Neuroscience Chapter on Resting Membrane Potential

Specialized sensory receptors that detect heat and temperature changes, essential for regulating body temperature.

Responsible for sensing touch, pressure, and vibrations. Various types exist, each with specific roles in tactile perception.

Sensory receptors responsible for taste and smell, detecting chemical stimuli.

Free nerve endings located in the skin, responsible for detecting light touch and rapid changes in touch sensation.

Found in the dermis, these receptors detect vibrations and contribute to sensitivity in light touch.

Slowly adapting receptors in the skin, essential for detailed perception of textures and edges.

Tonic receptors within the skin that respond to sustained stretch, providing proprioceptive feedback.

Sodium ions (Na+) are the primary trigger for activating salt receptors, triggering a taste sensation.

Hydrogen ions (H+) are the main players in detecting acidity, leading to the sour taste perception.

Umami, a savory taste sensation, is triggered by the presence of monosodium glutamate.

These receptors are specialized sensory cells found in muscles that provide information about body positioning and movement.

A type of proprioceptor found in muscle spindles, intrafusal fibers are central for monitoring muscle stretch and regulating reflexes.

Golgi tendon organs are mechanoreceptors embedded in tendons that respond to muscle tension, contributing to coordination and injury prevention.

Cold receptors are most active when exposed to temperatures below 30°C, playing a crucial role in thermoregulation and environmental response.

Warm receptors are activated by increasing temperatures, peaking at around 45°C, and signaling the presence of potentially harmful temperatures.

The measurement of how high or low a sound is, determined by the frequency of sound waves. It is perceived by humans as pitch.

The measurement of the intensity or strength of a sound wave, determined by the amplitude of the wave. It is perceived by humans as loudness.

The outer ear includes the pinna, which collects sound waves, and the external auditory canal, which transmits sound to the middle ear.

The middle ear contains three tiny bones called ossicles (malleus, incus, and stapes). These bones amplify and transmit sound vibrations from the eardrum to the inner ear.

The innermost part of the ear, containing the cochlea and vestibular system. The cochlea converts sound vibrations into electrical signals, while the vestibular system helps with balance and spatial orientation.

The cochlea is a fluid-filled, snail-shaped structure within the inner ear. It is lined with the basilar membrane, which vibrates in response to sound waves, triggering hair cells responsible for sound transduction.

The basilar membrane is a flexible structure within the cochlea that vibrates in response to sound waves. Different regions of the membrane are sensitive to different frequencies, allowing for frequency discrimination.

Hair cells are specialized sensory cells located in the cochlea. They are responsible for converting mechanical sound vibrations into electrical signals that the brain can interpret.

Inner hair cells (IHC) are primarily responsible for transducing sound vibrations into electrical signals, which are then transmitted to the brain via the auditory nerve.

Outer hair cells (OHC) help amplify sound and improve frequency resolution. They have a unique ability to change their length in response to electrical signals, enhancing the cochlea's response.

The stria vascularis is a specialized structure in the inner ear that plays a crucial role in generating and maintaining the endocochlear potential. It is responsible for the high potassium concentration in endolymph, which is essential for the proper functioning of hair cells, the sensory receptors of the inner ear.

The endocochlear potential is a positive electrical potential that exists within the endolymph of the inner ear, primarily generated by the stria vascularis. This potential gradient is crucial for the transduction of sound waves into electrical signals that the brain can interpret.

Outer hair cells are responsible for amplifying sounds and improving frequency selectivity, while inner hair cells are responsible for sending auditory information to the brain via the auditory nerve.

The cochlear amplifier, mainly attributed to the activity of outer hair cells, significantly enhances the sensitivity of the ear to quiet sounds and sharpens frequency discrimination. This mechanism is crucial for understanding complex sounds like speech.

Sound intensity is encoded by the firing rate of auditory nerve fibers, which increases with louder sounds, and the number of activated fibers. Frequency encoding is more complex, with lower frequencies being encoded via phase locking and higher frequencies encoded spatially along the cochlea.

Defined areas of skin that evoke responses from specific neurons, crucial for localizing stimuli.

Refers to the ability of the sensory system to distinguish between closely spaced stimuli. Closely spaced stimuli activate fewer neurons, while distant stimuli activate separate neurons, leading to better perception.

A process where sensory receptors respond less to a constant stimulus over time.

Receptors that respond quickly to changes in stimuli and then rapidly adapt. They are ideal for detecting movement and transitions in sensation.

Receptors that respond slowly to stimuli and maintain responsiveness for a longer duration. These receptors help you sense constant stimuli and keep track of ongoing sensations.

The process of enhancing the perception of stimuli by suppressing activity in neighboring neurons. This helps to sharpen the contrast and make the stimulus location clearer.

Sensory information is not just passively received but can be influenced by descending pathways in the brain. For example, pain can be modulated by factors like stress or expectation.

The thalamus acts as a central relay station for most sensory pathways before they reach the cortex. This allows the brain to process and integrate information from different senses in a coordinated way.

Different sensory modalities are processed in specialized regions of the cortex, allowing for distinct and detailed perception of each type of sensory information.

Descending pathways from higher brain regions can regulate the flow of sensory information, influencing how we perceive and respond to sensory stimuli.