Endocrine micro anatomy

Question 1

What is an Endocrine gland?

Answer 1

No connection to epithelial surface and release products into blood stream so high vascular network

Question 2

What is an Exocrine gland?

Answer 2

maintain contact with surface and secrete directly into surface

Question 3

What tissue does the posterior and anterior pituitary grow from?

Answer 3

Posterior = neural tissue (downward invagination of brain)
Anterior = buccal cavity (cheek of mouth), connection to mouth breaks off

Question 4

What is the invagination of the buccal cavity to form the anterior pituitary called?

Answer 4

Rathke’s pouch

Question 5

What is the part of the sphenoid bone that the pituitary glands sits in called?

Answer 5

Sella Turcica

Question 6

What is the division between the anterior and posterior pituitary called?

Answer 6

Pars Intermedia (technically part of anterior lobe)

Question 7

What is the connection between the hypothalamus and posterior pituitary called

Answer 7

Infundibulum

Question 8

What is the sheath which forms around the infundibulum called?

Answer 8

Pars Tuberalis

Question 9

What are the three parts of the anterior pituitary?

Answer 9

• Pars Tuberalis
• Pars intermedia
• Pars Distalis

Question 10

What are the two parts of the posterior pituitary?

Answer 10

• Pars Nervose

- Infundibular stalk

Question 11

What cells make up posterior and anterior pituitary?

Answer 11

Posterior = neurones (doesn't make its own cells)
anterior = glandular cells (makes its own cells)

Question 12

What are the two types of cells which can be seen on staining of the anterior pituitary?

Answer 12

Chromophils (brightly stained)

Chromophobes (Pale staining)

Question 13

What are the two types of chromophils?

Answer 13

Basophils (stained darker so more granular content)

Acidophils (stained red, less mature versions of basophils)

Question 14

What are the five cell types of the anterior pituitary and what hormone do they secrete?

Answer 14

Somatotrophs - growth hormone 
Mammotrophs - prolactin
Corticotrophs - adrenocorticoids 
Thyrotrophs- thyroid-stimulating hormone
Gonadotrophs - FSH and LH

Question 15

Which which hormone do the nuclei in the hypothalamus secrete?

Answer 15

Supraoptic - ADH

Paraventricular - Oxytocin

Question 16

Where in the posterior pituitary are the hormones stored?

Answer 16

Herring bodies (dilations of the axon)

Question 17

Describe histology of posterior pituitary?

Answer 17

• Herring bodies - dilation of axon bodies
• Pituicytes - support cells
• highly vascular

Question 18

Where is the thyroid located?

Answer 18

anterior and lateral surface of trachea spanning from C5 to T1

Question 19

What is the structure of the thyroid?

Answer 19

• Two lobes connected by central band of thyroid tissue
• Highly vascular
• superior to parathyroid

Question 20

Where are the parathyroid glands and what do they do?

Answer 20

Four glands posterior to the thyroid which are needed for calcium regulation
- without which muscles would go into tectonic failure

Question 21

What are the cell types that make up the thyroid follicle?

Answer 21

Follicular cells (epithelial cells which surround lumen)
Parafollicular cells (also called C cells)

Question 22

What do Follicular cells do?

Answer 22

• Produce T3 and T4

- which regulate cell and tissue metabolic rate, heat production and influence body growth and Development

Question 23

What do Parafollicular cells do?

Answer 23

• Regulate calcium levels
• Calcitonin decreases blood calcium by decreasing reabsorption by osteoclasts and increasing bone formation by osteoblasts

Question 24

What is found in lumen of follicles?

Answer 24

Colloid which stores thyroglobulin and inactive T3 and T4

Question 25

What can amount of colloid tell you about the thyroid?

Answer 25

Lots of colloid = overactive thyroid

Little colloid = underachieve thyroid

Question 26

What hormone stimulates release of thyroid hormone from follicle?

Answer 26

TSH from thyrotrophs of anterior pituitary

Question 27

Describe location and structure of adrenal glands?

Answer 27

Location: embedded in perinatal fat superior to kidneys
Structure: central medulla surrounded by a cortex, adrenal glands are surrounded by a layer of connective tissue also

Question 28

What are the cells which make up the medulla?

Answer 28

Neural crest cells

Question 29

Describe cells of Zona Glomerulosa?

Answer 29

circular pyramidal or columnar cells which secrete aldosterone

Question 30

Describe cells of Zona Fasciculata?

Answer 30

Large columnar cells which contain lots of fat droplets (cholesterol) which secrete aldosterone so controlled by ACTH

Question 31

Describe cells of Zona Reticularis?

Answer 31

small netlike arrangement of cells which secrete androgens

Question 32

What is the GEP?

Answer 32

• Gastrointestinal Enteroendocrine Pancreatic system

- Clusters or individual endocrine cells (i.e. hormone secreting) within the GI or pancreas

Question 33

What are the four cells in the Islets of Langerhan?

Answer 33

Alpha secrete glucagon
Beta secrete insulin
Delta secrete somatostatin
F cells secrete pancreatic polypeptide

Question 34

Function of GEP cells?

Answer 34

Secrete hormones which control gut function

Question 35

Give examples of GEP cells?

Answer 35

Gastrin - stimulates gastric acid secretion
Cholecystokinin - stimulates gall bladder contraction
Motilin - stimulates gastric and intestinal motility
Secretin - stimulates pancreatic enzyme secretion and inhibits gastric acid secretion

Question 36

What blood vessel brings hypothalamic hormones to the anterior pituitary?

Answer 36

Superior hypophyseal artery

Question 37

What blood vessel brings Trophic hormones into the circulation?

Answer 37

Hypophyseal vein