Sensory receptors
are the interface between the nervous system and the internal and external environment
1. general senses
2. special senses
1. Refers to temperature, pain, touch, pressure, vibration, and proprioception
2. Refers to smell, taste, balance, hearing, and vision
Receptors and Receptive Fields
1. __ are simplest receptors
2. receptors of the ___ are very specific and only respond to light
3. receptive fields (2)
1. free nerve endings
2. retina
3. A. Large receptive fields have receptors spread far apart, which makes it difficult to localize a stimulus
B. Small receptive fields have receptors close together, which makes it easy to localize a stimulus.
Interpretation of Sensory Information
1. info is relayed from___ to___
A. Labeled line
B. each labeled line transmits...
1. receptor to a specific neuron in the CNS
A. the connection b/w a receptor and a neuron
B. its own specific sensation
Classification of Receptors
1. tonic receptors
A. example
2. phasic receptors
A. example
1. Always active
A. Photoreceptors of the eye constantly monitor body position
2. Normally inactive but become active when necessary (for short periods of time)
A. Touch and pressure receptors of the skin (for example)
Central Processing and Adaptation
1. adaptation
2. peripheral adaptation
3. central adaptation
1. Reduction in sensitivity due to a constant stimulus
2. Receptors respond strongly at first and then decline
3. Adaptation within the CNS, Consciously aware of a stimulus, which quickly disappears
Classification of the General Senses
1. Exteroceptors
2. proprioceptors
3. interoceptors
1. provide information about the external environment
2. provide information about the position of the body
3. provide information about the inside of the body
Classification of the General Senses
1. nociceptors
2. thermoreceptors
3. mechanoreceptors
4. chemoreceptors
1. respond to the sensation of pain
2. respond to changes in temperature
3. activated by physical distortion of cell membranes
4. monitor the chemical composition of body fluids
The General Senses
1. Nociceptors
A. Associated with...
B. makes it difficult to...
C. three types...
A. free nerve endings and large receptor fields
B. pinpoint location of origin of pain
C. I. Receptors sensitive to extreme temperatures
II. Receptors sensitive to mechanical damage
III. Receptors sensitive to chemicals
The General Senses
1. Nociceptors
A. fast pain
B. Slow pain
C referred pain
A. Sensations reach the CNS fast, Associated with pricking pain or cuts
B. Sensations reach the CNS slowly, Associated with burns or aching pains
C. Sensations reach the spinal cord via the dorsal roots, Some visceral organ pain sensations may reach the spinal cord via the same dorsal root
The General Senses
2. Thermoreceptors
A. found in... (4)
B. __ receptors are more numerous than ___receptors
C. exit as...
D. these are ___ receptors
E. info transmitted along...
A. I. dermis II. skeletal muscle III. liver
IV. hypothalamus
B. Cold, Hot
C. free nerve endings
D. phasic
E. the same pathway as pain info
The General Senses
3. Mechanoreceptors
A. receptors that are...
B. three types
A. sensitive to stretch, compression, twisting, or distortion of the plasmalemmae
B. I. tactile receptors II. Baroreceptors
III. Proprioceptors
Mechanoreceptors
1. Tactile receptors
A. provides...
B. unencapsulated tactile receptors
C. encapsulated tactile receptors
1. sensations of touch, pressure, and vibrations
2. free nerve endings, tactile disc, and root hair plexus
3. tactile corpuscle, Ruffini corpuscle, and lamellated corpuscle
Mechanoreceptors
1. Unencapsulated tactile receptors
A. free nerve endings are common in the __
B. __ are in the stratum basale layer
C. root hair plexus monitors...
A. dermis
B. Tactile discs
C. distortions and movements of the body surface
Mechanoreceptors
2. Encapsulated tactile receptors
A. tactile corpuscle
B. Ruffini Corpuscle
C. lamellated corpuscle
A. common on eyelids, lips, fingertips, nipples, and genitalia
B. in the dermis, sensitive to pressure and distortion
C. consists of concentric cellular layers / sensitive to vibrations
Mechanoreceptors
3. Baroreceptors
A. Are...
B. found in...
A. Stretch receptors that monitor changes in the stretch of organs
B. stomach, small intestine, urinary bladder, carotid artery, lungs, and large intestine
Mechanoreceptors
4. Proprioceptors
Monitor the position of joints, tension in the tendons and ligaments, and the length of muscle fibers upon contraction
Chemoreceptors
1. detect...
2. respond...
3. found in...
1. small changes in the concentration of chemicals
2. water-soluble or lipid-soluble compounds
3. respiratory centers of the medulla oblongata, carotid arteries, and aortic arch
The special senses include (5)
1. Olfaction (smell)
2. Gustation (taste)
3. Equilibrium
4. Hearing
5. Vision
Olfaction
The olfactory epithelium consists of (3)
1. olfactory receptors
2. supporting cells
3. basal cells
Olfactory Pathways
1. axons leave
2. pass through
3. synapse on
4. impulses travel to
5. arrive at the..
1. olfactory ipithelium
2. the cribiform foramina
3. the olfactory bulbs
4. the brain via Olfactory CN I
5. cerebral cortex, hypothalamus, and limbic system

