Endocrine Physiology Part II Flashcards
List the purely endocrine glands.
Anterior pituitary
Thyroid gland
Parathyroid
Adrenal gland
What processes doew the hypothalamus regulate?
Regulation of thirst, hunger, fluid balance, body temperature, sleep/wake cycle, and certain reproductive functions
Compare and contrast topic and trophic hormones.
Tropic hormones control secretion of hormones from other endocrine glands (tropism - different levels/tiers).
Trophic hormones induce growth in target cells.
Some hormones have both tropic and trophic effects.
How do tropic hormones travel from the hypothalamus to the anterior pituitary gland?
Via the hypothalamic-hypophyseal portal system.
How does multiple tiers of control and negative feedback allow for the regulation of body conditions?
Allow endocrine system to tightlyregulate conditions within body
Critical for maintaining homeostasis
Outline the first tier of control.
Neuroendocrine cells of hypothalamus secrete releasing and inhibiting hormones in response to change in homeostatic variable (tropic hormones)
Outline the second tier of control.
Involves hypothalamus tropic hormones’ effect on anterior pituitary
Stimulates or inhibits anterior pituitary hormone secretion
Outline the third tier of control.
Involves actions of anterior pituitary hormones at target tissues
Target tissue glands secrete hormones that can affect various homeostatic variables
How does hormone secretion stop one a variable returns to its normal set point?
The hypothalamus stops secreting tropic hormones and the anterior pituitary changes its secretion accordingly. Target tissues follow suit closing the feedback loop.
What is another name for the pituitary gland?
The hypophysis.
How is the pituitary gland connected to the hypothalamus?
Via the infundibulum.
What protects the pituitary gland.
The sphenoid bone.
Describe the two different lobes of the pituitary gland.
Anterior pituitary - glandular tissue
Posterior pituitary - nervous tissue
Hiw is the anterior pituitary gland connected to the hypothalamus?
Via vascular pathways.
What types of hormones does the anterior pituitary secrete.
Peptide hormones.
What is another name for the anterior pituitary gland?
Adenohypophysis
How many hormones does the anterior pituitary secrete?
6
Four are tropic (stimulate other endocrine glands)
Two affect non-endocrine targets
What are the characterisitc of adenohypophyseal secretions?
Proteins/peptides
Act through second messenger systems
Reglated by hormonal stimuli - mostly negative feedback.
Is the posterior pituitary gland an endorine structure?
No. It is composed of nervous tissue and is continuous with nerve fibers of the hypothalamus. It stores and secretes neurohormones made in the hypothalamus.
What types of hormones does the posterior pituitary relesae?
Peptides
How are hormones stored in the posterior pituitary.
They are produced in the hypothalamus. They travel thorugh the infundibulum to the posterior pituitary via axons. They are stored in axon terminals.
Which hormones are stored in the posterior pituitary?
ADH and Oxytocin
ADH is also known as vasopressin
What are posterior pituitary secretions controlled by?
Hypothalamic secretions
Negative feedback of target gland hormones
How many hormones are produced by the hypothalamus?
7 regulatory hormones (control anterior pituitary)
2 hormones (which are stored in posterior pituitary)
All are peptide hormones
