Chapter 10 - Sensory Flashcards
What are the 5 types of sensory receptor and give an example(s) of each?
- Chemoreceptor - tast bud, olfactory epithelium, aortic and carotid bodies
- Photoreceptor - rods and cones in the retine
- Thermoreceptors -
- Mechanoreceptors - touch and pressure receptors in the skin and hair cells within inner ear
- Nociceptors - pain receptors
These receptors include muscle spindles, golgi tendon organs, and joint receptors and provide a sense of body position and allow fine control of skeletal muscle movement.
- proprioceptors
What is the difference ebtween exteroceptor and interoceptor….
Exteroceptor - responds to stimuli from outside the body (touch, hearing vision etc)
Interoceptor - responds to internal stimuli
This type of receptor is found in the skin and responds to pressure. It could be considered a [] receptor with its ability to adapt to a constant stimuli.
- Pacinian Corpuscle
- Phasic Receptor
What is a receptor potential?
- Also called a generator potential
- It is a graded potential formed in the sensory nerve ending…it acts like an EPSP in the dendrites
What type of sensations do naked nerve endings sense?
Heat, Cold, Pain
This cutaneous receptors are sensitive to the depth of skin indentation and have highest spatial resolution of the cutaneous receptors…providing information regarding the objects []
- Merkels Disc
- Texture
Which receptor is the main receptor in our finger tips…which receive sensations of touch and pressure and are mediated by dendrites that are encapsulated within variuos structures?
Meissner’s Corpuscles (pacinion corpuscle is also encapsulated)
The cold/menthol receptors and the heat/capsaicin receptors are members of the same family of cation (Na+ and Ca2+) channels called what?
Transient receptor potential channels (TRP)
Describe the differences in receptive field size of neurons in the legs or back compared to neurons in the finger tips…
- There are tons of sensory receptors in the finger tips, so their receptive field can be smaller
- There are not as many sensory receptors in the back or legs, so their receptive field has to be larger to acount for the larger skin area.
What is the two-point touch threshold?
The minimum distance at which two points of touch can be perceived as separate, is a measure of the distance between receptive fields.
Where is Lateral inhibition integrated and then “sharpened?”
The CNS
The sense of [], which provides orientation with respect to gravity, is due to the function of this organ….?
Vestibular apparatus
What 2 structures form the “inner ear?”
Vestibular Apparatus, Cochlea
What 2 structures make up the Vestibular Apparatus?
- Otolith Organs
- Utricle
- Saccule
- Semicircular canals
Where are the sensory structures of the inner ear (vestibular app and cochlea) located?
within the membranous labryinth….which is located within the bony labryinth of the skull.
Why do the mechanoreceptors in the inner ear use Ca2+ to initiate a depolarization, instead of Na2+?
- They don’t. The mechanoreceptors use K+
- The membranous labyrinth is filled with endolymph extracellular fluid. This extracellular fluid has an extremely high concentration of K+ (More than Na and Ca). So to make a depolarization, all K+ has to do, is move down its electrochemical gradient into hair cells when K+ channels open.
Which inner ear structure provide information about linear acceleration (vertical or horizontal)?
Which inner ear structure provides a sense of rotational, or angular acceleration?
Utricle and Saccule
Semicircular canals
What purpose does the endolymph serve in the otolithic membrane and semicircular canals?
- provides enertia so that the sensory processes will be bent in a direction opposite to that of the angular acceleration.
- When you turn your head left, the hair cells will be bent right
Which nerve receives sensory stimulation from the vestibular apparatus?
Where are these impulses sent to in the brain?
- Vestibulocochlear nerve (VIII)
- impulses sent to the cerebellum and vestibular nuclei of medulla oblongata
- Vestibular nuclei then sends impulse to oculomotor center of the brain to make sure the eyes are keeping track of movements….or something like that.
What 2 structures make up the outer ear?
Which structure channel the incoming sound waves to the eardurm, or another name for []?
- auricle - foldy outer part of the ear and the
- External auditory meatus - basically the canal to your eardrum
- Tympanic Membrane
Name the three Ossicles located in the middle ear?
T/F - these bones help depress incoming noise?
- Malleus - connected to the tympanic membrane
- Incus (Anvil)
- Stapes (Stirrups)
True
Which small bone vibrates in response to the tympanic membrane, and is attached to a membrane in the cochlea called the oval window?
Stapes
Fill in the blank -
Vibrations of the stapes an oval window displace [] fluid within a part of the bony labyrinth know as the [], the upper three chambers within the cochlea.
- perilymph
- Scala Vestibuli
What is the name lower half of the three chambers of the cochlea?
Scala Tympani
Fill in the blank -
The cochlear duct (or the []) is part of the [] labryinth and is the middle chamber of the cochlea. It also contains [] fluid.
