Pituitary gland Flashcards
pituitary gland lies where and connected to the hypothalamus by
sella turcica at base of brain and by the pituitary stalk
what are the 6 hormones secreted by anterior pituitary
GH, ACTH, TSH, FSH, LH, PRL
function of GH
Promotes growth of entire body by affecting protein formation cell multiplication, differentiation
GH promotes growth when baby grows up, and promotes muscle size increase in adulthood.
* GH can increase the physical size of cells
* GH can increase the number of cells
* GH can increase the amount of protein inside of a cell
function of ACTH
Controls secretion of hormones from adrenal cortex, affects metabolism of glucose, protein and fats.
function of TSH
Stimulating thyroid gland to control secretion rate of thyroxine and triiodothyronine
* control the rate of intracellular chemical reaction of entire body.
function of FSH
Control growth of gonads and hormonal and reproductive activities.
function of LH
Control growth of gonads and hormonal and reproductive activities.
function of PRL
Promotes mammary gland and milk production.
what are the 2 hormones secretes by the posterior pituitary
ADH, oxytocin
function of ADH
Control rate of water excretion into urine ➔ to help controlling water
concentration in body fluids.
function of oxytocin
Help for delivering milk from glands of breast to the nipples during
suckling.
Help baby delivery at the end of gestation.
what are the five main cell type of anterior pituitary (andenohypophyse)
somatotrope, corticotrope, thyrotrope, gonadotrope, lactotrope
30-40% of adenohypophysis hormone are which type of cell and secrete what
somatrotopes, GH
20% of adenohypophysis hormone are which type of cell and secrete what
corticotrope and secrete ACTH
3-5 % of adenohypophysis hormone are which type of cell and secrete what
thyrotrope and secrete TSH
gonadotrope and secrete LH and FSH
lactotropes and secrete prolactin
To raise the level of prolactin in the body, which change must occur?
prolactin inhibitory hormone (PIH) levels fall
A person is suspected to have defective adrenal cortex of the adrenal glands, and the doctor asked for a radioimmunoassay on their blood sample. What result might support the idea that the adrenal cortex is defective?
high radio-signal for corticotropin
If the entire pituitary gland were surgically removed for some reason, which of these hormones could still be produced relatively normally after a few days passes?
oxytocin
How many hormones does the parathyroid gland make?
one
How many parathyroid glands does the body have if you counted them? (count each part as one gland)
4
The anterior pituitary can secrete ____________ (GH growth hormone, or, Gl glucagon). The adrenal cortex can secrete ____________ (A: Androgen, or, Testosterone).
GH, A
How many hormones are produced (synthesized) within the hypothalamus?
8
If a person has very high blood pressure (say, due to blood doping), then the baroreceptors in the atria will _________ (R: relax, S: stretch) causing the levels of anti-diuretic hormone to __________ (R: rise, F: fall) in the blood.
s, f
A test for growth hormone is done on a patient’s blood sample and comes back with a high level. Other hormone tests are normal. What are two conditions that they could possibly have?
Gigantism or acromegaly
Which type of trope cells in the anterior pituitary responds to two different regulatory hormones?
somatotrope
Is this statement True or False? ‘Vasopressin has a pressor effect on blood vessels, and it acts on the kidney tubules to promote water re-absorption (from urine to blood).”
true
Which of the following effects of growth hormone can lead to a diabetes mellitus if its chronic and uncontrolled?
increase insulin secretion from islets of Langerhans
o have a lower level of growth hormone (GH) in the blood, the level of growth hormone releasing hormone (GHRH) would have to ______ (R: rise, F: fall), or, the level of growth hormone inhibiting hormone (GHIH) would have to ______ (R: rise, F: fall).
F, R
What is perhaps the best and clearest example of a local acting hormone secreted by the pituitary?
prolactin
secretion from posterior pituitary is controlled by what
nerve signal from hypothalamus
secretion from anterior pituitary is controlled by what
hormone
what are the cascade of event that lead secretion of hormone from anterior pituitary
- The hypothalamus receives signal from different sensory sources in the nervous system.
- Hypothalamic releasing and inhibitory hormones are synthesized in special neurons in the hypothalamus.
- The endings of these neurons (nerve fibers) connect to median eminence in hypophysial stalk.
- The releasing and inhibitory hormones release from these endings of neurons into tissue fluids.
- These hormones are absorbed into the hypothalamic-hypophysial portal vessels and are carried to the sinuses of the anterior pituitary gland.
what are the 6 hormones produced by hypothalamus that control the release of anterior pituitary secretion
GHRH, GHIH, CRH, TRH, GnRH, PIH
which hormone has inhibitory and releasing capacity
GH
which hormone can only be release and don’t have inhibitory function
CRH, TRH,GnRH
which hormone only have inhibitory effect
PIH
GH is a general or local hormone and why
général because it affect almost all tissue of body
effect of GH on protein synthesis
- GH can enhance transport of most amino acids through cell membrane to the
interior of cells → increase the concentration of amino acid in cells→ increase protein synthesis. - GH increases the formation of RNA → promotes more protein to be synthesized by ribosomes in cytoplasm→increases transcription of DNA in nucleus.
