Signaling molecules released by secretory cells of endocrine glands.

Types of Hormone Secretion:

The pituitary gland is composed of:

Anterior Pituitary Gland

• 75% of the Adenohypophysis • Two broad groups of cells based on staining affinity.

Chromophils

Acidophils

Basophils

Degranulated Cells

Stimulates growth in epiphyseal plates of long bones via insulin-like growth factors (IGFs) produced in liver

Promotes milk secretion

FSH promotes ovarian follicle development and estrogen secretion in women and spermatogenesis in men; LH promotes ovarian follicle maturation and progesterone secretion in women and interstitial cell androgen secretion in men

Stimulates thyroid hormone synthesis, storage, and liberation

• Stimulates secretion of adrenal cortex hormones • Helps regulate lipid metabolism

• Funnel – shaped region surrounding the infundibulum of the neurohypophysis • Most cells are basophilic gonadotrophic cells that secrete Follicle Stimulating Hormone (FSH), Luteinizing Hormone (LH)

• Thin zone of basophilic cells • Melanocyte Stimulating Hormone • Endorphin

acts on all body tissues, especially cartilage, bone, muscle, and adipose connective tissue to stimulate growth.

acts on the adrenal cortex to cause release of corticosteroids (eg, cortisol).

act on gonads (testes and ovaries) to stimulate development of gametes (sperm and oocyte)

acts on mammary glands to stimulate milk production.

stimulates the thyroid gland to release thyroid hormone (TH).

• Vasopressin or Antidiuretic hormone (ADH) • Response to increased tonicity of the blood • increased permeability of the collecting ducts of the kidney to water. As a result, more water is absorbed & replaced into blood instead of being eliminated in the urine.

• Oxytocin • Stimulates contraction of the myoepithelial cells around the alveoli & ducts of the mammry glands & of uterine smooth muscle during child birth.

are each covered by a dense connective tissue capsule that sends thin trabeculae into the gland’s parenchyma.

Adrenal glands are each covered by

The stroma consists in adrenal glands mainly of __________ supporting the secretory cells and microvasculature.

Adrenal Glands: Yellowish Peripheral Layer:

Adrenal Glands: Reddish Brown Central Layer:

Adrenal Cortex

Mineralcorticoids: affect the uptake of Na, K, H2O – Principal Product: Aldosterone – Controlled by Angiotensin II

- Glucocorticoids: Cortisol (GLUCONEOGENESIS, GLYCOGENOLYSIS) – Controlled by ACTH

Also produce cortisol but primarily secrete weak androgen.

The Adrenal Medulla contains many electron-dense granules for hormone storage & secretion.

are released to the blood in large quantities during intense emotional reactions, such as fright & produce vasoconstriction, increase BP, changes in heart rate & metabolic effects such as increase blood glucose.

" Fight or Flight Response” ▪ Normal Activity = small quantities of the hormone

Located in the cervical region anterior to the larynx, consists of 2 lobes united by an isthmus.

Thyroid Gland composed of millions of rounded epithelial structures called

Each follicle of the thyroid gland consists of a simple epithelium and a central lumen filled with a gelatinous substance called

Thyroid colloid contains the large glycoprotein _________, precursor for the active thyroid hormones

major regulator of the anatomic & functional state of thyroid follicles.

As we grew older: Cells ->

transitional derivatives of principal cells.

filled with secretory granules containing (PTH), major regulator of blood calcium levels.

Are compact spherical/ egg-shaped masses of endocrine tissue embedded within the acinar exocrine tissue of the pancreas.

Islet Cell

• Located in the posterior extremity of the third ventricle of the brain. ▪ Regulates the daily rhythms of bodily activities

most prominent and abundant secretory cells of the pineal gland

Pineal Gland: BRAIN SAND