Nervous System Flashcards

Reflex Arc Components

  • Receptors: Detect stimuli and generate nerve impulses.
  • Sensory Neurons: Carry information from receptors to the CNS.
  • CNS: Processes information and decides on a motor response.
  • Motor Neurons: Carry information from the CNS to effectors.
  • Effectors: Muscles and glands that respond to motor nerve impulses.

Reflexes

  • Reflexes are rapid, predictable, and involuntary responses to stimuli.
  • Reflexes are protective.
  • Involve the somatic or autonomic nervous system.
  • A reflex arc is the pathway followed by nerve impulses to produce a response; consists of all components of the general model.
  • Testing reflexes assesses nervous system health and aids in diagnosing disease.

Somatic Nervous System Reflex (Example: Patellar Tendon Reflex)

  • Receptors: Detect rapid stretch of the quadriceps muscle.
  • Sensory Neurons: Carry impulses to the spinal cord (CNS).
  • CNS: Processes impulses in the spinal cord.
  • Motor Neurons: Carry impulses to the quadriceps muscle.
  • Effector: Quadriceps muscle contracts.

Autonomic Nervous System Reflex (Example: Temperature Regulation)

  • Receptors: Detect increase in skin temperature.
  • Sensory Neurons: Carry impulses to the CNS.
  • CNS: Hypothalamus processes impulses.
  • Motor Neurons: Carry impulses to sweat glands.
  • Effectors: Sweat glands produce sweat, cooling the body.

Main Brain Regions

  • Cerebrum:
    • Sensory awareness.
    • Initiates voluntary motor activities.
    • Analyses information, learning.
    • Stores memory
  • Cerebellum:
    • Smooth, coordinated skeletal muscle movements.
    • Regulates posture and maintains balance.
  • Brain Stem:
    • Controls basic survival functions.
    • Cardiac (heart rate), respiratory (breathing), and vasomotor (blood vessel diameter) control centers.

Lobes of the Cerebrum

  • Frontal Lobe:
    • Motor cortex for skeletal muscle control.
    • Processes emotions related to social interactions.
    • Problem-solving and learning.
  • Parietal Lobe:
    • Primary sensory cortex.
    • Conscious awareness of sensations.
  • Occipital Lobe:
    • Visual cortex.
  • Temporal Lobe:
    • Smell, hearing, and taste.