Dr. Rafid Remthan AL-Temimi presents an overview of the organization of the nervous system. There are two main divisions: the central nervous system (CNS) comprising the brain and spinal cord, and the peripheral nervous system (PNS) outside the CNS. The CNS contains structures like the cerebrum, cerebellum, and brainstem. The PNS includes 12 pairs of cranial nerves and 31 pairs of spinal nerves. The autonomic nervous system is a division of the PNS that regulates involuntary body functions through the sympathetic and parasympathetic systems.

1. Done by
Dr. Rafid Remthan AL-Temimi
Clinical radiology
CABM ,DMRD,MBCHB,
‫الكلية‬ ‫اسم‬
:
‫المرحلة‬ ‫االسنان‬ ‫طب‬ ‫كلية‬
:
‫االول‬
‫ى‬
‫المادة‬
:
‫الكورس‬ ‫التشريح‬
:
‫االول‬
‫النظري‬
‫المحاضر‬
:
‫التميمي‬ ‫رمثان‬ ‫رافد‬ ‫الدكتور‬
National University Of
Science &Technology
College Of Dentistry

2. Organization of the Nervous System
Dr. Rafid Remthan AL-Temimi ; Clinical Radiology ( CABM) 2022
There are Two Anatomical Divisions:
• Central nervous system
(CNS):
 Brain
 Spinal cord
• Peripheral nervous system
(PNS):
• All the neural tissue outside CNS
• Afferent division (sensory input)
• Efferent division (motor output)
• Somatic nervous system
• Autonomic nervous system:
Sympathetic ANS
Parasympathetic ANC
‫والتكنول‬ ‫للعلوم‬ ‫الوطنية‬ ‫الجامعة‬
‫وجيا‬

3. The central nervous system (CNS) is
composed of the brain and spinal cord. These
neurons cannot regenerate if damaged.
Dr. Rafid Remthan AL-Temimi ; Clinical Radiology ( CABM) 2022
 BRAIN:
• Mass of nerve tissue
• Protected by membranes & the cranium or skull
 SPINALCORD:
• Goes down back of body from Medulla Oblongata
• Surrounded and protected by vertebrae
• Responsible for reflex actions
• Carries sensory and motor messages
• Spinal nerves are named for the region from which they
arise
‫والتكنول‬ ‫للعلوم‬ ‫الوطنية‬ ‫الجامعة‬
‫وجيا‬

4. Dr. Rafid Remthan AL-Temimi ; Clinical Radiology ( CABM) 2022
‫والتكنول‬ ‫للعلوم‬ ‫الوطنية‬ ‫الجامعة‬
‫وجيا‬

5. 1. CerebralHemispheres(Cerebrum)
• Largest section of the brain (Include more than half of the
brain mass)
• Responsible for: reasoning, thought, memory, speaking,
sensation, sight, hearing, voluntary body movement
• Paired (left and right) superior parts of the brain divided
by falx cerebri
• The surface is made of ridges (gyri) and grooves (sulci)
• Fissures (deep grooves) divide the cerebrum into lobes.
• Surface lobes of the cerebrum:
1. Frontal lobe.
2. Parietal lobe.
3. Temporal lobe.
4. Occipital lobe.
Dr. Rafid Remthan AL-Temimi ; Clinical Radiology ( CABM) 2022
‫والتكنول‬ ‫للعلوم‬ ‫الوطنية‬ ‫الجامعة‬
‫وجيا‬
falx cerebri
Right
cerebral
hemisphere
Left
cerebral
hemisphere
falx cerebri

6. :
2.Diencephalon
• Sits on top of the brain stem
• Enclosed by the cerebral hemispheres
• Made of three parts:
Dr. Rafid Remthan AL-Temimi ; Clinical Radiology ( CABM) 2022
1. Thalamus
2. Hypothalamus
3. Epithalamus
3.Cerebellum:
• Responsible for:
• coordination of muscles, balance,
posture, & muscle tone
‫والتكنول‬ ‫للعلوم‬ ‫الوطنية‬ ‫الجامعة‬
‫وجيا‬

7. :
4.BrainStem
• Attaches to the spinal cord
• Parts of the brain stem:
• Midbrain.
• Pons.
• Medulla oblongata.
Dr. Rafid Remthan AL-Temimi ; Clinical Radiology ( CABM), 2022
A. Midbrain:
• Mostly composed of tracts of nerve
fibers, responsible for:
• conducting impulses between brain
parts
• certain eye & hearing reflexes
‫والتكنول‬ ‫للعلوم‬ ‫الوطنية‬ ‫الجامعة‬
‫وجيا‬

8. B.Pons:
• The bulging center part of the brain stem
• Mostly composed of fiber tracts
• Responsible for:
• conducting messages to other parts of the
brain
• Reflex actions such as chewing, production of
saliva
Dr. Rafid Remthan AL-Temimi ; Clinical Radiology ( CABM) 2022
C. MedullaOblongata:
• Lowest part of brain stem, connects to the spinal
cord
• Responsible for:
• regulating heart beat, respirations,
swallowing, coughing, b/p
‫والتكنول‬ ‫للعلوم‬ ‫الوطنية‬ ‫الجامعة‬
‫وجيا‬

9. Meninges • Covers and protects the brain and spinal cord
Dr. Rafid Remthan AL-Temimi ; Clinical Radiology ( CABM) 2022
• Consists of 3 membranes:
1.Dura mater: thick, tough outer layer
2.Arachnoid membrane : middle delicate weblike layer
3.Pia mater: inner most layer with blood vessels to nourish the nerves
‫والتكنول‬ ‫للعلوم‬ ‫الوطنية‬ ‫الجامعة‬
‫وجيا‬

