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Flashcards in Heart & Diaphragm Deck (43):
1

What are the three parts of the conducting system of the heart

Sinoatrial Node
Atrioventricular Node
Atriventricular bundle of HIS

2

What are the functions of the sinoatrial node

1: Pacemaker
2: Initiates cardiac impulse
3: Send the impulse from SA node to AV node

3

What are the functions of the atrioventricular node

Delays the contractions of the ventricles

4

Where is the atrioventricular node located?

In the right atrium in the lower part of the interatrial septum

5

Describe the atrioventricular bundle of HIS

It descends into the interventricular septum and divides into:
1: Right ventricular branch
2: Left ventricular branch

These branches descend in the interventricular septum. They then spread out in the walls of respective ventricles to end as Purkinje fibres.

6

Where does the blood supply to the heart come from

The right and left coronary arteries

7

What is the atrioventricular groove also called

Coronary sulcus
Atrioventricular sulcus

8

What is the auricle

The muscular pouch that expands the capacity of the atria

9

What is the origin of the right coronary artery

Right aortic sinus

10

What is the course of the right coronary artery

1: Between pulmonary trunk and right auricle, descends to the right in the coronary sulcus

2: Turns posteriorly at junction of right and inferior border

3: Continues along the posterior part of the coronary sulcus (and then anastomoses with branch of left coronary artery)

11

What are the branches of the right coronary artery

Artery to SA node (65% of cases)

Right marginal artery

Posterior interventricular branch

Conus artery

Atrial and ventricular branches

12

What are the areas supplied by the right coronary artery

Most of the right atrium

Right ventricle, except area adjoining anterior interventricular groove

Left ventricle adjacent to posterior interventricular sulcus

Posterior third of interventricular septum

SA node (in 65% of cases)

AV node

Bundle of HIS (except left branch of bundle of HIS)

13

What is the origin of the left coronary artery

Left aortic sinus

14

What is the course of the left coronary artery

1: Behind, then to left of pulmonary trunk to reach left part of coronary sulcus

2: Divides into:
-- Anterior interventricular artery
-- Circumflex artery

15

What are the braches of the left coronary artery

Anterior interventricular artery

Circumflex artery

Diagonal artery

Atrial and ventricular branches

16

What are the areas supplied by the left coronary artery

Left atrium

Left ventricle (except area adjoining posterior interventricular groove)

Right ventricle adjacent to anterior interventricular sulcus

Anterior two-thirds of interventricular septum

SA node (35% of cases)

Part of the left branch of bundle of HIS

17

How is coronary artery dominance determined

Whether the posterior interventriuclar artery is attached to the right coronary artery or the left coronary artery

18

What are the three ways that the heart is drained

1: Coronary sinus

2: Anterior cardiac veins

3: Venus cordis minimae

19

Where is the coronary sinus

In the posterior part of the coronary sulcus

20

What are the tricutaries of the coronary sinus

Great cardiac vein
Middle cardiac vein
Small cardiac vein
Right marginal vein
Oblique vein of left atrium
Posterior ventricular vein

21

What are the anterior cardiac veins

Several small veins that drain anterior aspect of the right ventricle that open up into right atrium

22

What do the venus cordis minimae drain

Endocardium and deep myocardium

23

Where do the venus cordis minimae drain into

Open directly into each chamber of the heart

24

Explain the nerve supply of the heart

Carciac Plexus (Autonomic nervous system)

Made up of:
A: SYMPATHETIC FIBRES
-From the superior, middle and inferior cervical ganglia
-From the spinal segments (T1-T4)

B: PARASYMPATHETIC FIBRES
-Vagus nerve

25

What is the position of the superficial cardiac plexus

Inferior to the arch of the aorta

26

What is the position of the deep cardiac plexus

Posterior to arch of aorta

Anterior to tracheal bifurcation

27

Why are there different areas of referred pain in angina pectoris or myocardial infarction

Posterior roots of T1-T5 (afferent-containing) supply:

-- Sympathetic cardiac nerves

-- Medial border of left upper limb

--Left side of chest wall

28

What happens when the diaphragm contracts

Increases internal height of thoracic cavity

Lowers internal pressure

Inspiration of air

29

What are the peripheral attachments of the diaphragm

Lumbar vertebrae and arcuate ligaments

Costal cartilages (of ribs 7-10) ; ribs 11 and 12

Xiphoid process

30

Briefly, what are the crura

Parts of the diaphragm arising from the vertebrae that are tindinous in structure

31

Where does the right crus arise

From L1-L3 and their intervertebral disks

32

Where does the left crus arise

From L1-L2 and their intervertebral disks

33

What surrounds the oesophageal opening, acting as a physiological sphincter

Right crus

34

What is the central tendon of the diaphragm formed by

Convergence of muscle fibres of the diaphragm
Fuses with inferior surface of the pericardium

35

What are the three openings in the diaphragm

Oesphageal opening
Aortic opening
Caval opening

36

Where is the oesophageal opening located

At level of T10

37

What does the oesophageal opening contain

Oesophagus
Vagus nerves
Oesophageal branches of left gastric vessels

38

Where is the aortic opening located

T12

39

What does the aortic opening contain

Aorta
Thoracic duct
Azygous vein

40

Where is the caval opening located

T8

41

What does the caval opening contain

Inferior vena cava

42

What is the innervation of the diaphragm

Phrenic nerve
Cardiac plexus (C3-C5)

43

What is the vasculature of the diaphragm

Inferior phrenic artery (mostly)
Superior phrenic artery
Pericardiophrenic artery
Musculophrenic artery

Draining veins follow these arteries