. caffeine stimulates and binds to receptors. this increases electrical activity in SAN and increases power of contraction

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4
Q

explain why, in an emergency anyone can be given a transfusion with blood type O rhesus negative

A

no antigen in group O, so no reaction can occur from antibodies, therefore no blood clots will occur

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5
Q

state what is mean tby the term myogenic

A

myogenic = beat/contract without any stimulartion from the heart. the muscle cells can depolarize/generate their own electrical impulses

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6
Q

describe the function of the coronary artery

A

carries blood containing oxygen/glucose/lipids to the heart muscle/ventricle wall
carry oxygenated blood to the heart

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7
Q

explain how a blocked artery may lead to a heart attack

A

no blood is being able to pass meaning less oxygen is passed to the heart so less respiration, therefore less ATP energy so part od the heart can die (scar tissue). this means a heart attack can more likely occur

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8
Q

What is the cardiovascular
system and what is it’s function?

A

It consists of the heart, blood vessels and blood. The function is to transport important substances around the body eg oxygen, glucose.

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9
Q

The heart is part of a double circulatory system meaning?

A

Blood passes through the heart twice per cycle.

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10
Q

What is pulmonary circulation?

A

The blood passes through the heart and is pumped to the lungs returning back to the heart.

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11
Q

What is systematic circulation?

A

The blood then passes through the heart a second time (blood is
repressurised) and pumped around the body organs before returning to the heart.

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12
Q

What is mass flow? Give an example.

A

Blood moves around the body due to pressuredifference between the
pressure in the heart (high) and the pressure in the blood vessels (lOW).

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13
Q

Heart structure

A

The heart is a pump made of cardiac muscle (myogenic) - will beat/contract without any nervous stimulation.
Muscle cells-are able to depolarise/gene rate own electrical pulses. The heart has 4 chambers: seperated by muscular wall called septum, each side consists of upper chamber (atrium) and lower chamber (ventricle).

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14
Q

Describe the route that blood flows through the heart and around the body.

A

1) deoxygenated blood returns from the body in the vena cava and enters the right atrium.
2) the blood then passes via atrioventricular valve (tricuspid)
into the right ventricle and out, via semilunar valve, into the pulmonary artery.
3) The blood now passes through the lungs and returns to the left atrium via the pulmonary vein.
4) the blood passes through a second AV valve (bicuspid)
into left ventricle and then through semi lunar valve into the aorta and then body tissues.

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15
Q

Suggest the purpose of the valves in the heart

A

To prevent back flow of blood/ ensures that blood flows in one direction/ smooth flow of blood and maintains high blood pressure.

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16
Q

Role of the atrioventricular
valves

A
  • Left AV valve prevents back flow to left atria/ ensures blood pumped to aorta/ body.
  • Right AV valve prevents back flow from right ventricle to right atria/ ensures blood is pumped to the lungs.
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17
Q

Role of semilunar valves

A

These are at the base of the arteries leaving the heart, they prevent blood from returning to the ventricle during diastole (heart at rest).

18
Q

Characteristics of arteries

A
  • Transports blood from
    heart to organs (blood under high pressure).
  • Thick walls made of fibrous proteins to resist damage due to high pressure of the blood, many muscle tissue (strengthening) and elastin fibres to withstand the high pressure generated by left ventricle during contraction.
  • endothelium-reduced friction and gives a smooth flow
  • narrow lumen-maintains
    pressure
19
Q

Characteristics of capillaries

A
  • wall has endothelial layer, one cell thick
  • it’s involved in exchange of materials between blood and the tissue cells (site of diffusion)
  • diameter very small + large number of capillaries
  • this creates greater friction and high surface area, reducing blood pressure and blood flow
    -very thin walls-increased rate of diffusion
  • wall spaces-gaps between cells of the
    endothelial cells which allow rapid formation of tissue fluid and WBC to pass tissue spaces.
20
Q

Pressure changes in the arteries

A

Flow is fast and pressure is high and flunctuating due to the contraction of the left ventricle.

