Histology

Question 1

Answer 1

Question 2

anterior pituitary

Answer 2

adenohypophysis, made up of the pars distalis, pars intermedia, and pars tuberalis

embryonically from an outgrowth of endoderm called Rathke’s pouch

Question 3

posterior pituitary

Answer 3

pars nervosa (or infundibular process), the infundibular stem or stalk, and the median eminence

really an extension of the brain (the hypothalamus)

antidiuretic hormone (ADH, vasopressin) and oxytocin, are released from the ends of axons that arise from cell bodies of neurons present in the hypothalamus

pituicytes, which are supportive astrocyte-like glial cells

axons expand into bulbous structures that contain neurosecretory vesicles (Herring’s bodies)

Question 4

Pars Distalis

Answer 4

cells that synthesize and release hormones

Somatotrophs (GH)

Lactotrophs (PRL)-

Gonadotrophs (FSH, LH)

. Corticotrophs (ACTH)

Thyrotrophs (TSH)

extensive vasculature of small vessels/capillaries/sinusoids = rapid release into bloodstream

Question 5

Pars Tuberalis and the hypophyseal portal system

Answer 5

collar of cells around the infundibular stalk contains blood vessels that lead from capillaries of the median hypothalamic eminence to small vessels/capillaries of the pars distalis

capillaries deliver regulatory peptides from hypothalamic neurons (TSH-RH, GNRH, CRH, GHRH)

Question 6

Pars Intermedia

Answer 6

poorly developed in humans, consisting of colloidal cysts.

Some of the cells are positive for corticotrophic hormones such as melanocyte stimulating hormone (MSH)

Question 7

Adrenal Cortex

Answer 7

produces and releases various steroids

from outer to inner cortex layers as zones: the zona glomerulosa, the zona fasciculata, and the zona reticularis

Question 8

Zona glomerulosa

Answer 8

mineralocorticoids, most notably aldosterone

regulated through the angiotensin system

Question 9

Zona fasciculata

Answer 9

glucocorticoids such as cortisol

rich in large lipid droplets

controlled by ACTH

Question 10

Zona reticularis

Answer 10

Androgens of modest potency

controlled by ACTH

Question 11

Adrenal Medulla

Answer 11

contains epinephrine (adrenalin) and norepinephrine (noradrenalin) producing cells

arranged as clusters around venous channels/sinusoids that drain toward the central medullary vein

Enkephalins and chromogranins are also released

Question 12

Thyroglobulin

Answer 12

large protein rich in tyrosine residues, which are the sites of iodination and modification to generate the thyroid hormones

TSH stimulates synthesis = more release thyroid hormones

Question 13

Thyroid

Answer 13

multi-lobed gland comprised of a series of follicles, each having a single layer of epithelial cells surrounding a central chamber referred to as the colloid

Question 14

“C” cells

Answer 14

secretory granules containing calcitonin - decreases release of calcium from bones

Question 15

Parathyroid Glands

Answer 15

4 to 8

Chief cells, which produce parathyroid hormone - increases osteoclast release of calcium from bone, and increases calcium uptake

Oxyphil cells (unknown)

Adipose cells

Question 16

Answer 16

Adrenal Gland

Question 17

Answer 17

Thyroid

A - Colloid

B - Clear/parafollicular cells

C - Follicular cells

Question 18

Answer 18

Parathyroid

A - RBCS

B - Parathryoid cells