Dry Room 1

Question 1

What does the thoracic wall enclose?

Answer 1

The thoracic walls enclose the 2 pleural cavities and the centrally-situated mediastinum. The mediastinum contains the contents of the thorax other than the lungs and their covering pleurae. The heart lying within the pericardium is a major component of the mediastinum

Question 2

Answer 2

Question 3

What is the mediatinum subdivided into?

Answer 3

A superior and inferior mediastinum.

The inferior mediastinum is then further subdivided into the anterior, middle and posterior mediastinum

Question 4

Answer 4

Question 5

Which bone forms the anterior border of the superior mediastinum?

Answer 5

Manubrium of the sternum

Question 6

2.Which vertebrae form the posterior border of the superior mediastinum?

Answer 6

First four thoracic vertebral bodies

Question 7

3.What plane separates the superior from the inferior mediastinum?

Answer 7

Thoracic plane

Question 8

The inferior mediastinum is further divided into three parts – identify these on a skeleton, model and a wet specimen and label on the diagram below:

Answer 8

Question 9

What is the thymus?

Answer 9

Anterior superior mediastinum

Question 10

What is in the middle mediastinum?

Answer 10

Heart, pericardium and great vessels

Question 11

What is in the posterior mediastinum?

Answer 11

Posterior mediastinum

Thoracic duct

Sympathetic chain

Question 12

What is int he superior mediastinim?

Answer 12

Oesophagus

Azygous vein

Question 13

What does the pericardium cover?

Answer 13

Covering the heart, the pleura covering the lungs and the peritoneum covering the abdominal viscera all consist of similar outer parietal and inner visceral (serous) layers composed of simple epithelium of similar developmental origin.

The essential difference to this plan is that the heart has, in addition to these two serous membranes, an outermost, thick, fibrous connective tissue layer – the fibrous pericardium.

Question 14

Answer 14

Question 15

What are the 3 layers of the pericardium?

Answer 15

Superficial: Fibrous pericardium

Intermediate: Parietal pericardium

Deep: Visceral pericardium

Question 16

What is the pericardial cavity lie between?

Answer 16

Parietal and visceral pericardium

Question 17

The pericardial cavity lies between which 2 of the above layers?

Answer 17

Parietal and visceral pericardium

Question 18

The heart wall is composed of:

Answer 18

An inner Endo cardium composed of a single layer of Simple squamous epithelium

A middle Myo cardium composed of many layers of cardiac muscle

An outer Epi-cardium composed of a single layer of Simple squamous epithelium

Question 19

1.Which layer belongs simultaneously to the heart wall and the serous pericardium?

Answer 19

Epicardium

Question 20

2.Which layer of the serous pericardium is inseparably attached to the inner aspect of the fibrous pericardium?

Answer 20

Parietal pericardium

Question 21

What protective role is fulfilled by the fibrous pericardium?

Answer 21

Dense and loose connective tissue protect the heart by anchoring it to the surrounding walls and preventing it from overfilling with blood

Question 22

When does cardiac tamponade occur?

Answer 22

Occurs when excess fluid accumulates within the pericardial cavity as a result of a wide variety of pathophysiological factors. The increased pressure exerted by the excess fluid on the heart wall impedes the normal filling of the heart, and, at its most severe, can lead to cardiac failure.

Question 23

What is the innervation of the pericardium?

Answer 23

The visceral pericardium receives autonomic innervation from T1 –T4 nerves and vagus via the cardiac plexus (same as the heart wall itself).

The parietal and fibrous layers are innervated mainly by the phrenic nerve.

Question 24

Which layer/s of the pericardium are innervated by pain fibres?

Answer 24

Fibrous part and parietal part

Question 25

Can you see the left atrium in the in-situ wet specimen? Where is it situated?

Answer 25

Superior part of the heart. Just inside the second costal space on the left hand side

Question 26

What role do the auricles have in the adult?

Answer 26

Become part of the atrium and help pump blood

Question 27

Answer 27

Question 28

Answer 28

Question 29

Identify the left atrium on the isolated heart and the model provided. Anterior to what tubular organ does it lie? – Confirm this on a wet specimen of the thorax:

Answer 29

Oesophagus

Question 30

What shape is the heart?

Answer 30

Pyramidal shape

Question 31

5.Which chamber/s form a) the apex and b) the base of the heart?

Answer 31

a) Left ventricle b) Right ventricle

Question 32

Right atrium

Answer 32

Question 33

Fossa ovalis is a remnant of the foramen ovale in the foetus. What function did the latter perform?

Answer 33

Allows blood to cross atriums and bypass pulmonary circulation

Question 34

What is an atrial septal defect?

Answer 34

Is one of the more commonly recognized congenital cardiac anomalies presenting in adulthood. Atrial septal defect is characterized by a defect in the interatrial septum allowing pulmonary venous return from the left atrium to pass directly to the right atrium.

Question 35

Answer 35

Question 36

What is the function of the moderator band?

Answer 36

Convey the right branch of the atrioventricular bundle of the conducting system

Question 37

Compare the thickness of the right ventricular wall with that of the left: Which is thickest? By how many times? Why?

Answer 37

Left ventricle is six times as thick

Question 38

3.How many cusps make up the tricuspid valve? How many papillary muscles are found in the right ventricle?

Answer 38

3 cusps and there is also 3 papillary muscles

Question 39

What is the LA?

Answer 39

A small, smooth-walled chamber situated posterosuperiorly and forming the base of the heart. Immediately posterior to it lies the oesophagus.

Question 40

Answer 40

Question 41

Which valve guards the entry from the left atrium to the left ventricle?

Answer 41

MV

Question 42

How many cusps are present in this valve?

Answer 42

2

Question 43

How many papillary muscles are found in the left ventricle?

Answer 43

2

Question 44

What is the function of the papillary muscles?

Answer 44

Muscles attached to AV valves to prevent inversion

Question 45

What is the function of the chordae tendineae?

Answer 45

Tough tendinous strands in the heart

Question 46

Answer 46

Question 47

What is a VSD?

Answer 47

The interventricular septum separates the left and right ventricles of the heart. If there is a hole in the wall between the two ventricles, it is called a ventricular septal defect (VSD). Its aetiology (cause) is as yet indeterminate. Genes and environment may be a factor. A VSD is common in children with other genetic problems, such as Down’s syndrome.