Download VISCERAL FUNCTION REGULATED BY NERVOUS SYSTEM

Nervous system Ⅴ
VISCERAL FUNCTION REGULATED BY
NERVOUS SYSTEM
Autonomic Nervous System
 Parasympathetic nerve
 Sympathetic nerve
 Enteric divisions:
independent nervous in GIT
Somatic and Autonomic Nervous System
Somatic and Autonomic Nervous System
Somatic





Autonomic
Skeletal muscle

Conscious and
unconscious movement
Skeletal muscle
contracts
One synapse
Acetylcholine





Smooth and cardiac muscle
and glands
Unconscious regulation
Target tissues stimulated
or inhibited
Two synapses
preganglionic neurons: ACh
postganglionic neurons: ACh
or norepinephrine
Sympathetic Division
Sympathetic Division
 Preganglionic cell bodies in lateral horns
of spinal cord T1-L2:release ACh
 Preganglionic axons pass through
ventral roots to white ramus
communicans to sympathetic chain
ganglia
Parasympathetic Division
Parasympathetic Division
 Ⅲ，Ⅶ，Ⅸ，Ⅹ cranial nerve :
 Preganglionic cell bodies in nuclei of brainstem (mid
brain , pons and medulla)
 Sacral region of spinal cord:
 Preganglionic cell bodies in lateral parts of spinal cord
gray matter from S2-S4
 Postganglionic axons pass to terminal ganglia within
wall of or near organ innervated
 Preganglionic fiber
 Postganglionic fiber
Parasympathetic and
sympathetic nerve
distribution
Function property of ANS
Function property of ANS
 Dual innervation
 Exception
Most sweat glands，arrector pili muscle ，Adrenal medulla，
kidney (sympathetic , ACh )
 Salivary gland (dual but not antagonistic

 Sympathetic and para-sympathetic tone
 Ongoing action potential activity on the both nerves
 Under given circumstances : one division dominate another
Function property of ANS
 ANS activity characteristics

Mental and physical activity : oppose each other
Sympathetic nerve activity ↑
 Para-Sympathetic nerve activity ↓


Quiet condition
Sympathetic nerve activity↓
 Para-Sympathetic nerve activity ↑

Just like the
accelerator and brake
of a car
Sympathetic stress response
Effect of sympathetic and parasympathetic in specific organ
 The eyes
 Sympathetic : increase pupillary opening
 para-sympathetic: focusing of the lens
 blood vessels
 Sweat glands (sympathetic , ACh )
 Salivary gland (dual but not antagonistic)
 Sympathetic : small volume of thick saliva rich in
mucus
 para-sympathetic : large volume of watery saliva rich
in enzymes
 GIT
 Heart (parasympathetic nerve on SA node)
Neurotransmitters and receptors
 Acetylcholine and Norepinephrine
 All preganglionic neurons are cholinergic
 Parasympathetic post ganglionic neurons are cholinergic
 Sympathetic post ganglionic neurons are adrenergic except
sweat glands,
 Some blood vessels

Neurotransmitters
SOMATIC NERVOUS SYSTEM
ACh
Striated
muscle
NE
Heart
Sm. mus.
Glands
ACh
Sweat
glands
ACh
Heart
Sm. mus.
Glands
AUTONOMIC NERVOUS SYSTEM
Sympathetic
ACh
ACh
ACh
Parasympathetic
Ad. M. 
ACh
E,

NE
Acetylcholine
 Nicotinic receptors
 Nm: skeletal muscle
 Nn: autonomic ganglia, CNS
 Muscarinic receptors
 Postganglionic parasympathetic and a few sympathetic
sites, CNS (also autonomic gang.)
 Receptor subtypes: M1-5
Catecholamines
 Norepinephrine
 Postganglionic sympathetic, CNS, adrenal medulla
 Receptors: a1, a2, b1
 Epinephrine
 Adrenal medulla, CNS
 Receptors: a1, a2, b1 , b2
 Dopamine
 Autonomic ganglia, CNS
 Receptors: D(1-5), a1, b1 (also causes NE release)
Effect of the autonomic NS on various organs
Organ
Heart
Blood vessel
sympathetic stimulation
parasympathetic stimulation
β1 HR↑ contraction ↑
αconstriction
HR↓atria contraction ↓
dilation in penis and clitoris
β2 (heart and SM vessels)dilation
Lungs
GIT
Urinary bladder
β2 (airway) dilation
α, β2 (organ) motility↓
constriction
↑ motility
α (sphincters) contraction
relaxation
β2 relaxation
contraction (emptying)
Sweat gland
cholinergic , stimulating
stimulating
Saliva gland
Adrenal medulla
α , cholinergic, stimulating
cholinergic stimulation of NE,
E release
stmulating
none
CNS control of visceral activity
 Spinal cord
 Brain stem
 Hypothalamus
 Limbic cortex
Spinal cord
 Visceral reflexes
 Micturition reflex
 Defecation reflex
Lower brain stem
Hypothalamus
Hypothalamus
 Vegetative and endocrine control
functions
: Influence the CVS control
center
Hypothalamus
Regulation of body temperature
PO/AH (the preoptic area)
hypothalamus
Regulation of body water
AH:brain osmoreceptor
Supraoptic nucleus:ADH
hypothalamus
hypothalamus
hypothalamus
hypothalamus
hunger
hypothalamus
Summary
 Stress response of the sympathetic system
 The neurotransmitter in ANS ,their receptor and
function
 Cholinergic fiber