10. Ventricles
• Four hallow spaces located in the middle of the brain.
• Connected to each other
• Filled with fluid called cerebrospinal fluid
Dr. Rafid Remthan AL-Temimi ; Clinical Radiology ( CABM) 2022
Cerebrospinal Fluid((CSF ))
Circulates continuously from choroid
plexus in lateral venricle
Serves as shock absorber to protect brain
and spinal cord.
Carries nutrients to parts of brain and
spinal cord
helps remove metabolic products & wastes
after circulation, absorbed into the blood
vessels of the dura mater.
‫والتكنول‬ ‫للعلوم‬ ‫الوطنية‬ ‫الجامعة‬
‫وجيا‬

11. – Made of all nerves outside the brain and spinal cord
Dr. Rafid Remthan AL-Temimi ; Clinical Radiology ( CABM) 2022
(PNS) is made up of peripheral nerves that connect the CNS to the rest of the body.
These neurons can regenerate if damaged.
 12 pairs of cranial nerves
 31 pairs of spinal nerves
‫والتكنول‬ ‫للعلوم‬ ‫الوطنية‬ ‫الجامعة‬
‫وجيا‬

12.  PeripheralNervousSystem
• PNS can be subdivided into 2 divisions:
(1) Autonomic
• Cranial & spinal nerves connecting CNS to
heart, stomach, intestines, glands
• Controls unconscious activities
(2) Somatic
• Cranial & spinal nerves connecting CNS to skin
& skeletal muscles
• Oversees conscious activities
Dr. Rafid Remthan AL-Temimi ; Clinical Radiology ( CABM) 2022
‫والتكنول‬ ‫للعلوم‬ ‫الوطنية‬ ‫الجامعة‬
‫وجيا‬

13. A. Cranial Nerves:
• 12 pairs & their branches
• Some responsible for special
senses: sight, hearing, taste, smell
• Others receive sensations: touch,
pressure, pain, temperature
Dr. Rafid Remthan AL-Temimi ; Clinical Radiology ( CABM) 2022
‫والتكنول‬ ‫للعلوم‬ ‫الوطنية‬ ‫الجامعة‬
‫وجيا‬

14. Dr. Rafid Remthan AL-Temimi ; Clinical Radiology ( CABM) 2022
‫والتكنول‬ ‫للعلوم‬ ‫الوطنية‬ ‫الجامعة‬
‫وجيا‬

15. Cerebrum
from the telencephalon and diencephalon respectively :
1. olfactory nerve (CN I) ; Sense of smell
2. optic nerve (CN II); Sense of vision
Midbrain
1. oculomotor nerve (CN III) ; Eye movement
2. trochlear nerve (CN IV) ; Eye movement
Pons:
1. trigeminal nerve (CN V) Eye, jaws sensation/movement
2. abducens nerve (CN VI); Eye movement
3. facial nerve (CN VII); Face, scalp, tongue sensation/movement
4. vestibulocochlear nerve (CN VIII) ; Hearing, balance
Medulla oblongata:
1. glossopharyngeal nerve (CN IX) ; Taste, swallowing
2. vagus nerve (CN X) ; Autonomic control of viscera
3. accessory nerve (CN XI) ; Swallowing, pectoral girdle movement
4. hypoglossal nerve (CN XII) ; Tongue movement
Dr. Rafid Remthan AL-Temimi ; Clinical Radiology ( CABM) 2022
‫والتكنول‬ ‫للعلوم‬ ‫الوطنية‬ ‫الجامعة‬
‫وجيا‬

16. B.SpinalNerves
• 31 pairs & their branches
• carries messages to & from the
spinal cord
• Both sensory and motor nerves
• 31 spinal nerves:
– 8 cervical.
– 12 thoracic.
– 5 lumbar.
– 5 sacral.
– 1 coccygeal.
Dr. Rafid Remthan AL-Temimi ; Clinical Radiology ( CABM) 2022
‫والتكنول‬ ‫للعلوم‬ ‫الوطنية‬ ‫الجامعة‬
‫وجيا‬

17. AutonomicNervousSystem
• Helps maintain a balance in
involuntary functions of the
body. But allows the body to
react in times of emergency.
Dr. Rafid Remthan AL-Temimi ; Clinical Radiology ( CABM) 2022
Two divisions of ANS:
1. Sympathetic nervous
system: acts in emergency.
2. Parasympathetic nervous
system: counter acts the
sympathetic ns after the
emergency
‫والتكنول‬ ‫للعلوم‬ ‫الوطنية‬ ‫الجامعة‬
‫وجيا‬

18. Dr. Rafid Remthan AL-Temimi ; Clinical Radiology ( CABM) 2022
‫والتكنول‬ ‫للعلوم‬ ‫الوطنية‬ ‫الجامعة‬
‫وجيا‬

19. Dr. Rafid Remthan AL-Temimi ; Clinical Radiology ( CABM) 2021
‫والتكنول‬ ‫للعلوم‬ ‫الوطنية‬ ‫الجامعة‬
‫وجيا‬

20. Dr. Rafid Remthan AL-Temimi ; Clinical Radiology ( CABM) 2021
‫والتكنول‬ ‫للعلوم‬ ‫الوطنية‬ ‫الجامعة‬
‫وجيا‬