anatomy

Question 1

what is the anterior lobe of the pituitary gland called? what is it responsible for?

Answer 1

adenohypophysis

• pars distalis
• pars tuberalis
• pars intermedia

syntheis + release of most pituitary hormones

Question 2

what is the posterior lobe of the pituitary gland called? what is it responsible for?

Answer 2

neurohypophysis
- pars nervosa

releases ADH + oxytocin (synthesised in hypothalmus)

Question 3

describe the location of the pituitary gland

Answer 3

midline structure in the pituitary fossa of sphenoid bone

pituitary fossia lies in sella turcica

Question 4

what cranial nerve innervates the platysma muscles?

Answer 4

CN VII (facial nerve)

Question 5

in what week of development does the thyroid gland reach its final position?

Answer 5

7th week

Question 6

where are the 4 parathyroid glands located?

Answer 6

the posterior surfaces of thyroid gland lateral lobes

-> superior + inferior on each side

Question 7

the immediate superior relation to the pituitary gland is?

Answer 7

diaphragma sella

–> tough sheet of dura matter forming roof (diaphragm) over pituitary fossa

(also optic chiasma)

Question 8

how do axons from the optic tract get to the visual cortex? where is the visual cortex?

Answer 8

axons in chain pass via optic radiation to visual cortex in occipital lobe

Question 9

bilateral loss of temporal visual field

Answer 9

bitemporal hemianopia

–> can be caused by pituitary tumour crpressing optic chiasma

Question 10

how can the pituitary fossa be surgically accessed?

Answer 10

transcranial approach - subfrontal (inferior to frontal lobe)

transsphenoidal approach - via nasal cavities + sphenoid sinus

Question 11

what are paranasal sinuses? name them

Answer 11

air-filled sacs within bones surrounding nasal cavities

1. frontal sinuses
2. maxillary sinuses
3. ethmoid air cells
4. sphenoid sinuses

Question 12

function of paranasal sinuses

Answer 12

no real function - reduces weight in skull, adds resonance to voice

lined by mucus-secreting respiratory mucosa - drains into nasal cavities through ostia

Question 13

how are hypothalmic hormones transported to the pituitary

Answer 13

hypophyseal portal veins

–> to 2nd capillary bed in the anterior pituitary

Question 14

what hormones does the anterior pituitary secrete?

Answer 14

Growth hormone (GH)
prolactin (milk production)

thyroid stimulating hormone (TSH)
adrenocorticotrophic hormone (ACTH)
luteinising hormone (LH)
follicle stimulating hormone (FSH)

Question 15

what does functional deficiet to the optic chiasma lead to?

Answer 15

bitemporal hemianopia

function = conducts AP bilaterally from nasal retinae

Question 16

what does functional deficit to the trochlear nerve cause?

Answer 16

difficulty looking inferiorly and laterally

function = motor to one muscle that moves globe

Question 17

where do the superior, middle and inferior thyroid veins drain?

Answer 17

superior + middle = internal jugular -> brachiocephalic

inferior = directing into brachiocephalic

brachiocephalic -> SVC

Question 18

which nerve supplies the sternocleidomastoid and trapezius?

Answer 18

CN XI - spinal accessory nerve

Question 19

which muscle lies between the anterior and posterior trainagles of the neck?

Answer 19

sternocleidomastoid
sternal head - manubrium of sternum
clavicular head - medial end of clavicle
both attach to mastoid process of temporal bone

Question 20

which vein passes over sternocleidomastoid and can be seen superficially?

Answer 20

external jugular vein

Question 21

what muscles are found immediately deep to the skin of the neck? how are they innervated?

Answer 21

platysma muscles
belong to “muscles of facial expression”

CN VII = facial nerve

Question 22

what do the carotid sheaths contain?

Answer 22

internal jugular vein
common carotid artery
vagus nerve
deep cervical lymph nodes

(x2 carotid sheaths)

Question 23

which fascial compartment is the thyroid found in? what else is contained in this compartment?

Answer 23

pretracheal fascia

oesophagus
trachea
thyroid gland
strap muscles
recurrent laryngeal nerves

Question 24

which fascial compartment is the trapezius muscles found in? what other muscle is found in here?

Answer 24

INVESTING FASCIA

sternocleidomastoid

Question 25

what does the prevertebral (deep) fascial compartment contain?

Answer 25

postural neck muscles | cervical vertebra

Question 26

where is the retropharyngeal space? what is it's clinical importance?

Answer 26

between pretracheal + prevertebral sheath passes down to mediastinum - any infection that gets to this space has potential to track down

Question 27

where do the superior and inferior thyroid arteries branch from respectively?

Answer 27

superior - external jugular artery inferior - subclavian artery

Question 28

what does unilateral injury to the recurrent laryngeal nerve cause?

Answer 28

"hoarseness" or weakness of voice + weak cough

Question 29

what does bilateral injury to the recurrent laryngeal nerve cause?

Answer 29

aphonia = inability to produce sound inability to close rima glottidis (opening between vocal cords) - prevent aspiration, produce good cough (requires closure of rima glottidia)

Question 30

where does the recurrent laryngeal nerve lie in relation to the thyroid gland?

Answer 30

in the groove between trachea and oesophagus | ?vagus more lateral

Question 31

course of travel of vagus nerve (CN X) superior to thorax

Answer 31

emerge from medulla oblongata exit cranium via jugular foramen descend in carotid sheath

Question 32

how does the vagus nerve descend through the thorax?

Answer 32

right CN X = lateral to trachea left CN X = left side of aortic arch both - POSTERIOR to lung hilum + plexus around oesophagus

Question 33

whats the difference between the route of the left and the right recurrent laryngeal nerves?

Answer 33

left - wraps around arch of aorta right - wraps around subclavian artery

Question 34

which structure is at risk of haemorrhaging in a surgery to access the pituitary?

Answer 34

internal carotid artery

Question 35

which cranial nerves could be affected by a pituitary tumour?

Answer 35

CN III - eye movement deficit, dilated pupil IV - difficulty looking inferior + laterally V1, V2 - parathesia of face VI - difficulty abducting eye

Question 36

which bones must be fractures in a transsphenoidal approach?

Answer 36

nasal septum + floor roof of sphenoid sunuses (to access pituitary tumour)

Question 37

clinical term for enlargement of thyroid

Answer 37

goitre

Question 38

how does a swollen thyroid move in degluitition? why?

Answer 38

moves superiorly then inferiorly with larynx due to relationship with trachea and larybx

Question 39

from which embryological remnant is a pyramidal lobe from?

Answer 39

thyroglossal duct

Question 40

name the 4 strap muscles

Answer 40

sternohyoid thyrohyoid sternothyroid omohyoid (fascial sling)

Question 41

A 34-year-old lady undergoes a thyroidectomy for Graves disease. Post operatively she develops a tense haematoma in the neck. In which of the following fascial planes will it be contained?

Answer 41

pretracheal fascia The pretracheal fascia encloses the thyroid and is unyielding. Therefore tense haematomas can develop.

Question 42

what is colloid in the thyroid gland?

Answer 42

It is a high molecular weight protein that acts as a storage form of thyroid hormones. main component = thyroglobulin