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Anatomy Ch. 18- General and Special Senses

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sensory receptor
A ______ is a specialized cell or cell process that monitors conditions in the body or the external environment.
sensation
The sensory information arriving at the CNS is called a ______
general senses
The term ______ refers to sensations of temperature, pain, touch, pressure, vibration, and proprioception (body position). ______ receptors are distributed throughout the body
smell (olfaction), taste (gustation), balance (equilibrium), hearing, and vision.
The special senses are ______
receptor specificity.
a touch receptor is very sensitive to pressure but relatively insensitive to chemical stimuli. This concept is called ______
free nerve endings
The simplest receptors are the dendrites of sensory neurons, called ______
receptive field
The area monitored by a single receptor cell is its______ (Figure 18.1). Whenever a sufficiently strong stimulus arrives in the ______, the CNS receives the information. The larger the ______, the poorer our ability to localize a stimulus.
labeled line
The connection between receptor and cortical neuron is called a ______. Each ______ carries information concerning a specific sensation (touch, pressure, vision, and so forth) from receptors in a specific part of the body.
tonic
Some sensory neurons, called ______receptors, are always active The photoreceptors of the eye and various receptors that monitor body position are examples of ______receptors.
phasic receptors
receptors normally inactive, become active with change in monitor stimulus. i.e. touch and pressure receptors in skin
phasic, tonic
Receptors that combine ______receptors and ______ coding convey extremely complicated sensory information; receptors that monitor the positions and movements of joints are in this category.
adaptation
______ is the reduction of sensitivity with a constant stimulus
sensory adaptation
____ occurs when receptors or sensory neurons alter their levels of activity by responding strongly at first and then declining
phasic
fast adaption is characteristic of ____ receptors. Also called fast adapting receptions
tonic
slow adapting receptors are called ____receptors
central adaptation
a few seconds after exposure to a new smell the sensation fades. this is called ___
cerebral cortex
. Only about 1 percent of the information provided by afferent fibers reaches the _____and our conscious awareness.
Sensory Limitations
These are examples of _______:
1. Humans do not have receptors for every possible stimulus.
2. Our receptors have characteristic ranges of sensitivity.
3. A stimulus must be interpreted by the CNS. Our perception of a particular stimulus is an interpretation and not always a reality.
externoceptors
Senses: provide info re external environment
proprioceptors
Senses: monitor body position
interoceptors
Senses: monitor conditions inside the body
nociceptors
respond to tissue damage, activated feeling of pain
thermoreceptors
respond to temperate changes
mechanoreceptors
stimulated or inhibited by physical distortion contact or pressure
chemoreceptors
monitor chemical comp of body fluids and respond to specific molecules
Nociceptors
___ are common receptors in superficial areas of skin, joint capsules, periostea of bones and around wall of blood vessels. Few are in deep visceral organs.
nociceptors
three types of ______ : (1) receptors sensitive to extremes of temperature, (2) receptors sensitive to mechanical damage, and (3) receptors sensitive to dissolved chemicals, such as those released by injured cells
fast pain
_____ is caused by deep cuts. This sensations reach the CNS quickly and often trigger somatic responses. Info also sent to primary sensory cortex. Central adaption may reduce pain perception
slow pain
_____ or burning and aching pain sensations begin later and persist longer then the other pain sensation. Slow pain sensations cause a generalized activation of the reticular formation and thalamus.
thermoreceptors
___ (receptors) are found in the dermis of the skin, skeletal muscles, liver, hypothalamus
cold, warm
3 to 4X more ___ receptors than ____ receptors
pain
Temperature sensations are conducted along the same pathways that carry ______ sensations. They are sent to the reticular formation, thalamus, & primary sensory cortex
Mechanoreceptors
______ are sensitive to stimuli that stretch, compress, twist, or distort their plasmalemmae.
tactile receptors, baroreceptors, proprioceptors
There are three classes of mechanoreceptors______ , ______ , ______
tactile
______ receptors provide sensations of touch, pressure, and vibration
baroreceptors
______ detect pressure changes in the walls of blood vessels and in portions of the digestive, reproductive, and urinary tracts
proprioceptors
_______ monitor the positions of joints and muscles and are the most complex of the general sensory receptors.
Fine touch, pressure
_______ and _______ receptors provide detailed information about a source of stimulation, including its exact location, shape, size, texture, and movement
Crude touch pressure
_______ and _______ receptors provide poor localization and little additional information about the stimulus.
unencapsulated receptors, encapsulated receptors
six different types of tactile receptors in the skin. They can be subdivided into two groups:
free nerve endings, tactile disc, and root hair plexus
the unencapsulated receptors are:
tactile corpuscle, Ruffini corpuscle, and lamellated corpuscle
the encapsulated receptors are:
papillary
Free nerve endings are common in the _____ layer of the dermis
Merkel cell
Each _____ communicates with a sensory neuron across a vesicular synapse that involves an expanded nerve terminal known as a tactile disc
Merkel cells
In sensitive areas, the dendritic branches penetrate the epidermis and contact _______ in the stratum germinativum.
