lecuture 9 Flashcards
the somatotropin effects on the metabolism
increases rate of muscle mass and protein synthesis in the muscle
promotes fats to break down in adipocytes(mobilize fatty acids)
promotes storage of carbohydrate(decrease utilization of glucose)
somatotropin
is produced by pituitary gland, can make cell grow and promotes mitosis, promotes differentiation of different cells, have metabolic effects
somatotropin effect on bone
promotes elongation of bone
endochondial bone formation( specific to long bone )
Endochondial Bone Formation
when the bone is done growing the cartilage( epiphyseal plate) will die and bone tissue will replace the cartilage cell by the periosterum at puberty
Three type of bone growth
interstitial growth
appositional growth
acromegaly
Interstitial growth
bone grow length wise due to the present of epiphyseal plate. This growth stops after cartilage is replaced by bone tissue usually by puberty.
Apposition growth
growth of bone width wise making the bone thicker and bigger, appositional growth occurs after the epiphyseal plate closes usually after puberty
Acromegaly
A disease that causes appositional growth of bone. the anterior pituitary gland produces too much growth hormone after the closure of epiphyseal plate
Insulin-like growth factor ( IGF)
somato medins
Somatomedins
group of special protein synthesis. there are four kinds
type c is called IGF-I
Type-c IGF-I
essential for normal growth of individual
without IGF-I growth would be abnormal
IGF-I can increase muscle mass if injected directly into the skeleton
It promotes diffusion of satellite cels in the muscle fiber
it can not be detected by the blood.
growth hormones are usually secreted
usually peaks during sleep or at night, environmental factors can affect the amount of hormones being release
less growth hormones will be secreted as
as we age
Gherlin effects
hormone cycle
the hypothalamus regulate the amount of growth hormone by
GHRH which will bind to a receptor on the surface of the cell, thus promoting the cell to release more cAMP
The release of cAMP induce by the GHRH has two effects
Short term effects– release of growth hormones by somato tropins vesicles
Long Term Effects– can activate genes by activating transcription factors
panhypopituitarism
complication with adenohypophyseal cells, usually caused by tumor in the pituitary gland and will destroy cells around it or by clots formed in the brain
panhypopituitarism can cause
hypothyroid,obesity, sexual dysfuction, obtain lots of fluid caused by disruption in osmoregulation, and depression
dwarfism
Acromegaly
gigantism
dwarfism caused by Panhypopituitarism
this occurs when the individual develop this problem before they have a chance to fully develop Gonado trophs in the pituitary gland
Acromegaly
thickening of the bone( appositional growth bone)
Occurs after puberty
abnormal secretion of growth hormone in adult (post puberty)
individual will experience thickening of the hand, face, skull, jaws, etc
Gigantism
if it occurs before puberty when epiphyseal plate are still there
nuclei of hypothalamus
Supraoptic nucleus(SON) Para Ventricular Nucleus (PVN)
SON
release ADH into the pituitary gland. it release oxytocin as well, however only in a minimal amount
PVN
releases oxytocin into the pituitary, it will also release minimal amount of ADH
both ADH and Oxytocin are
peptide
pituicytes
supports the fibers that brings the ADH and Oxytocin to the pituitary
Neurophysins I and II
are peptide that links up tp oxytocin and ADH to keep them inactive in the fibers
ADH
anti diuretic hormone, secreted by the SON, blocks the excretion of water in kidneys, specifically in the tubule nepherons of the kidney, stimulate the insertion of aquaporins to the membrane of the tubule cells in the tubule in the kidney
Discondeluted tubules and collecting duct are the tubules affected by
ADH
alcohol inhibits the release of ADH therefore the body cannot
retain water thus dehydration….. ADH also control blood pressure and osmolarity.
in high production of ADH, ADH will also promote
blood vessel constriction
Osmolarity cell
in hypertonic situation cells will fire because it shrinks a little bit, when the cell shrinks the neuron fires causing the SON to release ADH. In a hypotonic solution it does not fire at all
Oxytocin
secreted by the PVN
It causes contraction of the uterus durning child birth(hormone of partiurtion)
plays a role in milk let down ( it stimulate the myoepithelial) cell to constrict)
Diabetes insipidus
caused by a deficiency of ADH, excessively urination is very diluted, can cause dehydration, treatment is an ADH agonist drug
Dephogenic diabetes insipidus
caused by disruption in ADH
Diabetes mellitis
excessively urination, glucose concentration is high. high glucose, concentration causes kidney to pull more water out so that it can dissolve glucose. caused by low insulin level
