Term
| peripheral nervous system components |
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Definition
| sensory and motor neurons. somatic ns & autonomic ns. nerves conduct impulses from the body to the CNS and from the CNS to the body. |
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Definition
| sensory and motor neurons that move body's skeletal muscles. motorl responses from brain to spinal cord called EFFOCTORs. these responses are voluntary. (like kicking a ball.) |
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Definition
| only motor neurons. heart rate, blood vessel constriction, smooth muscle contraction, & glandullar secretions. automatic/involuntary responses. |
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Definition
| fight or flight. involved in excitation & emotional stress. ^ blood pressure, responiration, dilation of sphineter muscles, iris. secretes norepinephrine (speeds up activites) and located in grey matter of the mid-spinal cord. |
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| rest and digest. involved in relaxatrion & maintenance of body activites. V heart rate, strength of contraction, stimulate digestion, constric pupils. secrete Ach. originate in brain stem and lower portions of spinal cord. |
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Definition
| how neurons communicate. neuron talking to self--negative feedback. neurons create pathways that wllow events and direct flow of communication between & among neurons. must develop in a specifc period of time. some continue to develop throughout one's life. develop for all throught processes--memory, associations, problem solving, behavior, etic. pain--fast patrhway & slow pathway. fast triggers neuron then turns it off. slow doesn't. |
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Definition
| sensory structure receive stimuli that trasnfers info in. receptors amplify weak stimuli. sensory receptors are isolated, so there's no confusion. incoming info is called a sensation. info received by brain -- perception. |
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| free nerve endings that detect pain, mechanoreceptors detect pressure & thermoreceptors detect heat & cold. free nerve endings (nocicreptors) detect pain. pacinian corpuscles detect heavy pressure. meissner's corpuscles detect light pressure. kause's end bulbs respond to cold. ruffini end organs respond to heat. |
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Definition
| external ear gathers and focuses sound. middle ear transmits sound vibrations via the hammer, anvil and stirrup to the inner ear. inner ear consists of cochlea and vestibular apparatus. the cochlea contains sensory neurons that transmit info to the brain's hearing centers. vestibular apparatus determines body position by detecting the position of its fluids and otolihs (calcium carbonate) in relation to the pull of gravity. |
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Definition
| sound is directed to middle ear by the pinna of the outer ear. sound travels to tympanic membrane through auditory canal vibrations cause bones (malleus, incus, stapes) to ^ force. vibrations picked up by cochlea where they create a wave of motion in its fluid chamber. fluid bends ciliated cells which activate neurons that connect to the vestibulocochlea nerve which leads to hearing centers in the brain |
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Definition
| vestibular apparatus functions in determining body position. inside the aparatus are 3 canals filled with fluid. 2 of them contain otoliths ( ear stones). these stones shift within the fluid as the position of the head moves in relation to the pull of gravity. sensory hairs detect the position of the fluid and otoliths and send that info to the cerebellum where it is integrated. the cerebellum sends out messages to the muscles that help maintain equalibrium. 2 types of balance--dynamic for sudden head movement, and static for normal posture and stability. |
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Definition
| consists of the eyeball and accessory structure that surround it. beaneath the clear membrane covering of the conjunctiva is the cornea which covers the iris. the iris contains muscles that regulate the diameter of the pupil opening. the pupil is the opening that lets in light. lens behind pupil. aqueous humor fluid in front of lends. behind lens is the the vitreous humor. |
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Definition
| has 3 distinct layers of tunics. fibrous tunic, protection & support, eye muscle attach, aids in focusing it. consists of sclera (white) and cornea (clear part over lends). vascular tunic--place for blood/lymph vessels that supply eye, where amount of light is regulated, secretes/reabsorbs a. humor, controls lens shape, includes iris and ciliary body. neural tunic--the retina. this is where photoreceptor cells receive light and send signal to the brain |
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Definition
| retina has rods and cones. rods--b+w, cones--color. stimulated rods and cones transmit visual impulses to the optic nerve, then onto the brain. discs of both rods and cones contain visual pigment derived from rhodopsin (made of protein, opsin and a pigment molecule called retinal, dervied from vit a) retinal is identical in both r+c's but the opsin is diff in rods, red, blue, green cones. when photons strike rods & cones, retinal changes shape the rhodopsin molecules come apart. |
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