Voluntary and Involuntary Actions

 
12.4 Voluntary and Involuntary Actions
 

Voluntary actions:

  • Example: writing, walking, drinking
  • Interpretation of information in the cerebrum
  • According to our own will
  • Effector: skeletal muscle
  • Involves somatic nervous system
  • Involve processes of analysis, integration, and interpretation of information
 

Involuntary actions:

  • Example: heartbeat, sneezing, blood pressure
  • Interpretation of information in the medulla oblongata
  • Occurs automatically without notice
  • Effector: smooth muscle, cardiac muscle, and glands
  • Do not involve processes of analysis, integration and interpretation of information
  • Involves the autonomic nervous system
 

Spinal reflex action involved skeletal muscle as an effector:

  • This action is an involuntary action controlled by the spinal cord and responds quickly and spontaneously toward the external stimulus
  • The nerve impulse is sent from receptors to the spinal cord and from the spinal cord to effectors
  • The pathway passed by the nerve impulse in a reflex action is known as the reflex arc
 

Reflex arc of knee jerk (involve two types of neurones):

  • Stimulus: the tendon below the kneecap is knocked
  • Sensory receptors: stretch out the quadriceps muscle (stretch receptor) and triggers a nerve impulse
  • Sensory neurone: sends nerve impulses to the spinal cord
  • Motor neurone: receives the nerve impulse from the sensory neurone and send it to the effector
  • Effector: quadriceps muscle contracts
  • Response: leg kicks forward
 

Reflex arc involving three neurones:

  • Stimulus: Finger touches fire.
  • Sensory receptor: Skin (heat receptor) detects the heat and nerve impulse is triggered.
  • Sensory neurone: Send nerve impulse to relay neurone.
  • Relay neurone (in the spinal cord): Strech out the quadriceps muscle.
    • Receives nerve impulse from the sensory neurone and send it to the motor neurone.
  • Motor neurone: Receives nerve impulse from relay neurone and transmits it to the effector.
  • Effector: Biceps contract, triceps relax.
  • Response: Hand pulls away from fire.
 

 

Voluntary and Involuntary Actions

 
12.4 Voluntary and Involuntary Actions
 

Voluntary actions:

  • Example: writing, walking, drinking
  • Interpretation of information in the cerebrum
  • According to our own will
  • Effector: skeletal muscle
  • Involves somatic nervous system
  • Involve processes of analysis, integration, and interpretation of information
 

Involuntary actions:

  • Example: heartbeat, sneezing, blood pressure
  • Interpretation of information in the medulla oblongata
  • Occurs automatically without notice
  • Effector: smooth muscle, cardiac muscle, and glands
  • Do not involve processes of analysis, integration and interpretation of information
  • Involves the autonomic nervous system
 

Spinal reflex action involved skeletal muscle as an effector:

  • This action is an involuntary action controlled by the spinal cord and responds quickly and spontaneously toward the external stimulus
  • The nerve impulse is sent from receptors to the spinal cord and from the spinal cord to effectors
  • The pathway passed by the nerve impulse in a reflex action is known as the reflex arc
 

Reflex arc of knee jerk (involve two types of neurones):

  • Stimulus: the tendon below the kneecap is knocked
  • Sensory receptors: stretch out the quadriceps muscle (stretch receptor) and triggers a nerve impulse
  • Sensory neurone: sends nerve impulses to the spinal cord
  • Motor neurone: receives the nerve impulse from the sensory neurone and send it to the effector
  • Effector: quadriceps muscle contracts
  • Response: leg kicks forward
 

Reflex arc involving three neurones:

  • Stimulus: Finger touches fire.
  • Sensory receptor: Skin (heat receptor) detects the heat and nerve impulse is triggered.
  • Sensory neurone: Send nerve impulse to relay neurone.
  • Relay neurone (in the spinal cord): Strech out the quadriceps muscle.
    • Receives nerve impulse from the sensory neurone and send it to the motor neurone.
  • Motor neurone: Receives nerve impulse from relay neurone and transmits it to the effector.
  • Effector: Biceps contract, triceps relax.
  • Response: Hand pulls away from fire.