Special Senses - Lecture notes 1-47 PDF

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Reviewer Special Senses The receptors for hearing are located in the cochlea. The center of the eardrum is connected to the malleus. The middle ear is a small air-filled cavity between the eardrum and the internal ear True A loss of transparency of the lens is known as cataracts. True When the ciliary muscle contracts, the lens flattens for far vision. False The inability to clearly see near objects is called Hypermetropia. Rods allow us to see in dim light True The senses for dynamic equilibrium are located in the Semicircular ducts. What is the function of the extrinsic eye muscles? Roll the eyes after taking a particularly awful test. (me) Sound is conducted through air, bone and fluid before it is changed to electrical impulses in the inner ear. True Conduction deafness is caused by damage to cochlear branch of the vestibulocochlear nerve. False The layer of the eye that contains photoreceptors is the retina. Some fibers of the optic nerve cross in the optic tract. False The middle tunic of the eye consists of choroids coat, cornea, lens and ciliary body. False “Pinkeye” is the common term for Conjunctivitis. The greatest single cause of blindness in the world is:

● ● ● ● ●

Trichinosis Glaucoma Trachoma Cataracts Otitis

The vallate papillae contains the most number of taste buds compared to other papillae. True The middle layer of the eyeball is the vascular tunic. True The clear jellylike substance behind the lens of the eye is the vitreous humor. Which of the following is abnormal in someone who is unable to see in low light (night blind)? Rods. The region that is most sensitive to bitter taste is the back of the tongue. Cones are specialized for color vision. True The cAMP opens a sodium ion (Na+) channel that allows Na+ to enter the cytosol, which causes a depolarizing generator potential to form in the membrane of the olfactory receptor cell. True The area containing the highest concentration of cones is the Central fovea. The cranial nerves involved in the gustatory pathway are the Facial, glossopharyngeal, and vagus. Night blindness is most often caused by a vitamin C deficiency. False The filiform papillae are tactile receptors without taste buds. True If you enter a room and smell a strong odor which seems to soon fade away, you have experienced: sensory adaptation The middle part of the bony labyrinth is the vestibule. Which of the ff areas of the brain are involved in olfaction? ● Limbic system ● Hypothalamus ● Temporal lobe ● All of the above ● None of the above

A ringing in the ears is scientifically referred to as: tinnitus The muscles of the iris and ciliary muscle are considered to be extrinsic eye muscle because they are voluntary. False The walls of the utricle contain a small, flat region called macula. True The eyelids are also called palpebrae. True The thresholds for salty and sweet substances are higher than those of bitter or sour substances. True The photopigment in rods is rhodopsin. Equilibrium is classified as a special sense. True Which of the ff belongs to the middle ear? ● Ossicles ● Cochlea ● Bony labyrinth ● Scala tympani ● Vestibule The highest concentration of taste buds is found in filiform papillae. False The sense of balance that tells you “where your head is at” when you are not moving is called __ equilibrium and is a function of the __ in the inner ear. ● static & semicircular canals ● Static & utricle and saccule ● Dynamic & semicircular canals ● Dynamic & utricle and saccule ● Static & cochlear duct Umami is believed to arise from taste receptors that are stimulated by L-glutamate and nucleotides, substances present in many foods. True When you sniff to help you detect or identify odors, you are: ● Increasing the pressure on the mechanoreceptors ● Forcing gasses into solution ● Forcing air to the top of the nasal cavity where the chemoreceptors are located ● Forcing air to the back of the throat towards the olfactory nerves

An abnormally high intraocular pressure is referred to as glaucoma. The eyes are responsible for the detection of visible light, the part of the electromagnetic spectrum with wavelengths ranging from about 400 to 700 nm. True Adaptation to odors occurs rapidly. True Total lack of the sense of smell is called anosmia. True Chemicals that stimulate gustatory receptor cells are known as tastants. True Taste receptors are called Gustatory receptors Olfaction has a high threshold. False The bactericidal enzymes present in tears are lysozyme. Which of these changes vibrations to nerve impulses? ● Stapes and oval window ● Retina ● Cochlea and Organ of Corti ● Tympanic membrane ● Utricle and saccule All of the ff belong to the external ear EXCEPT? ● Auditory tube ● Auricle ● Tympanic membrane ● External auditory canal ● Ceruminous glands The simplest sensory receptors are A) thermoreceptors. B) encapsulated nerve endings. C) proprioceptors. D) free nerve endings. E) touch receptors. Free nerve endings A decreased sensitivity that occurs when a stimulus is continuously applied to sensory receptors is called A) adaptation. B) relaxation. C) accommodation. D) refraction.

