flashcards

Somatosensory Transduction

The process by which mechanical stimuli are converted into electrical signals via ion channels opening in sensory receptors.

Ion Channels

Proteins embedded in the cell membrane that open in response to mechanical pressure, allowing positively charged ions like sodium to enter the cell.

Receptive Fields

Areas of sensory receptors that respond to stimulation, characterized by center-surround fields that enhance sensory detail.

Phasic Response

A short burst of neural firing followed by silence in response to stimulation.

Tonic Response

Sustained neural firing as long as the stimulus is present.

Homunculus

A map in the primary somatosensory cortex that represents the body based on sensory importance.

Pain Fibers

Types of nerve fibers that transmit pain signals, including free nerve endings, A-delta fibers, and C fibers.

Free Nerve Endings

Nerve endings that detect pain, temperature, and chemical irritation.

A-Delta Fibers

Myelinated fibers that conduct sharp, immediate pain.

C Fibers

Unmyelinated fibers that conduct dull, lingering pain.

Capsaicin Sensitivity

The response of C fibers to capsaicin, explaining the sensation of burning from spicy food.

Dorsal Column

The touch pathway that carries signals related to touch and proprioception.

Lateral Pathway

The pain pathway that carries signals related to pain and temperature sensations.

Gate Control Theory

The theory that non-painful stimuli can reduce pain by 'closing the gate' to pain signals.

TENS Stimulation

Transcutaneous Electrical Nerve Stimulation, a method that activates non-pain touch fibers to reduce pain.

Opioids

Substances that block pain by mimicking endorphins in the brain.

Primary Somatosensory Cortex (S1)

Located in the postcentral gyrus of the parietal lobe, this area processes contralateral sensory input.

Neuromuscular Junction

The site where motor neurons release neurotransmitters to stimulate muscle contractions.

Pyramidal Pathway

The motor pathway that originates in the primary motor cortex and controls voluntary movements.

Extrapyramidal Pathway

The motor pathway that originates in the basal ganglia and regulates posture and involuntary movement.

Proprioception

The body's ability to sense its position, movement, and orientation in space.

Motor Unit

A motor neuron and all the muscle fibers it controls.

Mirror Neurons

Neurons that fire both when performing an action and observing others perform the same action.

Movement Disorders

Pathological conditions affecting the ability to move, including paralysis and involuntary movements.

Huntington’s Disease

A progressive neurological disorder caused by basal ganglia degeneration resulting in involuntary jerky movements.

Parkinson’s Disease

A disorder caused by dopamine loss in the basal ganglia, characterized by tremors, rigidity, and bradykinesia.

Hair Cells

Sensory cells located in the cochlea that convert sound waves into electrical signals.

Cochlear Implants

Devices that bypass damaged hair cells by directly stimulating the auditory nerve.

Presbycusis

Age-related hearing loss, typically affecting the ability to hear higher frequencies.

Vestibular System

System that detects balance and head position, including the otolith organs and semicircular canals.

Taste Transduction

Process by which taste stimuli are converted into neural signals, involving ion channels and G-protein-coupled receptors.

Glomeruli

Clusters of neurons in the olfactory bulb that receive signals from olfactory receptors.

Visual Anatomy

Anatomical structures involved in vision, including the fovea and types of photoreceptors.

Visual Processing

The process of interpreting visual information, involving receptive fields and visual pathways.

Dorsal Stream

The pathway in visual processing that analyzes motion and spatial location.

Ventral Stream

The pathway responsible for object identification in visual processing.

Color Blindness

A condition resulting from missing or defective cones, affecting color perception.

Agnosia

The inability to recognize objects despite having intact vision.

Lateral Inhibition

A process that sharpens visual contrast by inhibiting neighboring cells.

Opponent Process Theory

A theory explaining color perception in terms of paired opposites.

Trichromatic Theory

A theory suggesting that three types of cones in the eye detect blue, green, and red wavelengths.

hearing transduction

The process by which sound waves are converted into neural signals in the auditory system

Central Hearing Loss

Damage to the auditory cortex which causes issues with interpreting sound

Conductive Hearing Loss

Hearing loss cased by problems in the middle ear that impede sound transmission. Ossicles make sound less loud if damaged

Sensorineural Hearing Loss

Damage to hair cells in inner ear or auditory nerve, often due to aging or exposure to lous noises

External Ear

Pinnae, Auditory Canal

Funnel sound waves into ear

Middle Ear

Ossicles: anvil, hammer, stirrup

Amplify and transmit sound vibration from eardrum to inner ear

Inner ear

Cochlea, ampulla, basilar membrane, semicircular canals and saccule/utricle

Process auditory info

Filled with fluid

Sound localization

Superior Olivary Complex in brain stem

Cochlear implants

Bypass damaged hair cells and directly stimulates auditory nerve

Dorsal Root Ganglion

Cluster of nerve cell bodies that transmits sensory info from the periphery to spinal cord

Motivational System

adds emotional response to pain

Somatosensory System

Processes sensations such as touch, temp, and pain from the body

Emotional Pain Processing

Perception and regulation of pain

Involves cingulate cortex and insula

Premotor Area

movements from external stimuli and planning voluntary movement

Supplementary Area

Preplanned sequences like playing an instrument

Motor Cortex Damage

leads to weakness/paralysis in voluntary movements

Basal Ganglia Damage

Can result in involuntary movement disorders

5 Tastes

Sweet, savory, umami, salty, sour

Regeneration of Olfactory Receptors

Regenerate regularly

Olfactory Pathway

Smell info from nose to the olfactory bulb to then the prefrontal cortex and amygdala

Fovea

Central region of the retina, responsible for sharp central vision and color perception

Rods

detect dim light

specialized for night vision

Cones

detect color and bright light

Visual Pathway

Retina —> optic nerve —> optic chiasm —> LGN —> primary visual cortex

LGN

thalamic relay nucleus for visual pathways, processing and conveying visual info to the primary visual cortex

On-center/Off Surround

center light excites, surround light inhibits

Off-center/On-Surround

Center light inhibits, surround light inhibits