Somatic Nervous System (SNS) Functions

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What type of muscles are controlled by the autonomic nervous system?

Skeletal muscles

Smooth muscles (correct)

Cardiac muscles

All of the above

What is the main function of the somatic nervous system?

Innervating visceral organs

Controlling the contractions of skeletal muscles (correct)

Controlling visceral effectors, such as smooth muscle and cardiac muscle

Regulating glands and adipocytes

What is the role of the upper motor neuron in the somatic motor pathway?

Synapsing on the lower motor neuron (correct)

Triggering a contraction in the innervated muscle

Eliminating voluntary and reflex control over the innervated motor unit

Innervating a single motor unit in a skeletal muscle

What happens when the lower motor neuron is activated?

A contraction is triggered in the innervated muscle Signup and view all the answers

Where is the cell body of the lower motor neuron located?

In a nucleus of the brain stem or spinal cord Signup and view all the answers

What is the result of destroying a lower motor neuron?

Voluntary and reflex control over the innervated motor unit is eliminated Signup and view all the answers

What is the primary function of the corticobulbar tracts?

To provide conscious control over skeletal muscles that move the eye, jaw, and face Signup and view all the answers

Which cranial nerves are involved in the corticobulbar tracts?

III, IV, V, VI, VII, IX, XI, and XII Signup and view all the answers

What is the percentage of axons that cross the midline in the pyramids of the corticospinal tracts?

85% Signup and view all the answers

What is the term for the crossing of axons over to the opposite side of the spinal cord in the corticospinal tracts?

Decussation Signup and view all the answers

What is the region of the spinal cord where the axons in the anterior corticospinal tracts synapse on lower motor neurons?

Anterior gray horns Signup and view all the answers

What is the name of the diagrammatic representation of the primary motor cortex corresponding to specific regions of the body?

Motor homunculus Signup and view all the answers

What is the primary function of the corticospinal pathway?

Voluntary control over skeletal muscles Signup and view all the answers

What is the term used to describe the system that includes the corticospinal pathway?

Pyramidal system Signup and view all the answers

How many descending tracts are found in the corticospinal pathway?

Three pairs Signup and view all the answers

Where do the axons of the pyramidal cells synapse?

On the lower motor neurons in the spinal cord Signup and view all the answers

What structure do the corticobulbar tracts, lateral corticospinal tracts, and anterior corticospinal tracts enter?

The white matter of the internal capsule Signup and view all the answers

What is the term used to describe the region where the corticospinal pathway emerges on either side of the midbrain?

Cerebral peduncles Signup and view all the answers