Exam 2 (Lecture 10) - Adrenal Medulla Flashcards
Describe the adrenal medulla and its relationship to the sympathetic nervous system.
The adrenal medulla is a modified sympathetic ganglion.
Which hormones are secreted by the adrenal medulla, what is the chemical nature of these hormones, what is the main trigger for their release, and which neurotransmitter stimulates chromaffin cells to release the medullary hormones?
1) Epinephrine and norepinephrine
2) Catecholamines
3) Emergency stress
4) ACh (acetylcholine)
Describe the fight-or-flight response.
The fight-or-flight response is an emotional, behavioral, and physiological response.
- increased HR
- pupillary dilation
- bronchiolar relaxation
- diversion of blood to muscles
- energy mobilization
Which property of target cells explains the wide variety of physiological actions of epinephrine and norepinephrine?
Alpha or beta receptors
What are the main consequences of stimulation of alpha-1, alpha-2, beta-1, and beta-2 receptors?
1) alpha-1
- smooth muscle contraction
- increased sweating
2) alpha-2
- neurotransmitter inhibition
- hormone release inhibition
- decreased insulin secretion
3) beta-1
- increased cardiac output
4) beta-2
- smooth muscle relaxation
- glycogenesis
- glycogenolysis
- lipolysis
- increased hormone secretion
Describe general features of the integrated response of the organism to the stress.
1) Somatic Nervous System:
- norepinephrine
- arousal, behavioral activation, aggressiveness
2) Sympathetic Nervous System:
- CRH > pituitary > ACTH > cortisol > energy mobilization and redistribution, cardiovascular responsivity
3) Hypothalamic-Pituitary Adrenal Axis:
- same as sympathetic NS above
What is pheochromocytoma, in which species will you most likely encounter it and how is it treated?
1) Catecholamine secreting tumors
2) Seen in older dogs
3) Treated by:
- tumor resection
- hypertension control drugs
