Autonomic Nervous system note

1. Autonomic Nervous System
Dr Dileep Verma
Associate Professor
Deptt of Physiology
KGMU

2. Lecture-2 :Topics
 Neurotransmitters of ANS
 Receptors of ANS
- Adrenergic
- Cholinergic

3. Learning Objectives
 List different types of adrenergic &
cholinergic receptors with their location
 Various autonomic neurotransmitters.
 Mechanisms of neurotransmitter release
in the sympathetic and parasympathetic
divisions.

4. Autonomic nervous System
 Neurotransmitters of ANS
Neurotransmitters of sympathetic
nervous system
Neurotransmitters of parasympathetic
nervous system

5. Sympathetic Nervous System
Neurotransmitters at-
A. Preganglionic nerve endings
B. Postganglionic nerve endings
C. Target tissue

6. Sympathetic Nervous System
Neurotransmitters at-
A. Preganglionic nerve endings
 Acetylcholine (ACh)
B. Postganglionic nerve endings
 Norepinephrine (NE)
 Acetylcholine (ACh)

7. Sympathetic Nervous System
Neurotransmitters at-
Target tissue
Epinephrine (Ep)
Norepinephrine (NE)
Acetylcholine (Ach)

8. Parasympathetic Nervous System
Neurotransmitters at-
A. Preganglionic nerve endings
 Acetylcholine (ACh)
B. Postganglionic nerve endings
 Acetylcholine (ACh)

9. Autonomic nervous System
Receptors of ANS
A. Receptors of Sympathetic
Nervous System
B. Receptors of Parasympathetic
Nervous System

10. Autonomic nervous System
Receptors of ANS
A. Receptors of Sympathetic
Nervous System
B. Receptors of Parasympathetic
Nervous System

11. Autonomic nervous System
Receptors of ANS
A. Receptors of Sympathetic
Nervous System
 Adrenergic Receptors
 Cholinergic Receptors
B. Receptors of Parasympathetic
Nervous System
 Cholinergic Receptors

12. Adrenergic Receptors
 Alpha adrenergic
Alpha-1 (a1)- Excitatory
Alpha-2 (a2)- Inhibitory
 Beta adrenergic
Beta-1(b1)- Excitatory
Beta-2 (b2) -Inhibitory
 Beta-3 (b3)- Excitatory

13. Alpha adrenergic receptor (a)
• Alpha-1 (a1)- Excitatory
Vascular smooth muscles
Skin
Splanchnic region
GI wall
Sphincters
Radial muscle of iris
• Alpha-2 (a2)- Inhibitory
Presynaptic nerve terminal
Platelets
GI wall

14. Beta adrenergic receptor (b)
• Beta-1(b1)- Excitatory
 SA Node
 AV Node
 Myocardium
• Beta-2 (b2) –Inhibitory
 Vascular smooth muscles
 Skeletal muscle
 Bronchial smooth muscles
 GI Wall
• Beta-3 (b3)- Excitatory
 Adipose tissue

15. Cholinergic Receptor
Cholinergic Receptors- 2 types
 Nicotinic Receptors (N)
 Nicotinic Neuronal (NN) Type
 Nicotinic Muscular (NM) Type
 Muscarinic Receptors (M)
 M1 to M7

16. Nicotinic Neuronal (NN) Type
• Location - Autonomic ganglia
• Activated by-
 Ach
 Nicotine
• Effect – Excitatory or Inhibitory
• Blocked by- Hexamethonium

17. Nicotinic Muscular (NM) Type
• Location - Neuromuscular Junction
• Activated by-
Ach
Nicotine
• Effect – Always Excitatory
• Blocked by- Curare

18. Muscarinic receptor
• Location -
 Myocardium
 Glands
 Smooth muscle
• Activated by-
Ach
Muscarine
• Effect – Inhibitory/Excitatory
• Blocked by- Atropine

19.  At Sweat Gland
 Neurotransmitter-Acetylcholine
 Receptors- Muscarinic
 At the adrenal cortex
 no postsynaptic neuron
 Neurotransmitter-Acetylcholine
 Receptors- Nicotinic

20. 1- Sympathetic postganglionic fibres
to sweat gland secrete--
A. Acetylcholine
B. Norepinephrine
C. Epinephrine
D. Serotonin

21. 2-Acetylcholine through nicotinic receptors
causes--
A. Constriction of pupil
B. Secretion of saliva
C. Decreases the heart rate
D. Contraction of skeletal muscle

22. 3-.Stimulation of alpha adrenergic
receptors results in-
A. Pupillary dilatation
B. Glycogenolysis
C. Inhibit intestinal motility
D. All of the above

23. 4. a1 adrenergic receptors are located
on/in
A. Presynaptic nerve terminal
B. Platelets
C. GI wall
D. Radial muscle of iris

24. 5-Which is true about b3 adrenergic
receptors ?
A. Located on adipose tissue
B. More sensitive to epinephrine
C. Stimulate glycogenesis
D. Inhibits lipolysis