E) consolidation

Adaptation

Which of the following senses does NOT belong to the group of somatic senses? A) touch receptors B) temperature receptors C) visceral receptors D) pressure receptors E) proprioceptors Visceral receptors All of the following are somatic sensations EXCEPT A) touch. B) pressure. C) temperature. D) equilibrium. E) vibration. Equilibrium All of the following are mechanoreceptors EXCEPT A) hair root plexuses. B) Meissner's corpuscles. C) nociceptors. D) Pacinian corpuscles. E) organs of Ruffini. Nociceptors Which of the following senses falls under the category of complex receptors? A) taste B) touch C) heat D) cold E) painTaste Touch receptors are classified as A) mechanoreceptors. B) nociceptors. C) chemoceptors. D) photoreceptors. E) proprioceptors Mechanoreceptors Pressure receptors, which are located around joints, tendons, and muscles, are A) Pacinian corpuscles. B) Meissner's corpuscle. C) organs of Ruffini. D) tactile receptors. E) nociceptors. Pacinian corpuscles

The sensation of itch results from the stimulation of A) Meissner's corpuscles. B) Pacinian corpuscles. C) free nerve endings. D) proprioceptors. E) tactile receptors. Free Nerve endings A kind of pain often experienced by people suffering a heart attack is called A) referred pain. B) delayed pain. C) dull pain. D) sharp pain. E) phantom pain. Referred pain The sense of muscle activity is called A) proprioception. B) nociception. C) stretch reception. D) adaptation. E) Gustation Proprioception Muscle spindles are examples of A) free nerve endings. B) proprioceptors. C) Pacinian corpuscles. D) itch receptors. E) None of the above.Proprioceptors Olfactory receptors A) are located in the nasal cavity. B) are stimulated by gaseous particles. C) adapt. D) have knob-shaped dendrites. E) all of the above are correct. All of the above are correct Which of the following areas of the brain are involved in olfaction? A) temporal lobe B) hypothalamus C) limbic system D) none of the above E) all of the above All of the above Taste receptors are called A) taste buds.

B) gustatory receptors. C) olfactory receptors. D) filiform papillae. E) taste pores.Gustatory Receptors The region that is most sensitive to bitter taste is the A) tip of the tongue. B) back of the tongue. C) middle of the tongue. D) margin of the tongue. E) side of the tongue. Back of the tongue The cranial nerves involved in the gustatory pathway are the A) glossopharyngeal, vagus, and gustatory. B) optic, glossopharyngeal, and facial. C) vagus, hypoglossal, and abducens. D) facial, glossopharyngeal, and vagus. E) vestibulochochlear, abducens, and hypoglossal. Facial, glossopharyngeal, and vagus The immediate structure leading tears away from the lacrimal glands is/are the A) nasolacrimal duct. B) lacrimal ducts. C) eustachian tube. D) nasal cavity. E) nasal concha. Lacrimal ducts The bactericidal enzymes present in tears are A) lysosomes. B) lysozyme. C) bacteriozyme. D) lipase. E) protease. Lysozyme The "white" of the eye is called A) conjunctiva. B) sclera. C) retina. D) cornea. E) iris. Schlera Which of the following belongs to the vascular tunic of the eye A) cornea. B) sclera. C) retina.

D) iris. E) pupil.

Iris

The muscle responsible for the change of the shape of the lens is the A) arrector pili muscle. B) orbicularis oculi. C) ciliary muscle. D) superior rectus muscle. E) retinal muscle. Ciliary Muscle The layer that contains photoreceptors is the A) iris. B) retina. C) sclera. D) cornea. E) iris. Retina Optic disc is also called the blind spot. True The area containing the highest concentration of cones is the A) central fovea. B) optic disc. C) iris. D) macula lutea. E) pupil. Answer: A Central fovea The clear jellylike substance behind the lens of the eye is the A) aqueous humor. B) cellular body. C) ciliary body. D) anterior humor. E) vitreous humor. Vitreous humor The bending of light that happens at the cornea and lens is A) accommodation. B) reflection. C) contraction. D) refraction. E) adaptation. Refraction The inability to clearly see near objects is called A) nearsightedness. B) astigmatism.

