B2W3 Trans Phys PACAP

Question 1

Adrenal Medulla Function at rest

Answer 1

Sympathetic tone
- low firing rate (0.5 Hz)
Modest Catecholamine
- Maintain homeostasis
Maintain Normal
- Blood Pressure
- Heart Rate
- Vascular Tone
- Enteric Activity
- Blood Glucose Level

Question 2

Adrenal Medulla under stress

Answer 2

Increased Sympathetic Tone
- Burst Mode Firing (20 Hz)
Maximal Catecholamine Release
- Co-releases array of peptide transmitters
Increased
- Blood Pressure
- Cardiac Output
- Pulmonary Ventilation
- Blood flow to muscle
- Glucagon Secretion

Question 3

Adrenal Medulla

Answer 3

Only Source of peripheral epinephrine

Question 4

Adrenal Gland

Answer 4

Made of a medulla and a surrounding cortex

Medulla releases peripheral epinephrine
Cortex releases hormones

Question 5

Adrenal Cortex

Answer 5

Releases hormones and surrounds the adrenal medulla.

Question 6

Innervation of the Medulla

Answer 6

Adrenal medulla has one nerve that goes directly from the CNS to itself making it act as its own preganglionic neuron. The adrenal cortex prevents the medulla from branching outward making it a group of neuronal endocrine cells without processes.

Is innervated by ACh

Question 7

Pituitary Adenylate Cyclase Activating Polypeptide (PACAP)

Answer 7

Released during high activity of the sympathetic nervous system

Causes cell to reach PACAP threshold but does not create an action potential

PACAP instead allows for the influx of calcium to trigger exocytosis

Question 8

PACAP Pathway

Answer 8

PACAP -> PAC1 Receptor -> Activates Adenylate Cyclase -> Produces cAMP -> Activates Exchange protein activated by cyclic AMP (Epac) -> Epac activates phospholipase C -> Uses diacyl glycerol generation to activate Protein Kinase C -> Protein Kinase C phosphorylates an inward sodium cation channels

Inward sodium channels depolarizes the cell enough to open low voltage gated calcium channels

Question 9

Chromaffin Cell

Answer 9

A cell whose synapse surrounds the axon of another neuron

Question 10

PACAP NE vs. Epi release

Answer 10

Whether epinephrine or norepinephrine is released is based entirely on which of the neurons are stimulated

Question 11

NE and Epi identification

Answer 11

Using cyclic voltammetry you can measure the oxidation of NE and Epi

Norepinephrine has one oxidation peak and epinephrine has 2 oxidation peaks

Question 12

Differential Catecholamine and Peptide Transmitter Release

Answer 12

What catecholamine and peptide are released are best on the how long the synapse is bound during the PACAP cycle. A longer time of exocytosis allows for larger and slower molecules to move out of the cell