Brainscape's Knowledge GenomeTM

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


See full index

biology module 3 > mammalian cardiac cycle > Flashcards

mammalian cardiac cycle Flashcards

1
Q

outline the movement of blood through the heart

A
  • deoxygenated blood enters RA through vena cava
  • goes to RV through tricuspid valves
  • goes to pulmonary artery through semi-lunar valves to lungs
  • from lungs oxygenated blood enters LA of heart through pulmonary vein
  • goes to LV through bicuspid valves
  • goes to aorta through aortic valve to rest of body
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is the heart made out of

A

cardiac muscle

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

function of coronary arteries

A

supply heart muscle with oxygen and glucose in order to keep it contracting and relaxing continuously

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

what are the pericardial membranes + their function

A

a protective, fluid-filled sac that surrounds the heart

it helps to prevent the heart from over distending / swelling with blood

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

which side of the heart is thicker + why

A

left side, because there is a thicker layer of muscle in left ventricle wall as it must pump blood around whole body and all extremities

this means it must provide sufficient force to overcome resistance of aorta and arterial systems of whole body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

systole definition

A

the state of contracting

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

diastole definition

A

the state of relaxing

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

outline the cardiac cycle with pressure differences and systole/diastole

A
  • blood flows into atria through veins, increasing atrial pressure
  • atrial pressure > ventricular pressure
  • this causes atrio-ventricular valves to open so blood flows into ventricles
  • atrium walls contract - ATRIAL SYSTOLE
  • this pushes all blood out of atria into ventricles, increasing ventricular pressure
  • ventricular pressure > atrial pressure
  • this causes atrio-ventricular valves to close and semi-lunar valves to open
  • ventricle walls contract - VENTRICULAR SYSTOLE
  • atrium walls relax - ATRIAL DIASTOLE
  • blood is pumped out of ventricles into arteries, increasing arterial pressure
  • pressure in blood vessels > ventricular pressure
  • this causes semi-lunar valves to close
  • ventricles relax - VENTRICULAR DISATOLE
  • cycle starts again
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

myogenic definition

A

muscle is intrinsically able to produce its own stimulus/rhythm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

outline the process by which the heart generates its own heart beat, which reference to atrial + ventricular systole

A
  • cells in SAN depolarise/become electrically excited
  • this triggers a wave of excitation to spread across atria - ATRIAL SYSTOLE
  • this wave cannot pass to ventricles due to non-conducting tissues separating them
  • this means the AVN detects the wave of excitation after a short delay
  • AVN transmits wave of excitation down purkyne fibres - VENTRICULAR SYSTOLE
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

SAN definition

A

sinoatrial node
located in the right atrium wall

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is the purpose of the SAN

A

it acts as a pacemaker
also known as the pacemaker region

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

AVN definition

A

atrioventricular node
located in between atria and connected to purkyne fibres

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

purkyne fibres definition

A

conducting fibres
initially bundled together in the Bundle of His, then they branch out as the fibres run down septum to the apex of the heart, then up ventricle walls

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

why is the short delay imposed by AVN important

A

this delay ensures the atria have contracted

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

what does a P-wave show on an ECG

A

electrical activity in atrial systole

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

what does the QRS complex show on an ECG

A

electrical activity in ventricular systole

18
Q

what does the Q-T interval represent in an ECG

A

ventricles contracting

19
Q

what does the T-wave show on an ECG

A

the recovery of the ventricles

20
Q

what does the T-P interval represent on an ECG

A

the heart is relaxed and filling with blood

21
Q

8 examples of heart conditions

A
  • tachycardia
  • bradycardia
  • heart block
  • hypertrophy
  • fibrillation
  • flat line
  • arrhythmia
  • ectopic heart beat
22
Q

what is tachycardia

A

elevated heart rate for no reason
- can sometimes be so high that little blood is pumped as filling time is too short
treatment - relaxation therapy, beta blockers

23
Q

what is bradycardia

A

reduced heart rate for no reason
- could indicate good aerobic fitness, or drug use
- leads to increased risk of blood clots + stagnation
treatment - lifestyle changes or pacemakers

24
Q

what is heart block

A

a delay in conduction between atria and ventricles, appears on an ECG as the separation of P-wave and QRS complex
treatment - pacemaker

25
Q

what is hypertrophy

A

when 1 side of the heart is enlarged, causes QRS complex to be distorted
- cause of enlargement could be high blood pressure that ends up thickening left ventricle
treatment - beta blockers

26
Q

what is fibrillation

A

cardiac muscle contraction is not coordinated, ECG will appear distorted
- little blood is pumped as a result

27
Q

what is flat line

A

no electrical activity within heart
- only 2% of people with a flatline leave the hospital alive

28
Q

what is the length of 1 cardiac cycle in humans

A

approx 0.8 seconds

29
Q

how to work out beats per minute

A

no. beats x 60/time
time = time that no. of beats was counted in

30
Q

function of the septum in heart

A

prevents the mixing of oxygenated and deoxygenated blood

31
Q

what is the function of valves in the heart

A

prevents backflow of blood and ensure efficient movement of blood

32
Q

why do ventricles contract from the apex up

A

blood needs to be moved upwards + ensures complete emptying of ventricles

33
Q

what does an ECG show

A

the spread of electrical excitation through the heart as a way of recording what is happening as it contracts
x axis = time
y axis = electrical potential mV

34
Q

what does ECG stand for

A

electrocardiogram

35
Q

how can heart rate be measured using an ECG

A

using the time between R peaks

36
Q

cardiac cycle definition

A

the sequence of events that occur in the heart during 1 heartbeat

37
Q

what causes the sounds of a heart beat

A

blood hitting the heart valves

38
Q

what causes the lub sound

A

blood hitting atrioventricular valves as ventricles contract
- occurs during ventricular systole

39
Q

what causes the dub sound

A

backflow of blood hitting semilunar valves
- occurs during ventricular diastole

40
Q

what is arrythmia

A

when the heart has an abnormal rhythm
treatment - pacemakers

41
Q

what is an ectopic heartbeat

A

when there are extra heartbeats outside of the normal rhythm
treatment - beta blockers

42
Q

how are ECGs measured

A

electrodes are stuck on skin which can measure electrical differences in the skin
this signal is fed into a machine which produces an ECG

biology module 3 (7 decks)

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