anatomy and histology of endocrine system

Question 1

What is the overall structure of endocrine glands

Answer 1

The functional unit is made up of cuboidal secretory cells with a lumen at the centre

secretory cells supported by myoepithelial cells

not all endocrine functional units have a lumen e.g. pituitary and parathyroid glands

Question 2

What are some clinical manifestations of endocrine diseases

Answer 2

Hormone over/under production

tumour/ mass lesion which can be :

• non functional—> pressure effect
• associated with the overproduction of hormones

Question 3

What are the 2 lobes of the pituitary gland

Answer 3

Adenohypophysis/ anterior lobe

neurohypophysis/ posterior lobe

Question 4

name the cells of the adenohypophysis that take up stains and its staining pattern

Answer 4

Acidophils- takes up acidic dyes
basophils- takes up basic dyes
chromophobe- no specific staining features

Question 5

name cells from the adenohypophysis

Answer 5

somatotroph, lactotroph, corticotroph, gonadotroph and thydrotrophs

Question 6

What hormone do somatotrophs make and what is its target organ

Answer 6

Growth hormone and the target is bones

Question 7

What hormone does lactotroph make and what is its target organ

Answer 7

prolactin and the target is breasts

Question 8

What hormone does gonadotroph make and what is its target organ

Answer 8

FSH, LH and the target is ovaries and testes

Question 9

What hormone do corticotrophs make and what is its target organ

Answer 9

ACTH and the target is adrenal glands

Question 10

What hormone do thydrotrophs make and what is its target organ

Answer 10

TSH and the target is the thyroid gland

Question 11

What are 2 hormones that are made in the neurohypophysis

Answer 11

ADH and Oxytocin

Question 12

What are 2 hormones that the thyroid gland makes

Answer 12

T4- thyroxine, T3- triiodothyronine
both of these stimulate metabolic rate

synthesis of both of these requires iodine, lack of iodine can lead to an enlarged thyroid gland (goitre), this is done to absorb max concentration of iodine.

Question 13

What are the chemical classifications of hormones

Answer 13

Steroid- e.g. testosterone
protein/ peptide- e.g. ADH, Oxytocin, insulin
amine- e.g. adrenaline, dopamine etc

Question 14

The hypophysis is suspended under the hypothalamus by what, where is the hypophysis located

Answer 14

by the infundibulum, located in the sella turcica

Question 15

Outline the blood supply to the hypophysis

Answer 15

2 vessels, branches of the int carotid
superior hypophyseal, supplies median eminence, the upper part of the infundibulum

inferior hypophyseal, supplies neurohypophysis, the lower part of the infundibulum

Question 16

Describe venous drainage in the hypophysis

Answer 16

Capillary plexuses in median eminence and infundibulum ending are drained by portal veins which pass to the adenohypophysis, the veins form a secondary cap plexus.

Question 17

Describe the structure of the thyroid gland, what controls it and its role

Answer 17

2 lobes, connected by an isthmus that courses anterior to the trachea, under control from hypothalamus and hypophysis,

the role in regulating tissue metabolism, growth and development

Question 18

What is the arterial supply to the thyroid

Answer 18

Superior thyroid artery (from external carotid) and inferior thyroid artery (from subclavian)

Question 19

What is the venous drainage of the thyroid

Answer 19

from an extensive plexus into the internal jugular vein and brachiocephalic vein.

Question 20

What are the parathyroid glands

Answer 20

4 parathyroid glands, 2 sup and 2 inf embedded in the capsule of the thyroid, posterior aspect on either side.

very small.

Question 21

What is the role of the parathyroid gland

Answer 21

secrete a parathyroid hormone which regulated calcium and phosphate level within homeostasis.

must be preserved during thyroidectomy, if removed then calcium levels fall, muscles, inc resp and laryngeal, go into tetanic contraction—-> death.

Question 22

Parathyroid hormone- VAN?

Answer 22

Vein: sup + med + inf thyroid
artery: primarily inf thyroid (also sup)
Nerve: from middle and inferior cervical ganglions

Question 23

What are the adrenal glands

Answer 23

Suprarenal glands, release hormones in response to stress, they are retroperitoneal.

capsule- secretes mineralcorticoids e.g. aldosterone
cortex- secretes adrenal androgens e.g. testosterone
deeper cortex- secretes glucocorticoids e.g. hydrocortisone.

Question 24

adrenal glands- blood supply and venous drainage

Answer 24

blood supplied by sup (inferior phrenic)
middle (from the aorta)
inferior suprarenal artery (renal)

venous drainage- adrenal veins which drain into IVC or renal veins

Question 25

What controls the adrenal glands

Answer 25

under control of the hypothalamus e.g. ACTH from hypophysis which stimulates the secretion and release of corticosteroids.