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

1/9

Click to flip

9 Cards in this Set

  • Front
  • Back
Three Parts of the Pituitary AKA Hypophysis (from left to right)
1) Pars Distalis - darker purple
2) Pars Intermedia - darkest purple, is patchy, but is not made up of basophils
3) Pars Nervosa - lighter (pink)

Pars Distalis + Pars Intermedia = Anterior Pituitary AKA Adenohypophysis

Pars Nervosa = Posterior Pituitary AKA Neurohypophysis. Also known as a neurohemal organ b/c many of the axons coming from the hypothalamus connect to a blood vessel in the post. pituitary.

*Blood vessels are seen in all three of these.

Median Eminence is a very vascular region under the hypothalamus, at the top of the pituitary gland.
Nuclei Found in the Pars Nervosa
These cells are called pituicytes and are "support" (glial) cells. There are also lots of nerves that you can see, it is very fibrous.
Where can Axons end?
Some axons end on capillary beds, releasing inhibitors or stimulators. These secretions are called "Hypothalamic Releasing Hormones" or "Factors." These factors determine what hormones go to distalis and intermedia

Other axons can end up another nerve cells.

Other axons can end on a blood vessel
Hormones of the Pars Nervosa (2)
1) Vasopressin = ADH
2) Oxytocin - stimulates contractions of the uterus and ejection of milk

*Both of these hormones are released directly into systemic blood (bloodstream)
Hormones of Pars Distalis (6)
1) Growth Hormone
2)Prolactin

*Both GH and Prolactin probably evolved from the same gene. Both have a similar structure.

3)Luteinizing Hormone (LH)
4)Follicle-Stimulating Hormone (FSH)
5)Thyroid-Stimulating Hormone (TSH)

*LH and FSH = gonadotropins

6) Adrenocorticotropic Hormone (ACTH)

*These 6 hormones can be released if the cells in the distalis have receptors for them.
Functions of GH (4)
-growth of epiphyseal plates (in long bone), CT
-has both an exciter and inhibitor
-released even after we stop growing
-in adults, GH increases protein synthesis and decreases fat synthesis
Functions of Prolactin (1)
-is responsible for milk synthesis
Hormones of the Pars Intermedia (2)
1) Melanocyte-Stimulating Hormone (MSH) - stimulates the production and release of melanin (melanogenesis) by melanocytes in skin and hair
2) B-Endorphin Painkiller - induces opiate-like responses to decrease pain

*Will also see remnants of Rathke's Pouch in here
Two Main Cell Types found in Pars Distalis and other cells
1) Acidophils - pink stain b/c of eosin, these make either prolactin or GH
2) Basophils - very dark blue stain b/c of hemotoxylin, are a bit larger than acidophils, are making TSH, FSH, or LH
3) Other dull blue cells are chromophobes, responsible for ACTH
4) Sinusoids are also found here, which are wide diameter capillaries

*Unlike the factors released from the axons in the Pars Nervosa, the releasing factors from the Pars Distalis travel via portal blood (not systemic blood/bloodstream) to acidophils, basophils, and chromophobes, which make the consequent hormones.