Endocrine Reviewer ni mam

• Hormones(proteins)affect only certain

  tissues or organs
• Target cells must have specific protein

  receptors
• Pituitary Gland - Hangs by a stalk from the hypothalamus
• Anterior pituitary (Adenohypophysis) - glandular tissue
• Posterior pituitary (Neurohypophysis) – pars nervosa (nervous tissue)
• Pituicytes: glial cells
• Axons of neuronal cells from the supraoptic and paraventricular nuclei of the hypothalamus
• Herring bodies( neurosecretory bodies)
• Oxytocin: contraction of smooth muscles in uterus and lactiferous glands
• Antidiuretic hormone (ADH): decreases urine formation
• Pinealocytes - main cell modified neurons; 95%
• Pinealocytes - poorly defined borders & basophilic cytoplasm &

  processes; secretes Melatonin
• Interstitial cells(glial cells )-5%; elongated nuclei

  w/ condensed chromatin processes;
• Interstitial cells(glial cells )-considered as

  astrocytes
• Brain sand (Acervulus, psammoma bodies,corpora arenacea)
• Brain sand - Elaborate melatonin
• MELATONIN: Normal level has diurnal pattern
• Pineal Gland: pinealocytes, Corpora arenacea or

  brain sands , astrocytes
• Thyroid Gland- found at the base of the throat
• •Thyroid hormone – T3 (Triiodothyronine) & T4 ( Levothyroxine )
• Calcitonin; decreases the blood calcium levels by deposition of calcium in the bones
• •Thyroxine (T4) – secreted by thyroid follicles
• Triiodothyronine (T3) – conversion of T4 at target tissues
• Follicular cells: squamous cells(hypoactive) to cuboidal cells (active), darkly stained produce T3,T4
• Parafollicular cells (C – cells): larger and lightly stain,

  produces Calcitonin
• Parathyroid Glands- Tiny masses found posteriorly on the

  thyroid
• Parathyroid gland:

  1. chief or principal cells
  2. oxyphil cells
• Secrete parathyroid hormone: increases

  the blood calcium level thru the release

  of calcium from the bones
• Adrenal Gland ( Suprarenal)
• Cortex ( derived from mesoderm) – Zona: Glomerulosa, Fasciculata, Reticularis
• Medulla ( derived from neural crest)– Chromaffin cells
• Adrenal Cortex: 3 zones ( GFR)

  1. glomerulosa – 15 %
  2. fasciculata – 65 -80 %
  3. reticularis – 10 %
• glomerulosa - cells form arched

  clusters (glomeruli), closely packed columnar

  or pyramidal cells; mineralocorticoids,
• fasciculata – cells form straight

  cord of polyhedral cells filled with lipids

  droplets (fascicles) spongy or vacuolated;

  glucocorticoids and some androgens
• reticularis – cells in irregular cords (reticulum)interwoven with capillaries; glucocorticoids and androgens
• Adrenalin rush → fight or flight reaction
• Pancreatic Islets- The islets of the pancreas
• Pancreatic Islets

  1. Alpha(A-cells) – peripheral
  2. Beta(B-cells)- central
  3. Delta(D-cells) – somatostatin
  4. F(PP cells) – pancreatic polypeptide,
• Pancreatic Islets: secretion

  Alpha(A-cells) – non-ROH soluble granules; glucagon
• Pancreatic Islets: secretion

  Beta(B-cells) – ROH soluble granules; insulin,