Term
| give me a description of the pns |
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Definition
| neural structures outside the brain and spinal cord. includes sensory receptors , periphal nerves, associated ganglia, and motor endings. provides links to and from the external environment |
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Term
| what are the sensory receptors of the pns? |
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Definition
| they are special structures to respond to stimuli. the activation of the sensory receptors activates depolirization that trigger impulses to the CNS. The realization of these stimuli, sensation and perception, occur in the brain |
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Term
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Definition
mechanoreceptors - respond to touch, pressure, itch, stretch, vibration.
thermotemperature - sensitive to change in temperature . photoreceptors - respond to light energy. chemoreceptors respond to smell, taste, change of blood chemistry |
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Term
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Definition
| respond to stimuli outside the body. sensitive to touch, pressure, pain and temperature. includes the special sense organs(ears, eyes) |
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Term
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Definition
| responds to stimuli inside the body such as the viscera and blood vessels . sensitive to chemical changes, |
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Term
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Definition
| they are similar to interoceptors but they are more particular, found in skeletal muscles, joints, tendons. constanntly advises the brain of ones movement |
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Term
| what are the classification by receptor structure |
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Definition
| they structured either simple of complex. most receptors are simple and contain capsulated and encapsulated varieties. the complex structure are special sense organs |
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Term
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Definition
| free dendrite nerve endings. they respond to temperature and pain. (merkel tactile discs, hair follices) |
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Term
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Definition
| meiseners corpsucles, pacinian corpscules, muscle spindles, golgi tendon organs and ruffinis corpsucles, joint kinesthetic receptors. |
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Term
| what is sensation and perception? and how important is both? |
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Definition
| sensation is the awareness of changes in the internal and external environment. perception is the conscious interpretation of those stimuli. survival depends on both sensation and perception |
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Term
| how does adaptation of sensory receptors work? |
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Definition
| adaptation occurs when the sensory receptors are subjected to an unchanging stimilus. receptor membranes become less responsive. receptor potentials decline in frequency or stop. |
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Term
| do receptors adapt to touch, smell, pressure |
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Definition
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Term
| receptors respond slowly to include merkel discs, ruffinis corpscules, and interoreceptors that respond to chemical levels in the blood, true or false |
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Definition
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Term
| pain receptors and proprioreceptors does exhibit adaptation, true or false? |
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Definition
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Term
| give me the classification of nerves for sensory and motor divisions |
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Definition
sensory(afferent) carry impulse to the cns
motor(efferent) carry impulse . mixed nerves sensory and motor carry impulses to and from the cns, most common type |
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Term
| what type of mixed periphal nerves are there? |
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Definition
| somatic afferent efferent and visceral afferent efferent |
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Term
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Definition
| originate from the brain and spinal column |
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Term
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Definition
| a reflex is a rapid, predictable motor response to a stimilus. reflexes may be (in born(intrinsic) or learned(acquired). involve only the periphal nerves and spinal cord. involve higher brain centers as well. |
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Term
| what are the components of the reflex arc? |
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Definition
| 1. receptor - site of stimilus 2. sensory neruon - transmits afferent impulses to the CNS. 3. either polysynaptic(multiple neurons) or monosynaptic(sensory and motor neuron). 4. motor neuron - conducts efferent impulses from integration to an effector. 5. effector - muscle fiber or gland that responds to the effector impulse. |
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Term
| for stretch muscles to perform normally, what needs to hapepn? |
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Definition
| the golgi tendon organs(proprioceptors) must keep informing the brain as to the state of the muscle. stretch reflexes initiated by muscle spindles must maintain healthy muscle tone. |
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Term
| how is stretch reflex activated? |
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Definition
| stretching the muscle activates the muscle spindle. excited motor neurons of the muscle spindle cause stretched muscles to contract. afferent impulses from the spindle result in inhibition of the antiagaonist. |
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Term
| give me an example of a stretch reflex. |
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Definition
| the patellar reflex. tapping the patella stretches the quadriceps and starts the reflex action. the quadriceps contract and antiagaonist hamstrings relax. |
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Term
| development aspects of the pns |
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Definition
| spinal nerves branch out from the developing spinal cord and neural crest cells . supply motor and sensory function to |
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