21
Q

Pressure changes in the capillaries

A

Increased cross-sectional area causes increased friction which reduces blood pressure and flow changes from pulsar to smooth and speed of flow decreases.

22
Q

structure of cardiac muscle

A
  • only found in heart but striated like skeletal muscle
  • less wide than skeletal muscle fibres
  • comtract without any stimulation by CNS
  • muscle cells are branched = faster signal propagation & contraction in 3 dimensions
  • their shape allows a wave of depo to pass through and allows the cells to contract as one - calcium ions are needed for this
  • mitochondria more reliant on aerobic respieration than skeletal
  • longer period of contraction & refraction = maintains a viable heartbeat
  • heart tissue not become fatigued unlike skeletal = life long contractions
  • interconnected network seperated between atria and ventrivles allowing them to contact seperately
23
Q

pressure in the chambers

A

the change in pressure in the heart chambers is as a result of both the changes in vol of blood and the contractions of the heart muscle.
1) blood enters atrium = • blood vol increases p in A, • pressure in A greater than V, • AVV opens
AM contracts = • further increases in p, • remaining blood forced into V from A
2) B enter V = • pressure in V greater than A, • increases in p due to vol of blood
3) VM contract = • further increases in p in V until greater than A/PA, • SLV opens
B enters A/PA = • B pumped to body (left) + lungs (right)
4) VM relax = • p in V is less than A/PA, • SLV close
B enters A
• blood vol increases p in A
(back to 1)

24
Q

control of heartrate

A

heat = myogenic > beat/contract without any nervous stimulation >able to depolarize + generate their own electrical impulses. internal pacemaker starts at the SAN > located
near the wall of the RA. electrical charges spontaneously pulse from the SA node, causing the two atria to contract in unison = atrial systole. the pulse reaches 2nd node, AVN, between the RA + RV, where a delay of 0.1 seconds occurs before spreading to the walls of the V. the pause allows blood in atria to empty completely into V before the V pump out the blood. From the AVN, the electrical impulse enters the BOH, then to the left and right bundle branches extending through the septum. Finally, the purkinje fibres conduct the impulse from the apex of the heart up the ventricular myocardium, causing the ventricles to contract. This is called ventricular systole

25
Q

cardiac cycle

A

main purpose of heart = pump blood around body > does so in repeating sequence called cardiac cycle. the CC is the coordination of filling + emptying of blood by electrical signals which cause heart to contract + relax. human heart beats = over 100,000 times per day. each CC heart contracts (systole) pushing out blood and pumping it through body. this is followed by relaxation phase (diastole) where heart fills with blood
cardiac diastole = all chambers relaxed, blood flows into heart
AS, VD = atria contract, pushing blood into V
AD, VS = after atria relaxes the V contract pushing blood out heart

26
Q

pressure changes

A

A = pressure in V rises above that in atria = AVV close
B = pressure in V rises above that in aorta = SLV open
C = pressure in V falls below that in aorta = SLV close
D = pressure in A rises above that in V = AVV open

27
Q

characteristic features (blood vessels)

A

all BV have a thin and smooth layer of cells called endothelium aswell as a number of layers outside which are common to arteries + veins i.e.
elastin = withstands pressure
collagen = for protection
smooth muscle tissue = strengthening
endothelium tissue = reduces friction and provides smooth flow
lumen = maintains pressure

28
Q

characteristics of veins

A
  • carry blood back to heart from tissues (blood is under lower pressure) - wall doesnt need to be thick
  • similar to artery however veins have:
    • large lumens = low resistance
    • thinner muscle layer = no need for vaso-constriction as all blood is going back to heart
    • thinner elastic layer = pressure low + wall doesnt need stretch or recoil
    • SLV = residual bp very low - blood moved along vein by squeezing of SM when they contract. the valves stop backflow - blood pass in one direction to ensure blood goes back to heart
29
Q

pressure in veins

A

pressure is low and flow is slow and non-pulsar

30
Q

explain two advantages of using blood vessel tissue taken from the patient rather than tissue taken from a donor