C) hypermetropia. D) presbyopia. E) myopia. Hypermetropia The "canal of Schlemm" is another term for the A) vitreous chamber. B) vitreous body. C) anterior cavity. D) aqueous humor. E) scleral venous sinus. Scleral venous sinus The photopigment in rods is A) chlorophyll. B) rhodopsin. C) opsin. D) melanin. E) retinal. Rhodopsin Which of the following form the optic nerve A) ganglion cells. B) retinal cells. C) bipolar cells. D) rods. E) cones. Ganglion cells All of the following belong to the external ear EXCEPT A) auditory tube. B) auricle. C) external auditory canal. D) tympanic membrane. E) ceruminous glands. Auditory tube . Which of the following belongs to the middle ear? A) cochlea. B) ossicles. C) bony labyrinth. D) vestibule. E) scala tympani Ossicles The middle part of the bony labyrinth is the A) cochlea. B) saccule. C) utricle. D) vestibule.

E) ampulla.

Vestibule

Located between the cochlear duct and the scala vestibuli is the A) vestibular membrane. B) tectorial membrane. C) basement membrane. D) cochlear duct. E) basilar membrane. Vestibular membrane The center of the eardrum is connected to the A) incus. B) cochlea. C) vestibule. D) malleus. E) staples. Malleus The receptors for hearing are located in the A) semicircular canals. B) cochlea. C) utricle. D) sacculae. E) vestibule. Cochlea The senses for dynamic equilibrium are located in the A) utricle. B) sacculae. C) Organ of Corti. D) cochlea. E) semicircular ducts. Semicircular ducts An abnormally high intraocular pressure is referred to as A) cataract. B) glaucoma. C) trachoma. D) vertigo. E) nystagmus. Glaucoma he most common cause of blindness in the United States is A) scotoma. B) trachoma. C) cataracts. D) glaucoma. E) macular degeneration Glaucoma

The ossicles of the ear are responsible for: A) sound conduction and amplification. B) static equilibrium. C) dynamic equilibrium. D) pressure equalization. E) conversion of waves into electrical impulses

Sound conduction and amplification

Accommodation involves changing the shape of the: A) cornea. B) stapes. C) lens. D) utricle and saccule. E) retina. Lens Which of these changes vibrations to nerve impulses? A) cochlea and Organ of Corti. B) stapes and oval window. C) utricle and saccule. D) tympanic membrane, E) retina Cochlea and organ of corti Referred pain occurs because of: A) shared pathways between visceral organs and body surfaces. B) adaptation of nerve pathways. C) lack of myelination on pain neurons. D) the autonomic nervous system. E) all of the above. Shared pathways between visceral organs and body surfaces All of the following use mechanoreceptors EXCEPT: A) hearing B) touch C) nociceptors D) pressure E) proprioceptors Nociceptors Pain that persists for at least two months without responding to appropriate treatment is: A) acute pain B) incurable pain C) unaccountable pain D) chronic pain E) therapeutic pain Chronic pain

Relaxation and meditation are used to control pain because: A) it distracts the patient B) it decreases anziety C) persons gain a sense of personal control D) certain thoughts and situations can reduce the pain E) of all of the above reasons Of all of the above where are the receptors for the sense of smell or olfaction located? epithelium of the nose

The olfactory

Where does the olfactory epithelium occupy? The superior part of the nasal cavity, covering the inferior surface of the cribriform plate and extending along the superior nasal concha What are the 3 types of cells the olfactory epithelium consists of? 1. Receptor cells 2. Supporting cells 3. Basal cells What are the first-order neurons of the olfactory pathway? Olfactory receptor cells Describe the olfactory receptor cells Each olfactory receptor cell is a bipolar neutron with an exposed, knob shaped dendrite and an axon projecting through the cribriform plate that ends in the olfactory bulb. Extending from the end of an olfactory receptor cell are several nonmotile olfactory cilia What are the sites of olfactory transduction?Olfactory cilia transduction is the conversion of stimulus energy into a graded potential in a sensory receptor. What detects inhaled chemicals? Olfactory receptor proteins within the plasma membranes of olfactory cilia detect inhaled proteins What are chemicals that bind to an stimulate the olfactory receptors in the olfactory cilia called? Odorants How do olfactory receptor cells respond to the chemical stimulation of an odourant molecule? By producing a receptor potential, thus initiating the olfactory response. What are supporting cells? What do they provide for the olfactory receptor cells? Columnar epithelial cells of the mucous membrane lining the nose. They provide physical support, nourishment, and electrical insulation for the olfactory receptor cells and help detoxify chemicals that come in contact with the olfactory epithelium.

