Endocrine- Anterior Pituitary

Question 1

Anterior Pituitary

Answer 1

Periventricular and Arcuate nuclei of the hypothalamus regulate the ant pituitary through a portal venous system
- INDIRECT COMMUNICATION
- so dependent on hypothalamus that it is not transplantable.

Question 2

Hypophyseal Portal System

Answer 2

The hypothalamus secretes releasing/ inhibiting factors that indirectly communicate with the anterior pituitary. Anterior pituitary secretes trophic factors to target organs
+ hypothalamic region-> primary plexus of hypophyseal portal -> anterior pituitary-> secondary plexus of hypophyseal portal -> systemic circulation

Question 3

Thyroid Gland/ Anterior Pituitary Pathway

Answer 3

1. Hypothalamus: releases Thyrotropin-releasing hormone
2. Anterior Pituitary: releases thyroid stimulating hormone
3. Systemic Circulation
4. Thyroid Gland: releases thyroid hormone

Question 4

Thyroid gland (anatomy)

Answer 4

located in anterior neck
Blood supply: superior and inferior thyroid arteries (4 arteries, 6 veins)

Question 5

T3/4 Hormones

Answer 5

Produced by thyroid gland from follicular cells
T4: 4 iodines, major form in circulation
T3: 3 iodines, active form controls metabolism

Question 6

Calcitonin

Answer 6

Produced by thyroid gland from parafollicular cells
- lowers blood Ca++, controlled by the levels of Ca++ NOT pituitaru

Question 7

Suprarenal Gland/ Anterior Pituitary

Answer 7

1. Hypothalamus: Corticotropin-releasing hormone
2. Anterior Pituitary: Adrenal corticotropic hormone
3. Suprarenal Gland: Glucocorticoids androgens

Question 8

Suprarenal/ Adrenal Glands (anatomy)

Answer 8

Superior aspect of kidney
BLOOD SUPPLY
Superior: branch of inferior phrenic
Middle: Branch of aorta
Inferior: Branch of renal artery

Question 9

Suprarenal Gland Secretions

Answer 9

Aldosterone: Zona Glomerulosa
Cortisol: Zona Fasciculata
Dehydroepiandrosterone (DHEA)/ Androstenedione: Zona Reticuaris

Question 10

Ovaries/ Anterior Pituitary

Answer 10

1. Hypothalamus: Gonadotropin-releasing hormone
2. Anterior Pituitary: Follicle stimulating hormone/ luteinizing hormone
3. Ovaries: estrogen and progesterone

Question 11

Ovaries (anatomy endocrine)

Answer 11

Within the pelvis
Blood Supply: Ovarian (gonadal) artery
- produces estrogen and progesterone

Question 12

Testes/ Anterior Pituitary

Answer 12

1. Hypothalamus: Gonadotropin releasing hormone
2. Anterior Pituitary: FSH/ LH
3. Testes: testosterone via leydig cells

Question 13

Testes (anatomy endocrine)

Answer 13

Located in scrotum
Blood Supply: Testicular (gonadal) artery

Question 14

Mammary Gland/ Anterior Pituitary

Answer 14

1. Hypothalamus: dopamine, prolactin releasing hormone
2. Anterior Pituitary: Prolactin
3. Mammary Glands: milk secretion

Question 15

Liver/ Anterior Pituitary

Answer 15

1. Hypothalamus: Growth releasing hormone, somatostatin
2. Anterior Pituitary: Growth hormone
3. Liver: IGF-1 (insulin like growth factor 1, stimulates cell division and overall growth)

Question 16

Pancreas

Answer 16

Endocrine pancreas, Pancreatic Islets
- Alpha Cells-> Glucagon: raises blood glucose
- Beta Cells-> Insulin: lowers blood glucose

Question 17

Parathyroid glands

Answer 17

raise ca++, embedded within thyroid gland

Question 18

Parathyroid Hormone

Answer 18

Regulates circulating Ca++, increases bone release of Ca++, Stimulates formation of Vit D, Increases reabsorption of Ca++ from kidney

Question 19

Pineal Gland

Answer 19

Part of epithalamus, dorsal + posterior to thalamus
- secretes melatonin
Suprachiasmatic Nucleus: Receives input from retina, mediates circadian rhythms

Question 20

Abdominal Fat

Answer 20

Secretes leptin, adipokines
- likely involved in metabolic syndrome and inflammation