A

• no risk of rejection
• it is not foreign as it is the same blood group
• therefore less risk of failure
• less risk of cancer
• immune system will not be weakened

31
Q

explain the importance of volume E

A

E is residual air before inhaling which stops lungs collapsing which does not reduce gaseous exchange so doesnt need to much energy

32
Q

what is the volume of air inhaled in one breath called

A

tidal volume

33
Q

what substance do alevoli cells make to prevent alveloi from collapsing

A

surfactant

34
Q

explain why the student had a higher rate of oxygen consumption when cycling vigorously than when at rest

A

because more energy being used when cycling vigorously this therefore increased the students heart rate so more ATP needed which means more aerobic respiration is needed in mitochondria to prevent build up of lactic acid and re-oxygenate myoglobin

35
Q

compare the structures ofbarteries veins and capillaries

A

arteries have wallas made of 3 laters whereas capillaru has one layer made of endothelium and is one cell thick. arterie has the thickest wall and veins is thinner that that of an artery and capillaries have the thinnest wall. there is alot of smooth musicle in the middle layer of an artery and less is found in the veins whereas capillaries have none. collagen found in middle layer of arteries whereas capillaries and veins have none. in the arteries endothelium is folded when not dialted and veins and capillaries smooth endothelium
the lumen shape in arteries is round whereas veins is oval and capillaries is round/oval
arteries lumen size is smaller than that of veins and veins larger than that of arteries and capillaries are very small and only allow 1 red blood cell at a time

36
Q

what are some CV disease

A

1 atherosclersosis
2 coronary hesry disease
3 stroke

37
Q

what are some factors that increase the risk of CVD

A

1 genetics = familt history
2 age = as you get older CVD risk increase
3 diet = consuming higher levels of saturated fat high intake of salts limited intske of healthy fats and vitamins increase your risk of CVD
• chlolestrol levels > blood chlolestrol levels can increase due to diet in high saturated fat
• role of phagocytes
• dietary sugar > greater proportion of sugar = ^ CVD
5 high BP = increases risk of CVD hypertension can be caused by, diet, genetics alcohol
6 smoking = smoking cigs will increase risk of CVD as nicotine can affect heart rate platelets red blood cells and plasma chlolestrol levels
7 inactivity = lack of physical activity can increase risk of suffering from CVD which is why exercise is valid

38
Q

treatments for CVD

A

• antihypertensive drugs = lower BP in diff ways e.g calcium channel blockers effective in black people and those aged over 55 side effects of headaches dizziness tiredness
• statins = medications used to lower level of chlolestrol in the blood and protect insides of artery walls. high levels of cholestrol can lead too fatty deposits building increasing risk of heart disease which lead to stroke or heart attack
• transplantation + immunopressants = major op comes w many risks and complications but may be final option to ensure survival of patient
1 rejection of the donor > occurs when immune system mistakes the new heart as forgein and attacks it can be after surgery or years later
2 infection > they are taken to reduce the chances of rejection weaken immune system by making patient more vulenrable to infections
3 failure to pump properly > donated heart may not work as it maybnot start beating or may stop beating soon after surgery
4 narrowing the arteries that are connected to heart > potentially serious could trigger heart attack

immunoappressant deugs can cause > kidney problems, high BP, diabetes, higher risk of cancer

39
Q

describe function of bicuspid valve

A

prevent backflow of blood from left ventricle to left atrium

40
Q

explain why in an emergency anyone can be given a transfusion with a blood of type O rhesus neg

A

no antingens in donor blood
so no attack with patient antibodies
no clotting occurs
no risk of heart attack

41
Q

Increasing the patient’s stroke volume increases their cellular respiration,
enabling them to be more active.
explain why

A

more blood pumped increased cardiac output
so increased blood to lungs
so increased oxygenation so more oxygen available
therefore more aerobic respiration therfore more ATP
for muscle contraction

42
Q

describe the function of the vena cava

A

carries deoxygenated blood
carries blood from body to heart

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