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Flashcards in Module 2 Deck (55):
1

describe the base of the heart

- superior
- wide surface
- posterior to sternum

2

describe the apex of the base

- inferior tip
- 12-14 cm from base

3

what cavity is the heart located in

- thoracic cavity
- anterior mediastinum

4

what is the pericardium
and its different layers

covers the heart
double walled sac

- outer parietal pericardium
- inner visceral pericardium or epicardium

5

What are the three layers of the heart wall

1. Epicardium
covers the heart

2. Endocardium
endothelium covers inner surfaces

3. Myocardium
muscular wall

6

features of the two 2 superior atria

- thin walled
0 receiving chambers
- externally separated from ventricles by the coronary sulcus

7

features of the 2 ventricles

- thick walled
- discharging chambers
- externally separated from each other by inter ventricular sulcus

8

where does the right atria revise deoxygenated blood from

- superior vena cava (from regions superior to diaphragm)
- inferior vena cava (from regions inferior to diaphragm)
- coronary sinus
(from coronary blood supply)

9

where does the left atria receive oxygenated blood from

- right and left pulmonary veins from the lungs

10

which vessels take blood away from the ventricles

- pulmonary trunk
- aorta

11

how are internal ventricles separated from the atria

- via atrioventricular valves
(right = tricuspid)
(left = bicuspid)

12

what does the chord tendinea anchor

atrioventricular valves

13

what are the chord tendinae attached to

- papillary muscles

14

which side of the ventricular muscle is thicker

- left = thicker
- generates 4-6X more force
- contracts from bottom - up

15

role of atrioventricular valves

- prevent back flow of blood into atria when ventricles contract
- tensing of chordae tendinea and contraction of papillary muscles stop valves from everting

16

role of semilunar valves

- forced open when ventricles contract
- close when ventricles relay and blood in arteries try to flow backwards

17

role of coronary circulation

- supply blood to the myocardium as blood flowing through the heart doesn't nourish tissue

18

where does the left coronary artery give rise to

anterior interventicular artery which supplied anterior ventricles

19

where does the right coronary artery give rise to

the posterior inter ventricular artery which supplies posterior ventricles

20

when does blood move into the coronary arteries

when the ventricles relax and blood in the aorta attempts to move backwards towards the heart

21

role of the great cardiac vein

drain the anterior regions supplied by the anterior inter ventricular artery

22

role of the middle cardiac vein

drains the posterior area supplied by the posterior interventricular artery

23

where do all veins drain to and then where does this drain to ?

- coronary sinus
- drains into right atrium

24

characteristics of angina pectoris

- temporary deficiency of myocardial blood supply (narrowed coronary vessels)
- thoracic pain
- increased physical demand on the heart
- myocardial cells weaken

25

characteristics of myocardial infarcation

- prolonged coronary artery blockage
- myocardium replaced by scar tissue
- weakens heart

26

what type of pump is the left side of heart

systemic

27

what type of pump is the right side of the heart

pulmonary

28

what pressure gradient does blood move

down
from an area of high pressure to low

29

what is the pathway of blood through the heart

- blood enters via:
superior and inferior vena cava, coronary sinus
- right atrium
- tricuspid valve
- right ventricle
- pulmonary semilunar valve
- pulmonary trunk
- to lungs


- to heart
- four pulmonary veins
- left atrium
- left ventricle
- aortic semilunar valve
- aorta

30

what two factors influence electrical events in the cardiac cycle

- autonomic nervous system
- intrinsic conduction system (hearts own electrical system)

31

what components make up the intrinsic conduction system

1. Sinoatrial Node
2. Atrioventricular node
3. Atrioventricular bundle
4. Bundle Branches
5. Purkinje fibres

32

intrinsic conduction system - role of sinoatrial node

- acts as pacemaker and determines heart rate

33

intrinsic conduction system - role of atrioventricular node

- pauses here for atria to complete contraction

34

intrinsic conduction system - atrioventricular bundle

- connects atria and ventricles

35

intrinsic conduction system - bundle branches

- conduct the impulses through inter ventricular septum

36

intrinsic conduction system - Purkinje Fibres

-penetrate ventricle walls
- depolarise ventricular myocardium

37

role of cardioacceleratory centre and where does it supply sympathetic input to

- increase heart rate and force of contraction
- sympathetic input via thoracic spinal cord to SA and AV node, Myocardium, Coronary arteries

38

role of cardioinhibitory centre and where does it supply parasympathetic input

- decreases heart rate
- parasympathetic input via vagus nerve to SA and AV nodes

39

describe electrocardiography

- detects cardiac electrical events
- electrodes placed on 12 parts of body
- composite of all the action potentials generated by the heart

40

ECG - P wave

- depolarisation of the atria
- beginning at the SA node

41

ECG - QRS complex

- depolarisation of the ventricles
- atrial repolarisation

42

ECG - T wave

- repolarisation of the ventricles

43

what can changes in an ECG pattern reveal

- if conduction pathway is normal
- if heart is enlarged
- if certain regions are damaged
- cause of chest pain

44

systole

contraction

45

diastole

relaxation

46

how long is the cardiac cycle

one complete heart beat

47

List the 8 stages in the cardiac cycle

1. All chambers relaxed - ventricles partially filled

2. Atrial Systole - contracts completely filling relaxed ventricles

3. Atrial Systole ends and atrial diastole egos

4. Ventricular Systole (part1) - beings at apex, closes Av valves but pressure not great enough to open SL valves = isovolumetric contraction

5. Ventricular Systole (part2) - SL valves open from increased pressure = ventricular ejection

6. Ventricular diastole (early) - ventricles relax, arterial blood flows backwards = SL closes

7. Isovolumetric Relaxation - no change in blood volume, blood flows backwards and Av valves remain closed

8. Ventricular diastole (late) - al heart chambers relaxed. AV valves open, blood moves passively from atria to the ventricles

48

what is the average resting heart rate

75bpm

49

what occurs in the cardiac cycle when heart rate increases

- all phases shortened
- especially ventricular diastole
- blood volume pumped by heart is reduced

50

What does the sound of Lubb s1 mean

closure of AV valves

51

what does the sound of Dupp s2 mean

closure of SL valves

52

what does a heart murmur mean

blood back flow through incompetent valve

53

correlating electrical and mechanical events - P wave

atrial depolarisation to atrial systole

54

correlating electrical and mechanical events - QRS complex

ventricular depolarisation to ventricular systole

55

correlating electrical and mechanical events - T wave

ventricular diastole