2nd sem finals

• Central Nervous System (CNS)


  Brain & Spinal Cord
• Peripheral Nervous System (PNS)

  • Cranial Nerves (12)
  • Spinal Nerves (31)
  • Sensory (Afferent)
  • Motor (Efferent)
  • Autonomic (internal organs & blood vessels)
• Cerebral Cortex


  • Center for a human's highest functions, governing thought, memory, reasoning, sensation and voluntary movement
• Left Cerebral Hemisphere


  • Dominant in most (95%) people, including those who are left-handed
  • Responsible for propositional language (grammar, syntax, and semantics), speech, and calculation
• Right Cerebral Hemisphere


  • Responsible for three dimensional, or spatial, perception and nonverbal ideation
  • Allows superior recognition of faces

  
• Lobes of the Cerebral Cortex

  • Frontal lobe
  • Parietal lobe
  • Occipital lobe
  • Temporal lobe
• Frontal lobe


  • Areas concerned with personality, behavior, emotions, and intellectual function
  • Precentral gyrus initiates voluntary movement
• Parietal lobe


  • Areas concerned with sensation
  • Postcentral gyrus is the primary center for sensation
• Occipital lobe


  • Primary visual receptor center
• Temporal lobe


  • Primary auditory reception center, with functions of hearing, taste, and smell
• Wernicke's area


  Associated with language comprehension
• Broca's area


  Mediates motor speech
• Frontal eye field


  Control of visual attention and eye movements
• Prefrontal cortex


  Concentration, orientation, abstracting ability, judgment, and problem-solving ability
• Telencephalon


  Most anterior region of the brain, composed of surface grey matter (the cerebral cortex) and underlying white matter, with deep masses of grey matter

  
• Structures of the Telencephalon

  • Cerebral hemispheres
  • Subcortical structures/Limbic system (Amygdala, Hippocampus, Olfactory bulbs)
  • Basal ganglia (Caudate Nucleus, Putamen, Globus pallidus)
  • White matter tracts

  
• Limbic System


  • Involved in emotional, memory, and motivational processes that connect to other parts of the brain
• Amygdala


  Located in the medial temporal lobe, whose role involves processing emotional responses- specifically fear, anxiety, and aggression
• Hippocampus


  Consolidation of information, including short-term, long-term, and spatial memory
• Basal ganglia


  Cluster of nuclei found deep to the neocortex of the brain, involved in motor control and a gate-keeping mechanism for the initiation of motor movement
• Diencephalon


  Caudal part of the forebrain that occupies the central region of the brain, acts as a primary relay and processing center for sensory information and autonomic control
• Thalamus


  Situated at the core of the diencephalon, deep to the cerebral cortices, relays and integrates a myriad of motor and sensory impulses between the higher centre of the brain and the peripheries

  
• Hypothalamus


  Principal visceral control center of the brain, mediates a broad range of functions via its connections with the endocrine, autonomic (visceral motor), somatic motor, and limbic systems, maintaining a state of homeostasis
• Cerebellum


  Largest part of the hindbrain, plays a role in motor movement regulation and balance control, coordinates gait and maintains posture, controls muscle tone and voluntary muscle activity
• Brainstem


  Connects the cerebrum of the brain to the spinal cord and cerebellum, involved in breathing, consciousness, blood pressure, heart rate, and sleep

  
• Midbrain

  Serves as the connection between the pons and the diencephalon, contains the relay nuclei involved in the processing of auditory and visual information
• Pons


  Largest part of the brainstem, contains two respiratory centers that coordinate with the main respiratory center in the medulla, serves as a bridge linking different regions of the nervous system
• Medulla


  Conduit for many ascending and descending nerve tracts that carry information between the brain and spinal cord, houses the centers for vital functions of the body such as heart rate, blood pressure, and breathing
• Spinal Cord


  Long, cylindric structure of nervous tissue, occupies the upper two thirds of the vertebral canal, mediates reflexes of posture control, urination, and pain response
• Segments of the Spinal Cord

  • Cervical: C1 to C8
  • Thoracic: T1 to T12
  • Lumbar: L1 to L5
  • Sacral: S1 to S5
  • Coccygeal
• Cauda equina


  Lumbar and sacral roots travel the longest intraspinal distance and fan out like a horse's tail at L1–2
• Lumbar puncture


  Performed at the L3–4 or L4–5 vertebral interspace to avoid injury to the spinal cord
• Crossed representation


  • Left cerebral cortex receives sensory information from and controls motor function to the right side of the body, and vice versa

  
• Sensory Pathways


  • Spinothalamic (Anterolateral) tract (pain, temperature, and crude or light touch)
  • Posterior (Dorsal) Columns (position, vibration, finely localized touch)
• Motor Pathways


  • Corticospinal or Pyramidal Tract (voluntary movement)
  • Extrapyramidal Tracts (maintain muscle tone and control body movements)
  • Cerebellar System (coordinates movement, maintains equilibrium, helps maintain posture)
• Upper motor neurons (UMN)

  Originate primarily in the cerebral cortex and extend towards the brainstem or spinal cord, where they synapse
• Lower motor neurons (LMN)

  Originate in the brainstem (cranial nerve nuclei) and the spinal cord (anterior horn) and project to innervate muscles and glands throughout the body
• Spinal nerves


  31 pairs, contain both sensory and motor fibers, enter and exit the cord through roots
• Dermatome


  Circumscribed skin area that is supplied mainly from one spinal cord segment through a particular spinal nerve
• Types of Reflexes


  • Deep Tendon reflexes
  • Superficial
  • Visceral
  • Pathologic