Anatomy Ch 18
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Anatomy Ch 18
NS General Special Senses
Anatomy, NS: General and Special Senses
What are the General Senses?
Temperature, pain, touch, pressure, vibration, and proprioception.
Where are receptors for the general senses?
Receptors for thee sensations are distributed throughout the body.
What are special senses?
Olfaction, gustation, equilibrium, hearing and vision.
Receptors for special senses are located in specialized areas called?
What is a Sensory Receptor?
It is a specialized cell that when stimulated sends a sensation to the CNS.
Receptor Specificity is what?
It allows each receptor to respond to particular stimuli.
What are free nerve endings?
They are simplest receptors.
Free nerve ending is monitored by single receptor cell is called?
What are Tonic Receptors?
They are always sending signals to the CNS; phasic receptors become active only when the conditions that they monitor change
What is Adaptation?
A reduction in sensitivity in the presence of a constant stimulus.
_________ may involve changes in receptor sensitivity or ________ along the sensory pathways.
What are Fast-adapting receptors?
What are slow-adapting receptors?
The information provided by our sensory receptor is incomplete because,
1. We do not have receptors for every stimulus
2. Our receptors have limited range of sensitivity
3. Stimulus produce a neural event that must be interpreted by the CNS
Receptors are classified as ________ if they provide information about the external environment and ________ if they monitor conditions inside the body.
What are Nociceptors?
Respond to a variety of stimuli usually associated with tissue damage.
What are two types of these painful sensations?
Fast Pain (prickling) and slow pain (burning and aching)
What are thermoreceptors?
Respond to temp
What are Mechanoreceptors?
Respond to physical distortion, contact, or pressure on their cell membrane.
What are Tactile Receptor?
to touch, pressure and vibration
What are baroreceptors?
To pressure change in the walls of blood vessels and the digestive, reproductive, and urinary tract.
What are Proprioreceptor?
to positions of joint and muscles.
Fine touch and pressure receptors provide what?
They provide detailed information about a source of stimulation .
What crude touch and pressure receptors?
they are poorly localized.
What are important tactile receptors?
Free nerve endings, root hair plexus, tactile discs.
Where are Merkel Cells located?
They are located in the stratum germinatum that are sensitive to fine touch.
What do Baroreceptors do?
Monitor changes in pressure they respond immediately but adapt rapidly.
Where are Baroreceptors location?
Are in the walls of major arteries and veins respond to changes in blood pressure.
What are Proprioceptors?
monitor the position of joints, tension in tendons and ligaments, and the state of muscular contraction.
What to do Chemoreceptors respond to?
It respond to water-soluble and lipid-soluble substance that are dissolved in the surrounding fluid, they monitor the chemical composition of body fluids.
What do the olfactory organs contain?
They contain Olfactory Epithelium and Olfactory Receptor, supporting cells, basal.
What are olfactory receptors sensitive to?
They are neurons sensitive to chemical dissolving in the overlying mucus.
What are basal cell consider as, in the olfactory Organs?
They are consider Stem Cells.
The olfactory organs are coasted with the secretions of what?
The olfactory receptors are modified neurons and decrease in the numbers of olfactory receptors cause what?
Lose of smell Sense
The olfactory system has extensive limbic and hypothalamic connections that help explain what?
It explains the emotional and behavioral responses that can be produced by certain smells.
What is Gustation?
Also known as taste, provides information about the food and liquids that we consume.
Gustatory Receptors are clustered in what?
In taste Buds. .
What does each taste bud contain?
They contain gustatory cells.
What are Gustatory Cells?
They extend taste hairs through a narrow taste pore.
What are taste buds associated with?
They are associated with epithelial projections ( Papillae )
The taste buds are monitored by which cranial nerves?
VII, IX, and X
The afferent fibers synapse with the _______ before proceeding to the thalamus and cerebral cortex.
What are the taste sensations?
Sweet, salty, sour, bitter unami, and water.
What is Auricle?
It is a part of the ear, which surrounds the entrance to the external acoustic meatus that end at the tympanic membrane or eardrum.
The ________, the _______ encloses and protects the auditory ossicles.
Middle Ear; Tympanic Cavity
What are the auditory Ossicles?
They connect the tympanic membrane with the receptor complex of inner ear.
The tympanic cavity communicates with the nasopharynx via the what?