- GH mobilizes large amounts of free fatty acids from adipose tissue → in turn the free fatty acids are used to supply most of energy for body cell → reduces the breakdown of cell protein.
how does GH enhance fat as source of energy
GH causes release of fatty acids from adipose tissue → increase the concentration of fatty acids in body fluids→enhances conversion of fatty acids to acetylcoenzyme A ( acetyl-CoA ) used for energy.
* GH mobilization of fat requires time ( hours to occur ).
what happen if GH is at excess amount
may cause ketosis and fatty liver disease
hyperglycemia
diabete mellitus
GH have what effect on glusoce and how
decrease the use of glucose for energyGHincreasesfattyacidsconversiontoacetyl-CoA,→negativefeedback effect to block breakdown of glycogen to glucose→enhances the deposition of glycogen in hepatic or muscle cells→glycogen accumulates
9
* GH diminishes the uptake of glucose by cells→increases the blood glucose concentration→hyperglycemia might occur if GH is excessive
how can diabetes mellitus can develop
If excessive GH chronically increases blood concentration of glucose increases to 50% or more above normal, called pituitary diabetes→GH over-stimulating islet of Langerhans to secrete extra insulin → diabetes mellitus may develop ( diabetogenic effect ).
GH secretion rate is affected by which factors
malnutrition, starvation, anorexia, bulimia
exercise, sleep, trauma
how many hour of strenuous active or sleep is needed to cause GH secretion
2h
low or high concentration of fatty acids is needed in blood to cause gh secretion ?
low
low or high concentration of glucose is needed to cause GH secretion
low
what are the short-term effect of GH secretion
Increase Ca ions transport into cell → fusion of GH secretory
vesicles with cell membrane → release of GH into blood.
what are the long term effect of GH secretion
Increase transcription in nucleus by the genes that cause new GH
synthesis.
what are the 5 abnormalities of GH secretion
panhypopituitarism, dwarfism, gigantism, acromegaly, aging
in which abnormality the body develop in appropriate proportion but rate of development decrease greatly
dwarfism
in which condition age 20 look like 7-10
dwarfism
in wich condition there is not enough gonadotropic hormone for developing sexual function
dwarfism
which condition result from a decreased secretion of all anterior pituitary hormone
panhypopituitarism
which condition can be congenital or occur durbing life
panhypopituitarism
which condition is due to excessive quantities of GH cause by tumour in pituitary
gigantism
which condition is due to a tutor after adolescence which result in soft tissue continuing to grow
acromegaly
which condition result from decreased protein synthesis in body tissue and increase deposition of fat
aging
what are the name of cell that is composed the post pituitary
pituicytes
where is the ADH synthesized
supraoptic nuclei of hypothalamus
oxytocin’s is syntized where
paraventricular nuclei of hypothalamus
what happen when a baby is sucking nipple
Suckling stimuli on nipple of the breast elicits signals, ➔ signals are transmitted through sensory nerves to the brain, ➔ reach to the oxytocin neurons in the paraventricular nuclei in the hypothalamus, ➔ cause release of oxytocin from posterior pituitary gland, ➔ oxytocin is carried by blood to breasts, ➔ cause contraction of myoepithelial cells, ➔ milk flow ( milk ejection or milk letdown ).
main purpose of ADH
maintain blood pressure homeostasis
what happen when osmotic pressure of blood change
osmeoreceptor cells change their size which affect ADH secretion
cascade of event leading to regulation of kidney
When the extracellular body fluid becomes highly concentrated, water in the osmoreceptor diffuses out of the cell membrane by osmosis ➔ decrease the size of osmoreceptor ➔ initiates the nerve impulses in the hypothalamus ➔ impulses are transmitted to the posterior pituitary ➔ cause secretion of ADH, water retention in kidney.
When the extracellular fluid becomes too dilute, water diffuses into the osmoreceptor ➔ increase the cell size of the osmoreceptor ➔ decrease the signal for ADH secretion, water excretion at kidney.
secretion of ADH is controlled by
CV reflexes in response to decrease in blood volume or blood pressure
when blood volume decrease 15-25% what happen
secretion rate of ADH increase to as high as 50 times normal
what happen when a reflex impulse from baroreceptor are transmitted to brain
inhibit ADH secretion
what happen when theres a high blood pressure
The reflex impulses from baroreceptors are transmitted to brain to inhibit ADH secretion.
what happen when blood volume or blood pressure decrease
increase the secretion of ADH ➔ cause constriction of blood vessels.
ADH increase or decrease excretion of water by kidney
decrease
cascade of event leading to change in urine
When ADH is released into blood and is transported to kidney, it binds with the receptors on luminal membranes ➔ cause formation of cAMP ➔ cause phosphorylation of chemicals in the special vesicles ➔ vesicles insert into apical cell membrane ➔ increase the permeability of collecting tubules and ducts to water ➔ water is reabsorbed from the collecting tubules and duct by osmosis ➔ water is conserved in the body ➔ producing very concentrated urine.
why ADH is also called vasopressin
because it has another type of effect that happens at the same time but in a different location. High concentration of ADH causes constriction of arterioles throughout the body to increase the arterial pressure. ADH thus has effects on arterial resistance.
