ppwt 8 development and puberty Flashcards
How growth hormone was discovered
Injection of crude extract of the pituitary gland in animal caused increased gorwth
what are the 2 parts of the pituitary gland
- anterior (adenohypophysis)
- posterior (neurohypophysis)
what hormones are excreted from the pituitary gland and where they have a function?
- prolactin (PRL) has a role in lactation
- thyrotropin or thyroid stimulating hormone (TSH) has an action on the thyroid
- adrenocorticotropin (ACTH) has a role in the adenal
- LH (luteinizing hormone) and FSH (follicle stimulating hormone) has an action on gonads
Where does theses hormones act
- PRL
- TSH
- ACTH (adrenocorticotropin)
- LH/FSH
- PRL - lactation
- TSH - thyroid
- ACTH - adrenal
- LH/FSH - gonads
the pituitary is controlled by
the hypothalamus
where does the pituitary gland sits on
hypophyseal fossa - sphenoid bone
explain what happens to the development of the hypothalamus and pituitary when a baby is developing
22 days: there os a pharyngeal opening and the ectodermal starts to thicken. The cells moves inward towards the central and they will form the Ratheke’s pouch
42 days : the rathke’s pouch is formed
60 days: the rathke’s pouch closes down and will become closer to the nuerohypophysis primordium which will form the posterior lobe and the rathke’s pouch will form the anterior pituitary
what will form the posterior and the anterior love
rathke’s pouch will form the anterior pituitary
neurohypophysis primordium will form the posterior pituitary
what are the nuclei that the hypothalamus forms
- paraventricular nuclei
- supraoptic nuclei
- arcuate nucleus
- anterior and posterior pituitary
- ventromedial nucleus
what hormones do supraoptic and paraventricular nuclei produces
oxytocin or vasopressin
how is the supraoptic and paraventricular nuclei and where does they terminate
- large neurons, terminate in the posterior pituitary
where does the hormones of the hypophysiotropic nuclei (PVN, Arc, PeVN) terminate
in the median eminence (ME)
how is the hypophysiotropic nuclei
smaller neurons
explain the location, what hormones are produce, where they will act on and what it happens to hypothalamic control over the endocrine system
- magnicellular neurons
magnicellular neurons are located in the supraoptic and periventricular.
They produce oxytocin and vasopressin hormones
and their axons go to the posterior pituitary land and secrete oxytocin and vasopressin that will go to the bloodstream and regulate kidney, uterus and mamary gland
explain the location, what hormones are produce, where they will act on and what it happens to hypothalamic control over the endocrine system
- parvicelluar hypophyseotropic neuron
parvicellular hypophyseotropic neuron are located on the Periventricular paraventricular and arcuate nucleus.
They produce TRH, CRH, somatostatin, GHRH, gnRH and dopamine.
The axon will terminate in the median eminence (ME) an it will secrete their hormone in the capillary blood and will come back by the portal vein that will produce a second wave of hormone having an effect on the cells that will secrete other hormones
- for example GHRH will have an effect on the call seomatotroph and it will secrete GH .
The pituitary hormone ester the blood stream via venous capillaries
where is the location of the magnicelluar neuron
supraoptic and paraventricular
where is the location of the parvicellular hypophyseotropic neuron
Arcuate, perivenetricular and paraventricular
which hormones is produced by arcuate
GHRH, GnRH and dopamine
which hormones are produced by the Periventricular and paraventricular
TRH, CRH and somastatin
true or false
hypothalamus integrates external and internal cues to secrete diverses hromones but because of the brain blood barrier is impermeable to various hormones
true
What parts of the brain have permeability which can interact with the hypothalamus also called (circumventricular organs)
- organum vasculosum of the lamina terminalis (OVLT)
- Subfornical organ (SFO)
- median eminence (ME)
- subcommissural organ (sco)
- area postrema (ap)
explain what is the circumventricular organs
they are permeable to the BBB and they have a connection to the hypothalamus meaning that the substances that come in can trigger reactions. The circumventricular organs are exposed to hormones, metabolites and toxins
where does hypothalamus receives sensory imputs from
- external environment (light, temperature…)
- internal (blood pressure, hormone levels)
where does the hypothalamus send signals to
- anterior and posteiror pituitary gland
- cerebral cortex
- parasymphatetic and symphathic neurons
