Special Senses Flashcards
Eye - Conjuctiva (Bulbar)
covers the anterior part of the sclera (white of the eye); stops at the junction between the sclera and the cornea
Eye - Conjuctiva (Palpebral)
covers the inner surface of both upper and lower eyelids
Lacrimal Gland
bilobed, tear shaped gland that with the primary function of secreting the aqueous portion of the tear film, thereby maintaining the ocular surface
Fibrous tunic - Cornea
front center part of the external tunic; functions as the eye’s window which lets the light in and bends the rays for better focusing power
Fibrous tunic - Sclera
covers nearly the entire surface of the eyeball; external surface being white colored
“white of the eye”
Vascular tunic - Iris
anterior most portion of the vascular tunic; functions as a moveable diaphragm between the anterior and posterior chambers
Vascular tunic - Choroid
takes up the posterior 5/6 of the bulb and is mainly comprised of blood vessels; main functions are oxygen supply and nutrition for the eye
Vascular tunic - Ciliary body/muscle
holds suspensory ligaments that attach to the lens and change lens shape for far and near vision; epithelium secretes aqueous humor
Vascular tunic - Suspensory ligaments
delicate fibrous membrane, composed of collagen fibers, which holds the lens of the eye in place
Vascular tunic - Pupil
middle of the iris; constricts or dilates in order to regulate the amount of light entering the eye
Nervous tunic - Neural retina
and
3 layers of cells
- photoreceptors (cones and rods)
- bipolar neurons
3, ganglion cells
nervous tissue responsible for photoreception
Nervous tunic - Pigmented epithelial layer
flat layer of epithelial cells; cover the ciliary body and posterior surface of the iris
Optic nerve
How does this relate to the blind spot?
transfers visual information from the retina to the vision centers of the brain via electrical impulses
axons that extend from the ganglionic cells into and through the optic disc converge to form the optic nerve as they exit the eye and extend toward the brain. the optic disk lacks photoreceptors, and consequently is called the blind spot becasue there are no receptors to detect an image that might fall there
Macula lutea
small yellowish area of the retina near the optic disk that provides central vision
Fovea centralis
What is the characteristic of this site?
small, central pit composed of closely packed cones in the eye. located in the macula lutea of the retina and responsible for sharp central vision
Lens
changes the focal distance of the eye; focuses the light rays that pass through it (and onto the retina) in order to create clear images of objects that are positioned at various distances
Anterior cavity - Aqueous humor
What are the two subdivisions?
front third of the eye that includes structures in front of the vitreous humor: the cornea, iris, ciliary body, and lens
AH: fills the spaces within the anterior cavity and provides nutrients to surrounding structures
Two chambers:
- Anterior chamber: between the posterior surface of the cornea and iris
- Posterior chamber: between the iris and front face of the vitreous
Posterior cavity - Vitreous humor
back two-thirds of the eye that includes the anterior hyaloid membrane and all of the optical structures behind it: the vitreous humor, retina, choroid, and optic nerve
VH: transparent, colorless, gelatinous mass that fills the space in the eye between the lens and the retina; helps support the shape of the eye and transmits light to the retina
External ear - Auricle
visible part of the ear that’s outside the head
External ear - External auditory meatus
passageway that leads from outside the head to the tympanic membrane, eardrum membrane; helps conduct soundwaves
External ear - Tympanic membrane/Tympanum
called eardrum, thin layer of tissue in the human ear that receives sound vibrations from the outer air and transmits them to the auditory ossicles, which are tiny bones
Middle ear - Malleus
small bone in the middle ear that transmits vibrations of the eardrum to the incus
Middle ear - Incus
a small anvil-shaped bone in the middle ear, transmitting vibrations between the malleus and stapes.
Middle ear - Stapes
a small stirrup-shaped bone in the middle ear, transmitting vibrations from the incus to the inner ear.
