CNS,PNS, ANS & Disorders

1. NERVOUS SYSTEM
T. Naga Varalakshmi,
Assistant Professor,
Dept of Pharmacology
Nirmala College of
Pharmacy, Guntur

2. 1. Sensory input – gathering information
 To monitor changes occurring inside and outside the
body (changes = stimuli)
2. Integration –
 to process and interpret sensory input and decide if
action is needed.
3. Motor output
 A response to integrated stimuli
 The response activates muscles or glands
Functions of the Nervous System

3. Classification of Nervous System

4. Neuron
• Cells of the nervous system are called nerve cells or
neurons which carry "messages" through an
electrochemical process called Action Potential.
• The human brain has about 100 billion neuron.
• Dendrites receive signals.
• The cell body integrates signals.
• The axon transmits action potential. The myelin
sheath makes the signal travel faster.
• Synaptic terminals transmit signals.

6. Basic nerve cell and Synapse

7. T.S. of Nerve

9. Action Potential

11. Some Neurotransmitters
Neurotransmitter Location Some Functions
Acetylcholine
Neuron-to-muscle
synapse
Activates muscles
Dopamine Mid-brain Control of movement
Epinephrine Sympathetic system Stress response
Serotonin
Midbrain, pons,
medulla
Mood, sleep
Endorphins Brain, spine Mood, pain reduction
Nitric Oxide Brain Memory storage

12. Supporting Cells (Neuroglia or Glia)

14. CENTRAL
NERVOUS SYSTEM

15. Parts of Brain

16. Meninges of brain

17. Divisions of the Brain
Major Division Subdivision Structures
Prosencephalon
(Forebrain)
Telencephalon
Neocortex; Basal Ganglia; Amygdala;
Hippocampus; Lateral Ventricles
Diencephalon
Thalamus; Hypothalamus; Epithalamus;
Third Ventricle
Mesencephalon
(Midbrain)
Mesencephalon Tectum; Tegmentum; Cerebral Aqueduct
Rhombencephalon
(Hindbrain)
Metencephalon Cerebellum; Pons; Fourth Ventricle
Myelencephalon Medulla Oblongata; Fourth Ventricle

18. Telencephalon Diencephalon
Mesencephalon
(Midbrain)
Metencephalon
Myelencephalon
The subdivisions of the brain

22. CEREBRUM
 The cerebrum is the largest portion of the brain, consists of 2
Cerebral hemispheres, which are connected by Corpus Callosum.
 The surface of the brain is marked by Gyri, Sulci, and Fissures.
 A thin layer of Gray matter, lines outside of the Cerebral cortex
and contains 75% of the cell bodies in the nervous system.
 Beneath the cortex is the White matter made up of myelinated
nerve fibers connecting the cell bodies of the cortex with the rest of
the nervous system.

24. Lobes of the Brain

25. Functional Areas of the Cerebral Cortex

27. Thalamus and Hypothalamus

28. Basal Ganglia

29. Brain Function: Cerebral Lateralization

30. Primary Motor Cortex Primary Somatosensory Cortex

31. Association areas of brain

32. Brain Stem
It consists of the
Midbrain,
Pons
 Medulla oblongata
MIDBRAIN:
 Located between Diencephalon and Pons,
 Contains bundles of myelinated nerve fibers that convey impulses to
and from higher parts of the brain, and masses of gray matter that
serve as reflex centers.
 It is the main centre for auditory and visual reflexes.

33. PONS
 Lying between the midbrain and medulla oblongata, transmits impulses
between the brain and spinal cord.
 It contains centers that regulate the rate and depth of breathing.
MEDULLA OBLONGATA
 It transmits all ascending and descending impulses between the brain and
spinal cord.
 It contain
 Cardiac center that controls heart rate,
 Vasomotor center for blood pressure control,
 Respiratory center that works along with the Pons, to control
the rate and depth of breathing.

34. Brain Stem: Midbrain, Pons & Medulla

35. Major Functions
1. Sensory perception
2. Voluntary control of movement
3. Language
4. Personality traits
5. Sophisticated mental events, such as thinking memory,
decision making, creativity, and self-consciousness
1. Inhibition of muscle tone
2. Coordination of slow, sustained movements
3. Suppression of useless patterns of movements
1. Relay station for all synaptic input
2. Crude awareness of sensation
3. Some degree of consciousness
4. Role in motor control
1. Regulation of many homeostatic functions, such as temperature
control, thirst, urine output, and food intake
2. Important link between nervous and endocrine systems
3. Extensive involvement with emotion and basic behavioral patterns
1. Maintenance of balance
2. Enhancement of muscle tone
3. Coordination and planning of skilled voluntary muscle activity
1. Origin of majority of peripheral cranial nerves
2. Cardiovascular, respiratory, and digestive control centers
3. Regulation of muscle reflexes involved with equilibrium and posture
4. Reception and integration of all synaptic input from spinal cord;
arousal and activation of cerebral cortex
5. Role in sleep-wake cycle
Cerebral cortex
Basal nuclei
Thalamus
Hypothalamus
Cerebellum
Brain stem
(midbrain, pons,
and medulla)

36. Cerebellum
 The cerebellum is made up of two hemispheres connected by a
vermis.
 A thin layer of gray matter called the cerebellar cortex lies
outside a core of white matter.
 The cerebellum communicates with other parts of the CNS
through cerebellar peduncles.
 Functions –
 integrate sensory information about the position of
body parts
 Coordinates skeletal muscle activity
 Maintains posture.

38. SPINAL CORD
 The spinal cord consists of 31segments, each of
which gives rise to a pair of spinal nerves.
 Two deep longitudinal grooves (anterior median
fissure and posterior median sulcus) divide the cord
into right and left halves.
 White matter, made up of bundles of myelinated
nerve fibers (nerve tracts), surrounds a butterfly-
shaped core of gray matter .
 A central canal contains cerebrospinal fluid.

39. 39

42.  To transmit impulses to and from
the brain,
 Carrying sensory information to the
brain are called ascending tracts;
 Descending tracts carry motor
information from the brain.
Functions of
the Spinal Cord

44. Cranial Nerves

48. Autonomic Nervous System
 Parasympathetic
 Sympathetic Nervous
System

52. Disorders of Nervous System
1. Alzheimer’s Disease
2. Parkinson’s Disease
3. Dementia
4. Cerebral Hypoxia
5. Multiple sclerosis
6. Phenylketonuria
7. Encephalitis
8. Neuritis
9. Spina bifida
10. Depression
11. Psychosis
12. Mania
13. Tumours
14. Neuropathy
15. Meningitis
16. Stroke
17. Hydrocephalus etc