Endocrine Histology

Question 1

What do ovarian follicles do?

Answer 1

They produce estradiol prior to menstruation and progesterone afterwards.

Follicle produces inhibin which prevents release of FSH.

Question 2

What do the testes produce?

Answer 2

Interstitial cells between seminiferous tubules secrete testosterone.

Sustentacular cells secerete inhibin which slow FSH release

Question 3

What hormones do the following organs secrete as part of their endocrine function? Heart, Kidneys, Liver, Stomach, Small intestine, Placenta

Answer 3

Heart = ANF

Kidneys = calcitriol, EPO

Liver = Somatomedins, EPO, angiotensinogen

Stomach + small intestine = enteric hormones that coordinate activity of GIT

Placenta = hormones that regulate pregnancy and prime the mammary glands

Question 4

What cell bodies does the thyroid gland contain? What happens to these cells in hypothyroidism?

Answer 4

Colloid bodies surrouinded by cuboidal cells

In hypothyroidism the colloid bodies are smaller and more cuboidal cells are present. (Due to production of T3 and T4)

Question 5

Where is the pituitary gland located?

Answer 5

In the sella turcica

Question 6

What is the pituitary made of embryologically?

Answer 6

Part of the gut (endoderm) and part of the brain (neural tube)

For this reason the anterior (glandular adenohypophysis) and posterior (Neurohypophysis) pituitary glands are different.

Question 7

What is a common consequence of sites where 2 embryological tissues come together?

Answer 7

Cancer often develops in these areas (eg pituitary cancers)

Question 8

What are the components of the posterior pituitary?

Answer 8

Paris nervosa containing herring body and pituicytes

Infundibulum stalk containing hypothalamic-hypophyseal tract

Question 9

What are the components of the anterior pituitary gland?

Answer 9

Pars distalis containing the chromophils which are the secretory cells. (Acidophilic cells secrete GH and prolactine whereas basophils secrete FSH, LH, and ACTH)

Pars intermedia (Mostly basophils which secrete MSH)

Pars tubularis

Question 10

What makes up the thyroid glands functional units?

Answer 10

Thyroid follicles which produce T4 and T3. These follicles surround colloid bodies which contain stores of prethyroid or thyroid hormones to produce T3 and T4.

Question 11

What do parafollicular cells (aka C cells) do?

Answer 11

They produce calcitonin hormone which lowers calcium levels.

Question 12

What is the parathyroid gland made up of?

Answer 12

4 small ovoid masses located on the back of the thyroid gland.

Question 13

What cells produce parathyroid hormone?

Answer 13

Principal (chief) cells of the parathyroid gland.

Question 14

What is the function of oxyphil cells?

Answer 14

Unknown function. They have long mitochondria

Question 15

What are the 3 layers of the adrenal cortex?

Answer 15

Zona glomerulosa (secretes mineralocorticoids (aldosterone))

Zona fasciculata (secretes glucocorticoids (corticosterone and cortisol)

Zona reticularis (secretes gonadocorticoids)

Question 16

What cells make up the adrenal medulla? What do these cells do?

Answer 16

Chromaffin cells which are modified sympathetic postganglionic neurons

These secrete catecholamines

Question 17

How are cells arranged in the pancreas?

Answer 17

Endocrine components (islets of langerhan) are located amongst the exocrine components.

3 types of cells secrete hormones to regulate blood glucose (A, B, and D cells)

Question 18

What are the components of the ovaries?

Answer 18

Cortex consists of follicles of varying size and medulla contains connective tissue and blood vessels.

Question 19

What hormones are released by the cells of the ovary?

Answer 19

Corpus luteum produces progesterone and estradiol

Growing ovarian follicle produces estradiol

Question 20

What do the testes do?

Answer 20

Produce sperm and testosterone.

Question 21

How are the testes functionally divided?

Answer 21

Into lobules, each lobule has 1 - 4 highly convoluted seminiferous tubules.

Seminiferous tubules are lined with epithelium which consists of spermatogenic and sertoli cells.

Each lobule contains sparse connective tissue with leydig cells that secrete testosterone.

Question 22

What happens to thymus gland after puberty?

Answer 22

It shrinks and is replaced by fat

Question 23

What happens in the thymus gland?

Answer 23

T lymphocytes mature.

Question 24

What are hassal corpuscles?

Answer 24

Unknown function found in larger amounts in older people

Question 25

Where is the pineal gland located?

Answer 25

Lies in midline of the brain just below the posterior end of the corpus callosum

Question 26

What is the function of the pineal gland?

Answer 26

Contains penealocytes which are responsible for the production of melatonin.

Question 27

What do the corpora amylacea do?

Answer 27

Corpora amylacea is a characteristic feature of the ageing pineal body. (aka brain sand)