What are basal cells? What do they continually undergo? They are stem cells located between the bases of the supporting cells. They continually undergo cell division to produce new olfactory receptor cells, which live for about a month before being replaced. How long do olfactory receptor cells live for?About a month What are olfactory glands? Where are they located? What do they do? Within the connective tissue that supports the olfactory epithelium are olfactory glands, which produce mucus that is carried to the surface of the epithelium by ducts. The secretion moistens the surface of the olfactory epithelium and dissolves odourants so that transduction can occur How do olfactory receptors react to odourant molecules? develops and triggers one or more nerve impulses

A receptor potential (depolarization)

"olfactory transduction" Binding of an odourant to an olfactory receptor protein in an olfactory cilium stimulates a membrane protein called __ _________ G protein G protein activates the enzyme.... to produce a substance called..... monophosphate (cAMP)

adenylyl cyclase to produce cyclic adenosine

What does cAMP do? Opens a cation channel that allow sodium and calcium ions to enter the cytosol which causes a depolarizing receptor potential to form in the membrane of the olfactory receptor cell If the depolarizing reaches threshold... the olfactory receptor cell

an action potential is generated along the axon of

The human nose contains about___ olfactory receptors, of which there are about ____ different functional types. 10 million 400 Humans can recognize about _______ different doors Olfaction has a _____ threshold

10,000

low

Only a few molecules of certain substances need to be present in air to be perceived as an odor. Olfactory receptors adapt by about ___% in the first second or so after stimulation but adapt very ________ thereafter. 50%

slowly Complete insensitivity to certain strong odors occurs about ________ after exposure. minute

A

Olfaction pathway Olfactory tract -axons mitral cells ↑ Olfactory bulb -mitral cells (second order neuron) ↑ olfactory bulb ↑ through cribriform plate (ethmoid bone) ↑ form olfactory (I) nerve (axons receptor cells) ↑ olfactory receptor cells (first order neuron) From the olfactory tract Some of the axons of the olfactory tract project to the primary olfactory area in the temporal lobe of the cerebral cortex, where conscious awareness of smell occurs Other axons of the olfactory tract project to the limbic system; these neural connections account for our emotional responses to odors. a pathway extends via the thalamus to the orbitofrontal cortex in the frontal lobe, where odor identification and discrimination occur Olfactory sensations are the only sensations that reach the cerebral cortex without first synapsing in the ______________. thalamus The orbitofrontal cortex of the __________ hemisphere exhibits greater activity during olfactory processing than the corresponding area in the __________ hemisphere. right left Do men or women have a keener sense of smell? Women, especially at the time of ovulation Hyposmia is a reduced ability to smell, affects half of those over age 65 and 75% of those over age 80. Hyposmia also can be caused by neurological changes, such as a head injury, Alzheimer's disease, or Parkinson's disease; certain drugs, such as antihistamines, analgesics, or steroids; and the damaging effects of smoking. Is gustation a chemical sense?

Yes

What are the 5 primary tastes

1. Salty

2. Sour 3. Sweet 4. Bitter 5. Umami Salty taste is caused by the presence of ________ ions Sour taste is produced by _______ ions. Sweet taste is elicited by

sodium

Hydrogen ions released from acids

sugars

Many poisonous substances have a ___________ taste What is the umami taste described as being?

bitter

meaty or savory

All other flavours such and chocolate, pepper, and coffee, are _______________ combinations of the 5 primary tastes, plus any accompanying olfactory, tactile, and thermal sensations Because olfaction is much more sensitive than taste, a given concentration of a food substance may stimulate the olfactory system _____________ of times ___________ than it stimulates the gustatory system. thousands of times more strongly When you have a cold or are suffering from allergies and cannot taste your food, it is actually _____________ that is blocked, not ____________. olfaction taste The receptors for sensations of taste are located in the? How many taste buds does a young adult have? Where are the taste buds located -soft palate -pharynx -epiglottis

taste buds

10,000

-tongue

Each taste bud is an oval body consisting of three kinds of epithelial cells: -supporting cells -gustatory receptor cells -basal cells The supporting cells surround about ____ gustatory receptor cells in each taste bud

50

Gustatory microvilli (gustatory hairs) project from each gustatory receptor cell to the external surface through the ________ _________, an opening in the taste bud. taste pore

Basal cells, stem cells found at the periphery of the taste bud near the connective tissue layer, produce ____________ ______________, which develop into _____________ ___________ ________ supporting cells gustatory receptor cells Each gustatory receptor cell has a life span of about

10 days

Why does your tongue recover fast from being burned? replaced every 10 days

because gustatory receptor cells are

At their base, the gustatory receptor cells ____________ with dendrites of the first-order neurons that form the first part of the gustatory pathway synapse Taste buds are found in elevation...