Endocrine Physiology Flashcards
(48 cards)
What is the purpose of the ENDOcrine system?
- to synthesize, store, and secrete HORMONES into the BLOOD to act on target tissues.
What is the purpose of the EXOcrine system?
- secretion of substances through DUCTS.
What is the purpose of Feedback regulation?
- to maintain a balance of hormone quantity and effects.
What is the chemical modulation of metabolic events?
- adaption to surrounding environment
What is an example of systems integration of the endocrine system?
- integration of sympathetic nervous system (autonomic nervous system) with the adrenals to increase release of epinephrine and norepinephrine.
- integration of parasympathetic nervous system with GI hormones following a meal to increase splanchnic blood flow for absorption of nutrients.
From where does the endocrine system begin?
- hypothalamus and pituitary
*** What is a hormone?
- polypeptide/protein secreted by one cell cluster or organ, which is then secreted into the blood stream or bodily fluid and acts on a TARGET TISSUE elsewhere in the body.
What are some examples of hormones that act LOCALLY?
- acetylcholine
- secretin
- cholecystokinin (gall bladder contraction)
- pancreatic HCO3 secretion
What are some examples of GENERAL hormones?
- epinephrine (fight or flight)
- norepinephrine (fight or flight)
- thyroid hormone (metabolism/growth)
What are the major endocrine organs?
- hypothalamus
- PITUITARY
- pineal gland
- thyroid
- parathyroid
- thymus
- adrenals
- pancreas
- ovary
- testes
- placenta
What is the endocrine function of the heart?
- secretion of natriuretic peptide, which affects whether we retain water or not.
Why would a person who has a thyroidectomy have a seizure?
- calcium deficiency secondary to removal of parathyroid glands with the thyroid tissue.
What are the 2 parts of the pituitary gland (hypophysis)?
- ADENOhypophysis (anterior)
- NEUROhypophysis (posterior)
- nerve fibers enter from the supraoptic and paraventricular nuclei sitting above the optic chiasm
From where does the majority of the blood supply enter/exit the pituitary?
- infundibular process
* aka where the pituitary hormones are exit upon release from the anterior or posterior pituitary.
Can trauma or infection of the nose/nasopharynx affect the pituitary gland?
YES
How can anatomic pituitary problems (tumors) affect vision?
- spacial relationship to optic chiasm of optic nerves.
What is the importance of the anatomic relationship of the pituitary gland with the cavernous sinus?
- it rests within this sinus and a clot here could lead devastating changes in the blood flow.
What hormones are secreted from the ANTERIOR pituitary (adenohypophysis)?
- GH
- ACTH
- TSH
- FSH
- LH
- prolactin (milk production)
What are the 5 cell types of the ANTERIOR pituitary (adenohypophysis)?
- somatotropes (GH)
- cotricotropes (ACTH)
- thyrotropes (TSH)
- gonadotropes (FSH/LH)
- lactotropes (prolactin)
What hormones are released from the HYPOTHALAMUS that affect the anterior pituitary?
- GHRH= GH release
- CRH= ACTH release
- TRH= TSH release
- GnRH= FSH/LH release
- PIH (prolactin inhibitory hormone)= suppresses prolactin release.
What are the POSTERIOR pituitary hormones (neurohypophysis)?
- oxytocin= uterine contractions and release of breast milk.
- vasopressin (ADH)= increases blood pressure via renal permeability (for water reabsorption) and vasoconstriction. Also increases thirst to drink more.
What is the function of ACTH on the ADRENAL CORTEX?
- stimulates ALDOSTERONE production in the adrenal cortex (zona glomerulosa) to increase Na+ and water reabsorption in the DCT to increase BP.
- stimulates the adrenal cortex (zona fasiculata) to synthesize and release CORTISOL (made from cholesterol) which helps up to deal with stress (fight or flight).
What are the STEROID hormones?
- cortisol
- aldosterone
What are the TYROSINE derivative hormones? (obtained from eating protein rich foods)
- thyroxine
- triiodothytronine
- epinephrine/norepi
- produced in the cytoplasm
