1. Drugs Affecting the Autonomic Nervous System
BY : DR ISRAA OMAR

2. Organization of the Peripheral Nervous System
Three major divisions:
Efferent
Somatic (motor)
Autonomic
Sympathetic and Parasympathetic
Afferent
Sensory

3. Some Basic Plumbing: The Peripheral Nervous System
Sensory
Motor
Sympathetic
Parasympathetic

4. Basic anatomy of the ANS
The ANS comprises 2 divisions : sympathetic and parasympathetic
The basic 2 neuron pattern consist of preganglionic neuron cell body in the CNS and post ganglionic neuron cell body in the autonomic ganglia
The parasympathetic system is connected to CNS via: Cranial nerves outflow 10, 9, 7, 3 and sacral outflow

5. Basic anatomy of the ANS
Parasympathetic ganglia usually lies close to the or within the effector organ
Sympathetic outflow leave the CNS in the thoracic and lumbar roots. Sympathetic ganglia form 2 paravertebral chains, plus some midline ganglia
Adrenal medulla is considered to be modified sympathetic ganglia

6. Functions of the autonomic nervous system(sympathetic division)
Increase the heart rate and blood pressure
Increase blood flow to skeletal muscle and heart, while diverting flow from skin and internal organs
Increases the secretion of adrenaline and NE by adrenal medulla
Dilation of pupils and bronchioles
Relaxation of the GIT and bladder
In sexual process the SNS is responsible of ejaculation, in female it relaxes the uterus

7. Fight or flight response
The changes experienced by the body during emergencies have been referred to as fight and flight response
These reaction are triggered by stimulation of the nervous system and stimulation of the adrenal medulla to release adrenaline and to some extent noradrenaline which in turn produce response in the system contain adrenergic receptors

8. Fight or flight response
SNS often discharges as a complete system-for example, during sever exercise or in reaction to fear
Although this system involved in wide array of physiological activities it is not essential for life

9. Functions of the parasympathetic nervous system
Decrease the heart rate, contractility
Constriction of pupils and contraction of the ciliary muscle( accommodation for near vision)
Increase motility and secretion in the GIT and stimulate contraction of the bladder
In sexual process the PSNS is responsible of erection
Bronchial muscle constriction and increase secretion, increase secretion of watery saliva from SG

10. Functions of the parasympathetic nervous system
It maintain essential body function such as digestion and elimination of waste
This division of the ANS is essential for life
It is generally dominant in rest and digest situation over the SNS
It is not a functional entity and doesn’t discharge as a complete system

11. Functions of the parasympathetic nervous system
If it did, it will lead to massive, unpleasant, undesirable symptoms
Instead fibers are stimulated separately, and the system function to affect specific organ, such as stomach or eyes

12. Innervation of the ANS
Dual innervation: most organs are innervated by both division of ANS. Thus, vagal stimulation slows the heart rate, and sympathetic stimulation increase the heart rate
This type of antagonism is fine-tuned at any given time to control homeostatic organ functions

13. Organs receiving only sympathetic innervation
Adrenal medulla
Kidneys( secretion of renin)
Pilomotor muscles
Sweat glands
Blood pressure is also mainly under sympathetic control, with essentially no participation of PSNS

14. Preganglionic Nerves
Sympathetic
Parasympathetic
Sympathetic AND Parasympathetic preganglionic fibers release Acetylcholine (ACh)
Postganglionic nerves have Nicotinic receptors
ACh

15. Postganglionic Nerves
Sympathetic
Parasympathetic
Sympathetic post ganglionic neurons release Norepinephrine except in the sweat gland they secrete ACh
Parasympathetic post ganglionic neurons release ACh
Norepinephrine binds to adrenergic receptors
ACh binds to Muscarinic receptors
ACh NE

16. What Happens at the Effectors?
NE from postganglionic sympathetics binds to Adrenergic Receptors
ACh from postganglionic parasympathetics binds to Muscarinic Receptors NE
ACh
Adrenergic
Receptor
Muscarinic
Receptor
Sympathetic
Parasympathetic

17. THANK YOU

18. REFERNCES
LIPPINCOTTS PHARMACOLOGY
RANG AND DALE PHARMACOLOGY