Function
• Influences growth, metabolism, and homeostasis over prolonged periods
• Secretes hormone products into interstitial spaces which are then absorbed into the blood and transported throughout the body
• Hormonal control is much slower than nervous control, but the effects of the endocrine system are much longer lasting
Key Features of Endocrine Glands
• A rich capillary blood supply is necessary for secretion and reception of hormones
• Endocrine glands are, by definition, ductless
• Organelles required to synthesize specific hormones are in great supply

Amino Acid Derivatives
• Hormones derived from the amino acid tyrosine
• Epinephrine, norepinephrine, and thyroxine
Polypeptide Hormones
• Hormones with a peptide structure
• Insulin, prolactin, NGF, EGF, GH, PTH, TSH, enkephalin, TRH, ADH
Steroids
• Hormones derived from cholesterol
• Testosterone, cortisol, aldosterone, progesterone, estradiol

• Controlled by hypothalamus
• Infundibulum serves as a communication channel between the hypothalamus and pituitary
• The hypothalamohypophyseal neural tract is the passageway for two hypothalamic hormones to the posterior pituitary
• The hypothalamohypophyseal portal system carries hypothalamic hormones that regulate secretion from the anterior pituitary
• The anterior pituitary secretes hormones that regulate lactation, metabolism, growth, stress response, and reproduction

A: Adenohypophysis ( anterior pituitary ):
1. Pars distalis .
2. Pars intermedia
3. Pars tuberalis
B: Neurohypophysis ( posterior pituitary ):
1. Infundibulum
2. Pars nervosa
B
A

D
E
C
B
A

A: Chromophobes
B: Basophilic chromophils
Gonadotrophs – FSH and LH
Corticotrophs – ACTH
Thyrotrophs – TSH
C: Acidophilic chromophils
Somatotrophs – GH
Mammotrophs – Prolactin

C
A
B

A: Pituicytes
H: Herring Bodies
A

Fill in the missing hormones secreted from the pituitary or list their respective functions
Hormone
FSH
LH
ACTH
TSH
GH
Prolactin
ADH
Oxytocin
Function
Follicle maturation and spermatogenesis
Causes follicle maturation and testosterone production in leydig cells
Stimulates adrenal cortex
Stimulates T3 and T4 secretion from thyroid
Controls growth
Stimulates mammary glands
Stimulates water resorption
Smooth muscle contraction and milk letdown

A: Follicular cells
B: Parafollicular cells
4
A
B

A: Adipose tissue.
C: Capillaries
P: Principal or chief cells
O: Oxyphil cells

A
B

A
B

A: Islets of Langerhans contain four different cells:
1. α-cells
2.
β-cells
3. δ-cells .
4. PP – cells
A

Gastrin or G-cells
A: Parietal cell.
B: Chief cell.
A
B

A: Zona glomerulosa
B : Zona fasciculata
C: Zona reticularis
D: Medulla
A B C D

• Neuroendocrine tumor of the adrenal medulla
• Results in excessive secretion of catecholamines
• Diagnosed by measuring plasma or urine levels of catecholamines
Source: http://en.wikipedia.org/wiki/Pheochromocytoma

A: Argentaffin cells
B: Central Lacteal
A
B

Know the following hormones, where they are secreted, their function, and target organ.
Anterior Pituitary
FSH
LH
ACTH
TSH
GH
Prolactin
Thyroid
T3 and T4
Calcitonin
Parathyroid
PTH
Stomach
Gastrin
Adrenal
Aldosterone
Cortisol
DHEA
Posterior Pituitary
ADH
Oxytocin
Pancreas
Glucagon
Insulin
Somatostatin
Pancreatic Peptide
Argentaffin Cell
CCK
Secretin
Serotonin