0. Anatomy & Physiology

• Neurons

  • basic unit of the nervous system
  • consists of a cell body with attached filamentous extensions called dendrites that carry information toward the cell body and a filamentous axon that carries information away from the cell body
    • axons: insulated by a lipoprotein covering called myelin that forms a sheath
  • type 1: Interneuron
    • carries nervous impulses between neurons
  • type 2: sensory neuron
    • detects environmental stimuli such as touch, light, or pain and transmits messages to the brain or spinal cord
  • type 3: motor neuron
    • conveys messages from the central nervous system to muscles, causing contraction, or to gland, triggering secretion

  1.1 Central Nerves System (CNS)

  • composed of the brain & spinal cord

  • integrate and interpret sensory input and direct all activities of the body

    1.1.1 The Brain

    • integrates and stores information, interprets sensory input, and directs all body functions
    • Crainium-dura mater-subdural space-arachnoid-subarachnoid space-pia mater-cerebrospinal fluid & ventricles
    • cerebrospinal fluid (CSF): a clear liquid composed of water, protein, glucose, and minerals
    • cerebrum: the largest part of the brain, interprets sensory information, directs motor activities, and houses intelligence and personality
      • two hemispheres (control the opposite side) are connected by nerve gibers of the corpus callosum so the two hemispheres are able to communicate & share info
      • the outer region of the cerebrum is the cerebral cortex: a distinctively wrinkled region described as gray matter because it consists of neuron cell bodies that appear dull gray
      • the inner region of the cerebrum consists of axons and is described as white matter because the axons’ myelin imparts white color to this area
      • the inner part of the cerebrum also contains basal ganglia that control muscle coordination and steady movement
      • lobes:
        • frontal lobe: controls voluntary muscle actions & the muscles of speech; govern personality, judgement, memory, and other cognitive functions
        • temporal lobes: responsible for senses (hearing, taste, smell), the ability to understand spoken languages
        • parietal lobes: interpret the meaning of incoming sensory signals that arrive from the opposite of the body
        • occipital lobe: interpret visual input
    • thalamus
      • lies below the cerebrum
      • relays sensory information to the correct areas of the cerebral cortex
    • hypothalamus
      • lies below the thalamus
      • controls vital body functions such as temperature, blood pressure, breathing, appetite, and the sleep/awake cycle
      • produces some hormones, controls part of the pituitary gland, and serves as intermediary between the nervous and endocrine systems
    • cerebellum
      • lies below the occipital lobe
      • controls smooth voluntary movement
      • enables equilibrium & muscle tone
    • medulla oblongate
      • lies at the base of the brain
      • helps regulate heart & respiratory rate
    • pons
      • lies at the base of the brain
      • links your brain to your spinal cord
      • handles unconscious processes and jobs, such as your sleep-wake cycle and breathing

    1.1.2 The Spinal Cord

    • carries nerve impulses between the brain and the body
    • Continuous with the medulla oblongata, extends from the foramen magnum to the first or second lumbar vertebra
    • Vertebrae, meninges, and the CSF protect the spinal cord
    • 31 pairs of spinal nerves originate in the spinal cord
    • spinal cord also directs some muscular reflexes in response to sensory input

  1.2 Peripheral Nervous System (PNS)

  • composed of nerves, ganglia, sensory receptors, and sensory organs

    1.2.1 The Somatic System

    • controls voluntary muscle actions
    • receive input from sensory receptors & sensory organs
    • include 12 pairs of cranial nerves & 12 pairs of spinal nerves; these nerves are composed of sensory neurons/motor neurons/both

    1.2.2 The Autonomic Nervous System (ANS)

    • control glands & involuntary muscle (including cardiac muscle & smooth muscles in the walls of blood vessels, bronchi, intestines, and other abdominal organs)
    • subdivision 1: sympathetic subdivision
      • composed of nerves that arise from the thoracic and lumbar areas of the spinal cord
      • prepares organs & glands for “fight or flight,” triggering causing bronchial dilation and increased heart rate & blood pressure
    • subdivision 2: parasympathetic subdivision
      • includes nerves arising from the cranial & sacral regions
      • regulate the resting functions of the body
    • subdivision 3: enteric subdivision
      • a network of nerves in the abdomen that control the gastrointestinal organs

• Diagnostic Tests & Procedures

  2.1 Noninvasive

  • history
  • imaging tests: x-ray, CT, ultrasound, MRI
  • electroencephalography (EEG)

  2.2 Invasive

  • lumbar puncture (spinal tap)
  • myelography: a radiopaque dye is injected into the subarachnoid space to visualize the spinal cord structure
  • aniography: visualize the cerebral circulation

1. Brain & Spinal Cord Trauma

• The Glasgow Coma Scale (GCS) is a common diagnostic procedure when it comes to neurological traumas, it measures mental function, sensory responsiveness, and motor ability

1.1 Epidural and Subdural Hematomas

1.1.1 epidural hematoma

• symptoms typically appear within a few hours of head trauma
• signs & symptoms: sudden headache, dilated pupils, nausea, and often vomiting, increased drowsiness, perhaps hemiparesis
• if untreated: unconsciousness, coma, and death occur

1.1.2 subdural hematomas

• onset is delayed; this delayed onset may mimic the symptoms of a TIA, stroke, or dementia
• signs & symptoms: diplopia
• etiology:
• diagnosis:
• treatment:

1.2 Cerebral Concussion

• possible bruising of the cerebral tissue that can be caused by back and forth movement of the head
• signs & symptoms:
• etiology:
• diagnosis:
• treatment:

1.3 Cerebral Contusion (contrecoup insult)

• bruising of tissue along or just beneath the surface of the brain
• signs & symptoms:
• etiology:
• diagnosis:
• treatment:

1.4 Depressed Skull Fracture

• a break or fracture in one of the bones of the cranium

2. Intervertebral Disk Disorders

3. Functional Disorders

Developmental and Congenital Disorders