The document provides information about the autonomic nervous system. It discusses: - The autonomic nervous system controls involuntary body functions through the sympathetic and parasympathetic divisions. - The sympathetic division is involved in the "fight or flight" response and increases heart rate and blood pressure. The parasympathetic division has opposing effects and is involved in "rest and digest" functions. - Both divisions work through two neurons - a preganglionic neuron from the CNS and a postganglionic neuron - to innervate organs like the heart, lungs and digestive system.

1. GROUP 3
B7 biochemistry

2. GROUP 3
NAMES ID CARD
 Saadaq cabdi ahmed
 Shaafici abdullahi osmaan
 Abdullahi bilaal abdi
 Maxamed bashiir abdi
 Shukri cali axmed
 Saabriin cali ahmed
 Nuuro mahdi xasan
 Xabiibo maxamed urur
 Nasro abdrisaaq cusmaan
 Abdiweli maxamed xaashi
 Ilhaam abdullahi ali
 Yasiin daaud raage
 Abdiaziiz bashiir maxamed
 1024
 1022
 968
 1100
 1041
 923
 1031
 898

3. AUTONOMIC NERVOUSE SYSTEM
 The autonomic or invaluntary part of nervous system
controls invaluntary body function
 Although stimulation doesn’t occur voluntarily the
individual can somtimes be conscious of it’s effect
 E.g an increase intheir heart rate
 Autonomic nervouse system is seperated into two division
 ▪︎ sympathetic ( thoracolumbar outflow)
 ▪︎parasympathetic (craniosacral outflow)

5.  The two division works in an integrated and complementary manner
to maintain invaluntary function and homeostasis .
 Such activities include coordination and control of breathing ,
blood pressure , water balance digestion and metabolic rate .
 The effects of autonomic activity ar rapid .
 The effector organs are
 •smooth muscle which controls the diameter of smaller airways and
blood vessels
 Cardioc muscle which controls the rate and force of cardioc
contraction
 Glands that control the volumes of gastrointestinal secretion

6.  Efferent or motor nerves
 The efferent (motor) nerves of the autonomic nervous
system arises from the brain and emerge at various levels
b/w the mid brain and sacral region of the spinal cord
 Many of them travel whith the same nerve sheath as
peripheral nerves to reach the organs they innervate
 Each division has two efferent neurones b/w the centeral
nervous system and effector organs these are
 ▪︎ the preganglionic neurone
 ▪︎ the postganglionic neurone

7. Sympathetic nervous sytem
 Since the preganglionic neurones orginates in the spinal cord at the
thoracic and lumbar levels ,the alternative name of thoracolumbar
outflow is apt .
 Preganglionic neurone :
 This has its cell body in the lateral column of gray matter in the
spinal cord the levels of 1st thoracic and 2nd and 3rd lumabar vertebrea
 Acetyl choline is neurotransmitter at sympathetic ganglia
 The nerve fiber of this cell leaves the cord by the anterior root and
terminates at the synapse in one ganglia eather in the lateral of
sympathetic ganglia through it to one of prevertebral ganglia

8.  Post ganlganlionic neurone
 This has its cell body in the ganglion and terminates in the organ
or tissue supplied .
 Noradrenaline (norepinephrine ) is usually neuro- transmitter at
sympathetic effector organs .
 The major exception is that there is no parasympathetic supply
to sweat glands , the skin and blood vessels of skeletal muscle
.
 Thsese structure are suplied by one only sympathetic post
ganganglionic neurones which are known as sympathetic
cholinergic nerves and usually have acetylcholine as their
neurotansmitter

10. Sympathetic ganglia
 ●The leteral chain of sympathetic ganglia :
 ● prevertebral ganglia : these are three
 * coeliac mesentric ganglion
 * superior mesenteric ganglion
 *inferior mesenteric ganglion
 These three prevertebral ganglia situated in the abdominal
cavity close to the orgins of arteries of the same name
 The ganglia consist of nerve cell body diffusely distributed
among network of nerve fiber that form plexuses

