Yasser is falling behind

Macro-anatomy of pituitary gland
1. location
  1. sella turcica (hypophyseal fossa) cavity within body of sphenoid bone housing pituitary gland, capsule of the gland is adherent to dura mater
  2. diaphragma sellae : fold of dura mater cover the superior aspect of pituitary, Extend b/t ant. & post clinoid processes,Forming roof to sella turcica
  3. infundibulum pierces the diaphragma sellae, connect the pituitary to the hypothalamus
2. Lobes
  1. Adenohypophysis (75% of total wt.) anterior lobe
    1. Vascular connection
    2. parts
      1. pars distalis
      2. Pars intermedia
      3. Pars tuberalis.
    3. supplied by superior hypophysial artery
  2. Neurohypophysis (posterior lobe)
    1. neuronal connection
    2. is directly connected to Supraoptic paraventricular nuclei of the hypothalamus
    3. supplied by inferior hypophysial artery
    4. parts
      1. Pars nervosa
      2. Median eminence
      3. Infundibulum
Histological Structure of Pituitary Gland
1. Neurohypophysis
  1. Unmyelinated nerve fibers
  2. pituicyte
  3. capillaries
2. Adenohypophysis
  1. cells of pars distalis
    1. Chromophobes
    2. Chromophils
      1. Acidophils
        somatotrophs
        mammotrophs
      2. Basophils
        gonadotrophs
        thyrotrophs
        corticotrophs
  2. cells of Pars Intermedia
    1. Basophil cells secrete MSH (melanocyte stimulating hormone).
  3. Cells of Pars tuberalis
    1. Cuboidal cells with Basophilic granules.
PATHOLOGY OF PITUITARY GLAND
1. Hypopituitarism
  1. Causes
    1. PITUITARY TUMORS
    2. Ischæmic necrosis of the pituitary gland
    3. PITUITARY APOPLEXY
    4. IATROGENIC HYPOPITUITARISM
    5. TRAUMA + INFILTRATIVE DISEASES
  2. pharmacological treatment 1-Somatropin 2-Mecasermin ..etc
2. Hyperpituitarism
  1. The most common cause of hyperpituitarism is an adenoma arising in the anterior lobe. Other, less common causes include hyperplasia and carcinomas of the anterior pituitary
  2. pharmacological treatment : 1. somatostatin receptor agonists (also known as somatostatin receptor ligands [SRLs] or somatostatin analogues), 2. dopamine analogues 3. GH receptor antagonists
3. Pituitary Adenomas
  1. Pituitary adenomas are benign neoplasms of the anterior lobe of the pituitary and are often associated with excess secretion of pituitary hormones treated by surgical resection, medical therapy, and radiation therapy.
physiology of hormones
1. 1-Amines: catecholamine, etc 2--Peptides/polypeptides: insulin,etc
  1. GROWTH HORMONE
    1. ACTIONS
      1. 1-The most dramatic effect of GH is stimulation of postnatal linear growth.2- Local production of IGF-1 3-GH stimulates lipolysis ,GH increases gluconeogenesis ,GH increases protein synthesis in muscle.etc.
    2. Control of GH Secretion
      1. Hypoglycemia ,Hyperglycemia ,exercise,Somatostatin Sex steroids ,sleep
    3. Assessment of GH
      1. 1-Insulin Stress Test. 2-Glucose Tolerance Test. 3-Measurement of IGF-1 to assess GH excess (not confirmative).
  2. Water-soluble ,Short half-life (minutes), Pulsatile secretion,Act on cell surface receptors Act via second messenger (cAMP, a rise in intracellular Calcium, or a receptor tyrosine kinase).
2. 3-Steroids: cortisol, etc
  1. Longer half-life (hours) Act on intracellular receptors Act on DNA to alter gene transcription

Siguiente

Yasser is falling behind

Descripción

Resumen del Recurso

Similar

	Creado por hassan mohammed hace más de 7 años