- Scala Media
- Membranous
- Endolymph Fluid
Displacement of the [] is central to pitch discriminiation
basilar membrane
Which membrane surrounds the scala media on the top and bottom?
Top - Vestibular Membrane
Bottom - Basilar Membrane
In the Cochlea - where are the hair cells found?
In the basilar membrane with their hairs projecting into the endolymph of the cochlear duct.
The inner hair cells transform sound waves in cochlear fluid into nerve impulses, so they must be. [] ?
Mechanoreceptors
This membrane is within the cochlear duct and holds the hair cells in place, projecting them into the endolymph.
Tectorial membrane
The association of the basilar membrane, inner ahir cells with sensory fibers, and tectorial membrane forms a function unit called [] or []
Spiral Organ
Organ of Corti
Which monoamine neurotransmitter do Hair Cells release when they are depolarized by the inflow of [] +?
Glutamate - which then stimulates associated sensory neurons
K+
Which nerve sends the information from tbe ear, and where is it sent to?
- Vestibulocochlear (VIII)
- The impulses are sent to one of 2 cochlear nuclei in the junction of the medulla and pons of the brain stem
Fill in the blank -
Whatever the route, all auditory paths synapse in the [] []. Neurons in the [] [] then send axons to the medial [] [] of the thalamus, which in turn proejcts to the audtory cortex of the [] lobe.
- inferior colliculus
- inferior colliculus
- Geniculate body
- Temporal
The loudness of sounds, unlike their pitch, is coded by the [] of action potentials.
Frequency
Outermost layer of the eye, tough coat of connective tissue called the….
sclera
The tissue of the sclera is continuous with the transparent []?
Cornea
This mucous membrane covers the sclera and internal surface of the eyelid. As well as being continous with the cornea…
Conjuctiva
Light passes through the cornea to enter the [] []
Anterior Chamber
After passing through the anterior chamber, light then passes though the opening called the [], which is surroudn by a pigmented muscle known as the []
Pupil
Iris
After passing through the pupil, light enters the lens
Constriction of the pupils results from [] stimulation
Dilation results from [] stimulation
Both stimulations come from the [] nerve (III)
- Parasympathetic
- Sympathetic
- Occulomotor nerve (III)
Fill in the Blank -
Constriction of the pupils is produced by contraction of [] muscles within the iris; dilation is produces by contraction of [] muscles
- Circular muscles
- Radial Muscles
Fill in the blank -
Light that passes from a medium of one desnity into a medium of a different density is [], or bent
refracted
What portion of the eye bends light the most?
cornea
Even though the cornea bends light most, which portion of the eye allows for the fine control for focusing light on the retina?
lens
The ability of the eyes to keep the image focused on the retina as the distance between the eyes and object varies is called…
accommodation
Which muscle controls the eye’s ability to accomodate objects at varying distances?
Ciliary muscle
Fill in the Blank -
When the ciliary muscle relaxes, its [] is wide. Relaxtion of the ciliary muscle thus places tension on the [] fibers of the suspensory ligament and pulls the lens []. The lens is now [] and focused for distant vision.
This action is performed when objects are far or close?
- aperture
- zonular
- Taut
- thin
- This happens when objects are 20 feet or more from the eye
Fill in the blank -
When ciliary muscles [], it narrows the aperture of the ciliary body and thus reduces the [] on the zonular fibers of the [] ligament. The lens is now [] and focused for close vision.
This action is for when an object is close or far away?
- contract
- tension
- suspensory
- thick
- Used for when objects are close to the eye.
Presbyopia is the loss of [] as people age?
accommodation
Emmetropia is what kind of vision and why?
What type of correction is used?
Normal vision - light rays focus on the retina
Nothing needed to correct vision.
Constriction does what to they eye?
Dilates the pupil, allowing more light to enter the eye.
What type of vision is myopia? Why?
How is it corrected?
- Nearsightedness (cant see long distances). Due to a “longer” eyeball the rays focus in front of the retina.
- Concave lens correct nearsightedness
Why type of vision is hyperopia? Why?
How is it corrected?
- Farsightedness (see long distances). Due to a “shorter” eyeball, the rays focus behind the retina.
- Convex lens is used for correction
What type of vision is an Astigmatism? Why?
How is it corrected?
- The cornea and lens are asymmetrical, so the rays of light do not focus.
- Uneven lens correct this.
The [] consists of a single cell-thick pigmented epithelium, photoreceptor neurons called rods and [], and layers of other neurons.
Retina
Rods
Do rods or cones maximize sensitivity to low levels of light? Why?
- Rods.
- Multiple Rods are connected to multiple bipolar neurons which all connect to 1 ganglion.
Do Rods or cones have high visual acuity but sensitivity when light is reduced? Why?
- Cones in fovea
- 1 cones is connected to 1 bipolar neuron which is connected to 1 ganglion. High acuity on what your seeing, just not good in low lights.
