Special senses

Exteroceptors

Receptors that provide information about the external environment and detect stimuli outside the body

Interoceptors

Receptors that monitor internal body conditions and help maintain homeostasis

Proprioceptors

Receptors that monitor body position and movement, providing awareness of limb orientation

Nociceptors

Receptors that respond to tissue damage to produce the sensation of pain

Mechanoreceptors

Receptors that respond to physical distortion, pressure, or touch

Thermoreceptors

Receptors specialized to detect changes in temperature

Chemoreceptors

Receptors that monitor the chemical composition of body fluids

Photoreceptors

Receptors in the eyes that detect light intensity and changes in light

Receptor Specificity

The concept that each receptor has a characteristic sensitivity based on its structure and accessory cells

Receptive Field

The specific area monitored by a single receptor; smaller fields allow for greater sensitivity and precision

Phasic Adaptation

Fast-adapting receptors that quickly stop firing during a constant stimulus

Tonic Adaptation

Slow-adapting receptors that continue firing at a reduced rate during constant stimulation

Nasal Conchae and Meati

Cranial structures that create air tunnels to distribute airborne molecules across the olfactory epithelium

Olfactory Epithelium

Located at the roof of the nasal cavity and contains specialized olfactory receptors

Cribriform Plate

A bone structure with small holes that allow olfactory receptor fibers to pass into the brain

Olfactory Bulb

The site where sensory fibers synapse with multiple neurons before signals travel further

Olfactory Tract

Pathway that carries signals to the temporal lobe or limbic system

Cranial Nerve VII (Facial)

Transmits taste information from the front two-thirds of the tongue

Cranial Nerve IX (Glossopharyngeal)

Transmits taste information from the back one-third of the tongue

Rods

Photoreceptors that detect light intensity and function in low-light vision

Cones

Photoreceptors responsible for color vision and sharp detail

Cornea

The transparent front part of the eye where light first enters

Lens

Structure that changes shape to focus light on the retina

Iris

Controls pupil size to regulate the amount of light entering the eye

Retina

The inner layer of the eye containing photoreceptors and neural cells

Ciliary Muscle

Muscle that changes lens shape by adjusting tension on ligaments

Fovea Centralis

The region with the highest concentration of cones for sharp vision

Optic Disc

The blind spot where the optic nerve exits and no photoreceptors are present

Choroid

The vascular layer that supplies nutrients and oxygen to the eye

Macula Lutea

A region of the retina responsible for detailed central vision with many cones

Cochlea

The spiral structure responsible for hearing

Cochlear Duct

A fluid-filled chamber where sound vibrations activate receptors

Organ of Corti

The receptor organ in the cochlea containing hair cells

Tectorial Membrane

A membrane that moves hair cells to generate sound signals

Semicircular Canals

Structures that detect rotational movement

Ampullae

Enlarged regions of semicircular canals containing rotation receptors

Cristae

Sensory structures with hair cells that detect rotational movement

Utricle and Saccule

Structures that detect linear acceleration and gravity

Maculae

Sensory structures that use crystals to detect head position