W5 - Endocrine System

Question 1

Why is the pituitary gland considered the ‘master gland’?

Answer 1

It can control the function of multiple other endocrine glands

Question 2

When staining the pituitary gland with H+E, which lobe of the PG stains darker?

Answer 2

Anterior PG

Question 3

How does the PP lobe and APG form from tissue growths?

Answer 3

PP lobe - downgrowth of nervous tissue from hypothalamus, APG - upgrowth from roof of primitive oropharynx

Question 4

What controls the pituitary gland?

Answer 4

The hypothalamus

Question 5

What 5 HMs produced by the PG act on non-endocrine tissues?

Answer 5

GH, ADH, PRL, OT, MSH

Question 6

What 4 HMs act on endocrine tissues?

Answer 6

TSH, ACTH, FSH and LH

Question 7

What are the thyroid, adrenal and gonad glands referred to as?

Answer 7

Pituitary-dependent endocrine glands

Question 8

THe PP lobe releases ADH and OT, where are these synthesised?

Answer 8

ADH - supraoptic nucleus, OT - paraventricular nucleus

Question 9

ADH and OT pass down the axons of the ??? within the pituitary stalk

Answer 9

Hypothalamo-hypophyseal tract

Question 10

Where are ADH and OT stored and what controls their release?

Answer 10

The axon terminals, nerve impulses from HT

Question 11

What wraps around the infundibular stalk?

Answer 11

Pars tuberalis

Question 12

What are Herring bodies?

Answer 12

Clusters of neurosecretory

Question 13

The APG has 3 divisions, what are these?

Answer 13

Pars distalis, intermedia and tubularis

Question 14

What is the difference between PP lobe and APG?

Answer 14

PP - only stores HMs, no production, APG - can produce and secrete HMs

Question 15

The APG have two main cell types, when staining with H+E, which stains darker and which stains lighter?

Answer 15

Darker - chromophils, Lighter - chromophobes

Question 16

What are the two types of chromophil cells?

Answer 16

Acidophils and basophils

Question 17

THe pars intermedia is derived from remnants of Rathke’s pouch and is located between the AP and PP, what cells is it composed of?

Answer 17

Basophilic cells

Question 18

What does the pars intermedia consist of?

Answer 18

Cysts filled with colloid that are lined by cuboidal epithelium

Question 19

What controls the thyroid gland and what two hormones are produced/secreted by the HT and by the APG?

Answer 19

The hypothalamus, thyrotropin releasing HM (HT) and thyroid stimulating HM (APG)

Question 20

What is the spheroidal, basic unit of a thyroid gland and what type of epithelium lines these?

Answer 20

Follicle, cuboidal epithelium

Question 21

Follicles are filled by colloid, what divides the thyroid gland into lobules?

Answer 21

Fibrous sepate

Question 22

What are the two major HMs that are produced by the thyroid gland? (And what is another minor HM produced?)

Answer 22

T3 and T4 (Calcitonin for Ca2+ homeostasis)

Question 23

T3 and T4 regulate metabolic functions, what are the 3 things that they can do?

Answer 23

Controls how quickly the body burns energy, makes proteins and how sensitive the body is to other HMs

Question 24

When the thyroid gland is inactive, what happens to the follicles and epithelial cells?

Answer 24

Follicles - stain darker (colloid containing), epithelial cells become flattened

Question 25

When the thyroid gland is active the epithelial cells become taller and the follicles stain paler with scalloped edges, why does it stain paler?

Answer 25

More cytoplasm is produces alongside the colloid

Question 26

Calcitonin is produced by parafollicular C cells, how are these seen?

Answer 26

Small clumps in between follicles

Question 27

Calcitonin is the physiological antagonist of parathyroid HM, what does it do?

Answer 27

Lowers blood calcium

Question 28

Parathyroid glands are thin and closely related to the posterior surface of the thyroid, what two cells are found in the parathyroid gland?

Answer 28

Chief cells and oxyphil cells

Question 29

Chief cells are small with dark nuclei, what is the difference between the cytoplasm of chief cells and of oxyphil cells? (+ what do they do?)

Answer 29

Chief - pale (secrete PTH), oxyphil - very pink (not secretory, mainly just structural)

Question 30

What is the main function of parathyroid HM?

Answer 30

Regulate levels of calcium, phosphorus and magnesium