Middle ear - Auditory tube
tube that runs from the middle ear to the pharynx; to protect, aerate, and drain the middle ear
Inner ear - Cochlea
contains spiral organ of corti (receptor responsible for hearing); consists of tiny hair cells that translate the fluid vibration of sounds from its surrounding ducts into electrical impulses that are carried to the brain by sensory nerves
Inner ear - Cochlear duct
cavity filled with endolymph and is a component of the membranous labyrinth of the ear 4. It is held in position by the lamina of the modiolus; The cochlear duct subdivides the bony labyrinth into two perilymph chambers, namely the scala vestibuli anteriorly (opens into the vestibule) and the scala tympani posteriorly (ends at the round window
Inner ear - Tectorial membrane
ribbon-like strip of extracellular matrix that spirals along the entire length of the cochlea
Inner ear - Scala vestibuli
perilymph-filled cavity inside the cochlea of the inner ear that conducts sound vibrations to the cochlear duct. It is separated from the cochlear duct by Reissner’s membrane and extends from the vestibule of the ear to the helicotrema where it joins the tympanic duct.
Inner ear - Vestibular membrane
a membrane inside the cochlea of the inner ear. It separates the cochlear duct from the vestibular duct.
Inner ear - Spiral organ (of Corti)
receptor organ for hearing and is located in the mammalian cochlea. This highly varied strip of epithelial cells allows for transduction of auditory signals into nerve impulses’ action potential.
Inner ear - Scala tympani
one of the perilymph-filled cavities in the inner ear of the human. It is separated from the cochlear duct by the basilar membrane, and it extends from the round window to the helicotrema, where it continues as vestibular duct.
Inner ear - Basilar membrane
stiff structural element within the cochlea of the inner ear which separates two liquid-filled tubes that run along the coil of the cochlea, the scala media and the scala tympani.
Inner ear - Hair cells
the receptive cells of the inner ear. They are stretched along the cochlear duct in two rows (the inner and outer hair cells) positioned on a thickened ridge of the basilar membrane.
Semicircular canals - Lateral
detects angular acceleration of the head when the head is turned and the superior and posterior canals detect vertical head movements when the head is moved up or down.
Semicircular canals - Posterior
part of the vestibular system that detects rotation of the head around the antero-posterior (sagittal) axis, or in other words rotation in the coronal plane
Semicircular canals - Anterior
part of the vestibular system and detects rotations of the head in around the lateral axis, or in other words rotation in the sagittal plane
Its lateral extremity is ampullated, and opens into the upper part of the vestibule; the opposite end joins with the upper part of the posterior canal to form the crus commune, which opens into the upper and medial part of the vestibule
Vestibule - Saccule
a bed of sensory cells in the inner ear. It translates head movements into neural impulses for the brain to interpret. The saccule detects linear accelerations and head tilts in the vertical plan
Vestibule - Utricle
a small membranous sac (part of the membranous labyrinth) and paired with the saccule lies within the vestibule of the inner ear. It has an important role in orientation and static balance, particularly in horizontal tilt
Vestibulocochlear nerve (CN VIII)
eighth paired cranial nerve. It is comprised of two parts – vestibular fibres and cochlear fibres. Both have a purely sensory function.
Tongue - Papilla
elevations on tongue where taste buds are found
stratified squamous ET covers superior surface
Tongue - Taste bud and pore
small openings in the tongue epithelium, called taste pores, parts of the food dissolved in saliva come into contact with taste receptors. These are located on top of the taste receptor cells that constitute the taste buds.
Tongue - Gustatory cell
Taste buds contain the taste receptor cells, which are also known as gustatory cells.[1] The taste receptors are located around the small structures known as papillae found on the upper surface of the tongue, soft palate, upper esophagus, the cheek, and epiglottis.
Which two cranial nerves carry afferent taste signals?
The afferent fibers of first-order taste neurons (special visceral afferent [SVA/VA]) innervating oropharyngeal taste buds travel in the facial (VII), glossopharyngeal (IX), and vagus (X) nerves
