A&P Chapter 13, 15, 16
A structure that is located at the medial angle of the eye and contains glands that contribute to a gritty deposit is the
lacrimal caruncle
The hair cells of the utricle and saccule are clustered in
maculae
Each gustatory cell extends ________ (or taste hairs) into the surrounding fluids through a narrow taste pore.
microvilli
The olfactory receptors are highly modified
neurons
function of tears
nourishes the cornea and conjunctiva washes away debris provides oxygen lubricates the eye
Which cranial nerves have motor functions only?
oculomotor, trochlear, abducens, accessory, hypoglossal
The cranial nerves that innervate the eye muscles are
III, IV, and VI
Some neural tissues retain stem cells and thus the capacity to divide and replace lost neurons. Which of these special senses can replace its damaged neural receptors?
olfaction
Which cranial nerve carries visual information from the eyeball to the brain?
optic nerve
Which cranial nerves are involved with the eye?
optic, oculomotor, abducens, and troclear nerves
The hair cells of the cochlear duct are located in the
organ of Corti
Stimulation of nociceptive receptors within the trigeminal nerve might produce a perception of
peppery hot
Taste receptors are distributed in which of the following places?
surface of the tongue portions of the pharynx surface of the epiglottis
primary taste sensations
sweet, sour, bitter, salty, umami
Trace the gustatory pathway from the taste receptors to the cerebral cortex
taste receptors — facial, glossopharyngeal, and vagus nerves — synapse in the solitary nucleus of the medulla oblongata — medial lemniscus — synapse in the thalamus — gustatory cortex of the insula
The structure that overlies the organ of Corti is the
tectorial membrane
Perception of gravity and linear acceleration depends on
the force exerted by otoliths on hair cells of the maculae in the utricle or saccule
What is the function of the auditory tube?
to allow pressure equalization on both sides of the tympanic membrane
Jean needs to have a tooth in her mandible filled. Her dentist injects a local anesthetic to block pain afferents in one of her cranial nerves. What cranial nerve does the dentist numb?
trigeminal
Sound waves are converted into mechanical movements by the
tympanic membrane
The external ear ends at the
tympanic membrane
The auditory ossicles connect the
tympanic membrane to the oval window
Which of the following anatomical sequences is correct?
tympanum - malleus - incus - stapes - oval window - round window
The taste sensation that is triggered by the amino acids and small peptides is known as
umami
Difficulty in swallowing may be a sign of damage to which cranial nerve(s)?
vagus and glossopharyngeal
Where are the hair cell receptors for equilibrium located?
vestibule and semicircular ducts
The Roman numeral VIII indicates the ________ nerve
vestibulocochlear
Regarding the events involved in hearing:
vibration of the basilar membrane causes vibration of hair cells against the tectorial membrane
Where are visual images perceived?
visual cortex of the occipital lobe
When analyzing sound waves in the ear, the number of hair cells stimulated is interpreted as which characteristic?
volume
Which of the following symptoms would you associate with damage to the spinal accessory nerve?
weakness of the sternocleidomastoid muscle
The frequency of a perceived sound depends on
which part of the cochlear duct is stimulated
Define otoliths
They are densely packed calcium carbonate crystals that sit upon the gelatinous otolithic membrane in the maculae
Which of the cranial nerves is named for the fact that it "wanders," that is, innervates structures throughout the thorax and abdomen?
X
The first step in the process of photoreception is
absorption of a photon by a visual pigment
Visual pigments undergo which three changes during photoreception?
activation, bleaching, and reassembly
Hormones known as "catecholamines" are
amino acid derivatives
The sensory receptors of the semicircular canals are located in the
ampullae
Which of the following descriptions best matches the term stereocilia?
bending these produces receptor potential in hair cells
What are the two configurations of retinal?
bent 11-cis form and the linear 11-trans form
The ________ is a region of dense bone that surrounds and protects the membranous labyrinth
bony labyrinth
The abnormality that develops when a lens loses its transparency is known as
cataracts
Olfactory information is first received by which part of the brain?
cerebrum
The sensory neurons within the olfactory organ are stimulated by ________ in the air
chemicals
________ cells connect photoreceptors to ganglion cells.
Bipolar
Which statement correctly describes the process that occurs when light strikes a visual pigment?
Bleaching occurs when the rhodopsin molecule breaks down into retinal and opsin
Identify the structure that regulates the amount of light entering the posterior segment of the eye
Iris
Olfactory glands
coat the olfactory epithelium with a pigmented mucus
Where is the spiral organ located?
cochlea of the internal ear
Peptide hormones are
composed of amino acids
The ________ covers most of the exposed surface of the eye
conjunctiva
Identify the areas that are filled with aqueous humor.
The anterior and posterior chambers
A ray of light entering the eye will encounter these structures in which order?
cornea - aqueous humor - lens - vitreous body - retina - choroid
Define focal point
Focal point is the point at which the light rays from an object intersect on the retina
vitreous body
Holds the retina against the choroid Transmits light Supports the posterior surface of the lens
________ are chemical messengers that are released in one tissue and transported in the bloodstream to alter the activities of specific cells in other tissues.
