Ch 13: The PNS

CH 13: THE PNS

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FIRST SOME VOCABULARY

Sensory receptor: responds to changes in the environment (stimuli)

Stimuli: change in the body which can cause nerve impulses

Ganglia: collection of cell bodies in the PNS, these are called Nuceli in the CNS

Sensation: you are aware of the stimulus

Perception: you understand the stimulus THIS IS ONLY DONE BY THE BRAIN!!

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Open Ended

If you are understanding the stimulus that triggered a response by your body, what would that be called, perception or sensation?

*From the CNS to the organs, muscles and glands

• Divided into the somatic NS (from the CNS to skeletal muscles)

• Autonomic NS (Includes the smooth and cardiacmuscles,and glands

motor (efferent) division

• it goes to the CNS (Brain and spinal cord)

• Has both somatic and visceral nerve fibers

• Ex- somatic (skin) visceral (stomach)

sensory (afferent) division

the Somatic and Motor divisions of the ns

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Open Ended

Of what division is the autonomic NS part of?

Open Ended

What system is known as the rest and digest?

Types of receptors

Thermoreceptors: responsible for picking up temperature changes

Photoreceptors: responsible for picking up light energy (retina of the eye) ONLY PRESENT IN THE EYE

Chemoreceptors: responsible for picking up chemicals in a solution Ex. smell, taste, changes in blood O or CO2

Nocireceptors: responsible for picking up potentially harmful stimuli (pain) work with thermoreceptors, mechanoreceptors, and chemoreceptors

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Exteroreceptors: responsible for picking up external stimuli, most are at or close to the body surface. Ex. special senses (vision, taste, smell, hearing, equilibrium)

Interoreceptors: responsible for picking up internal stimuli, monitor chemical changes, tissue stretch, temperature

Propioreceptors: responsible for picking up internal stimuli only in skeletal muscle, tendons, joints, ligaments* , monitor body position based on stretch

simple receptors: associated with general sense. One type of receptor can respond to many stimuli

Complex receptors: are localized in special senses

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Tonic receptors: have a sustained response (do NOT adapt) ex. nocireceptors, most propioreceptors

Phasic receptors: fast adapting, mainly report changes ex. Meisner's corpuscles ( low preassure changes)

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Open Ended

What type of receptors pick up stretch signals to determine position?

Poll

On what topics do you need further assistance?

• types of receptors

• graded potential and action potentials

• order of neuron processing

• no questions