Lecture 29: Somatic System / Reflex Arc

Question 1

Reflex Movements are generated in the….

Answer 1

• Spinal cord

Question 2

The reflex arc consists of…

Answer 2

• Stimulus
• Receptor
• Afferent Neuron
• Interneuron (CNS)
• Efferent neuron
• Effector
• Response

Question 3

What is a reflex?

Answer 3

• A predictable response

Question 4

The withdrawal reflex…

Answer 4

• We only really realise we’ve hurt ourselves after removing the painful stimulus
• Before the signal reaches the brain

Question 5

What is the corticospinal (pyramidal) pathway?

Answer 5

• Upper motor neuron
• Crosses over at medulla
• Lower motor neuron
• Controls precise movement of hands and feet

Question 6

What are the non-corticospinal pathway?

Answer 6

• End up on to the final common pathway
• Involved in regulation of posture
• E.g. walking, chewing, smiling

Question 7

Integration between motor and sensory systems occur in the…How does this happen?

Answer 7

• Basal ganglia
• They modify movement using a ‘loop’ system with the cortex
• The cerebellum (‘little brain’) is also involved
• Ensures the selected movement is coordinated, and guided by sensory feedback

Question 8

Procedural memory…

Answer 8

• Development of automatic movements / motor programmes

Question 9

The basal ganglia is a collection…

Answer 9

• Of cell bodies below cortex

Question 10

Cerebral cortex integration…

Answer 10

• Basal ganglia
• Thalamus
• Cerebellum
• Brainstem
• Spinal cord
• Interneurons
• Anterior horn motor neurons
• Somatic effectors (skeletal muscle)