Chapter 9
Choroid
contains blood vessels that provide nutrients to the retina
Anterior Cavity:
contains the aqueous humor that supplies oxygen and nutrients to the lens and cornea
Posterior Cavity
contains the vitreous humor that maintain the shape of the eye and keeps the retina attached to the choroid
Retina
converts light into action potentials
Phasic
fast adapting and react when the stimulus is first applied and cease to respond while stimulus is maintained.
nociceptors
respond to painful stimuli resulting from physical or chemical damage to tissues
Ciliary body:
responsible for secreting aqueous humor
Pain information goes through the ________, __________, __________ without passing through the thalamus.
reticular formation, limbic system, hypothalamus
The ______ is the middle part of the bony labyrinth in the vestibule and consists of two sacs called the ______ and the ________
vestibule, utricle, saccule
What does acuity mean?
Acuity is sharpness of perception—the ability to precisely locate and distinguish one stimulus from another.
What is an electrode?
An electrode is a device that conducts electrical charges.
What are the three main regions of the ear? What are their functions?
External ear- collects sound waves and channels them inward Middle ear - conveys vibrations to the oval window Inner ear - houses receptors for hearing and equilibrium
Pupil
Hole in the center of the iris by which light enters the posterior cavity of the eyeball.
__________ are sensory receptors that respond to internal stimuli, while ________ are sensory receptors that detect stimuli from the external environment.
Interoceptors, Exteroceptors
_______ _____ is when input from sensory receptors on the border of the stimulus is inhibited compared to input from sensory receptors on the center of the stimulus.
Lateral inhibition
______ _________ are touch receptors located on upper part of dermis.
Meissner Corpuscles
__________ and _________ are two types of slowly adapting touch receptors.
Merkel Discs , Ruffini corpuscles
What are the five primary tastes?
Sweet, salty, sour, bitter, umami
What do the eyes detect?
The eyes detect visible light, light with wavelengths ranging from 400 to 700 nm.
Where in the eye is visual acuity the highest?
The fovea of the retina has the highest visual acuity.
What part of the eye is responsible for converting light into action potentials?
The retina.
Define referred pain. Give an example.
When pain is felt in another area of the body, than it's actual sources
Sensory information is converted to ________ ________ before it is sent to the CNS for integration.
action potentials
Tonic
adapt slowly and continue to produce significant response a slong as the stimulus is present.
Lens
an elastic structure that refracts light rays
thermoreceptors
detect changes in temperature
chemoreceptors
detect chemicals in the mouth, nose and body fluids
photoreceptors
detect light that strikes the retina of the eye
Canal of Schlemm
drains the aqueous humor from the anterior cavity. From here, it reenters the blood
Stimulus modality:
each unique sensation, encoded by the sensory receptors and neural pathways that are activated when stimulus is applied
Stimulus Duration
encoded by duration of action potentials in sensory neurons.
Stimulus Location:
encoded by the location of the activated receptive field.
Stimulus Intensity:
encoded by two main factors, frequency of action potentials generated in response to stimulus, and number of sensory receptors activated by stimulus
The ______ is a curved tube that conveys sound waves from the pinna to the tympanic membrane
external auditory canal
The ______ and ______ hair cells have different roles. The _________ are the receptors for hearing, while the _____ hair cells are _______ the sensitivity of the _______
inner, outer, inner hair cells, outer, increasing, inner hair cells
The presence of overlapping receptive fields improves stimulus ___________.
localization
The inner ear consists of two main sections: an ___________ that encloses an________
outer bony labyrinth , inner membranous labyrinth
Within the partition separating the middle and inner ears are two membrane-covered openings: an upper ________ and a lower _______
oval window, round window
Feeling ______ protects the body from stimuli that can cause tissue damage.
pain
Iris
part of the eye responsible for color of the eye. Not detection of color.
Receptive field
particular region of sensory space in where the stimulus would make that neuron fire. This varies depending on the stimulus Examples : Skin - region of skin where sensory neurons are located ; olfactory - odorants (chemicals in odor) to which the olfactory receptor cells can respond ; auditory - particular set of sound frequencies that elicits response in auditory neuron ; gustatory - specific type of tastants (chemicals in food) that cause response in taste neuron.
The _______ collects and directs sound waves into the external auditory canal.
pinna
Mechanoreceptors
sensitive to mechanical stimuli such as the deformation, stretching, or bending of cells. Provide sensations of touch, pressure, vibration, proprioception (muscle and joint position), and hearing and equilibrium. They also monitor the stretching of blood vessels and internal organs
Fovea
small depression in the macula lutea which is the highest area of visual acuity
Zonular fibers/suspensory ligaments:
suspensory ligaments that attach to the lens
Pain information that arrives in the primary somatosensory cortex first passes through the _________.
thalamus
Sclera
the "white" of the eye. It is a tough coat of connective tissue that covers the entire eyeball except the cornea
Optic disc:
the site where the optic nerve (II) exits the eyeball. Contains no photoreceptors
Cornea
transparent structure that admits and refracts incoming light rays into the eye
Sensory coding
use of organizational and functional features of the nervous system to represent specific details about a stimulus.
The main function of the _________ is to transmit and amplify vibrations to the__________
auditory ossicles, oval window
The middle ear is connected to the pharynx by the __________, also known as the ________
eustachian tube, auditory tube
