sensory-system-reviewer

Sensory reception

The process by which an animal's nervous system detects and responds to stimuli from the environment.

Sensory transduction

The conversion of stimulus energy into a change in membrane potential, which can then be transmitted to the central nervous system (CNS) as an electrical signal.

Sensory transmission

The process by which sensory signals are transmitted to the CNS via sensory nerves.

Sensory perception

The process by which the brain interprets sensory signals and gives rise to conscious experiences.

Sensory receptors

Specialized cells that are tuned to detect specific types of stimuli from the environment.

Receptor potential

A change in membrane potential triggered by a stimulus binding to a sensory receptor.

Action potentials

All-or-none signals that are transmitted from sensory receptors to the CNS via sensory nerves.

Graded signals

Receptor potentials that have an amplitude proportional to the intensity of the stimulus.

Neuronal sensory receptors

Sensory receptors that produce action potentials directly.

Non-neuronal sensory receptors

Sensory receptors that release neurotransmitters when stimulated, which bind to receptors on sensory neurons and cause them to produce action potentials.

Frequency coding

The encoding of stimulus intensity in the frequency of action potentials produced by sensory neurons.

Amplification

The process of increasing the strength or magnitude of sensory signals during transduction.

Adaptation

A decrease in responsiveness to a constant stimulus.

Mechanoreceptors

Sensory receptors that sense physical deformation caused by mechanical energy such as pressure, touch, stretch, motion, and sound.

Electromagnetic receptors

Sensory receptors that detect forms of electromagnetic energy, such as light, electricity, and magnetism.

Pain receptors

Sensory receptors that detect extreme pressure, temperature, and certain chemicals that can damage animal tissues.

Chemoreceptors

Specialized sensory receptors that detect changes in the chemical composition of the environment.

Thermoreceptors

Specialized sensory receptors that detect changes in temperature.

Photoreceptors

Light-detecting sensory cells found in the retinas of the eyes of many animals, including humans.

Rod cells

Photoreceptor cells responsible for scotopic vision (night vision) and detecting motion and shapes in low-light environments.

Cone cells

Photoreceptor cells responsible for color vision and visual acuity in bright light conditions.

Compound eyes

Visual organs found in many arthropods, consisting of several thousand light detectors called ommatidia that provide a wide field of view and the ability to detect motion effectively.

Single-lens eyes

Eye structures found in camera-like eyes, characterized by a single, transparent lens that helps focus light onto a light-sensitive retina.

Eyelids

Outermost protective parts of the eye that act as shutters and barriers against the external environment.

Pupil

The opening in the center of the iris that regulates the amount of light entering the eye.

Pupil

The black, central opening in the iris that changes size in response to varying light conditions.

Sclera

The tough, white, outer layer of the eye that provides structural support and protection.

Iris

The colored part of the eye surrounding the pupil that regulates the size of the pupil.

Ciliary muscle

A ring of smooth muscle tissue located behind the iris and in front of the lens that plays a crucial role in accommodation.

Cornea

The clear, outermost layer of the eye that acts as a protective barrier and helps focus light onto the lens.

Lens

A transparent, flexible structure located behind the iris that fine-tunes the focus of light onto the retina.

Retina

The innermost layer of the eye that contains light-sensitive cells responsible for capturing visual stimuli.

Rod cells

Responsible for low-light vision and detecting motion, more abundant in the peripheral retina.

Cone cells

Responsible for color vision and high-resolution detail, sensitive to specific ranges of wavelengths.

Optic nerve

A bundle of nerve fibers that carries electrical signals from the retina to the brain's visual processing centers.

Choroid

A layer of blood vessels located between the retina and the sclera that supplies blood and nutrients to the retina.

Aqueous humor

A clear, watery fluid found in the front portion of the eye that helps maintain the eye's shape and nourishes the cornea and lens.

Vitreous humor

A gel-like substance that fills the space behind the lens and in front of the retina, helping to maintain the eye's shape.

Medial rectus muscle

Situated on the inner side of the eye, near the nasal side of the eye socket, responsible for eye abduction.

Lateral rectus muscle

Situated on the outer side of the eye, near the temporal side of the eye socket, responsible for eye abduction.

Photoreceptor cells

Cells in the retina that contain light-sensitive pigments and convert light into electrical signals.

Visual pigments

Light-sensitive molecules found in photoreceptor cells that consist of opsin and retinal.

Sensory transduction

The process by which light stimuli are converted into electrical signals in the retina.

Rod cells

Photoreceptor cells responsible for low-light vision, not sensitive to color.

Cone cells

Photoreceptor cells responsible for color vision, sensitive to specific wavelengths of light.

Volume

Determined by sound wave amplitude, influences the perception of loudness.

Pitch

Influenced by sound wave frequency, influences the perception of high or low tones.

Basilar membrane

Varying structure in the cochlea that allows the ear to distinguish pitch based on different vibration frequencies.

Tympanic membrane

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

Oval window

A membrane beneath the stapes bone in the middle ear that transmits vibrations to the cochlea.

Cochlea

A bony chamber in the inner ear involved in hearing, contains the organ of Corti with hair cells.

Mechanoreceptors

Specialized sensory receptors located throughout the skin, muscles, tendons, and joints that detect mechanical stimuli.

Central nervous system

The brain and spinal cord, responsible for processing and interpreting tactile signals.

Nociceptors

A type of mechanoreceptor that detects noxious stimuli and contributes to the perception of pain.

Thermoregulation

The ability to perceive changes in temperature through touch receptors in the skin.

Protective Mechanism

The sense of touch serves as a protective mechanism, alerting us to potential hazards in our environment, such as sharp objects or extreme temperatures.

Gustation system

The sense of taste, allows us to identify and learn how foods taste.

Tongue

The sensory organ responsible for tasting.

Chemoreceptors

Transduction of sense of taste are called chemoreceptors, which detect the molecules in our food, contained within taste buds on the surface of the tongue.

Receptors of Taste

Clusters of nerve cells that transmit sensory messages to your brain, located in taste buds on the tongue.

Sweet

Perceived at the tip of the tongue. It is associated with sugars and is often found in foods like fruits, candies, and desserts.

Sour

Detected along the sides of the tongue. Sour taste is associated with acids and can be found in foods like citrus fruits and vinegar.

Salty

Recognized on the front sides of the tongue. Saltiness is associated with sodium-containing compounds and is found in various savory foods.

Bitter

Detected at the back of the tongue. Bitter taste is often associated with alkaline substances and can be found in foods like coffee, dark chocolate, and certain vegetables.

Umami

Perceived throughout the tongue, but particularly on the back. Umami is associated with savory or meaty flavors and is found in foods like meat, mushrooms, and certain cheeses.

Epithelial Receptor Cells

Cells that register and respond to different molecules of food, located in taste buds on the tongue.

Gustatory cells

Cells responsible for the actual taste.

Basal cells

Stem cells that replace gustatory cells every week.

Taste Pore

Small openings on the surface of the tongue through which tastants enter and come into contact with gustatory cells.

Gustatory Hair (Microvilli)

Tiny projections that extend from the surface of gustatory cells into the taste pore, containing the actual receptors that interact with tastants.

Ageusia

The complete loss or absence of the sense of taste.

Hypogeusia

A reduced or diminished sense of taste.

Dysgeusia

A distortion or alteration of the sense of taste.

Taste Blindness

Informally used to describe conditions like ageusia or severe taste impairments.