olfactory organs
1. olfactory epithelium 2. cribiform plate
3. olfactory tract 4. olfactory CN I fibers
5. olfactory bulb

olfactory organs
1. olfactory nerve fibers 2. cribiform plate
3. olfactory (bowmans) gland 4. olfactory epithelia
Olfactory Discrimination
1. the epithelial receptors have...
2. olfactory receptors can be...
3. replacement activity ___ with age
1. different sensitivities an therefore detect different smells
2. replaced
3. decrease
Gustation (taste)
1. the tongue consists of..
2. papillae consist of...
3. taste buds consist of...
4. each gustatory cell has...
1. papillae
2. taste buds
3. gustatory cells
4. a slender microvilli that extends through the taste pore into the surrounding fluid
Gustation Pathways
1. dissolved chemicals contact...
2. impulses go from the...
3. synapse in the...
4. the impulses eventually arrive at the...
1. the taste hairs (microvilli)
2. gustatory cell through CN VII (facial), IX (glossopharyngeal), and X (vagus)
3. nucleus solitarius of the medulla oblongata
4. cerebral cortex
Gustation Discrimination
1. begin life with more than ___ taste buds
2. the number ___ rapidly by age __
3. threshold level is ___ for gustatory cells responsible for unpleasant stimuli
4. Threshold level is __ for gustatory cells responsible for pleasant stimuli
1. 10,000
2. declines, 50
3. low
4. high
Equilibrium and Hearing
1. structures of the ear are involved in...
2. the ear is subdivided into 3 regions
1. balance and hearing
2. A. external ear
B. middle ear
C. inner ear
The External Ear
Consists of: (4)
1. Auricle
2. External acoustic meatus
3. Tympanic membrane
4. Ceruminous glands

Anatomy of the ear
1. external ear 2. auricle
3. external acoustic meatus 4. tympanic membrane
5. middle ear 6. tympanic cavity
7. auditory ossicles 8. Auditory tube
9. Inner ear 10. semicircular canals
11. vestibule 12. cochlea
13. bony labyrinth 14. vestibulocochlear N
The Middle Ear
Consists of: (3)
1. Tympanic cavity
2. Auditory ossicles
3. Auditory tube (pharyngotympanic tube)

middle ear
1. tympanic cavity 2. auditory canal
3. stapedius muscle 4. stapes
5. tensor tympanic muscle 6. incus
7. malleus
The Inner Ear
Consists of: (8)
1. Receptors 2. Bony labyrinth
3. Membranous labyrinth (within the bony labyrinth)
4. Vestibule 5. Semicircular canals
6. Cochlea 7. Utricle
8. Saccule

1. semicircular canal 2. anterior
3. lateral 4. posterior
5. semicircular ducts 6. vestibule
7. cochlea

