Lecture 10 sensory system 06.11.24 (1)

Sensation

Sensation

The conscious or subconscious awareness of external or internal stimuli.

Sensory Neurons

Neurons that carry sensory information to the central nervous system (CNS).

Perception

The conscious awareness and interpretation of the meaning of sensations.

Sensory Modalities

Each unique type of sensation, such as pain, vision, and hearing.

General Senses

Somatic and visceral senses that provide information about conditions within the body.

Special Senses

Senses that include smell, taste, vision, hearing, and balance.

Sensory Receptor

A specialized cell or dendrite of a sensory neuron that detects stimuli.

Action Potential (AP)

An electrical impulse that travels along the neuron.

Generator Potential

A graded potential produced by free and encapsulated nerve endings in response to stimuli.

Receptor Potential

A postsynaptic potential caused by neurotransmitter release that may trigger an action potential.

Divergence

The spread of information from one neuron to several neurons, permitting broad distribution of input.

Convergence

Several neurons synapsing on the same postsynaptic neuron, allowing multiple patterns of activity to influence one output.

Acuity

The precision of stimulus location, influenced by the size and number of receptive fields.

Lateral Inhibition

A process that increases the contrast of signals in the nervous system by inhibiting signals from neighboring neurons.

Nociceptors

Pain receptors that are free nerve endings found in nearly every tissue in the body.

Prostaglandins

Compounds released during tissue injury that stimulate nociceptors, contributing to pain.

First-order Neurons

Sensory neurons that conduct impulses from sensory receptors into the CNS.

Second-order Neurons

Neurons that conduct messages from the spinal cord and brainstem to the thalamus.

Third-order Neurons

Neurons that conduct impulses from the thalamus to the primary somatosensory area of the cortex.