MCAT Behavioral

• Sensory receptors are sensory nerves that respond to stimuli.
• Give the visual pathway : Eye, optic nerves, optic chiasm, optic tracts, lateral geniculate nucleus (LGN), visual radiations, visual cortex
• Weber's law states that the just noticable difference for a stimulus is proportional to the magnitude of the stimulus.
• The iris controls the size of the pupil.
• The lens refracts incoming light to focus it on the retina.
• The cornea gathers and filters incoming light.
• Sensory adaptation can increase or decrease our receptors sensitivity to the stimulus.
• amplification - an increase in sensitivity
• Aqueous humor is the clear, watery fluid that fills the space between the cornea and lens of the eye. It provides pressure to maintain the shape of the eye ball. Produced by the ciliary body and drains through the canal of Schlemm.
• The retina is the sensory membrane that lines the back of the eye which contains rods and cones.
• Rods are photoreceptors in the retina that detect light and dark.
• Cones are photoreceptors in the retina that detect color.
• The threshold of conscious perception is the minimum stimulus enegry that will create a signal large enough in size and long enough in duration to be brought into awareness.
• The absolute threshold is the minimum stimulus energy that will activate a sensory system.
• Sensory ganglia are enlargements along peripheral nerves that transmit signals to the CNS.
• Retinal disparity provides a biocular cue that helps us percieve depth.
• Horizonatal and amacrine cells integrate signals from ganglion cells and perform edge-sharpening .
• Parvocellular cells process shape.
• Magnocellular cells process motion.
• Signal detection theory refers to the effects of nonsensory factors, such as experiences, motives, and expectations on perception of stimuli and accounts for the response bias.
• Parallel processing is the idea that our eyes process color, form and motion at the same time.
• The three main divisions of the ear are outer, middle, and inner.
• The outer ear includes the pinna, external auditory canal, and the tympanic membrane. Collects sound and transmits to eardrum.
• The middle ear includes the malleus, the incus, and the stapes.
• The malleus is one of the three ossicles in the middle ear and is the hammer.
• Projection areas are areas in the four lobes of the brain where sensory processing occurs.
• The difference threshold is the minimum difference in magnitude between two stimuli before one can percieve the difference.
• The incus is one of three ossicles in the middle ear and is the anvil.
• The stapes is one of three ossicles in the middle ear and is the stirrup.
• The inner ear includes the cochlea, the vestibular system, and the semicircular canals.
• The pinna ( auricle) acts as a funnel which assists in directing the sound further into the ear.
• External auditory canal transmits sound from the pinna to the eardrum. " Ear canal"
• Tympanic membrane is a thin flap of skin that is stretched tight like a drum and vibrates when sound hits it. "Eardrum" . Seperates the outer ear from the middle ear.
• The cochlea is used for hearing while the vestibular system and the semicircular canals are used for balance.
• The cochlea translates sound into nerve impulses to be sent to the brain.
• The vestibular system is a sensory system responsible for providing our brain with information about motion, head position, and spatial orientation. It also is involved with motor functions that allow us to keep our balance. The system includes the semicircular canals. When your head moves around, the endolymph ( liquid) inside the semicircular canals sloshes around and moves the tiny hairs that line each canal.
• The superior olive is located in the brain stem and its function is to localize sound.
• The inferior colliculus is responsible for the startle reflex and vestibulo-ocular reflex.
• The vestibulo-ocular reflex keeps the eye fixed on a single point as the head rotates.
• Give the auditory pathway: Cochlea, vestibulocochlear nerve, medial geniculate nucleus, auditory cortex.