1. perilymph 2. bony labyrinth
3. endolumph 4. membranous labyrinth
The Inner Ear
1. The vestibular complex and equilibrium
2. consists of... (3)
1. Part of inner ear that provides equilibrium sensations by detecting rotation, gravity, and acceleration
2. A. semicircular canals
B. utricle
C. Saccule
The Vestibular Complex and Equilibrium
1. The semicircular canals
A. each semicircular canal...
B. ampulla
C. within each ampulla is a
A. encases a duct.
B. the beginning of each duct
C. cristae with hair cells
The Vestibular Complex and Equilibrium
1. The semicircular canals
D. each hair cell contains
E. these are...
F. the moement of the body causes...
D. kinocilium and stereocilia
E. embedded in gelatinous material called the cupula
F. causes movement of fluid in the canal, which in turn causes movement ofthe cupula and hair cells, which the brain detects
The Vestibular Complex and Equilibrium
2. The utricle and saccule
A. the utricle and saccule are...
B. hair cells of the utricle and saccule are...
C. hair cells are embedded in...
D. gelatinous material and statoconia...
A. connected to the ampulla and to each other and to the fluid within the cochlea
B. in clusters called maculae
C. gelatinous material consisting of statoconia
D. collectively are called an otolith
Equilibrium Process
When you rotate your head:
1. The endolymph in the...
2. this causes the...
3. this causes...
4. when you rotate your head to the right the hair cells are...
5. when you move in a circle and then stop abruptly. the endolymph...
1. cemicircular canals begins to move
2. bending of the kinocilium and stereocilia
3. depolarization of the associated sensory nerve
4. to the left
5. moves back and forth causing the hair cells to bend back and forth resulting in confusing signals, thus dizziness
Equilibrium Process (cont.)
1. when you move up or down (elevator movement)
A. ___ rest on top of the maculae
B. when moving upward, the otoliths....
C. when moving downward, the otoliths...
2. when you tilt side to side:
A. when tilting to one side, the otoliths..
1. A. otoliths
B. press down on the macular surface
C. lift off the macular surface
2. A. shift to one side of the macular surface
The Cochlea
1. Consists of...
2. spirals coil around...
3. within the ___ are sensory neurons
4. the sensory neurons are associated with...
5. organ of...
1. snail-shaped spirals
2. a central area called the modiolus
3. modiolus
4. CN VIII (vestivulocochlear)
5. corti
The Cochlea (cont.)
1. Each spiral consists of 3 layers
2. there is a ___ b/w each layer
3. the scala vestibuli and scala tympani are...
4. sense organs rest on the...
1. A. Scala vestibuli
B. Scala tympani
C. Scala media
2. basilar membrane
3. connected at the apical end of the cochlea
4. basilar membrane within the scala media
The Cochlea (cont.)
1. Each spiral consists of 3 layers
A. Scala vestibuli
B. Scala tympani
C. Scala media
A. (vestibular duct): consists of perilymph
B. (tympanic duct): consists of perilymph
C. (cochlear duct): consists of endolymph / this layer is between the scala vestibuli and scala tympani
The Cochlea
The Organ of Corti
1. AKA..
2. rests on___ b/w ___ and ___
3. hair cells are...
1. spiral organ
2. basilar membrane, scala media, scala tympani
3. in contact with an overlaying tectorial membrane
Auditory Pathways
1. sound waves enter
2. the ___ vibrates
3. causes...
4. the ___ vibrates against the __ of the __
5. __ begins to move
1. the external acoustic meatus
2. tympanic membrane
3. the vibration of the ossicles
4. stapes, oval window, scala tympani
5. perilymph
Auditory Pathways (cont.)
5. as __ moves:
6. __ is put on the scala media
7. this pressure...
8. this distortion...
9. nerve signals are sent to...
5. perilymph
6. pressure
7. distorts the hair cells of the organ of corti
8. depolarizes the neurons
9. brain via CN VIII(vestibulocochlear)
Vision
Accessory structures of the eye
1. palpebrae
2. medial and lateral canthus
3. palpebral fissure
4. eyelashes
5. conjunctiva
6. Glands (4)
1. eyelids
2. connect the eyelids at the corners of the eye
3. area between the eyelids
4. contain root hair plexus, which triggers the blinking reflex
5. epithelial lining of the eyelids
6. glands of Zeis, tarsal glands, lacrimal gland, lacrimal caruncle
Accessory Structures of the Eye
5. Conjunctiva
A. covers the...
B. fluid production helps...
C. palpebral conjunctiva
D. ocular conjunctiva
A. inside lining of the eyelids and the outside lining of the eye
B. prevent these layers from becoming dry
C. inner lining of the eyelids
D. outer lining of the eye
Accessory Structures
6. Glands
A. Glands of zeis
B. Tarsal glands
C. Lacrimal glands
D. Lacrimal caruncle glands
A. sebaceous glands / associated with eyelashes
B. secrete a lipid-rich product / keeps theeyelids from sticking together / located along the inner margin of the eyelids
C. produce tears / located at the superior, lateral portion of the eye
D. produce thick secretions /located within the canthus areas
Accessory Structures
6. Glands
A. cyst
B. sty
A. An infection of the tarsal gland may result in a
B. An infection of any of the other glands may result in a
Accessory Structures
Lacrimal glands
1. par of the...
2. consists of... (4)
1. lacrimal apparatus
2. A. Lacrimal glands
B. Lacrimal canaliculi
C. Lacrimal sac
D. Nasolacrimal duct
Accessory Structures
Lacrimal glands
1. tears are produced by...
2. flow over the
3. flow into the
4. this enters into the...
1. lacrimal glands
2. ocular surface
3. nasolacrimal canal
4. into the nasal cavity

