Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key

image

Play button

image

Play button

image

Progress

1/43

Click to flip

43 Cards in this Set

  • Front
  • Back
What are the two embryological portions of the pituitary gland?
The adenohypophysis and the neurohypophysis
Which part of the pituitary gland is the epithelial, glandular portion?
The adenohypophysis
What are the three parts of the adenohypophysis?
The pars distalis (hormone center), pars intermedia, and pars tuberlis
What part of the brain stimulates the pituitary gland?
The hypothalamus
What are the parts of the neurohypophysis?
The pars nervosa (a "downgrowth" of the brain), infundibular process and median eminence(extension of the hypothalamus)
What path do inhibiting and releasing factors take in the hypothalamic/hypophyseal portal system?
Factors produced in the hypothalamus enter fenestrated capillaries, which go into veins (portal veins), which bring the factors to the pars distalis, where veins turn into fenestrated capillaries, where the factors leave the capillaries and affect the appropriate cell
How does the hypothalamic/hypophyseal tract work?
It is NON-VASCULAR; neuroendocrine hormones travel from the hypothalamic nuclei down microtubules in axons which travel from the nuclei to the pars nervosa
What are the three components of the adenohypophysis (specifically the pars distalis)?
Supportive cells, endocrine cells, and fenestrated capillaries
What are the three types of cells in the pars distalis?
Acidophils (90% of chromophils), basophils (10% of chromophils), and chromophobes(50% of total cells)
What do acidophils secrete?
Growth hormone and prolactin
What do basophils secrete?
Gonadotropins (FSH and LH), thyroid stimulating hormone (TSH), and adrenal corticotropic hormone (ACTH)
How does growth hormone work?
It stimulates hepatocytes (targets liver) to secrete somatomedin C, which stimulates growth
How is growth hormone released?
In pulses throughout the day, with its peak time just before waking
What are the two hormones that regulate growth hormone?
Growth hormone releasing hormone(GHRH)is stimulatory, somatostatin is inhibitory.
What hormone is the main inhibitor of prolactin?
Dopamine
What does prolactin do?
It targets the mammary glands, stimulating the ductal and secretory portions; stimulates milk sythesis and lactation
When is prolactin important?
During puberty, pregnancy, and lactation
What can result from too much prolactin?
Infertility in males and females and erectile dysfunction in men
What does follicle stimulating hormone (FSH) do?
In females, stimulates ovarian follicle development; in males, stimulates Sertoli cells in testes to produce androgen binding protein
What does lutenizing hormone (LH) do?
In females, stimulates steroidgenesis in the ovarian follicles and corpus luteum; in males, regulates testosterone production (controls rate of production by Leydig cells)
About how many anterior hypophysial cells are TSH secreting cells?
About 5%
What does thyroid-stimulating hormone do?
Regulates the function and growth of thyroid; can also affect bone growth and metabolic rate
What portion of the adrenal cortex is stimulated by ACTH?
The zona fasciculata and zona reticularis
What cells are stimulated by ACTH?
Cortisol-producing cells
What hormone is associated with the release of B-lipotropic hormone, B-endorphin, and B-msh?
Adrenal corticotropic hormone
What is the relationship between ACTH and the circadian rhythm?
ACTH release peaks in the morning and slowly declines the rest of the day.
How does the neurohypophysis receive neurosecretory substances from the hypothalamic nuclei?
Via the hypothalamic/hypophyseal tract
What is a Herring body?
Droplets of hormone that are transported into fenestrated capillaries located in the pars nervosa
What are the three main components of the pars nervosa?
Axons carrying neurosecretory material, supportive cells (pituicytes), and fenestrated capillaries
What cells in the pituitary resemble astrocytes in the CNS?
Pituicytes
How do pitiuicytes work?
They act as supporting cells; prevent hormones from getting out into the surrounding tissue until it reaches the fenestrated capillaries
From where do the microtubules in axons transport neurosecretory material?
From the supraoptic and paraventricular nuclei in the hypothalamus
What hormones from the hypothalamus are released in the pars nervosa?
Antidiuretic hormone (ADH) and oxytocin
What does ADH do?
Brings about resorption of water in the collecting tubule of the kidney; can also elevate BP during severe blood loss by forcing arteries to clamp down
What does oxytocin target?
Myoepithelial cells of the mammary gland and the smooth muscle of the uterine wall; can be used to induce labor
Where is the pineal gland located?
In the third ventricle of the brain
How does the pineal gland maintain contact with the brain?
Via postganglionic sympathetic nerve fibers (no direct connection, despite close proximity)
What are the supportive cells of the pineal gland?
Glial-type cells; interstitial cells support pinealocytes
How are pinealocytes organized?
Into cords and clusters on the basal lamina, surrounded by C.T.
What do pinealocytes secrete?
Melatonin
How does melatonin influence the sleep cycle?
Darkness stimulates the production of melatonin; it's at its highest content during the night (synthesized from tryptophan, makes people sleepy)
What is corpora arahacea?
Also known as brain sand; is calcified granules that accumulate in the brain and pineal gland as people age
What is precocious puberty?
When children become sexually mature by eight years old for girls, and eight or nine years old for boys; caused by a tumor in the pineal gland and is usually fatal