Hypertension

Question 1

What is the mediastinum?

Answer 1

Thick, flexible soft tissue partition enclosing everything in the thorax by the pleural cavities (heart, oesophagus, trachea, major nerves etc.)
Acts as a conduit for structures that pass from thorax to other regions

Question 2

List the parts of the sternum

Answer 2

Manubrium, body and diploid process

Question 3

How do ribs articulate posteriorly?

Answer 3

(Ribs II-IX) have 3 articulations with the vertebral column. The head of the rib with the body of its own vertebrae and the vertebrae above and with the transverse process of its own vertebra.

Question 4

What makes up the thoracic wall?

Answer 4

Posteriorly - 12 thoracic vertebrae and their intervening intervertebral discs
Laterally - 12 ribs on each side, 3 layers of intercostal muscles
Anteriorly - sternum

Question 5

How do ribs articulate anteriorly?

Answer 5

Ribs 1-7 articulate with the sternum
Ribs 8-10 articulate with the inferior margins of the costal cartilages above them

Ribs 11-12 are floating ribs as they do not articulate with sternum, ribs or costal cartilages. Their costal cartilages only cover their tip.

Question 6

What are the component parts of the thorax?

Answer 6

Thoracic wall, superior thoracic aperture, inferior thoracic aperture, diaphragm, mediastinum, pleural cavities

Question 7

What is the superior thoracic aperture?

Answer 7

Body of vertebra T1 posteriorly, medial margin of rib 1 and the manubrium anteriorly

Question 8

What passes through the superior thoracic aperture?

Answer 8

trachea, oesophagus, common carotid artery, apex of right lung, subclavian artery and vein, internal jugular vein, nerves

Question 9

What is the inferior thoracic aperture?

Answer 9

Large, expandable closed by the diaphragm that separates the thorax and abdomen

Question 10

Skeletal elements of the inferior thoracic aperture

Answer 10

Body of vertebra T12
Rib 12 and distal end of rib 11
Distal cartilaginous ends of ribs 7-10 which unite to form costal margin
Diploid process

Question 11

Describe and explain the component parts of mediastinum

Answer 11

Superior and inferior mediastinum are separated by the intervertebral disc between T4 and T5.

Inferior mediastinum is further divided into anterior, middle and posterior. Pericardium and heart mate up middle mediastinum.

Question 12

Why is T4/5 vertebral level important for clinicians? (6 points)

Answer 12

Horizontal plane passing through T4/5 passes through:
1. sternal angle articulates with rib 2 (reference to count ribs)
- separates superior and
2. inferior mediastinum and marks superior limit of pericardium
3. arch of aorta begins and ends
4. superior vena cava penetrates pericardium to enter heart
5. trachea bifurcates into right and left main bronchi
6. superior limit of pulmonary trunk

Question 13

What are the 3 layers of the heart wall?

Answer 13

Endocardium: inner layer - endothelium
Myocardium: middle layer - cardiac muscle
Epicardium: outer layer - visceral pericardium

Question 14

What is the fibrous pericardium?

Answer 14

inelastic connective tissue making up the outer covering of the heart

Question 15

What is the role of the fibrous pericardium?

Answer 15

prevents overfilling of the heart and anchors it in position (by fusing with diaphragm inferiorly and great vessels superiorly)

Question 16

Where does the heart sit in the thorax?

Answer 16

between ribs 2-5, left of midline, apex lies in the 5th intercostal space in midclavicular line

Question 17

What makes up the serous pericardium?

Answer 17

Parietal pericardium - lines inner surface of fibrous pericardium
Visceral (epicardium) - adheres to surface of the heart
Pericardial cavity - potential space between the layers, contains pericardial fluid - prevents friction

Question 18

What are the layers of the heart wall?

Answer 18

Endocardium: inner endothelium layer
Myocardium: middle, cardiac muscle
Epicardium: outer, visceral pericardium

Question 19

What is an endothelium?

Answer 19

Single layer of squamous endothelial cells lining blood vessels and lymphatic vessels

Question 20

What is pericarditis?

Answer 20

Inflammation of the lining of the heart

Question 21

What is cardiac tamponade?

Answer 21

Blood leaking into pericardial cavity