CHAPTER 6

Amplitude

The height of a sound wave, which determines its loudness. Greater amplitude corresponds to a louder sound.

Amusia

A disorder characterized by an inability to recognize musical tones or reproduce them. Often referred to as 'tone deafness.'

Cochlea

A spiral-shaped, fluid-filled structure in the inner ear that translates sound waves into nerve impulses through hair cells.

Conductive Deafness (Middle-Ear Deafness)

Hearing loss caused by damage to the middle ear, preventing sound waves from being properly conducted to the inner ear.

Frequency

The number of sound wave cycles per second, measured in Hertz (Hz). Frequency determines the pitch of the sound.

Frequency Theory

Theory suggesting that the rate of nerve impulses sent to the brain matches the frequency of the tone, which is used to detect pitch.

Hair Cells

Sensory cells located in the cochlea that transform sound vibrations into electrical signals for the auditory nerve.

Nerve Deafness (Inner-Ear Deafness)

Hearing loss resulting from damage to the cochlea, hair cells, or auditory nerve, impacting the ability to transmit sound to the brain.

Oval Window

A membrane-covered opening in the cochlea that receives vibrations from the middle ear and transmits them to the inner ear fluid.

Pinna

The external part of the ear that collects sound waves and funnels them into the ear canal toward the eardrum.

Pitch

The perception of how high or low a sound is, determined by the frequency of sound waves.

Place Theory

Theory that suggests different areas of the cochlea are activated by different frequencies, which helps us perceive pitch.

Primary Auditory Cortex (Area A1)

The brain region in the temporal lobe responsible for processing auditory information and essential for sound perception.

Timbre

The quality or color of a sound that distinguishes it from others, even if they have the same pitch and loudness.

Tinnitus

A condition characterized by a persistent ringing, buzzing, or hissing sound in the ears, often due to hearing loss or ear injury.

Tympanic Membrane

Also known as the eardrum, it vibrates in response to sound waves and transmits these vibrations to the ossicles in the middle ear.

Capsaicin

A compound found in chili peppers that stimulates pain receptors, often used in topical treatments for pain relief due to its desensitizing effect on sensory neurons.

Dermatome

An area of the skin supplied by sensory neurons from a single spinal nerve. Different dermatomes correspond to specific spinal nerves.

Endorphins

Natural pain-relieving chemicals produced by the body that bind to opioid receptors, reducing the perception of pain and promoting a sense of well-being.

Gate Theory

Theory suggesting that non-painful input can close 'gates' to painful input, thus blocking pain perception in the central nervous system.

Neuropathic Pain

Chronic pain caused by damage or dysfunction in the nervous system, often described as burning, tingling, or shooting pain.

Nocebo

A negative placebo effect where expectations of adverse effects contribute to real negative symptoms, often psychological in origin.

Numbsense

A condition in which a person lacks conscious sensory perception in a particular area but can respond to stimuli unconsciously.

Opioid Mechanisms

Biological processes that involve opioid receptors in the brain, reducing pain perception through endogenous and exogenous opioids.

Pacinian Corpuscle

A type of sensory receptor in the skin that detects mechanical pressure and vibration, essential for tactile sensation.

Periaqueductal Gray Area

A region in the midbrain involved in pain suppression; it activates descending pain-modulation pathways and is influenced by opioids.

Placebo

An inert substance or treatment that can produce real, positive effects on health due to the patient's belief in its efficacy.

S1 (Primary Somatosensory Cortex)

The brain area responsible for processing sensory information from the body, such as touch, temperature, and pain, located in the parietal lobe.

Semicircular Canals

Structures in the inner ear that detect rotational movement and help maintain balance through fluid movement and sensory cells.

Somatosensory System

The sensory system responsible for processing information related to touch, temperature, body position, and pain across the body.

Adaptation

The process by which sensory receptors become less responsive to constant stimuli over time, resulting in decreased perception of the stimulus.

Cross-Adaptation

A reduced response to one stimulus after exposure to a different but similar stimulus, commonly seen in taste and smell.

Olfaction

The sense of smell, which involves detecting and processing odor molecules through the olfactory system.

Olfactory Cells

Specialized sensory neurons located in the nasal cavity that detect odor molecules and transmit signals to the brain.

Papillae

Small bumps on the surface of the tongue that contain taste buds, which are responsible for detecting different flavors.

Supertasters

Individuals with a high density of taste buds, making them more sensitive to bitter and other strong flavors compared to average tasters.

Synesthesia

A condition in which stimulation of one sensory pathway leads to automatic, involuntary experiences in a second sensory pathway, such as 'seeing' sounds as colors.

Taste Buds

Clusters of sensory cells on the tongue and in the mouth that detect different flavors and send taste signals to the brain.

anterior cingulate cortex

region of the brain located in the frontal part of the cingulate cortex. It plays a crucial role in various functions, including: Emotion Regulation, Pain Perception, Cognitive Functions, Attention