Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

PHA112 > The Circulatory System 2 > Flashcards

The Circulatory System 2 Flashcards

1
Q

what is the arctic arch?

A

fat covered on the heart

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is the heart?

A

a hollow, 4 chambered muscular organ

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

where is the heart located?

A

in mediastinum

(section of thoracic cavity)

midline between sternum + vertebrae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is the heart surrounded by?

A

double layered membrane - pericardium

  • inner, visceral pericardium covers full heart (epicardium)
  • outer parietal pericardium attaches to vessels, sternum + diaphragm
  • pericardial activity contains 30-50 ml serous fluid
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

the heart functions as 2 separate functional pumps.

describe this?

A
  • each pump divided into upper chamber + lower chamber
  • upper chambers open into lower chambers via valve (tricuspid / mitral)
  • left + right pumps separated by septum
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

right sided pump

A

pulmonary circulation + gaseous exchange

  • receives DE-OXYGENATED blood from systemic circulation
  • pumps into lungs for re-oxygenation + CO2 removal

ventricle opens into pulmonary artery via pulmonic valve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

left sided pump

A

systemic circulation + O2 + nutrient supply

  • receives re-oxygenate blood from lungs (p.circulation)
  • pumps into systemic circulation

ventricle opens into aorta via aortic valve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what are the 2 main types of blood vessels in the heart?

A
  • great cardiac vessels

- the coronary vessels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

great cardiac vessels

A

carry blood to + from heart chambers and systemic + pulmonary circulations

inc:

  • superior + inferior vena cava
  • pulmonary artery
  • pulmonary veins
  • aorta
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

coronary vessels

A

= coronary circulation - specialised blood supply system of heart

inc:

  • left + right coronary arteries
  • coronary sinus, great/middle/anterior + posterior cardiac veins, thebesian veins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

aorta

A
  • accepts output of left ventricle
  • 1st vessel of systemic circulation
  • has highest systolic pressure ~140mmHg
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

pulmonary artery

A
  • accepts output of right ventricle
  • 1st vessel of pulmonary circulation
  • has peak pressure ~25mmHg
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

superior vena cava / inferior vena cava

A

largest vessels returning deoxygenated blood to right atrium from s.circulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

pulmonary veins

A

largest vessels returning oxygenated blood to left atrium from p.circulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

coronary arteries + veins

A

supply blood to cardiac muscle tissue

branch off from aorta above aortic valve

veins drain blood into right atrium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

coronary circulation

myocardial O2 + nutrient demand

A
  • heart beats constantly through life

- needs constant + adequate supply of oxygen + nutrients

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

coronary circulation

myocardial O2 + nutrient supply

A
  • supplied by special network of blood vessels

- made of left + right coronary arteries

18
Q

coronary circulation

delicate balance between demand + supply

A
  • reduced coronary blood flow during systole
  • disproportionate share of cardiac output
  • high O2 extraction -> low O2 reserve
19
Q

what are the benefits of having a one-way opening valve?

A
  • prevents back flow of blood

- ensures unidirectional flow of blood through heart

20
Q

AV valves

A
  • TRISCUPID valve - bet. right atrium + ventricle

- BICUSPID/MITRAL valve - bet. left atrium + ventricle

21
Q

semilunar valves

A
  • PULMONIC valve - bet. right ventricle + pulmonary artery

- AORTIC valve - bet. left ventricle + aorta

22
Q

AV heart valves in function process

A
  • blood returns to heart
  • fills atria
  • puts pressure against AV vales -> open
  • as ventricles fill, AV valves flap -> hang limply into ventricles
  • atria contract -> forcing extra blood into ventricles
  • ventricles contract -> forcing blood against AV valves cusps
  • AV valves close
  • papillary muscles contract + chordae tendineae tighten
  • prevents valve flaps everting into atria
23
Q

semilunar heart valves in function process

A
  • ventricles contract, intraventricular pressure rises
  • blood pushed up against SL valves—> open
  • as ventricles relax, intraventricular pressure falls
  • blood flows back from arteries
  • fills cusps of SL valves + forces them to close
24
Q

what are the 3 layers the heart wall consists of?

A
  • endocardium
  • myocardium
  • epicardium
25
Q

endocardium

A
  • innermost thin lining of endothelial cells
  • allows smooth flow of blood
  • prevents clotting
26
Q

myocardium

A
  • middle layer - made of cardiac muscle

- forms bulk of heart wall

27
Q

epicardium

A
  • protective outer layer

- embeds coronary blood vessels

28
Q

what are the 2 main SPECIALISED types of heart cells?

A
  • contractile cells

- electrical / autorhythmic cells

29
Q

contractile cells

A
  • 99% of heart cells
  • mainly in myocardium + septum
  • mediate mechanical, pumping work of heart
  • form interlacing bundles - arranges spirally around circumference of heart
  • electrically quiescent
  • comprise: atrial + ventricular muscle cells
30
Q

what does electrically quiescent mean?

A

do not normally initiate own AP

31
Q

electrical/autorhythmic cells

A
  • don’t contract
  • specialised for initiating + conducting AP -> activation + contract of muscle cells

inc: SAN, AVN, Bundle of His, purkinje fibres

32
Q

cardiacs RMP

A
  • at rest = POLARISED
    (inside = NEG)
  • unequal distrib of ions across membrane
  • opening + closing of ion channels = voltage + time-dependent
  • K+ channels selectively open in memb at rest (RMP = CLOSER to K+ equilib potential)
  • slow spontaneous depolarisation in automatic cells
33
Q

define excitability?

A

ability of cardiac cells to respond to electrical stimulus by firing AP

34
Q

fast AP

A

high conduction velocity ~1-4m/s

35
Q

slow AP

A

slow conduction velocity ~0.02-0.1m/s

  • more easily blocked
  • liable to conduction failure at high repetition rates
36
Q

define refractoriness?

A

inability of more than enough stimulus to elicit an AP

37
Q

refractoriness of cardia cells

A
  • happens for some time after previous AP

- gives rise to ABSOLUTE/EFFECTIVE ARP/ERP + relative refractory periods

38
Q

what are the benefits of the refractory period?

A

protects against premature excitation + tetany

39
Q

time of recovery for fast response

A

faster recovery of excitability

40
Q

time of recovery for slow response

A

slower recovery of excitability —> inc risk of conduction block

PHA112 (37 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions