Dr. Waqas Nawaz PMAS arid agriculture university rawalpindi

1. NERVOUS SYSTEM
BY
Waqas Nawaz
11-ARID-975

2. The Nervous System
Major division -
Central & Peripheral
Central or CNS-
brain and spinal
cord
Peripheral- nerves
connecting CNS to
muscles and organs

3. Peripheral Nervous System
3 kinds of neurons
connect CNS to the body
sensory
motor
interneurons
Motor - CNS to muscles
and organs
Sensory - sensory
receptors to CNS
Interneurons:
Connections Within CNS

4. Peripheral Nervous System
Peripheral Nervous System
Skeletal Autonomic
(Somatic)
Sympathetic Parasympathetic

5. Somatic System
Nerves to/from Brain
spinal cord
control muscle
movements Sensory
Neuron
somatosensory
inputs
Both Voluntary and
reflex movements Motor
Skin receptors Neuron
Skeletal Reflexes
Interneuron
simplest is spinal
reflex arc
Muscle

6. Autonomic System
Two divisions:
sympathetic
Parasympatheitic
Control involuntary functions
heartbeat
blood pressure
respiration
perspiration
digestion
Can be influenced by thought and emotion

7. Sympathetic
CENTRAL NERVOUS SYSTEM SYMPATHETIC
Brain
“ Fight or flight” Dilates pupil
response Stimulates salivation Salivary
Release adrenaline and Relaxes bronchi
glands
noradrenaline Spinal
Lungs
cord
Increases heart rate and
blood pressure Accelerates heartbeat
Heart
Increases blood flow to Inhibits activity Stomach
skeletal muscles
Pancreas
Inhibits digestive
Stimulates glucose Liver
functions
Secretion of adrenaline, Adrenal
nonadrenaline gland
Kidney
Relaxes bladder
Sympathetic Stimulates ejaculation
ganglia in male

8. Parasympathetic
CENTRAL NERVOUS SYSTEM PARASYMPATHETIC
Brain
“ Rest and digest ”
Contracts pupil
Stimulates salivation
system Constricts bronchi
Spinal
Calms body to cord
conserve and
Slows heartbeat
maintain energy
Lowers heartbeat, Stimulates activity
breathing rate,
blood pressure
Stimulates gallbladder
Gallbladder
Contracts bladder
Stimulates erection
of sex organs

9. Summary of autonomic
differences
Autonomic nervous system controls physiological arousal
Sympathetic Parasympathetic
division (arousing) division (calming)
Pupils dilate EYES Pupils contract
Decreases SALVATION Increases
Perspires SKIN Dries
Increases RESPERATION Decreases
Accelerates HEART Slows
Inhibits DIGESTION Activates
Secrete stress ADRENAL Decrease secretion
hormones GLANDS of stress hormones

10. Central Nervous System
Brain and Spinal Cord

11. Brain has 2 Hemispheres
Left & Right sides are
Corpus Callosum
separate Right
Corpus Callosum : Hemisphere
major pathway
between hemispheres
Some functions are
‘lateralized’
language on left
math, music on right
Lateralization is never Left
100% Hemisphere

12. The Nervous System:
Summary
Major structures of the
nervous
CNS, Somatic, Autonomic
Two hemispheres & 4 lobes
Organization
contralateral input & output
primary sensory areas
motor areas
Commissure
Localization of functions