Chapter 6: Special Senses Flashcards
Special senses
Smell, Hearing, Equilibrium, Taste & Sight “SHETS”
General senses
Touch, Temperature, Pressure & Pain “TTPP”
70% of all sensory receptors are in here. It has over a million nerve fibers.
Eyes
Protection for the eye: most of the eye is enclosed in a _________. And cushion of ____ surrounds most of the eye.
Bony orbit. Fat.
Early ______: optic vesicle forms a two-layered ______: overlying ectoderm forms a ________.
Week 4. Optic cup. Lens pit.
______ week 4: optic cup ______ and forms inner & outer layers; lens pit forms ________.
Late. Deepens. Lens vesicle.
Week __: lens become an ______ structure. ______, _______ & _______ start to form.
- Internal. Cornea, Sclera & Choroid.
Includes sclera & cornea
Corneoscleral coat
A vascular layer including choroid, ciliary body & iris.
Uvea
Third layer of the eyeball includes
Retina, including outer pigment epithelium & inner neutral retina
Sclera consists ____________ making it opaque.m
Dense Irregular Connective Tissue
Covers the anterior one sixth of the eye, and is continuous with the fibrous sclera posteriorly.
Sclera
5 layers of the Cornea
Stratified squamous non keratinizing corneal epithelium, Bowman’s membrane, Corneal stroma(substancia propia), Descemet’s membrane & Simple squamous, the corneal endothelium “SBC DiS”
Made of 60 layers of long type I collagen fibers arranged in a precise orthogonal array and alternating flattened cells called _______.
Stroma. Keratocytes.
Corneal epithelium rests on _______. _______ is avascular.
Bowman’s membrane. Stroma.
In uvea, _______ extends inwards to form a ring-like thickening. With _______ on its anterior third. _______ of the lens arises from the ciliary process. Ciliary body continues posteriorly until it merges with the retina at ________.
Ciliary body extends. Ciliary process. Suspensory ligament(zonular ligament). Ora serrata.
Consists mainly of choroid, has a dark brown colour. _________, which helps to reduce glare within the eye. Many venous plexuses and capillaries.
Uvea. Melanin pigment.
Is where transparent corneal stroma emerges with opaque, vascular sclera.
Limbus or Corneoscleral junction
Stroma of limbus contains _________, or canal ________, which receives aqueous humor from _______.
Scleral venous sinus. Schlemm. Anterior chamber.
In uvea, this extends over the anterior surface of the lens from the anterior border of the ciliary body.
Iris
Iris consists of 5 layers: 1. A discontinuous layer of _______ & ______.
Fibroblast & Melanocytes.
Iris consists of 5 layers: 2. The avascular anterior _________.
Stromal sheet(lamella)
Iris consists of 5 layers: 3. A vascular layer of __________ forming the bulk of the _____.
Loose connective tissue. Iris.
Iris consists of 5 layers: 4. The posterior membrane containing the ____________ and _________ muscles.
Circular sphincter pupillae & Radial dilator pupillae muscles “CR”
Iris consists of 5 layers: A double layer of ________ epithelium.
Pigmented
Including outer pigment epithelium, inner neural retina and epithelium, ciliary body and iris.
Retina
Layer 3 retina: Composed of the basal lamina of Muller’s cells
Inner limiting membrane
Layer 3 retina: Processes of ganglion cells traveling to the brain
Layer optic nerve fiber
Layer 3 retina: cell bodies of ganglion cells
Ganglion cell layer
Layer 3 retina: 2nd synaptic layer, between horizontal, amacrine and bipolar cells and ganglion cells
Inner plexiform layer
Layer 3 retina: cell bodies of horizontal, amacrine, bipolar and Muller’s cells
Inner nuclear layer
Layer 3 retina: 1st synaptic layer, between photoreceptors and horizontal, amacrine and bipolar cells
Outer plexiform layer
Layer 3 retina: cell bodies of rods and cones
Outer nuclear layer
Layer 3 retina: apical boundary of Muller’s cells
Outer limiting membrane
Layer 3 retina: inner & outer segments of photoreceptor cells
Layer of rods and cones
Layer 3 retina: melanin containing cells
Retinal Pigment Epithelium
Following the path of light, what are the layers
ILL, NFL, GL, IPL, INL, OPL, ONL, OLL, RCL & PL
Sensory retinal receptors, the ____ are about 20x as numerous as the cones. The rods and cones differ in their distribution along the _______. In humans, a modified region of the retina, the _____, contains only cones is adapted for high visual acuity.m
Rods. Retina. Fovea.
