Unit 8 - Signalling in the Autonomic Nervous System

Question 1

Autonomic NS (Visceral NS)

Answer 1

Control System: below level of consciousness Involuntary functions

Question 2

Divisions in ANS

Answer 2

Sympathetic: “Fight or Flight” = increased heart rate etc. Parasympathetic: “Rest or digest” = slow heart rate

Question 3

How many different neurotransmitters are released to elicit all the controlled responses?

Answer 3

Two: ACh & NE Acts independently control diverse effects. (salivation) Multiplicity responses depending on effector organ. “Same key different locks”

Question 4

Signalling in the ANS

Answer 4

Parasympathetic: ACh + ACh = Various Organs Sympathetic: ACh + NE = Various Organs ACh + ACh = Sweat Glands ACh (Adrenal Medulla)+ Epi = Various Organs Somatic Motor System: Motor Neuron + ACh = Skeletel Muscle

Question 5

Cholinergic & Adrenergic Axons

Answer 5

Cholinergic: Preganglionic & Preganglionic sympathetic axons
Neurotransmitters: Acetylcholine

Adrenesigic: Postganglionic Sympathetic Axons
Neurotransmitters: Norepinephrine
*Except for sweat glands*

Question 6

Neurotransmitters (2) of the Symapthertic ANS

Answer 6

Biogenic Aminos termed catecholamines, derived from phenyalaine and tyrosine.

Epinephrine: stress hormone relased from Adrenal Medulla(kidney)

Norepinephrine: involved in sleep and wake, fullness attention and feeding beahviour

Question 7

Adrenal Medulla

Answer 7

Is a modified symapthetic ganglion. Is supplied by cholingeric preganglionic sympathetic fibres that secrets ACh.

It Secretes epinephrine and morepinephrine into the circulation.

Question 8

Effects of Epinephrine

Answer 8

Bind both to a- and ß- adrenegeric receptors.

Sympathetic branch of the ANS prepares the body for “fight or flight”

Release of adrenaline form the kidney into the blood ensures that all cells of the body will be exposed to Sympathetic stimulation even if no postganglionic neurons reach them directly.

Question 9

Epinephrine Cycle

Answer 9

Epinphrine(hydrophilic) - ßreceptor - GDP - GTP - cAMP - Protein Kinase - Phosphorylase Kinase - Glycogen Phosphorylase - Glycogen

= Glucose

(activates Fight or Flight)

Question 10

Walter Bradford Cannon

Answer 10

First described the Fight or Flight response.

First stage of a general adaptation that regulates stress among vetebrates and other organisms.