Hormones
_______ fills the membranous labyrinth
endolymph
The formal term for the sense of gravity, rotation, and linear acceleration is the sense of
equilibrium
Identify the accessory structures of the eye
eyelids, eyelashes, the superficial epithelium of the eye, and the structures associated with the production, secretion, and removal of tears
An area of the retina that contains only cones and is the site of sharpest vision is the
fovea centralis
Light passing through the eye along the visual axis strikes what part of the retina?
fovea centralis
Gustatory receptors are found in the taste buds of all the following papillae
fungiform vallate foliate
The axons of which cells converge at the optic disc to form the blind spot?
ganglion cells
All target cells
have hormone receptors and can respond to chemical signals
Norepinephrine and epinephrine are considered to be ________ when released into the bloodstream, but ________ when released at synapses
hormones; neurotransmitters
A patient develops a tumor of a cranial nerve that leads to difficulty in speaking from a loss of tongue movement. Which cranial nerve is affected?
hypoglossal
Movement of the endolymph in the semicircular canals
signals rotational movements
You suspect your friend has damage to cranial nerve I when he is unable to
smell his food
Why does the near point of vision typically increase with age?
Elasticity of the lens decreases with age
The following steps occur in rods when they are excited by photons of light
1.) Retinal changes to a more linear form 2.) Opsin activation occurs 3.) Opsin changes the membrane permeability of the outer segment to Na+ 4.) Neurotransmitter release changes 5.) Ganglia cells detect changes in bipolar cell activity 6.) Rhodopsin breaks down (bleaches)
A typical gustatory cell survives for only about ________ days before it is replaced
10
There are ________ pairs of cranial nerves
12
The following is a list of the steps that occur in the production of an auditory sensation. 1. The pressure wave distorts the basilar membrane on its way to the round window. 2. Movement of the tympanic membrane causes displacement of the malleus. 3. Displacement of the stereocilia stimulates sensory neurons of the cochlear nerve. 4. Movement of the malleus causes movement of the incus and stapes. 5. Distortion of the basilar membrane forces the hair cells of the organ of Corti toward or away from the tectorial membrane. 6. Movement of the oval window establishes pressure waves in the perilymph of the vestibular duct. What is the proper sequence for these steps?
2, 4, 6, 1, 5, 3
The olfactory receptor cell can be activated by as few as ________ odorant molecules
4
Identify the fluid filled space between the cornea and iris
Anterior chamber
Which of the following structures is highly vascular?
Choroid
Identify the muscular structure that anchors the lens in place
Ciliary body
Identify the structure that allows light to first enter the eye
Cornea
During the process of olfaction, which molecular event occurs?
Cyclic AMP opens sodium channels in the plasma membrane
Compare olfactory receptors with receptors for the other special senses
Olfactory receptors are the dendrites of specialized excitable olfactory neurons, whereas the receptors for the other special senses are receptor cells with inexcitable membranes and form synapses with the processes of sensory neurons
Which of the following choices best describes the correct sequence of the nervous pathway structures for the sense of smell?
Olfactory receptors, olfactory bulb, olfactory tract, olfactory cortex
Which of the following regions is known as the blind spot?
Optic disc
In order to perceive a "smell," certain components must be present to transmit an olfactory message to the brain. Which of the following components is required?
Receptor proteins in the receptor cell membrane The enzyme adenylate cyclase Cyclic AMP opening sodium channels in the receptor membrane
Compare rods with cones
Rods are active in dim light, and objects appear black and white. Cones require intense light, and objects appear in color.
For distant vision, which event is true?
The ciliary muscle relaxes
Which of the following statements most accurately describes the olfactory organ that allows us to detect odorants we come in contact with?
The olfactory epithelium contains millions of modified neurons with multiple cilia-like dendrites that project into the surface mucus layer.
Describe the structural classification of hormones
The structural classification of hormones divides them into amino acid derivatives, peptide hormones (built from amino acids as prohormones), and lipid derivatives (built from fatty acids or cholesterol).
What is the common goal of the nervous and endocrine systems?
To coordinate and regulate the activities of other cells, tissues, organs, and organ systems
Only the fibrous layer can be observed in its entirety from the superficial surface of the cow eye
True
The iris changes the diameter of the opening at its center, which is known as the pupil.
True
The lens divides the eye into the anterior segment, located in front of the lens, and the posterior segment, located behind the lens.
True
Which cranial nerve monitors all the taste buds located on the anterior two-thirds of the tongue?
VII
Where is the vitreous body located?
posterior segment
Identify the three types of cones
red, green and blue cones
Identify the neural layer
retina
A pigment synthesized from vitamin A is
retinal
In the retina, the correct sequence of neural wiring is
rod - bipolar cell - ganglion cell - thalamus
Gravity and linear acceleration are sensed in the
saccule and utricle
Name the largest portion of the fibrous layer
sclera
identify the parts of the fibrous layer
sclera and cornea