PSYCH Chp. 2 Sensation & Perception Flashcards
What are ganglia?
collection of neurons outside of the CNS
What is the purpose of osmoreceptors?
respond to osmolarity in the blood (water homeostasis)
What is the purpose of nociceptors?
respond to painful or noxious stimuli (somatosensation)
What is the diff b/w absolute threshold and just-noticeable difference?
absolute threshold is the minimum of stimulus energy needed to active a sensory system, while JND refers to the minimum difference in magnitude b/w 2 stimuli before one can perceive this difference
What is the frontmost portion of the eye?
cornea - gathers and focuses the light
What are the blood vessels that supply nutrients to the eyes?
the choroidal vessels - complex intermingling b/w the sclera and retina, and the retinal vessels
What is the innermost portion of the eye?
retina - houses photoreceptors that transduce light into electrical impulses to the brain for processing
What is the iris?
colored portion of the eye that separates the front of the eye into anterior and posterior chambers. is composed of the dilator and constrictor pupillae muscles that dilate and constrict the pupil under sympathetic and parasympathetic stimulating
What is the iris continuous with?
the choroid and the ciliary body
What is the purpose of the lens?
helps to control the refraction of incoming light, and is held in place by ciliary muscles
What is the purpose of the ciliary body?
produce aqueous humor that bathes on the front part of the eye before draining into the canal of schlemm
Why is visual acuity best at the fovea?
because it contains only cones
What is the purpose of the rods?
detects light and darks and contains a pigment called rhodopsin, which permits night vision
What is accommodation?
the ciliary muscles of the ciliary body contract under Parasympathic control, pulling on the sensory ligaments and changing the shapes of the lens
What are the cells that make up the optic nerve?
bipolar and ganglion cells
What is the purpose of amacrine and horizontal cells?
they are important for edge detection
What is the visual pathway?
cornea –> pupil –> lens –> vitreous –> rods and cones –> bipolar cells –> ganglion cells –> optic nerve –> optic chiasm –> optic tracts –> lateral geniculate nucleus of the thalamus –> or visual radiations of the parietal lobe –> visual cortex of the occipital lobe
What is the purpose of the paravocelluar cells?
detects shapes, with high spatial resolutions and low temporal resolution
What is the purpose of the magnocellular cells?
have very high temporal resolutions which allow us to detect motion, but because they have low spital resolutions, we cannot see the details of the moving object
What is the role of the ear?
hearing, and rotational and the detection of linear acceleration (vestibular sense)
What are the parts of the outer ear?
the pinna/auricle channel sound waves into the external auditory canal which then directs the waves into the tympanic membrane (eardrum)
What are the 3 smallest bones in the body?
the ossicles in the middle of the ear - malleus/ammer, incus/avil, and stapes/stirrup. the stapes rest on the oval window
What is the role of the ossicles?
to help transmit and amplify the vibrations from the tympanic membrane into the inner ear
How is the middle ear connected to the nasal cavity?
via the Eustachian tube which helps equalize pressure b/w the middle ear and the environment
What are the parts of the inner ear?
cochlea, vestibule, and semicircular canals filled with membranous labyrinth
What fluid makes up the bony and membranous labyrinth?
the bony labyrinth is suspended in a thin layer of perilymph, and the membraneous is filled with endolymph
What is the role of the perilymph?
transmit vibrations from the outside world, and cushion the inner ear structures
What are the parts that make up the cochlea?
the scalae
Where is the organ of corti houses?
in the middle scalae of the cochlea
What is the organ of Corti?
the hearing apparatus of the ear; has thousands of hair cells bathed in endolymph
What are the other 2 scalae filled with?
perilymph
What are the other 2 scalae filled continous with?
the oval and round window
What is the vestibule?
the portion of the bony labyrinth that contains the utricle and saccule
What is the purpose of the utricle and saccule?
sensitivity to linear acceleration, used for balancing and determining one’s orientation in 3D space. the utricle and saccule contain modified hair cells covered with otoliths, and as the body accelerates, these otoliths resist motions
What is the purpose of the semicircular canals?
sensitivity to rotational acceleration. contains the ampulla where hair cells are located. As the head rotates, the endolymph in the canals resists this motion.
What is the auditory pathway?
pinna –? external auditory canal –? tympanic membrane–> malleus –> incus –> stapes > oval window –> perilymph in cochlea –> basilar membrane –> hair cells –> vestibulocochlear nerve –> brainstem –> medial geniculate nucleus of the thalamus –> auditory cortex in the temporal lobe for processing
What causes depoloarizaiton of neurons in hair cells?
movement of endolymph inside the organ of Corti causes the opening of ion channels which causes receptor potential
What is the purpose of the olfactiry cheoreceptors?
smell responds to volatile and aerosolized compounds
What is the olfactory pathway?
nostrils –> nasal cavity –> olfactory chemoreceptors (olfactory nerve) in the olfactory epithelium –> olfactory bulb –> olfactory tract –> limbic system
Which sense does not pass through the thalamus?
smell
What is taste?
detection of dissolved compounds via papillae/taste buds
What is the taste pathway?
taste travels from the taste buds to the brainstem, and then ascends to the taste centers in the thalamus then to the somatosensory cortex in the partial lobe
What are the 5 types of pain receptors?
Pacinian corpuscles - respond to deep pressure and vibration
Meissner corpuscles - respond to light touch
Merkle cells (disc) - respond to deep pressure and texture
Ruffini endings - respond to stretch
Free nerve endings - respond to pain and temperature
What is physiological zero?
the normal body temp of the skin, between 86-97 degrees
What is the purpose of kinesthetic sense/proprioception?
the ability to tell where one’s body is in space. found mostly in muscles and joints, and play a role in hand-eye coordination, balance, and mobility
What is button-up/data-driven processing?
Refer to object recognition by parallel processing and feature detection. slower, but less prone to mistakes
What is top-down/conceptually driven processing?
refers to the recognition of an object by memories and expectations, with little attention. faster but more prone to mistakes
What is the law of proximity?
elements close to one another tend to be perceived as a unit
What is the law of similarity?
similar objects tend to be grouped together
What is the law of good continuation?
elements that appear to follow in the same pathway tend to be grouped together
What is the law of closure?
certain figures tend to be perceived as more complete/closed than they are
What is the law of contours?
edges or shapes that are not present can be implied by the surrounding objects
