Endocrine Anatomy

Question 1

How is the optic chasm related to the pituitary gland?

Answer 1

Superior to it

Question 2

Which fibres from the optic nerve, nasal or temporal, cross over to the opposite side at the optic chiasm?

Answer 2

nasal

Question 3

What is the visual field defect caused by enlargement of the pituitary gland?

Answer 3

Bitemporal hemianopia

Question 4

How is the pituitary gland connected to the hypothalamus?

Answer 4

By the pituitary stalk

Question 5

What two parts for the pituitary gland?

Answer 5

Anterior lobe (pars anterior/adenohypophysis) and the posterior lobe (pars nervosa/neurohypophysis)

Question 6

What is the space which sits above the pituitary gland and behind the optic chiasm?

Answer 6

3rd ventricle

Question 7

What lies between the anterior and inferior lobes of the pituitary gland?

Answer 7

Intermediate lobe

Question 8

Which of the two lobes in the pituitary gland is larger?

Answer 8

Anterior lobe

Question 9

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

Answer 9

Anterior lobe

Question 10

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

Answer 10

Releases ADH and oxytocin (non-tropic)

Question 11

How does the hypothalamus connect with each of the lobes of the pituitary?

Answer 11

• Posterior -> via pituitary stalk neurons

* Anterior -> the release of neurotransmitters into the bloodstream via the hypothalamo-hypophysial portal system

Question 12

What are the three cell types found in the anterior pituitary and what is the effect on histological staining?

Answer 12

Acidophils and basophils
• Acid -> stains pink
• Baso -> stains purple

Also has chromophores (don’t take up much stain and therefore appear pale)

Question 13

What are the functions of chromophils in the pituitary gland (acidophils and basophils)?

Answer 13

Divided into different classes of cells which have different secretory products and target organs

Question 14

What are the two classes of acidophil cells in the anterior pituitary and what hormones do they release?

Answer 14

1. Somatotrophs -> releases GH (or somatotrophin)

2. Mammotrphic -> prolactin: milk producting tissue

Question 15

What is the function of GH (or somatrophin)

Answer 15

To chondrocytes in epiphyseal plate to promote growth (with insulin like growth factors)

Question 16

What are the three classes of basophil cells in the anterior pituitary?

Answer 16

1. Corticosteroids:
   
   • Adrenocorticotrophic hormone (ACTH): promotes activity in corticosteroid cells in adrenal cortex
   • Melanocyte-stimulating hormone (MSH): to melanocytes
2. Thyrotrophs -> Thyroid stimulating hormone (TSH): to follicular epithelial cells of thyroid
3. Gonadotrophs
   
   • Follicle stimulating hormone: to ovaries and testes
   • Lutenising hormone: promotes ovulation or promoted androgen secretion in testes

Question 17

What are the main type of secretory cells of the posterior pituitary?

Answer 17

Non-myelinated, neurosecretory cells

Question 18

What artery supplies the posterior pituitary?

Answer 18

Inferior hypophyseal artery

Question 19

What veins drain the pituitary gland?

Answer 19

Hypophyseal veins into he cavernous sinus

Question 20

What is the level of the thyroid gland?

Answer 20

C5-T1

Question 21

At which tracheal ring is the isthmus of the thyroid gland?

Answer 21

2nd- 4th

Question 22

What is the first branch of the ECA?

Answer 22

Superior thyroid artery

Question 23

What are the three thyroid veins?

Answer 23

Superior -> drains to IJV
Middle -> IJV
Inferior -> brachiocephalic

Question 24

What three strap muscle overlie the thyroid gland?

Answer 24

Sternohyoid
Omohyoid
Sternothyroid

Question 25

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

Answer 25

1. Recurrent laryngeal nerve - runs between trachea and oesophagus 2. Superior laryngeal nerve - lies close to superior thyroid artery

Question 26

What does the recurrent laryngeal nerve supply?

Answer 26

Sensory: lower half pharynx, upper trachea and oesophagus Motor: all muscle of larynx, smooth muscle of trachea and oesophagus

Question 27

What does the external layrngeal nerve (branch of superior laryngeal nerve) supply?

