Somatic Nervous System Lecture Notes

These flashcards cover the key concepts related to the somatic nervous system, sensory receptors, and the pathways involved in sensation and motor control.

Somatic Nervous System

Part of the PNS responsible for conscious perception and voluntary motor control.

Afferent Impulses

Nerve impulses that travel from sensory receptors to the spinal cord.

Efferent Impulses

Nerve impulses that travel from the spinal cord to muscles, causing contraction.

Reciprocal Inhibition

Damping of efferent impulses to antagonist muscles during muscle contraction.

Sensation

The raw detection of a stimulus by sensory receptors.

Perception

The interpretation of sensations by the brain.

Mechanoreceptors

Receptors that detect touch, pressure, vibration, and stretch.

Thermoreceptors

Receptors that detect temperature changes.

Nociceptors

Receptors that detect tissue damage and signal pain.

Chemoreceptors

Receptors that detect chemical changes, primarily in taste and smell.

Photoreceptors

Receptors that detect light, enabling vision.

Somatotopy

Mapping of specific regions of the cortex to specific body areas.

Neuromuscular Junction

The synapse where lower motor neurons communicate with muscle fibers.

Corticospinal Tract

The main pathway for voluntary motor control that decussates in the medulla.

Sensory Homunculus

A visual representation of the body on the cortex, showing proportional cortical representation.

First-order Neuron

A neuron that transmits sensory information from receptors to the spinal cord or brainstem.

Second-order Neuron

A neuron that carries sensory information from the spinal cord or brainstem to the thalamus.

Third-order Neuron

A neuron that transmits sensory information from the thalamus to the primary somatosensory cortex.