Sense organs Flashcards
Accommodation
Focusing of the lens of the eye to allow close-up and distant vision.
Ampulla
Enlargement in each semicircular canal that contains the receptor structure (crista)
Analgesia
Decreased perception of pain
Anterior chamber
Portion of the aqueous compartment of the eye in front of the Iris
Aqueous compartment
- Compartment of the eye in front of the lens and ciliary body that contains aqueous humor
- Divided into anterior and posterior chambers by the iris
Aqueous humor
Watery fluid that fills the aqueous compartment of the eye that is produced and drained from the anterior chamber by the canal of Schlemm
Bulbar conjunctiva
Transparent membrane that covers the front portion of the eyeball
Canal of Schlemm
- Structure that drains aqueous humor from the anterior chamber of the eye.
- Located at edge of the anterior chamber where Iris and cornea meet.
Canthus
Corner of the eyelids where they come together.
Choroid
- Portion of the uvea that consists mainly of blood vessels and pigment.
- Located between the sclera and retina.
Ciliary body
Ring-shaped portion of the uvea located immediately behind the Iris and contains the ciliary muscles that adjust the shape of the lens and the cells that produce aqueous humor.
Ciliary muscles
Multi unit smooth muscles of the ciliary body that adjusts the shape of the lens.
Cochlear duct
Long, fluid-filled tube that runs the length of the cochlea and contains the organ of Corti
Cones
Photoreceptors in the retina that perceive color and detail
Conjunctiva
Thin, transparent membrane that covers the front portion of the eyeball and lines the interior surfaces of the eyelid
Conjunctival sac
Space between bulbar and palpebral conjunctiva.
Cornea
Clear window on the front of the eyeball that admits light to the interior of the eye and is part of the outer fibrous layer
Crista ampullaris
Receptor structure of the semicircular canals
Cupula
Gelatinous structure that sits on top of the receptor hairs in the crista ampullaris is of the semicircular canals
Endolymph
Fluid in the receptor structures of the inner ear
Eustachian tube
Tube that connects the middle ear cavity with the pharynx and allows equalization of the air pressure on either side of the tympanic membrane
External auditory canal
Tube that begins at the base of the pinna and carries sound waves to the tympanic membrane.
External ear
Outer portion of the ear. Contains pinna, external auditory canal, and tympanic membrane
Extraocular muscles
Small skeletal muscles that move and position the eyeball
Eyelids
Conjunctiva-lined folds of skin that protect and cover the eyeball
Fundus of the eye
Caudal interior surface of the eye that includes the retina and optic disc
General senses
- Senses that are distributed throughout the body.
2. Receptors are simple and keep the CNS informed about general conditions inside and outside the body
Gustatory sense
Sense of taste
Inner ear
Most internal portion of the ear contained within the temporal bone and contains hearing and equilibrium structures
Lacrimal apparatus
Tear-producing and draining structures of the eye
Lacrimal gland
Main tear-producing gland located dorsal and lateral to the eyeball inside the bony orbit
Lacrimal puncta
Openings in the eyelid margins located near the medial canthi that drain tears away from the eye
Limbus
Junction of the cornea and sclera
Macula
Part of sensory epithelium in the vestibule of the inner ear that senses head position and that consists of hair cells converted by a gelatinous mass containing otoliths.
Meibomian glands
Tarsal glands of the eyelid margins that produce a waxy substance that helps prevent tears from overflowing on the face
Middle ear
- Air-filled cavity in temporal bone that contains ossicles and opening of the Eustachian tube.
- Amplifies and transmits sound wave vibrations from eardrum to the cochlea
Modulation
Dorsal horn neurons in the spinal cord can amplify or suppress pain impulses before they reach the brain
Nasolacrimal duct
Tube that carries tears from the lacrimal sac to the nasal cavity
Nictitating membrane
Thin, translucent third eyelid that moves across the eye to moisten and protect the eye. No muscles attach to it.
Nociception
Pain perception
Nociceptors
Pain receptors
Optic disc
Area of retina where nerve fibers on its surface converge to form the beginning of the optic nerve. Contains no photoreceptors
Organ of Corti
- Receptor organ of hearing located in the cochlea that consists of hair cells with a gelatinous structure resting on the hairs surrounded by fluid.
- Vibrations of fluid cause distortion of the hairs, which generate nerve impulses that are interpreted by the brain as sound.
Otoliths
Tiny crystals of calcium carbonate that lie in the gelatinous matrix that covers the hair cells of the macula.
Oval window
- Membrane-covered opening into the cochlea that the stapes lies against.
- Vibrations of the oval window membrane move the fluid in the cochlea, which stimulates the organ of Corti
Palpebral conjunctiva
Transparent membrane that lines the inner portion of the eyelid
Photoreceptors
Rods and cones that convert photons of light energy to nerve impulses that are interpreted by the brain as vision
Pinna
Externally visible part of the ear that collects sound waves and funnels them into the external ear canal
Posterior chamber
Portion of the aqueous compartment of the eye behind the Iris
Pressure
Sense of something pressure on the body surface
Proprioception
Sense of body position and movement
Pupil
Opening in the center of the Iris
Retina
Inner nervous layer of the eye where photoreceptors are located.
Rods
Photoreceptors in the retina that perceive dim light images in shades of gray
Round window
Membrane covered opening into the cochlea that functions as a pressure relief device
Saccule
One of two saclike spaces in the vestibule that contain sensory structure that monitor head position
Sclera
White portion of the eyeball that is part of the outer fibrous layer
Semicircular canals
Three semicircular canals in each inner ear that are part of the vestibular system and sense rotary motion of the head
Special senses
Taste, smell, hearing, equilibrium, and vision
Suspensory ligaments
Tiny ligaments that attach to the periphery of the lens of the eye and connect it to the ciliary body
Tapetum lucidum
Highly reflective area of the choroid in the eye that acts to amplify light to improve vision in dim lighting
Tectorial membrane
Gelatinous sheet that lies on the hair cells of the organ of Corti that bend the hairs to create sensory nerve impulses that turn into sound interpretation
Transduction
Conversion of a sensory impulse to a nerve impulse
Transmission
Conduction of a nerve impulse along a nerve fiber
Utricle
One of two saclike spaces in the vestibule of the inner ear that contain sensory structures that monitor head position
Uvea
Middle, vascular layer of the eye that contains the choroid, ciliary body, and the Iris
Vestibule of the ear
Portion of the inner ear that senses head position and contains the utricle and saccule
Visceral sensations
Inner body sensations that include hunger, thirst, and hollow organ stretching
Vitreous compartment
Compartment of the eye behind the lens and ciliary body that contains vitreous humor
Vitreous humor
Soft, gelatinous fluid that fills the vitreous compartment of the eye