Merkel
______cells are sensitive to fine touch and pressure. They are tonically active and extremely sensitive and have narrow receptive fields. Free nerve endings are also associated with hair follicles.
root hair plexus
The free nerve endings of the _______ monitor distortions and movements across the body surface. When the hair is displaced, the movement of the follicle distorts the sensory dendrites and produces action potentials in the afferent fiber.
tactile corpuscles
Touch receptors located within dermal papillae adjacent to the basement membrane of the epidermis; also called Meissner's corpuscles.
tactile discs
Sensory nerve endings that contact special receptors called Merkel cells, located within the deeper layers of the epidermis; also called Merkel's discs.
tactile
Large, oval _____ corpuscles (also called Meissner's corpuscles) are found where tactile sensitivities are extremely well developed. They are especially common at the eyelids, lips, fingertips, nipples, and external genitalia.
Tactile
______ corpuscles detect light touch, movement, and vibration; they adapt to stimulation within a second after contact.
Ruffini
_____ corpuscles, located in the dermis, are also sensitive to pressure and distortion of the skin, but they are tonically active and show little if any adaptation.
Lamellated corpuscles
_____ are considerably larger encapsulated receptors. layers shield the dendrite from virtually every source of stimulation other than direct pressure.
Lamellated
______ corpuscles respond to deep pressure but are most sensitive to pulsing or vibrating stimuli
lamellated, Ruffini
Although both _____corpuscles and ____ corpuscles respond to pressure, the ____ corpuscles adapt rapidly while the ____ corpuscles adapt quite slowly
lamellated corpuscles, Ruffini corpuscles
These receptors are scattered throughout the dermis, notably in the fingers, breasts, and external genitalia.
Baroreceptors
______ are stretch receptors that monitor changes in pressure.
Baroreceptors
a ______ consists of free nerve endings that branch within the elastic tissues in the wall of a hollow organ, a blood vessel, or the respiratory, digestive, or urinary tract
Baroreceptors
_____ monitor blood pressure in the walls of major vessels, including the carotid artery (at the carotid sinus) and the aorta (at the aortic sinus).
Baroreceptors
_________ in the lungs monitor the degree of lung expansion. This information is relayed to the respiratory rhythmicity center, which sets the pace of respiration.
Baroreceptors
________ in the urinary and digestive tracts trigger a variety of visceral reflexes, such as urination.
Proprioceptors
________ monitor the position of joints, the tension in tendons and ligaments, and the state of muscular contraction.
proprioceptors
Generally, _____ do not adapt to constant stimulation. Muscle spindles are _______ that monitor the length of skeletal muscles
Golgi tendon organs
_______ monitor the tension in tendons during muscle contraction.
Chemoreceptors
_______ are specialized neurons that can detect small changes in the concentration of specific chemicals or compounds.
chemoreceptors
In general, _______ respond only to water-soluble and lipid-soluble substances that are dissolved in the surrounding fluid.
Chemoreceptive
____________ neurons are found within the carotid bodies, near the origin of the internal carotid arteries on each side of the neck, and in the aortic bodies between the major branches of the aortic arch.
carotid body
A group of receptors adjacent to the carotid sinus that are sensitive to changes in the carbon dioxide levels, pH, and oxygen concentrations of the arterial blood.
olfactory epithelium
A specialized neuroepithelium, the _________, which contains the bipolar olfactory receptors, supporting cells, and basal cells (stem cells).
olfactory receptors
Despite ongoing replacement, the total number of _________ declines with age, and the remaining receptors become less sensitive. As a result, elderly individuals have difficulty detecting odors in low concentrations.
