Exam 2 power points

Question 1

Cerebral cortex

Answer 1

Center of functions governing thought, memory, reasoning, sensation, and voluntary movement
Each half of cerebrum is hemisphere
Each hemisphere divided into four lobes: frontal, parietal, temporal, and occipital

Question 2

Cerebral cortex (cont.)

Answer 2

Lobes have areas that mediate specific functions:

1) Frontal lobe concerned with personality, behavior, emotions, and intellectual function
- Precentral gyrus of frontal lobe initiates voluntary movement
2) Parietal lobe’s postcentral gyrus is primary center for sensation
3) Occipital lobe is primary visual receptor center
4) Temporal lobe behind ear, has primary auditory reception center, taste, and smell

Question 3

Cerebral cortex: Damage to specific cortical areas produces a?

Answer 3

Corresponding loss of function:
Motor weakness
Paralysis 
Loss of sensation
Impaired ability to understand and process language

Question 4

Cerebellum

Answer 4

• Coiled structure located under occipital lobe concerned with coordination of voluntary movements, equilibrium, and muscle tone
• Does not initiate, but coordinates and smoothes movements
• Coordinates many different muscles needed in playing piano, swimming, or juggling
• Adjusts and corrects voluntary movements, but operates entirely below conscious level

Question 5

Spinal Cord

Answer 5

• Long cylindrical structure of nervous tissue that occupies upper two thirds of vertebral canal from medulla to lumbar vertebrae L1 to L2
• Main highway for ascending and descending fiber tracts that connect the brain to spinal nerves, and it mediates reflexes
• Nerve cell bodies, or gray matter, arranged in butterfly shape with anterior and posterior “horns”

Question 6

Pathways of CNS

Answer 6

• Crossed representation is notable feature of nerve tracts
  
  • Left cerebral cortex receives sensory information from and controls motor function to right side of the body
  • Right cerebral cortex likewise interacts with left side of body
• Knowledge of where fibers cross midline will help interpret clinical findings

Question 7

Sensory pathways

Answer 7

• Millions of sensory receptors are embroidered into skin, mucous membranes, muscles, tendons, and viscera
  
  • Monitor conscious sensation, internal organ functions, body position, and reflexes
  • Sensation travels in afferent fibers in peripheral nerve, through posterior (dorsal) root, and into spinal cord
• There, may take one of two routes: spinothalamic tract or posterior (dorsal) columns