What two things contact to reduce the amount of motion of the tympanum when very loud sound arrive?
They Tensor Tympani and Stapedius Muscles.
The senses of equilibrium and hearing are provided by the receptors of the what?
The inner ear is housed within fluid-filled tubes and chambers known as?
The Inner ears chambers and canals contain what?
The bony Labyrinth does what?
It surrounds and protects the membranous labyrinth.
The bony labyrinth can be subdivided into what?
The Vestibule and Semicircular Canals and the cochlea.
What does the Vestibule and semicircular canal provide?
They provide the sense of equilibrium
What does the Cochlea provide?
It provides the sense of hearing.
What membranous sacs do the vestibule include?
They include the utricle and saccule.
What do the Utricle and Saccule receptors provide?
They provide sensation of gravity and linear acceleration.
The cochlea contains the _______, and elongated portion of the membranous labyrinth.
The basic receptors of the inner ear are ________, whose surfaces support stereocilia.
What do Hair Cells provide?
They provide information about the direction and strength of varied mechanical stimuli.
The ________, _________, and ________are continuous with utricle.
Anterior; Posterior; lateral semicircular ducts.
All semicircular duct contains a(n)?
Are the Ampulla the cilia contact a gelationous?
The utricle and saccule are connected by a passageway continuous with the _________, which teminates the _________.
Endolymphatic duct; endolymphatic Sac.
In the Saccule and utricle, hair cells cluster with ______, where their cells contract otoliths consisting of densel packed mineral crystals (called ________ ) in a gelatinous matrix.
When the head tilts, the mass of each otolith shifts, and the resulting distortion in the sensory hair signals the what?
The vestibular receptors activate sensory neurons of the?
The axons form the _______ of the vestibulocochlear nerve VIII, synapsing within the _______.
Vestibular branch; vestibular nuclei.
Sound waves travel toward the tympanum, which vibrates:
The auditory ossicles conduct the vibrations to the base of the stapes at the oval window.
Movement at the oval window applies pressure first to the perilymph of the what?
Vestibular Duct pressure is passed on the perilymph in the what?
What are palpebrae?
Also known as eyelids, which are separated by the palpebral fissure.
What lines the palpebral margins?
What are tarsal glands?
They secrete a lipid-rich product, line the inner margins of the eyelids.
What do Lacrimal Caruncle produce?
They produce other secretions.
what bathe the conjunctiva; thee secretions are slightly alkaline and contain lysozymes.
The secretions of the lacrimal gland.
Tear collect in the?
The tears reach the inferior meatus of the nose after passing through the?
Lacimal puncta, lacrimal canaliculi, lacrimal sac and nasolacrimal duct.
The eye has three layers which are?
An outer fibrous tunic
a vascular tunic
and inner neural tunic.
The Fibrous tunic includes what?
Includes mot of the ocular surface.
The fiberous tunic is covered by the?
The corneal limbus is what?
It is the border between the clear and the cornea
What covers most of the exposed surface of the eye?
What covers most of the exposed surface of the eye?
The Bublar, ocular conjunctive
What does the palpebral conjunctiva do?
Lines the inner surface of the eyelids.
Is the cornea transparent?
What does the vascular tunic include?
it includes the iris, the ciliary body and choroid
They cornea forms what boundaries?
The Anterior and posterior chambers.
The ciliary body contains what?
The ciliary muscle and the ciliary processes
The ciliary muscle and the ciliary process attach to what?
The suspensory ligaments (zonnular fibers) of the lens
The neural tunic (retina) consists of what?
An outer pigmented layer and an inner neural retina.
There are two types of photoreceptors which are?
Rods and cones.
What are Rods?
They provide black-and-white vision in dim light.
What are cones?
They provide color vision in bright light.
What is the area in which cones are concentrated and has the sharpest vision?
Macula lutea and fovea.
Damages to the fovea do what?
Interferes with the ability to see color.
The direct line to the CNS proceeds from photoreceptors to?
bipolar cells, then to ganglion cells, and to the brain via the optic nerve.
What two cells modify the signals passed between other retinal components.
Horizontal cells and amacrine cells.
The ______, held in place by the suspensory ligaments, lies posterior to the cornea and forms the anterior boundary of the vitreous chamber.
Vitreous chamber contains the what?
What is the vitreous body?
A gelatinous mass the helps stabilize the shape of the eye and support the retina.