Panopto 39: Endocrine Flashcards
How are the neurohypothesis parts arranged?
in a continuous line, pars nervosa is furthest from the brain at the bottom, and the infindibulum is just above, closer to the brain, then the median eminence is at the border of the hypothalamus or the base of the brain. Left side of the brain in the diagram
How are the adenohypothesis parts arranged?
more scattered and a bit more separated. The pars intermedia is in between the pars tuberalis and pars distalis. The pars tuberalis is separated up by the infundibulum. (the right side of the diagram)
adenohypophysis, other name
anterior pituitary
Neurohypophysis, other name
posterior pituitary
another name for pars nervosa
posterior lobe
another name for pars distalis
anterior lobe
neurohypophysis, where do neurons originate from and where do they go to?
neurons originate in the hypothalamus and extend down into the infundibulum and then into the pars nervosa
neurons create 2 groups in the hypothalamus
supraoptic nucelus
paraventricular nucleus
what are bundled axons called
hypothalamic hypothesis tract. why is it called a tract? a collection of axons in the central nervous system
what is the equivalent to the hypothalamo-hypophseal tract in the peripheral nervous system?
called a nerve
What are the neurons in the hypothalamic hypothesis tract specialized for?
secretion of peptide hormones that are endocrine in their function
hormones that come from the neural hypothesis
- antidiuretic hormone (ADH): it causes the collecting ducts of the kidney to conserve water from the urine and to put it back into the blood. As a result, the urine is more concentrated
- oxytocin: stimulates the release of milk and lactation; a nervous message gets sent to the hypothalamus, where it stimulates the release of the hormone and then the release of milk.
whats another word for ADH?
vasopressin
When would high amounts of ADH be released, and what happens?
when blood volume and blood pressure get low. causes the smooth muscle in the blood vessels to contract, and the result would be that the blood pressure would rise (this is why its called vasopressin)
what happens when someone can’t secrete ADH?
can’t conserve volumes of water, which leads to drinking more water. these large amounts of urine are called polyurea and this gives rise to a condition called diabetes insipidus
What do the paraventricular nuclei secrete?
oxytocin
what do the supraoptic nuclei produce?
ADH
neurophysin
transport protein that hormones are bound to after synthesis. transported down the axon to the pars nervosa where theyre stored in the axon terminals.
herring bodies
when the axon terminals holding the hormones swell. They are acidophilic.
what other cells are in the nuerohypothsis
Pituicytes: pigmented specialized glial cells; they have GFAP (glial fibrillary acidic protein) support for the neurons in the neuralhypothsis
what is the most productive part of the pituitary
adenohypophysis due to the number of cell types
what hormones does the adenohypophysis secrete?
tropic hormones that stimulate the release of another hormone and increase the activity of target cell
hypothalamus additional function and what it secretes
control the release of hormones from the adenohypophysis
secretes: hypothalamic regulating factors (2 kinds)
1. releasing factors that stimulate secretion
2. inhibiting factors that inhibit secretion (these allow the adenohypothsis to secrete its hormones)
How do the releasing factors work in the hypothalamus?
starts with a stimulus (ex: low concentration of a hormone)
then the appropriate releasing factor is secreted (goes to the pars distalis and controls the release of a tropic hormone)
how are cells secreted by the pars distalis separated?
5 cells are divided into 2 groups based on acidophilic and basophilic
acidophils in the pars distalis
somatotropic: secrete growth hormone: influences the growth of our long bones
lactotropic: secretes prolactin functions in both the male (testosterone influences leydig cells) and female (lactatation)
basophils in the pars distalis
Gonadotropic: LH and FSH functional in both males (LH:stimulates leydig cells to secrete testosterone) and females (ovulation) cells division in the seminiferous tubule (FSH)
Thyrotropic: thyroid stimulating hormone (TSH) stimulates the production of thyroid hormone T3 or T4
Adrenocorticotropic: produces adrenocorticotropin (ACTH) and influences cells we find in the adrenal cortex (zona fasiculata: produces glucose or glucocorticoid)
what does the pars intermedia produce
MSH melanocyte stimulating hormone
what does the pars tuberalis produce?
gonadotropic cells
