Zusammenfassung der Ressource
Yasser is falling
behind
- Macro-anatomy of pituitary gland
- location
- sella turcica (hypophyseal fossa) cavity within
body of sphenoid bone housing pituitary gland,
capsule of the gland is adherent to dura mater
- diaphragma sellae : fold of dura mater cover the
superior aspect of pituitary, Extend b/t ant. & post
clinoid processes,Forming roof to sella turcica
- infundibulum pierces the diaphragma
sellae, connect the pituitary to the
hypothalamus
- Lobes
- Adenohypophysis (75% of
total wt.) anterior lobe
- Vascular
connection
- parts
- pars distalis
- Pars intermedia
- Pars tuberalis.
- supplied by superior
hypophysial
artery
- Neurohypophysis (posterior lobe)
- neuronal connection
- is directly connected to
Supraoptic paraventricular
nuclei of the hypothalamus
- supplied by inferior
hypophysial artery
- parts
- Pars nervosa
- Median eminence
- Infundibulum
- Histological Structure
of Pituitary Gland
- Neurohypophysis
- Unmyelinated nerve fibers
- pituicyte
- capillaries
- Adenohypophysis
- cells of pars distalis
- Chromophobes
- Chromophils
- Acidophils
- somatotrophs
- mammotrophs
- Basophils
- gonadotrophs
- thyrotrophs
- corticotrophs
- cells of Pars Intermedia
- Basophil cells secrete
MSH (melanocyte
stimulating hormone).
- Cells of Pars
tuberalis
- Cuboidal cells with
Basophilic granules.
- PATHOLOGY OF
PITUITARY GLAND
- Hypopituitarism
- Causes
- PITUITARY TUMORS
- Ischæmic necrosis of the pituitary gland
- PITUITARY APOPLEXY
- IATROGENIC HYPOPITUITARISM
- TRAUMA + INFILTRATIVE DISEASES
- pharmacological treatment
1-Somatropin 2-Mecasermin
..etc
- Hyperpituitarism
- 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
- pharmacological treatment : 1. somatostatin receptor
agonists (also known as somatostatin receptor ligands
[SRLs] or somatostatin analogues), 2. dopamine
analogues 3. GH receptor antagonists
- Pituitary Adenomas
- 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-Amines: catecholamine,
etc
2--Peptides/polypeptides:
insulin,etc
- GROWTH HORMONE
- ACTIONS
- 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.
- Control of GH Secretion
- Hypoglycemia ,Hyperglycemia
,exercise,Somatostatin Sex
steroids ,sleep
- Assessment of GH
- 1-Insulin Stress Test. 2-Glucose
Tolerance Test. 3-Measurement
of IGF-1 to assess GH excess (not
confirmative).
- 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).
- 3-Steroids: cortisol, etc
- Longer half-life (hours) Act on
intracellular receptors Act on
DNA to alter gene transcription