Histology of Endocrine System

Question 1

Hypothalamus hormones directly targets what endocrine organs

Answer 1

Anterior pituitary
Kidney and uterus - ADH, oxytocin (stored in posterior pituitary and then released when necessary)
Adrenal medulla- via sympathetics

Question 2

Posterior pituitary stimulation

Answer 2

PP is comprised of axons from hypothalamus

These axons carry ADH and oxytocin for storage and release in the posterior pituitary

Question 3

Anterior pituitary structures

Answer 3

Pars tuberalis
Pars intermedia
Pars distalis

Question 4

Posterior pituitary structures

Answer 4

Infundibular stalk

Pars nervosa

Question 5

Somatotropic cells

Answer 5

Secrete growth hormone

Question 6

Corticotropic cells

Answer 6

Secrete ACTH and MSH

Question 7

Gonadotropic cells

Answer 7

Secrete FSH and luteinizing hormone (LH)

Question 8

Mammotropic cells

Answer 8

Secrete prolactin

Question 9

Cells of pars distalis

Answer 9

Acidfils -Somatotrophs, mammotrophs

Basophils- corticotrophs, thyrotrophs, gonadotrophs

Question 10

Pars nervosa

Answer 10

Does not manufacture hormones

Contains axons from cell bodies in the hypothalamus

Question 11

Hypothalamo-hypophyseal portal system

Answer 11

Hypothalamic neurons synthesize and release hormones into the primary capillary plexus
That blood is carried into the anterior pituitary by veins and enters another capillary bed, and the hormones are distributed in the anterior pituitary, which responds appropriately
There is no portal system for hormone distribution to the posterior pituitary

Question 12

Pineal gland

Answer 12

Out pocketing of diencephalons roof of third ventricle
Covered in pia mater
Role in growth, development and circadian rhythms
Synthesizes melatonin and serotonin
Contains calcium phosphate crystals which are an important radiological marker

Question 13

Thyroid hormone synthesis

Answer 13

Generated and stored extracellularly as thyroglobulin
Thyroglobulin synthesized in rER, glycosylated in Golgi and secreted
Iodinated at apical surface, forming T3/T4 bound to thyroglobulin
TSH stimulates release of T3/T4

Question 14

Parafollicular C cells

Answer 14

Secrete calcitonin when blood levels of calcium are high

Question 15

Graves disease

Answer 15

Abnormal Abs stimulated TSH receptors causing over secretion of T3/T4 - hyperthyroidism

Question 16

Zona glomerulosa of adrenal cortex

Answer 16

Releases aldosterone (mineralocorticoid)- targets kidney
Secreted in response to low blood pressure/volume
Controlled by renin-angiotensin system

Question 17

Zona fasciculata of adrenal cortex

Answer 17

Releases cortisol (glucocorticoid) in response to ACTH from anterior pituitary

Question 18

Zona reticularis

Answer 18

Releases androgens which influence secondary sex characteristics

Question 19

Addisons disease

Answer 19

Hyposecretory disorder in both glucocorticoids and mineralocorticoids
Blood glucose and sodium levels drop, severe dehydration and low blood pressure

Question 20

Cushing syndrome

Answer 20

Hypersecretion of glucocorticoids because of either ACTH secreting pituitary tumor or a tumor in adrenal cortex
High serum glucose, protein loss in muscles, muscle weakness, lethargy

Question 21

Pancreatic cells

Answer 21

Alpha cells- secrete glucagon
Beta cells- secrete insulin
Delta cells- secrete somatostatin- slows the release of insulin and glucagon
F cells- secrete pancreatic polypeptide which inhibits somatostatin release