For central vision, during bright light vision, and in color discrimination.
Cones
Peripheral vision and during dim light vision
Rods
The outer segments of rods and cones contain the visual pigments
Rhodopsin and Iodopsin
Epithelium of ciliary process: double layer of pigmented and nonpigmented epithelial ________ or ________ cells. No true basal lamina is present. Beneath the double epithelium is a core of connective tissue with many small blood vessels. Fluid from these vessels is pumped by the epithelial cells out of the ciliary processes as _________.
Low columnar or cuboidal cells. Aqueous humor.
Three chambers of the eye
Anterior chamber, Vitreous space & Posterior chamber
Chamber of the eye: between the posterior surface of the iris and the anterior surface of the lens
Posterior chamber
Chamber of the eye: between the posterior surface of the lens and the neural retina
Vitreous space
Chamber of the eye: between the cornea and the iris
Anterior chamber
Unpigmented layer of ciliary process > aqueous humor in posterior chamber > passes through pupillary aperture > aqueous humor in anterior chamber > Drains via ___________ (canal of schlemm)
sclero venous sinus
Transparent, avascular, biconvex structure, suspended by suspensory ligament of the lens.
Lens of the eye
3 components of the lens of the eye
Lens capsule, Subscapular epithelium & Lens fibers “LSL”
3 components of the lens of the eye: lens capsule, produced by __________.
Anterior lens cells
3 components of the lens of the eye: ________, a cuboidal/columnar layer of cells that is only present on the anterior surface of the lens
Subscapular epithelium
3 components of the lens of the eye: _______ derived from the subscapular epithelial cells
Lens fibres
Is a thick, homogenous external lamina formed by the epithelial cells and fibres.
Lens capsule
Anterior surface of the lens, is covered by what epithelium
Simple columnar lens epithelium
Still have their nuclei, but are greatly elongating and filling their cytoplasm with proteins called ________.
Differentiating lens fibers. Crystallins.
Have lost their nuclei and become densely packed to produce a unique transparent structure
Mature lens fibers
Thin, transparent mucous membrane. Lateral margin of cornea. Across sclera and covering internal surface of eyelids. __________, containing many goblet cells, that rests on a lamina propria of loose connective tissue.
Conjunctiva of the eye. Stratified columnar epithelium.
Major divisions of the ear
External, Middle & Internal regions of the right ear
The inner ear consists of
2 labyrinthine compartments
2 labyrinthine compartments include
Bony(osseous) labyrinth & Membranous layer “BM”
labyrinthine compartments: in the petrous portion of the temporal bone
Bony(osseous) labyrinth
labyrinthine compartments: within the bony labyrinth
Membranous labyrinth
In the bony labyrinth: ________ the central space of the bony labyrinth
Vestibule
In the bony labyrinth: _________ extending from the vestibule posteriorly
Semicircular canals
In the bony labyrinth: extending from the vestibule anteriorly
Cochlea
In the membranous labyrinth: utricle and saccule, connected by the
Utricosaccular duct
In the membranous labyrinth: __________, within the semicircular canals
Membranous semicircular ducts
In the membranous labyrinth: ___________, within the bony cochlea, continuous with saccule
Membranous cochlear duct
Houses a fluid-filled membranous labyrinth
Bony labyrinth
Includes organs for sense of equilibrium and balance ( ________, ______ & _______) and cochlea for the sense of hearing
Membranous labyrinth. Saccule, utricle and semicircular ducts “SUS”
Is the awareness of the position and movement of the head
Equilibrium/Vestibular sense
Receptors of Equilibrium
Maculae & Cristae Ampullaris
Maculae are located in the epithelial walls of the _______ & _______ in the vestibular complex. Contain _______ to detect the orientation of the stationary head and linear acceleration of the moving head.