receptors on tongue, ventral to dorsal
Filiform papillae, Fungiform papillae, Circumvallate papillae
gustatory cells
Each taste bud contains around 40 slender receptors, called _________
Taste buds monitors by 3 cranial nerves:
cranial nerves VII (facial), IX (glossopharyngeal), and X (vagus)
Umami
_________is a pleasant taste that is characteristic of beef broth and chicken broth.
the external ear, the middle ear, and the inner ear
The ear is divided into three anatomical regions: _________
ceruminous glands
_________ secrete a waxy material, help deny access to foreign objects or insects.
tympanic cavity
_________, contains the auditory ossicles
auditory tube
The_________serves to equalize the pressure in the middle ear cavity with external, atmospheric pressure.
malleus, the incus, and the stapes
he three auditory ossicles are the_________
tensor tympani
muscle that inserts on the handle of the malleus
stapedius
muscle that inserts on the stapes
endolymph
fluid of the inner ear
membranous labyrinth
Endolymph-filled tubes of the inner ear that enclose the receptors of the inner ear.
perilymph
Between the bony and membranous labyrinths flows the _________, a liquid whose properties closely resemble those of cerebrospinal fluid.
vestibule the semicircular canals, and the cochlea
The bony labyrinth can be subdivided into the (3)_________
utricle, saccule
Receptors in the _________and ____provide sensations of gravity and linear acceleration. Those in the semicircular canals are stimulated by rotation of the head.
oval window
Opening in the bony labyrinth where the stapes attaches to the membranous wall of the scala vestibuli.
hair cells
The sensory receptors of the inner ear are called _________
vestibular complex
It consists of the semicircular canals, the utricle, and the saccule.
oval maculae
The hair cells of the utricle and saccule are clustered in the _________
otoliths
when an elevator starts its downward plunge, we are immediately aware of it because the _________no longer push so forcefully against the surface of the receptor cells.
The two vestibular nuclei
1. integrate the sensory information concerning balance and equilibrium arriving from each side of the head;
2. relay information from the vestibular apparatus to the cerebellum;cerebral cortex
4. send commands to motor nuclei in the brain stem and spinal cord.
vestibular
The oval window is at the base of the _________duct
tympanic
the round window is at the base of the _________duct.
organ of Corti
The hair cells of the cochlear duct are found in the _________
tectorial membrane
Gelatinous membrane suspended over the hair cells of the organ of Corti.
perilymph
Movement of the stapes sets up pressure waves in the _________. These waves distort the cochlear duct and the organ of Corti, stimulating the hair cells.
thalamus
Before reaching the cerebral cortex and our conscious awareness, ascending auditory sensations synapse in the _________
accessory structures
The _________ of the eye include the eyelids, the superficial epithelium of the eye, and the structures associated with the production, secretion, and removal of tears.
lacrimal caruncle
the _________ (Figure 18.19a) produce the thick secretions that contribute to the gritty deposits occasionally found after a good night's sleep.
conjunctiva
The epithelium covering the inner surface of the eyelids and the outer surface of the eye is called the _________
lacrimal apparatus
The _________ produces, distributes, and removes tears.
(1) a lacrimal gland, (2) superior and inferior lacrimal canaliculi, (3) a lacrimal sac, and (4) a nasolacrimal duct
The lacrimal apparatus of each eye consists of (4) _________
lacrimal gland
Tear gland on the dorsolateral surface of the eye.
nasolacrimal duct
Passageway that transports tears from the nasolacrimal sac to the nasal cavity.
lacrimal puncta
the superior and inferior _________ drain the lacrimal lake
fibrous tunic
outer layer of the eye
vascular tunic
middle layer of the eye
neural tunic
inner layer of the eye
vitreous chamber
The large posterior cavity of the eye is called the _________
aqueous humor
The 2 part anterior cavity of the eye is called the
sclera and the cornea
The fibrous tunic, the outermost layer of the eye, consists of the (2) _________
The functions of this layer include (1) providing a route for blood vessels and lymphatics (2) regulating the amount of light entering the eye, (3) secreting and reabsorbing the aqueous humor (4) controlling the shape of the lens,
functions of the vascular tunic
ciliary body
A thickened region of the choroid that encircles the lens of the eye; it includes the ciliary muscle and the ciliary processes that support the suspensory ligaments of the lens.
ora serrata
The anterior edge of the neural retina.
pigmented layer
The neural tunic outer layer _________
neural layer
The neural tunic inner layer _________
macula lutea
area w no rods
bipolar cells
rods and cones synapse with ____
ganglion cells
_________ are the only cells in the retina that generate action potentials to the brain.
optic disc
it is commonly called the blind spot
lens
The transparent body lying behind the iris and pupil and in front of the vitreous humor.
distant
tension in the suspensory ligaments flattens the lens. In this position the eye is focused for _________vision.