DO YOU HAVE THE NERVE?

1. DO YOU HAVE THE NERVE? Kcom Anatomy Fellows 2017-18

2. Overview

3. Central Nervous System (CNS) • Impulse: The Spinal Cord Ends in the Vertebral Column at the L1/L2 Levels in Adults • The Spinal Cord continues into the lower lumbar vertebral segments as the Cauda Equina (Latin: Horse’s Tail).

4. The Skull • How Many Bones Do You Think Are in Our Skull? • Answer: There are a total of 22 bones that make up our skull • 8 cranial bones that encase our brain • 14 facial skeletal bones that make up our underlying facial features

5. Brain Overview • The Brain is composed of 3 main Segments: • The Cerebrum is the largest and is responsible for most of our neural processes • The Cerebellum is more posterior and inferior and is primarily for balance and fine tuning motor control • The brain stem is the conduit of axons from the brain into the spinal cord and then into the body as the PNS

6. The Vertebral Column • The Spinal Cord is protected by the vertebral column, which will allow it to travel down the body to deliver the Peripheral Nervous System to the Body • There are a total of 33 vertebral Segments: • 7 Cervical • 12 Thoracic • 5 Lumbar • 5 Sacral (fused) • 4 Coccygeal (fused)

7. Protection to Our CNS • The Meninges • 3 Layers: • Dura Mater (toughest) • Arachnoid Mater (Filled with CSF – cerebral spinal fluid to cushion and protect the brain) • Pia Mater (Closest to the brain/spinal cord and anchors it to the bones of the skull and spinal cord) • Impulse: The meninges are continuous from the brain all the way to the bottom of the spinal cord.

8. Case Files #1 • J. Brudzinski is a 20 year old male who attends a local college and lives in the communal dormitories on campus. He is brought into the ER with Fever, Confusion, and Neck Stiffness. 2 minutes into the examination he vomits and then goes quickly into a coma. His vaccination status is unknown. • What is the likely diagnosis? • A. Brain Hemorrhage • B. Common Cold • C. Meningitis • D. Tendonitis • E. Anxiety • Impulse: A Lumbar Puncture or Spinal Tap would be done to diagnose this condition.

9. The Cerebrum FRONTAL LOBE PARIETAL LOBE FRONTAL LOBE TEMPORAL LOBE PARIETAL LOBE OCCIPITAL LOBE TEMPORAL LOBE OCCIPITAL LOBE

10. Brain Functions • Impulse: The nerves for motor function crisscross in the brainstem effectively leading to the left cerebral hemisphere controlling motor function to the right side of the body and vise versa. Personality/Motor Function Sensory Personality/Motor Function Sensory Hearing Sight Sight Hearing

11. Case Files #2 • PG is a 25-year-old railroad worker that is rushed to the ER with a railroad spike protruding from his skull. CT of the patient shows injury to the left frontal lobe. Neurosurgery is performed and the patient makes a partial recovery. What deficits would be seen in this patient after the procedure? • A. Motor problems on the right side of the body • B. Motor problems on the left side of the body • C. Loss of sensation in his arms • D. Hearing Loss in the right ear • E. Sight Loss in the left eye

12. Anatomical Basis of Stroke • Impulse: The circle of Willis gives off 3 main branches that supply the brain with blood: • Anterior, Posterior, and Middle Cerebral Arteries

13. Cranial Nerves 1-12 • Impulse: Bell’s Palsy or facial muscle paralysis is due to inflammation or damage to Cranial Nerve VII, the facial Nerve.

14. Case Files #3 • D.R., a 26-year-old restaurant server, is brought into the ER after a motorcycle accident. He is alert and under goes neurological testing to access brain damage. Cranial nerve testing reveals that he has lost his sense of smell in both nostrils. What Cranial Nerve is responsible for his sense of smell? • A. CN III Oculomotor • B. CN X Vagus • C. CN XII Hypoglossal • D. CN. VI Abducens • E. CN I Olfactory

15. Anatomy of a Nerve • Impulse: Dendrites receive incoming signals from other neurons via neurotransmitters, while axons carry signals away from the neuron to either another neuron or to a particular target organ, such as skeletal muscle.

16. Action Potential • Impulse: The separation between the schwann cells and myelin on axons are called Nodes of Ranvier. This allows a phenomenon called saltatory conduction to be possible.

17. Anatomy Question • What is the substance that wraps around nerve axons to increase their speed of signal transmission? • A. Glutamine • B. Ribosomes • C. Neurotransmitters • D. Myelin • E. Glucosamine

18. Spinal Cord Overview

19. Spinal Cord Layers • Impulse: The White matter in both the brain and spinal cord is made up only of axons covered by myelin (a specialized fat or lipid), while the gray matter is composed of neuronal cell bodies. White Matter Dura Mater Arachnoid Pia Mater Gray Matter Ventral Median Fissure

20. Spinal Cord Continued • Impulse: The Dorsal or posterior horn is for sensation, while the anterior or ventral horn is for motor control.

21. Peripheral Nervous System (PNS) • Impulse: Carpel Tunnel Syndrome is due to irritation or compression of the median nerve where it enters into the wrist from the arm.

22. Dermatomes • Impulse: Dermatome Maps allow physicians to access damage to a spinal cord segment or nerve root based on where it picks up sensory information from.