chapter 13 Flashcards
can you list the structures of the PNS?
any nerve structure outside of the brain and spinal cord. This includes receptors,nerves and ganglia and motor endings
do you know the general function of the PNS?
information highway -receptors are activated by stimuli and that information travels toward the brain and spinal cord. Motor information for an effector organ will travel along nerves in the periphery as well
What are the structures in the PNS specialized to respond to?
stimuli such as changes in temperature, pressure, pH, chemicals, itch, pain, light, sound waves…
Do you know where perception of stimuli occurs?
the brain
can you list and describe the classification of receptors in the PNS by stimulus type?
a. mechanoreceptors- activated by pressure
b. photoreceptors- activated by light (photons)
c. chemoreceptors- activated by chemicals
d. thermoreceptors- activated by change in temperature( measurement of heat)
e. nociceptors- can be any of the above types, but are only activated by excess stimulus and is interpreted by the brain as pain
can you list and describe the classification of receptors in the PNS by location?
type:
a. exteroceptors- close to the skin and respond to stimuli outside the body( external stimuli)
b. interoceptor- deep within tissue and respond to internal stimuli
i. only type is referred to as proprioceptors, which are interoceptors that are found in joints, skeletal muscles, skin, and bone coverings and give information regarding body’s position
can you list the different types of sensation?
pressure (touch, itch, vibration), temperature, light, chemicals (smell, taste, on the skin, within the body)
can you list and describe the classification of receptors in the PNS by structural complexity?
a. which of these are our special senses?
type:
a. simple receptors- include encapsulated and unencapsulated types. activated by general sensory stimuli( temperature, pain, itch, pressure)
b. complex receptors- these receptors have complex structures and respond to light, chemicals for smell and taste, sound waves and movements of the head for equilibruim
c. special senses are complex receptors
do you know the difference between simple unencapsulated and simple encapusulated receptors?
encapsulated receptors have CT capsule over the receptor. Unencapsulated does not
can you describe the structure of a nerve?
many axons traveling to a similar destination , wrapped in CT sheaths
can you describe the connective tissue sheaths associated with a nerve?
sheaths:
a. endoneurium- CT sheath aroud each axon (fiber)
b. perineurium- CT sheath that holds fibers together in bundles called fasicles
c. epineuriom- around entire nerve
can you describe what sensory and motor nerves are? what classification of nerve is most of the nerves in our body?
sensory nerves are composed of axons traveling afferently, and motor nerves are composed of axons traveling efferently. Most nerves in the body are mixed, meaning they carry both types of axons. The only nerve that are sensory only or motor only are a few of the cranial nerves
can you list and describe the four possible types of nerve fibers?
visceral sensory, somatic sensory, visceral motor and somatic motor
do yo know how many nerves have parasympathetic functions? do you know how many don’t?
4 have parasympathetic function, while 8 do not
do you know how many spinal nerves pairs there are? do you know how they are numbered?
C1-C7 are named for the vertebra below them and T1-S5 are named for the vertebra above them
