NEUROLOGY 2 MARKS : PART 11

  • CENTRAL NERVOUS SYSTEM:
  • Central nervous system (CNS): The central nervous system is that part of the nervous system that consists of the brain and spinal cord.
  • The brain plays a central role in the control of most bodily functions, including awareness, movements, sensations, thoughts, speech, and memory.
  • The spinal cord is connected to a section of the brain called the brainstem and runs through the spinal canal.
  • Cerebrospinal fluid surrounds the brain and the spinal cord and also circulates within the cavities (called ventricles) of the central nervous system.
  • PERIPHERAL NERVOUS SYSTEM (PNS) :
  • The peripheral nervous system (PNS) is the division of the nervous system containing all the nerves that lie outside of the central nervous system (CNS). The Primary role of the PNS is to connect the CNS to the organs, limbs, and skin.
  • The peripheral nervous system (PNS) connects the central nervous system (CNS) to sensory organs such as the eye and ear, other organs of the body, muscles, blood vessels and glands.
  • The peripheral nerves include the 12 cranial nerves.
  • Voluntary control – the nerves that carry instructions from your brain to your limbs.
  • NAME THE 12 PAIRS OF CRANIAL NERVES:
  1. I Olfactory (Smell)
  2. II Optic (Sight)
  3. III Oculomotor (Moves eyelid and eyeball and adjusts the pupil and lens of the eye)
  4. IV Trochlear (Moves eyeballs)
  5. V Trigeminal (Facial muscles incl. chewing; Facial sensations)
  6. VI Abducens (Moves eyeballs)
  7. VII Facial (Taste, tears, saliva, facial expressions)
  8. VIII Vestibulocochlear (Auditory)
  9. IX Glossopharyngeal (Swallowing, saliva, taste)
  10. X Vagus (Control of PNS e.g. smooth muscles of GI tract)
  11. XI Accessory (Moving head & shoulders, swallowing)
  12. XII Hypoglossal (Tongue muscles – speech & swallowing)
  • HOW MANY PAIRS OF SPINAL NERVES:
  1. 8 pairs of cervical nerves (C1-C8)
  2. 12 pairs of thoracic nerves (T1 – T12)
  3. 5 pairs of lumbar nerves (L1-L5)
  4. 5 pairs of sacral nerves (S1-S5)
  5. 1 pair of coccygeal nerves (Co1)
  • MEDULLA OBLONGATA:
  • The medulla oblongata helps regulate breathing, heart and blood vessel function,digestion, sneezing, and swallowing.
  • This part of the brain is a center forrespiration and circulation. 
  • Sensory and motor neurons (nerve cells) from the forebrain and midbrain travel through the medulla.
  • If the medulla oblongata or the nerves that pass through it are injured or damaged, May experience paralysis or loss of muscle coordination. lose your sense of touch, develop vertigo or have trouble swallowing.
  • PONS:
  • Besides the medulla oblongata,  brainstem also has a structure called the pons.
  • The pons is a major structure in the upper part of your brainstem.
  • It is involved in the control of breathing, communication between different parts of the brain, and sensations such as hearing, taste, and balance.
  • Damage to the pons can result in serious problems as this brain area is important for connecting areas of the brain that control autonomic functions and movement.
  • Locked-in syndrome is a condition resulting from damage to nerve pathways in the pons that connect the cerebrum, spinal cord, and cerebellum.
  • CEREBELLUM:
  • The cerebellum is located behind the top part of the brain stem.
  • The cerebellum coordinates voluntary movements such as posture, balance, coordination, and speech, resulting in smooth and balanced muscular activity. 
  • The cerebellum receives information from the sensory systems, the spinal cord, and other parts of the brain and then regulates motor movements.
  • BASAL GANGLIA:
  • The basal ganglia are a collection of nuclei found on both sides of the thalamus, outside and above the limbic system, but below the cingulate gyrus and within the temporal lobes.
  • Basal ganglia are strongly interconnected with the cerebral cortex, thalamus, and brainstem, as well as several other brain areas.
  • The basal ganglia are associated with a variety of functions, including control of voluntary motor movements, procedural learning, habit learning, eye movements, cognition, and emotion.
  • HYPOTHALAMUS:
  • The hypothalamus is a small region of the brain. It’s located at the base of the brain, near the pituitary gland.
  • While it’s very small, the hypothalamus plays a crucial role in many important functions, including: releasing hormones. regulating body temperature.

Hormones of the Hypothalamus

  • Thyrotropin-releasing hormone (TRH)
  • Gonadotropin-releasing hormone (GnRH)
  • Growth hormone-releasing hormone (GHRH)
  • Corticotropin-releasing hormone (CRH)
  • Somatostatin.
  • Dopamine.

MENINGES:

  • The main functions of the meninges include: Protecting the brain and spinal cord form mechanical injury.
  • Providing blood supply to the skull and to the hemispheres. Providing a space for the flow of cerebrospinal fluid.
  • There are three layers of meninges around the brain and spinal cord.
  • The outer layer, the dura mater, is tough, white fibrous connective tissue.
  • The middle layer of meninges is arachnoid, a thin layer resembling a cobweb with numerous threadlike strands attaching it to the innermost layer.

CATHERINE SHALINI RAJA
M.P.T.,MIAP.,PGDYN
CARDIO RESPIRATORY PHYSICAL THERAPIST
FITNESS & SPORTS REHABILITATION SPECIALIST.

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