Endocrine Anatomy

Question 1

What bony structure does the pituitary gland reside in?

Answer 1

Pituitary fossa of the sphenoid bone

Question 2

How is the optic chiasm related to the pituitary gland; what clinical relevance does this have?

Answer 2

The chiasm is superior to the pituitary gland; any enlargement (e.g. by a tumour) will compress this dessucation and cause bitemporal homonymous hemianopia)

Question 3

Which fibres from the optic nerve cross over to the opposite side at the optic chiasm?

Answer 3

Nasal

Question 4

What is the larger of the two pituitary lobes?

Answer 4

Anterior

Question 5

Which of the two lobes is glandular and manufactures numerous hormones?

Answer 5

Anterior

Question 6

What is the function of the posterior lobe of the pituitary?

Answer 6

Neuroendocrine secretion

Question 7

Histologically, which of the lobes of the pituitary appears lighter?

Answer 7

Posterior

Question 8

Why does the posterior pituitary stain lighter than the anterior?

Answer 8

Posterior has a high population of acidophilic cells

Question 9

What are the three types of cells are present in the pituitary gland?

Answer 9

Acidophilic, basophilic and chromophobic

Question 10

What two classes of hormones are produced by the acidophilic cells?

Answer 10

Somatotrophs and mammotrophs

Question 11

What is the secretory product of somotrophic acidophils?

Answer 11

Somatotrophin (GH)

Question 12

What is the secretory product of mammotrophic acidophils?

Answer 12

Prolactin

Question 13

What three classes of hormones are produced by the basophilic cells?

Answer 13

Croticotrophs, thryotrophs and gonadotrophs

Question 14

What are the secretory products of corticotrophic basophils?

Answer 14

ACTH and MSH

Question 15

What is MSH?

Answer 15

Melanotrophic stimulating hormone

Question 16

What is the secretory product of thyrotrophic basophils?

Answer 16

TSH

Question 17

What are the secretory products of gondaotrophic basophils?

Answer 17

LH and FSH

Question 18

What hormones do the posterior pituitary produce?

Answer 18

Oxytocin and ADH

Question 19

What two branches of the internal carotid artery supply the pituitary gland?

Answer 19

Superior and inferior hypophysial arteries

Question 20

Which artery supplies the anterior pituitary?

Answer 20

Superior hypophysial a.

Question 21

Which artery supplies the posterior pituitary?

Answer 21

Inferior hypophysial a.

Question 22

How does the hypothalamus communicate with the anterior pituitary?

Answer 22

Capillary network transmitted through the infidibulum

Question 23

How does the hypothalamus communicate with the posterior pituitary?

Answer 23

Neuronal network transmitted through the infidibulum

Question 24

What vertebral level is the thyroid located at?

Answer 24

C5 to T1

Question 25

Which cartilages is the thyroid located between?

Answer 25

Cricoid cartilage and the 6th tracheal ring

Question 26

Where does the isthmus lie?

Answer 26

Between the two lobes of the thyroid at the level between the 2nd and 4th tracheal ring

Question 27

The thyroid histology changes depending on the activity of the gland; how is this the case?

Answer 27

Active gland - columnar cells | Inactive gland - cuboidal

Question 28

Identify the three strap muscles that overlie the thyroid

Answer 28

Sternohyoid, omohyoid and sternothyroid

Question 29

Name the two nerves that supply the muscles of the vocal cords and describe their location in relation to the thyroid gland

Answer 29

Recurrent laryngeal nerve - runs between the trachea and the oesophagus External laryngeal nerve - close to superior thyroid artery

Question 30

From which major artery in the neck does the superior thyroid artery arise?

Answer 30

ECA

Question 31

From which artery does the inferior thyroid artery arise?

Answer 31

Subclavian artery

Question 32

Into which vein does the superior thyroid vein drain?

Answer 32

IJV

Question 33

Into which vein does the middle thyroid vein drain?

Answer 33

IJV

Question 34

Into which vein does the inferior thyroid vein drain?

