Anatomical structures of the thorax

Question 1

Why is the horizontal plane between T4 and T5 important

Answer 1

Passes through the sternal angle
Separates the superior mediastinum from the inferior mediastinum
Marks where the arch of the aorta begins and ends
Passes through the site where the SVC enters the heart
Is the site where the trachea bifurcates into right and left main bronchi
Marks the superior limit of the pulmonary trunk

Question 2

Where is thyroid glands located

Answer 2

Anterior neck
Between C5 and T1 vertebrae
Lies behind the sternohyoid and sternothyroid muscles, wrapping around the cricoid cartilage and superior tracheal rings

Question 3

What are the two lobes of thyroid gland Connected by

Answer 3

Isthmus

Question 4

What does the thyroid gland initially form during development

Answer 4

Floor of the primitive pharynx, near the base of the tongue

Question 5

Two main arteries supplying the thyroid gland

Answer 5

Superior and inferior thyroid arteries

Question 6

What is the artery that only 10% of the population have

Answer 6

Thyroid ima artery

Question 7

Where does the thyroid ima artery branch from

Answer 7

Brachiocephalic trunk of the arch of aorta

Question 8

What does the hydroid ima artery supply

Answer 8

Anterior surface and isthmus of thyroid gland

Question 9

How is the venous drainage of the thyroid gland carried out

Answer 9

By the superior, middle and inferior thyroid veins
Superior and middle veins drain into the internal jugular veins, whereas the inferior drains into the brachiocephalic vein

Question 10

What is the thymus gland involved in during adolescence

Answer 10

Development of immune system

Question 11

what happens to the thymus gland after puberty

Answer 11

It decreases in size and slowly replaced with fat

Question 12

Where is the thymus gland located

Answer 12

Within the thoracic superior mediastinum posterior to the manubrium of the sternum
Can extend superiorly into the neck and inferior into the anterior mediastinum

Question 13

Describe the structure of thymus glsnd

Answer 13

Asymmetrical flat shape with a lobular structure

Lobules comprised of a series of follicles which have a medullary and cortical component

Question 14

What is the cortical portion of thymus

Answer 14

Located peripherally within each follicle

Largely composed of lymphocytes, supported epithelial reticular cells

Question 15

what is the medullary portion of thymus

Answer 15

Located centrally within each follicle
Contains fewer lymphocytes and an increased number of epithelial cells
Hassall’s corpuscles are also present

Question 16

what are Hassall’s corpuscles

Answer 16

Concentric arrangements of epithelial reticular cells

Question 17

Relations of thymus

Answer 17

Anteriorly: sternum
Posteriorly: pericardium, aortic arch, great vessels, left brachiocephalic vein, trachea
Laterally: pleura, pretracheal fascia

Question 18

Sensory vagus nerve innervations

Answer 18

Innervates the skin of the external acoustic meat is and the internal surfaces of the laryngopharynx and larynx
Provides visceral sensation to the heart and abdominal viscera

Question 19

Special sensory innervation of vagus nerve

Answer 19

Provides taste sensation to the epiglottis and root of the tongue

Question 20

Motor innervations of vagus nerve

Answer 20

Provides motor innervation to majority of the muscles of the pharynx, soft palate and larynx

Question 21

Parasympathetic innnervations of vagus nerve

Answer 21

Innervates smooth muscle of the trachea, bronchi and GI tract and regulates heart rhythm

Question 22

where does the vagus nerve originate

Answer 22

Medulla of brainstem

Question 23

Where does the vagus nerve exit the cranium from

Answer 23

Jugular foramen

Question 24

With what other two cranial nerves does the vagus nerve exit the jugular foramen with

Answer 24

Glossopharyngeal (IX)
Accessory nerves (XI)

Question 25

What branch arises within the cranium

Answer 25

Auricular branch

Question 26

What does the auricular branch do

Answer 26

Supplies sensation to the posterior part of the external auditory canal and external ear

Question 27

What is the course of the vagus nerve in the neck

Answer 27

Passes into the carotid sheath travelling inferiorly with the internal jugular vein and common carotid artery

Question 28

What is the course of the right vagus nerve

Answer 28

Passes anterior to the subclavian artery and posterior to the sternoclsvicular joint

Question 29

What is the course of the left vagus nerve

Answer 29

Passes inferiorly between the left common carotid and left subclavian arteries, posterior to the sternoclavicular joint

Question 30

what are the pharyngeal branches of the vagus nerve

Answer 30

Provides motor innervation to the majority of the muscles of the pharynx and soft palate

Question 31

At what level does the superior laryngeal nerve divide

Answer 31

At the level of hyoid bone

Question 32

where does the internal branch of laryngeal nerve provide innervation

Answer 32

provides sensory innervation to the level above vocal cord

Question 33

what does the external laryngeal nerve innervate

Answer 33

external muscle

Question 34

between what two structures does the recurrent laryngeal loop ascend through

Answer 34

oesophagus and trachea

Question 35

where does the right recurrent laryngeal. erve originate from and loop around

Answer 35

root of the neck

wraps around the right subclavian artery

Question 36

where does the left recurrent laryngeal nerve originate and wrap around

Answer 36

originates in the thorax

wraps around the arch of the aorta