anatomy of the eye
1. optic nerve 2. fovea
3. retina 4. choroid
5. sclera 6. posterior cavity
7. ora serrata 8. ciliary body
9. anterior chamber 10. lens
11. pupil 12. cornea
13.posterior chamber 14. corneal limbus
15. suspensory ligaments 16. vitreous humor
17. aqueous humor
The Eyes
1. The Fibrous Tunic
2. makes up the ___ and ___
3. provides
4. provides...
5. the ___ is modified sclera
1. outer layer
2. sclera and cornea
3. some degree of protection
4. attachment sites for extra-ocular muscles
5. cornea
The Eyes
1. The Vascular Tunic
2. consists of...
3. regulates
4. ___ and ___ aqueous fluid
5. controls...
6. includes the...
1. middle layer
2. blood vessels, lymphatics, and intrinsic eye muscles
3. the amount of light entering the eye
4. secretes and reabsorbs
5. shape of the lens
6. iris, ciliary body, and the choroid
The Vascular Tunic
The iris
1. consists of
2. the pigment creates...
3. the __ contract to change the diameter of the __
1. blood vessels, pigment, and smooth muscles
2. the color of the eye
3. smooth muscles, pupil
The Vascular Tunic
The ciliary body
1. consists of...
ciliary muscles connected to suspensory ligaments, which are connected to the lens
The Vascular Tunic
The choroid
1. highly...
2. the innermost portion of the choroid attaches to the...
1. vascularized
2. outermost portion of the retina
The Eyes
1. The Neural Tunic
2. AKA...
3. made of 2 layers...
4. retina cells (2)
1. inner layer
2. retina
3. A. pigment layer- outer layer
B. neural layer- inner layer
4. A. rods- night vision
B. cones - color vision

1. neural part 2. pigmented part
3. neural tunic (retina) 4. choroid
5. ciliary body 6. iris
7. vasicular tunic (uvea) 8. cornea
9. sclera 10. fibrous tunic

retinal organization
1. cone 2. rod
3. bipolar cells 4. ganglion cells
5. horizontal cell
Cavities and Chambers of the Eye
1. anterior cavity
A. consists of (2)
B. filled with...
2. posterior cavity
A. consists of (1)
B. filled with...
1. A. I. anterior chamber
A. II. posterior chamber
B. aqueous fluid
2. A. vitreous chamber
B. vitreous fluid
Aqueous fluid
1. secreted by...
2. enters the...
3. flows through
4. enters the...
5. flows through
6. enters into
1. cells at the ciliary body area
2. posterior chamber
3. pupil area
4. anterior chamber
5. canal or schlemm
6. venous ciculation

1. ciliary process
Vitreous fluid
1. is..
2. supports...
3. supports...
4. supports...
1. gelatinous material in the posterior chamber
2. shape of eye
3. position of lens
4. position of retina
Aqueous fluid
1. Glaucoma
Vitreous Fluid
2. Detached retina
1. If this fluid cannot drain through the canal of Schlemm, pressure builds up
2. If this fluid is not of the right consistency, the pressure is reduced against the retina
Visual Pathways
1. light waves pass through the...
2. pass through the...
3. pass through the...
4. pass through the...
5. pass through the...
6. the ___ focuses the image on some part of the ___
1. cornea
2. anterior chamber
3. pupil
4. posterior chamber
5. lens
6. lense, retina
Visual Pathways
The retina
1. there are _____ all over the retina
2. 100% cone in the ___
3. 0% rods or cones in the ____
A. AKA
1. rods and cones
2. fovea centralis acrea
3. optic disc area
A. blind spot
Visual Pathways
The retina (cont.)
1. Cones require...
2. at night...
1. light to be stimulated
2. cones deactivate and rods begin to be activated