Utricle & Saccule. Hair cells.
Is composed of hair cells, supporting cells, and endings of the vestibular branch of the eight cranial nerve. Covered by a gelatinous ________ layer or membrane.
Macular wall. Otolithic.
Are crystalline structures in the outer part of the otolithic membrane. Composed of _________ on a matrix of proteoglycans. Facilitates bending of the _________ & _________ embedded in this membrane by the gravity or the movement of the head.
Otoliths. Calcium carbonate. Kinocilia & Stereocilia.
Two types of hair cells
Basal ends of type I hair cells & Type II hair cells
Are _______ and associated with typical buoton synaptic connections to their afferents
Type II hair cells. Columnar.
Are rounded and enclosed within a nerve calyx on the afferent fiber
Basal ends of type I hair
Wall of the each ampulla is raised as a ridge called
Crista ampullaris
Hair cells of crista epithelium with hair bundles project into a dome shape proteoglycans called
Cupula
Cupula is attached to opposite wall and is moved by
Endolymph
The bony cochlea has three compartments
Scala vestibuli, Scala tympani & Scala media
Upper compartment of the bony cochlea
Scala vestibuli
Lower compartment of the bony cochlea
Scala tympani
Middle compartment of the bony cochlea
Scala media
Organs of Hearing : located within the cochlea. Gel like tectorial membrane is capable of bending hair cells. __________ attached to hair cells transmit nerve impulses to auditory cortex on temporal lobe.
Organ of Corti. Cochlear nerve.
Receptor of Organ of Corti
Hair cells on the basilar membrane
Mechanisms of Hearing: vibrations from sound waves move ________. Hair cells are bent by the membrane. An action potential starts in the __________. Continued stimulation can lead to adaptation.
Tectorial membrane. Cochlear nerve.
Two types of cells of Organ of Corti
Hair cells & Supporting cells
Tall, slender cells extending from the basilar membrane tomthe free surface of the organs of Corti.
Supporting cells
The sense of smell
Olfaction
Olfactory receptors are in the
Roof of the nasal cavity
Olfactory receptors: neurons with _________. Chemicals must be dissolved in mucus for detection. Impulses are transmitted via the _________. Interpretation of smells is made in the _______.
Long cilia. Olfactory nerve. Cortex.
Houses the receptor organs of the taste
Taste buds
Location of taste buds
Most are in the tongue. Soft palate and cheeks.
The tongue is covered with projections called
Papillae
Sharp with no taste buds
Filiform papillae
Rounded with taste buds
Fungiform papillae
Large papillae with taste buds
Circumvallate papillae
Taste buds are found on the
Sides of papillae
Receptor cell of the taste buds
Gustatory cells
Gustatory cells have ______. Hairs are stimulated by chemicals dissolved in ______.
Long microvilli. Saliva.
Impulses are carried to the _______ by several cranial nerves because taste buds are found in different areas: _____, ______ & _______.
Gustatory complex. Facial nerve, Glossopharyngeal nerve & Vagus nerve.
Types of deafness
Conduction & Sensorineural
Hearing loss, vertigo and tinnitus
Meniere’s syndrome
Peripheral, central or psychogenic
Vertigo
Middle ear problem
Otitis media
Inner ear problem
Labyrinthitis
Eardrum problem
Myringitis/tympanitis
