Endocrinology Practical 2.1.8

Question 1

where is the pituitary gland located?

Answer 1

depression of the sphenoid bone (hypophyseal or pituitary fossa)

Question 2

what is the name for the shelf of dura matter that covers the pituitary fossa?

Answer 2

sellar diaphragm

Question 3

What structure passes through the sellar diaphragm and connects the pituitary gland to the base of the brain?

Answer 3

infundibulum/ pituitary stalk

Question 4

Where are the cell bodies, axons and synapses of the magnocellular neurons located?

Answer 4

• Cell bodies: Supraoptic and Paraventricular nuclei of the hypothalamus
• Axons: Travel in the pituitary stalk
• Synapses: Posterior Pituitary

Question 5

What hormones travel down the axons of the magnocellular neurons?

Answer 5

• Oxytocin (for the cells which originate from the PVN) and Vasopressin (for the cells which originate from the SON)

Question 6

What hormones are made in the anterior pituitary?

Answer 6

ACTH, GH, PRL, FSH,LH. TSH

Question 7

How is the release of the pituitary hormones controlled?

Answer 7

from the hypothalamus :
CRH - ACTH
GHRH - GH
GnRH - FSH LH
TRH - TSH
PRLH - PRL

Question 8

How is the release of the pituitary hormones controlled?

Answer 8

from the hypothalamus :
CRH - ACTH
GHRH - GH
GnRH - FSH LH
TRH - TSH
PRLH - PRL
transported in the pituitary portal system

Question 9

What structure is located immediately below the pituitary fossa?

Answer 9

• The sphenoid sinus.- Note that the proximity of the pituitary gland to the sphenoid sinus, allows transphenoidal surgery, an endoscope route to access the pituitary gland via the nasal cavity.

Question 10

What nerve do the superior and recurrent laryngeal nerves both originate from?

Answer 10

vagus

Question 11

The recurrent laryngeal nerve is vulnerable to damage during thyroid surgery. What would be the consequence of damaging these nerves?

Answer 11

hoarse voice

Question 12

What hormone(s) are released by the thyroid gland?

Answer 12

T4, T3 , calcitonin

Question 13

How is the release T3, T4, and calcitonin hormones controlled?

Answer 13

TSH

Question 14

Where would you expect to find the parathyroid glands?

Answer 14

behind the thyroid

Question 15

What hormones are released by the parathyroid glands?

Answer 15

PTH

Question 16

where is the recurrent laryngeal nerve?

Answer 16

on the left hand side of the inferior thyroid gland

Question 17

what is one of the first branches of the external carotid artery?

Answer 17

superior thyroid artery

Question 18

what is the blood supply to the thyroid gland?

Answer 18

inferior thyroid artery

Question 19

what is the inferior thyroid artery a branch of?

Answer 19

thyrocervical trunk, which is a branch of the subclavian

Question 20

Which veins do the thyroid veins drain in to?

Answer 20

• Superior and middle thyroid veins – to internal jugular vein
• Inferior thyroid veins – to the brachiocephalic veins.

Question 21

What is the blood supply to the parathyroid glands?

Answer 21

• Primarily branches from the inferior thyroid arteries, collateral supply from superior thyroid arteries.

Question 22

Why is it important to be aware of the thyroid arteries during thyroid surgery?

Answer 22

• There is a risk of disrupting parathyroid blood supply when the blood supply to the thyroid is ligated during surgery

Question 23

is the external or internal carotid more posterior?

Answer 23

internal

Question 24

How do you know you are looking at the common carotid arteries, and not the internal / external carotid arteries?

Answer 24

• The bifurcation of the common carotid artery to form the internal and external carotid arteries happens above the level of the upper border of the thyroid cartilage: we are viewing a region inferior to this.

Question 25

What is the exocrine role of the pancreas?

Answer 25

digestive enzymes

Question 26

The pancreas also has an endocrine role. What hormones does it produce?

Answer 26

alpha- glucagon
beta - insulin
delta - somatostatin

Question 27

Where are the endocrine cells of the pancreas located?

Answer 27

islets of langerhan

Question 28

what supplies the pancreas?

Answer 28

celiac trunk (splenic artery which gives rise to the great pancreatic artery, which then gives rise to the anterior and posterior pancreaticduodenal arteries) and superior mesenteric which gives rise to the inferior pancreaticoduodenal arteries

Question 29

Where are alpha and beta cells found?

Answer 29

iselts of langerhan in the pancreas

Question 30

What hormone do alpha cells secrete, and what does it do?

Answer 30

glucagon raises BG levels encourages glycogen to be made into glucose (3ATP generated when glycogen undergoes glycolytic pathway)

Question 31

What hormone do beta cells secrete, and what does it do?

Answer 31

insulin lowers BG levels encourages liver to convert glucose to glycogen via UDP glucose

Question 32

1. Which of the following sentences about the hypothalamus is true?
   a. Magnocellular neurons located in the supraoptic nucleus project to the posterior pituitary where they release vasopressin into the circulation
   b. Magnocellular neurons located in the paraventricular nucleus project to the posterior pituitary where they release vasopressin into the circulation
   c. Magnocellular neurons located in the supraoptic nucleus project to the anterior pituitary where they release vasopressin into the circulation
   d. Magnocellular neurons located in the paraventricular nucleus project to the anterior pituitary where they release vasopressin into the circulation
   e. Both A and B are true.

Answer 32

a

Question 33

2. Which of the following statements about the pituitary gland are true
   a. The anterior pituitary synthesizes and releases prolactin
   b. The posterior pituitary releases vasopressin into the circulation
   c. The anterior pituitary communicates with the hypothalamus via small blood vessels
   d. The posterior pituitary communicates with the hypothalamus via axons carried in the pituitary stalk
   e. A-D are all correct

Answer 33

e