Superior mediastinum and external heart

Question 1

What does the mediastinum contain?

Answer 1

Thoracic viscera apart from lugs
e.g.- heart, trachea, lymphatics

Question 2

What is the division of the mediastinum?

Answer 2

Superior and inferior
Sternal angle- anteriorly T4/5 junction
Inferior further divided-
Anterior- Thymus gland
Middle- Heart, pulmonary trunk, ascend aorta
Posterior- Vertebrae

Question 3

Main contents of superior mediastinum?

Answer 3

Arch aorta
Sup vena cava
Trachea
Oesophagus
Phrenic and vagus
Thoracic duct

Question 4

What are 3 parts of aorta in thorax?

Answer 4

Ascending aorta- forms coronary arteries
Arch aorta- curves posterior, sup mediastinum
Descending aorta- posterior mediastinum

Question 5

What branches of aorta supply upper body?

Answer 5

Brachiocephalic trunk- RCCA supplies right side
head and neck
- R subclavian- R upper
limb
LCCA- supplies left side head, neck, brain
L subclavian artery- L upper limb

Question 6

Where are chemoreceptors located?

Answer 6

Aortic body

Question 7

Function of chemoreceptors?

Answer 7

Monitor arterial oxygen and CO2
Info travels along vagus nerve

Question 8

Label

Answer 8

Question 9

What connects the pulmonary trunk and arch of aorta?

Answer 9

Ligamentum arteriosum
Remenant ductus arteriosus

Question 10

In a foetus where does gas exchange occur?

Answer 10

Placenta
Ductus arteriosus diverts blood to aortic arch
When lungs start work- da closes and blood in pulmonary trunk enters lungs

Question 11

What are the veins that carry deoxygenated blood, enter R atrium?

Answer 11

Superior Vena Cava
Inferior Vena Cava

Question 12

What does the SVC do?

Answer 12

Blood from heart to head, neck, upper limbs
Superior mediastinum

Question 13

What is the SVC formed from?

Answer 13

L and R brachiocephalic veins
Brachiocephalic formed internal jugular and subclavian

Question 14

What does the IVC do?

Answer 14

Return blood from regions to heart

Question 15

Function of trachea? structure?

Answer 15

Conducts air to and from L and R main bronchi
Semi-rigid- C-shaped incomplete cartilage

Question 16

Where does the trachea extend to?

Answer 16

Larynx- superior mediastinum

Question 17

Where does the trachea terminate?

Answer 17

Lvl sternal angle (junction T4 and T5)- bifurcate into L and R main bronchi

Question 18

Function of oesphagus?

Answer 18

Pharynx to midline stomach neck
Waves contraction of smooth muscle move food and fluid distally (peristalsis)

Question 19

What nerves innervate the diaphragm?

Answer 19

C3, C4, C5- spinal nerves
Phrenic nerves- somatic- motor and sensory

Question 20

Where do phrenic nerves emerge?

Answer 20

Superior thoracic aperture

Question 21

What do vagus nerves innervate?

Answer 21

Thorax, abdomen, head, neck
Somatic and para

Question 22

Where do vagus nerves travel?

Answer 22

Descend neck, enter thorax via superior thoracic aperture
Give rise RLN- innervate muscle larynx
Left recurrent- arch aorta
Right recurrent- subclavian
Heart, lungs, oesophagus
Viscera

Question 23

Function of thoracic duct?

Answer 23

Lymphatic drainage

Question 24

What gland is found in children but not adults?

Answer 24

Thymus gland
Atrophy age

Question 25

What is the pericardium?

Answer 25

Tough, fibrous sac encloses heart Loose- allow movement heart

Question 26

What layers of pericardium?

Answer 26

Tough, outer fibrous later Thin, inner serous- 2 parts - parietal- inner fibrous peri - visceral- surface heart

Question 27

What is the space called between layers of serous paricardium?

Answer 27

Pericardial cavity- pericardial fluid

Question 28

What does pericardial fluid do?

Answer 28

Lubricates serous membranes Allow slide over when heart moves

Question 29

What innervates fibrous pericardium?

Answer 29

L and R phrenic nerves

Question 30

What is the point of heart called? top area?

Answer 30

Apex- left sternum

Question 31

Where is inferior part?

Answer 31

Left ventricle, part right

Question 32

Where is anterior part?

Answer 32

Right ventricle

Question 33

Where is left pulmonary part?

Answer 33

Left ventricle

Question 34

Where is right pulmonary?

Answer 34

Right atrium

Question 35

What forms apex? and where?

Answer 35

Left ventricle 5th intercostal space in midclavic line

Question 36

Where is apex beat palpable?

Answer 36

5th intercostal space

Question 37

Where is right border?

Answer 37

Right atrium 3rd-6th costal cartilage

Question 38

Where is left border?

Answer 38

Left ventricle 2nd-5th intercostal space

Question 39

Superior and inferior borders?

Answer 39

Sup- sup extent R and L border 3rd CC-2nd IC Inf- end right border with apex (R ventricle)

Question 40

What are auricles?

Answer 40

Outpouchings from walls R and L atria

Question 41

Sulci?

Answer 41

Grooves