11. Parasympathetic nervous sytem
 The preganglionic neurone
 Post ganglionic neurone
 Function of autonomic nervous system
 The autonomic nevous sytem is involved in many complex invaluntary
activities
 The majority of the body organs are suplied by both symoathetic and
parasymathetic nerves.
 Symapthetic stimulation prepares the body to deal whith exciting stress
situation

13. Sympathetic stimulation couses the adrenal glands to
secrete the hormone adrenaline( epinephrine ) and
noradrenaline( nora epinephrine)
Parsymthetic has tendency to slow down cardiac and
respirotory activity .
But it stimulates absorption of food digestion and the
function of genitourinary system
Its generaly effects’ peace maker’

14. Effects of autonomic stimulation
 ▪︎︎ cardiovascular system
 Sympathetic function
 * accelerates firing of the sinoatrial node in the heart
increasing the rate and force of heart beat
 * Dilates chronary arteries
 *Dilates the blood vessels supplying to skeletal muscoe
 *Rise prephirel resistence and blood pressure
 *accelerates blood coaglation becou.se of vascoconstriction

15.  ▪︎ constricts the blood vessels in the secratory glands of diggestive sytem
 Parasympathetic stimulation
 *Decrease the rate and force of heart beat
 *Blood vessels to skeletal muscles no effect
 *Constric coronary arteries ,reducing the blood supply to cardioc muscle.
 Respiratory system
 Sympathetic stimulation
 Couses smooth muscle relexation
 The branchioles allowing greater amount of air to enter the lungs and each
inspiration
 Increases respiratory rate
 Increase heart rate oxygen intake and CO2 are increased

16. Parasympathetic stimulation .
*couses constraction of smooth muscle in the air way walls
leading to branchoconstraction
Digestive system
Sympathetic stimulation
*the leaver increase conversion of glycogen to glucose
*the bladder will relaxes
* the metabolic rate is greatly increased

17. Pasympathetic stimulation
* the liver . Increases secration of bile
* the stomach and small intestinal motility and
secration are increased
*the pancreas. The secration of pancreatic juice is
increased
* urethral and sphincters relaxation
* the adrenal glands no effect
* the metabolic rate no effect

18.  Eye
 Sympathetic stimulation
 *this couse constriction of radiating muscles fiber of the iris
 *Dilating pupil retraction
 * the calary muscle that adjust thr thickness of the lens is
slightly relaxed
Parsympathetic stimulation
• *This contracts the circular muscle fiber of the iris
• *Constricting the pupil
• *Eylids tend to close

19. Skin
 Sympathetic stimulation
 *Increases sweat secretion
 *Contract the arrector pili giving the appearance of “goose flesh”
 Parasympathetic stimulation
 There is no parasympthetic nerve fiber
 Afferent impulse from viscera
 Sensory fiber from the viscera travel whith autonomic fibers and are
sometimes called autonomic afferent
 The impulse they transmit are associated

20.  Visceral reflexes usualy at an unconscious level e.g cough blood pressure
 Sensation of e.g hunger , thrist nausea ,sexual
 Vesceral pain
 ●visceral reflexes
 Are insensitive to cutting burnig and crushing
 Sensation of dull poorly located pain is expreinced when
 * vesceral nerves are stretched
 * large number of fiber are stimulated
 * there is schaemia and local accumulation of metabolites
 *Sensitivity of nerve ending to painful stimuli is increased e.g during
inflamation

21. Effects of ageing on the nervous system
 As neurons are not replaced after birth anatural decrease in number
occurs whith ageing
 1: the brain of older adults is generally reduced insize and weight
 2: the gyri become narrower and sulci wider in older adults , plaques
accumulation of protein material are often found Cns neurons and
neurofibrillary tangles may develop inside them their signifance is
unknow
 3: Decreases blood flow may develop in arteries that supply brain
over along period( atheroma and arteriosclerosis making their walls
more prone to repture should this occur damage to the soround
brain tissue couses signs and symptoms of stroke

22.  4: motor control of precise movement diminishes
 5; memory of the recent past typically difficult to access through long
 Term memory include problem solving ,