Answer 34

Braceocelphalic

Question 35

Hormones of the thyroid are stored in cavities, surrounded by secretory cells; what is the name of these structures?

Answer 35

Follicles

Question 36

Within the cavities; how is the hormone stored?

Answer 36

In complex with a glycoprotein

Question 37

What is the glycoprotein bound to thyroid hormones in the follicle called?

Answer 37

Colloid

Question 38

How is stored thyroid hormones secreted?

Answer 38

Reabsorbed from colloid and secreted out of secretory cell

Question 39

What is the secretory cell of the follicle called?

Answer 39

Follicular cells

Question 40

What colour do follicular cells stain?

Answer 40

Pink

Question 41

Where can you find clear/parafillicular/C cells?

Answer 41

Attached between the follicles

Question 42

What do C-cells secrete?

Answer 42

Calcitonin

Question 43

What hormones do the thyroid release?

Answer 43

T3 and T4

Question 44

Which thyroid hormones is also called thyroxine?

Answer 44

T4

Question 45

What is the name of T3?

Answer 45

Tri-iodothyronine

Question 46

Where do the parathyroid glands lie in relation to the thyroid gland?

Answer 46

Lateral posterior surface external to the thyroid fibrous capsule

Question 47

How many PT glands do most people have?

Answer 47

4

Question 48

Where are the superior PT glands located?

Answer 48

At the level of the inferior border of the cricoid cartilage

Question 49

Where are the inferoir PT glands located?

Answer 49

Near the inferior poles of the thyroid glands (although their position is variable)

Question 50

Describe the arterial supply of the PT glands

Answer 50

Inferior thyroid arteries

Question 51

Describe the venous drainage of the PT glands

Answer 51

Via the draining veins of the thyroid and into the IJV

Question 52

What two types of cells are present in the PT?

Answer 52

Chief cells and oxyphil cells

Question 53

How do you distinguish between the two types of PT cells?

Answer 53

Chief cells are more numerous and have darker staining of the cytoplasm

Question 54

What hormone is secreted by the PT gland?

Answer 54

PTH

Question 55

What is the action of PTH?

Answer 55

Acts to increase free calcium by stimulating osteoclasts and inhibiting PCT cell reabsorption of PO3-

Question 56

How are the surparenal glands separated from the kidneys?

Answer 56

By a capsule

Question 57

How are the suprarenal glands peritonised?

Answer 57

Retroperitoneal

Question 58

What are the embryological origins of the different layers of the adrenal glands?

Answer 58

Cortex - mesodermal epithelium | Medulla - neuroectoderm

Question 59

Describe the blood supply to the adrenals

Answer 59

Rich blood supply from the adrenal arteries which arise from the inferior phrenic vessels, aorta and renal arteries

Question 60

How many suprarenal veins are their?

Answer 60

One on each side

Question 61

Where does the right suprarenal vein drain into?

Answer 61

IVC

Question 62

Where does the left suprarenal vein drain into?

Answer 62

Left renal/left inferior phrenic vein

Question 63

The adrenal cortex is decided into three distinct zones; what are they?

Answer 63

Outer - zona glomerulosa (thin) Middle - zone fasciculata (thick) Inner - zona reticularis (adjacent to the medulla)

Question 64

What cells populate the adrenal medulla and what do they secrete?

Answer 64

Large ovoid chromaffin cells that secrete adrenaline and noradrenaline

Question 65

Name the three hormone types secreted from each of the three layers of the adrenal cortex

Answer 65

Mineralocorticoids - ZG Glucocoirticoids - ZF Androgens - ZR

Question 66

Describe the peritonisation fo the pancreas

Answer 66

All retroperitoneal except for the tail

Question 67

How do you differentiate the endocrine and exocrine parts of the pancreas histologically?

Answer 67

Islets of Langerhans are large, lightly stained clusters of cells

Question 68

What cell types are found in the Islets of the pancreas?

Answer 68

alpha cells - glucagon beta cells - insulin delta-cells - somatostatin