Disease Defences 6.2 Flashcards

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1
Q

From where to where do arteries convey the blood at high pressure?

A

from the ventricles to the tissues of the body

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2
Q

What do arteries have in their walls?

A
  • muscle cells
  • elastic fibers
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3
Q

What do muscle cells and elastic fibers assist?

A

maintaining blood pressure btw pump cycles

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4
Q

Where do blood flow in the finest stage?

A

trough tissues of the capillary

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5
Q

What do capillaries do?

A

allow exchange of materials btw cells in the tissue and the blood

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6
Q

What do veins do?

A
  • collect blood at low pressure from the tissues of the body
  • returns it to the atria of the heart
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7
Q

What prevents backflow in veins?

A

Valves

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8
Q

What type is the lung’s circulation?

A

separate

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9
Q

Where is the heartbeat initiated?

A

in the sinoatrial node

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10
Q

What does the sinoatrial node act as?

A

pacemaker

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11
Q

How does the sinoatrial node send its signal?

A

through the walls of the atria -> walls of the ventricles

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12
Q

How can the heart rate be reduced of increased?

A

through two nerves in the medulla of the brain

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13
Q

What chemical increases heart rate?

A

Epinephrine

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14
Q

Who discovered circulation?

A

William Harvey

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15
Q

During the cardiac cycle…

A

pressure changes occur from the left atrium, left ventricle and aorta

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16
Q

What is transported through the blood?

A
  • oxygen
  • nutrients
  • antibodies
  • hormons
  • heat
  • carbon dioxide
  • urea
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17
Q

Plasma

A

Dissolves or carries all other components of blood, nutrients, wastes

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18
Q

Erythrocytes

A

Transport oxygen in haemoglobin molecules

19
Q

Leucocytes

A

Phagocytes - “eat up” pathogen and dead cells
Lymphocytes - B-cells and T-cells for the immune response

20
Q

Platelets

A

clotting of blood following damage to cells or erythrocytes

21
Q

arteries

A
  • carry high pressure blood
  • away from the heart -> tissue that need it
22
Q

capillaries

A
  • very small
  • blood moves slowly under low pressure for the exchange of substances.
23
Q

veins

A
  • low pressure blood
  • back to the heart
  • valves that allow the blood to flow in the correct direction
24
Q

structure of arteries

A
  • small lumen
  • high blood pressure
25
Q

adaptations of arteries

A
  • muscle contraction-> high blood pressure
  • elastic fiber stretch
  • thick muscular wall and fibrous outer layer
26
Q

structure of capillaries

A
  • smallest blood vessels
  • adapted to the exchange of substances to and from the blood
27
Q

adaptations of capillaries

A
  • basement membrane permeable
  • wall is one cell thick
  • contains pores
28
Q

structure of veins

A
  • large lumen
  • low pressure
29
Q

adaptations of veins

A
  • less muscle
  • walls are thinner
  • less elastic
  • valves required to prevent back-flow of blood
30
Q

double circulation

A

-deoxygenated blood -> right atrium ->right ventricle to the lungs - where CO2 is offloaded and O2 is picked up
- it is now oxygenated blood, -> left atrium ->left ventricle of the body - O2 is used and CO2 is collected as a waste product
- now its deoxygenated blood -> right atrium

31
Q

what is the beating of the heart due to?

A

myogenic muscle contraction

32
Q

what is the characteristic of muscle contraction in the heart?

A

it’s not controlled externally

33
Q

what is the region of myocytes called?

A

sinoatrial node

34
Q

what is the OTHER region of myocytes called?

A

atrioventricular node

35
Q

myogenic initiation

A

the heart does not stop beating

36
Q

cardiac muscle is

A

indefatigable

37
Q

when exercising

A
  • more co2 is present in the blood
  • it is detected by the chemoreceptors in the brain’s medulla oblongada
  • speeding the heart rate
38
Q

when CO2 levels fall

A

the nerve (vagus) reduces heart rate

39
Q

adrenaline

A

epinephrine

40
Q

the cardiac cycle

A

DIASTOLE
- atria and ventricles relaxed
- blood flows into heart from veins
- AV valves open
- SL valves closed

ATRIAL SYSTOLE
- atria contract and ventricles relaxed
- blood pushed into ventricles
- AV valves open
- SL valves closed

VENTRICULAR SYSTOLE
- atria relaxed and ventricles contract
- blood pushed into arteries
- AV valves closed
- SL valves open

41
Q

Atherosclerosis

A

degenerative disease - areas of the artery wall become damaged

42
Q

What happens in atherosclerosis?

A
  • macrophages release growth factors, encouraging growth of fibrous tissue
  • cholesterol builds up in damaged areas -> plaques and arteries lose their elasticity
  • as the build up grows the lumen narrows restricting blood flow
  • if blood clotting is triggered the blood cloths are known as CORONARY THROMBOSIS
43
Q

risk factors of coronary heart disease

A

Genetic
Age
Sex
Smoking
Diet
Exercise
Obesity
Stress