Answer 27

Cricothyroid muscle

Question 28

Where do most lymph vessels from the thyroid gland drain into?

Answer 28

The deep cervical group

Question 29

How are hormone of the thyroid gland stored?

Answer 29

In cavities, surrounded by secretory cells --> follicle Within the cavity of a follicle, hormone is bound to a glycoprotein --> forms the colloid

Question 30

What happens to the hormone in the follicle of a thyroid gland during secretion?

Answer 30

Hormone is re-absorbed from the city (colloid) and then released into surrounding interstitial spaces

Question 31

What cells line the follicles in the thryoid gland?

Answer 31

Simple cuboidal epithelium

Question 32

What colour does the colloid in a thyroid follicle stain?

Answer 32

Pink

Question 33

What type of cell is found scattered among follicular cells in the thyroid and what is their function?

Answer 33

Clear/parafollicular/ C cells -> secrete calcitonin in response to increased levels of plasma Ca

Question 34

What hormones does the thyroid gland secrete?

Answer 34

Tri-iodo thyronin and thyroxine

Question 35

Where are the parathyroid glands located?

Answer 35

On the lateral half of the posterior surface of each thyroid lobe, external to the thyroid fibrous capsule. Most people have 4. They are separated from the thyroid gland by a thin fibrous capsule.

Question 36

Describe the position of the superior and inferior parathyroid glands

Answer 36

Superior are situated at level of inferior border of cricoid cartilage. Inferior are near the inferior poles of the thyroid (position variable)

Question 37

Describe the blood supply to the parathyroid glands

Answer 37

Inferior thyroid arteries | Venous drainage via veins draining the thyroid to the IJV

Question 38

What are the two cell types found in the parathryroid glands?

Answer 38

Chief cells and oxyphil cells

Question 39

What hormone is secreted by the parathyroid gland and what is the action of it?

Answer 39

Parathyroid hormone (PTH) - acts osteoclasts, and the epithelial cells of the renal tubule, to increase plasma Ca by promoting bone respiration and increases renal calcium resorption

Question 40

What are the suprarenal glands?

Answer 40

Pair of endocrine glands on upper pole of each kidney which are enclosed in and separated from the kidney by means of a capsule.

Question 41

How are the suprarenal glands peritonised?

Answer 41

Retroperitoneal

Question 42

What are the two parts to the suprarenal glands?

Answer 42

The outer cortex and inner medulla

Question 43

What is the embryological origin of the suprarenal cortex and medulla?

Answer 43

Mesodermal epithelium gives rise to the cortex and neuroectoderm gives rise to the medulla

Question 44

What is the blood supply to the suprarenal glands?

Answer 44

* Superior adrenal aa - from inferior phrenic aa * Middle adrenal aa - from abdominal aorta * Inferior adrenal aa - from renal arteries

Question 45

What is the venous drainage from the suprarenal glands?

Answer 45

* R side -> IVC | * L side -> L renal vein -> IVC

Question 46

What are the three distinct zones of the cortex of the suprarenal glands?

Answer 46

1. Outer zona glomerulosa (thin) 2. Middle Zona fasciculata (thick) 3. Inner zona reticularis (immediately adjacent to the medulla)

Question 47

What is the function of the medulla of the suprarenal gland?

Answer 47

It has collections of large ovoid chromatin cells which secrete adrenaline and noradrenalin

Question 48

What are the 3 main hormone types secreted from each of the 3 zones of the suprarenal gland cortex?

Answer 48

* Z Glomerulosa - Mineral corticoids (aldosterone) * Z Fasciculata - Glucocorticoids (cortisol) * Z Reticularis - sex hormones

Question 49

What cells are found in a pancreas Islet of langerhans and what do they produce?

Answer 49

* Beta cells - insulin * Alpha cells - glucagon * Delta cells - somatostatin

Question 50

What are the different parts to the pancreas?

Answer 50

Exocrine part (pancreatic acini) and endocrine part (Islet of Langerhans: light staining)