Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
68 Cards in this Set
- Front
- Back
|
What is the PNS?
|
all neural structures outside the brain and spinal cord
|
|
|
What does the PNS include?
|
sensory receptors, peripheral nerves, associated ganglia, and motor endings
|
|
|
What is the function of the PNS?
|
it provides links to and from the external environment
|
|
|
What are sensory receptors?
|
structures specialized to respond to stimuli
|
|
|
What happens when sensory receptors are activated?
|
it results in depolarization that trigger impulses to the CNS
|
|
|
What are the five types of receptors?
|
1. Mechanoreceptors
2. Thermoreceptors 3. Photoreceptors 4. Chemoreceptors 5. Nocireceptors |
|
|
What are exteroreceptors?
|
they are receptors that responds to stimuli outside the body
|
|
|
What are mechanoreceptors?
|
they respond to touch, pressure, vibration, stretch and touch
|
|
|
What are thermoreceptors?
|
receptors that are sensitive to changes in temperature
|
|
|
What are photoreceptors?
|
they respond to light energy (retina)
|
|
|
What are chemoreceptors?
|
they respond to chemicals (smell, taste, changes in blood chemistry)
|
|
|
What are nocireceptors?
|
they are receptors that are sensitive to pain causing stimuli
|
|
|
Where are exteroreceptors found?
|
They are found near the body surface
|
|
|
What are exteroreceptors sensitive to?
|
touch, pressure, pain and temperature
|
|
|
What organs do exteroreceptors include?
|
they include the special sense organs
|
|
|
What are interoceptors?
|
they are receptors that respond to stimuli arising within the body
|
|
|
Where are interoceptors found?
|
found in internal viscera and blood vessels
|
|
|
What are interoceptors sensitive to?
|
they are sensitive to chemical changes, stretch, and temperature changes
|
|
|
What is the EEG representation of brain waves during death?
|
flat one
|
|
|
What are proprioceptors?
|
they respond to degree of stretch of the organs they occupy
|
|
|
What are the receptor classes by location?
|
1. proprioceptors
2. interoceptors 3. exteroceptors |
|
|
Where are proprioceptors found?
|
skeletal muscles, tendons, joints, ligaments, and connective tissue coverings of bones and muscles
|
|
|
What does survival depend on?
|
sensation and perception
|
|
|
What is sensation?
|
the awareness of changes in the internal environment and external environment
|
|
|
What is perception?
|
the conscious interpretation of those stimuli
|
|
|
Where does input come from?
|
exteroceptors, interoceptors, proprioceptors
|
|
|
What are the three main levels of neural integration of the sensory system?
|
1. Receptor Level
2. Circuit Level 3. Perceptual Level |
|
|
What is the receptor level of neural integration?
|
the sensor receptors
|
|
|
What is the circuit level of neural integration?
|
ascending pathways
|
|
|
What is the perceptual level of neural integration?
|
neuronal circuits in the cerebral cortex
|
|
|
Processing at the Circuit Level
|
chains of three neurons (first, second, third order) conduct sensory impulses upward to the brain
|
|
|
Where are first order neurons located?
|
in dorsal root or cranial ganglia
|
|
|
What is the function of first order neurons?
|
to conduct impulses from the skin to the spinal cord or brain stem
|
|
|
Where are second order neurons located?
|
in the dorsal horn of the spinal cord, or medullary nuclei
|
|
|
What is the function of second order neurons?
|
they transmit impulses to the thalamus or cerebellum
|
|
|
Where are third order neurons located?
|
located in the thalamus
|
|
|
What is the function of third order neurons?
|
conduct impulses to the somatosensory cortex of the cerebrum
|
|
|
Where does the thalamus project fibers to?
|
a. the somatosensory cortex
b. sensory association areas |
|
|
What is a nerve?
|
cordlike organ of the PNS made up of peripheral axons enclosed by connective tissue
|
|
|
What do connective tissue coverings of nerves include?
|
a. Endoneurium
b. Perineurium c. Epineurium |
|
|
What is the endoneurium?
|
loose connective tissue that surrounds axons
|
|
|
What is the perineurium?
|
coarse connective tissue that bundles fibers into fasicles
|
|
|
What is the epineurium?
|
tough fibrous sheath around a nerve
|
|
|
What are the two division of the nerves?
|
Sensory and motor divisions
|
|
|
What do sensory (afferent) nerves do?
|
carry impulse to the CNS
|
|
|
What do motor (efferent) nerves do?
|
carry impulses from CNS
|
|
|
What are mixed nerves?
|
sensory and motor fibers carry impulses to and from CNS
|
|
|
What is the most common type of nerve?
|
a mixed nerve
|
|
|
Why is damage to nerve tissue serious?
|
because mature neurons are amitotic
|
|
|
If the soma of a damaged nerve remains intact what can be done?
|
the damage can be repaired
|
|
|
How many cranial nerves are there?
|
12 that arise from the brain
|
|
|
What type of functions do the cranial nerves have?
|
sensory, motor, or both
|
|
|
How is each cranial nerve identified?
|
by a name and roman numerals
|
|
|
How many cranial nerves carry parasympathetic fibers?
|
4
|
|
|
What do these cranial nerves serve?
|
muscles and glands
|
|
|
What does regeneration of nerve fibers involve?
|
a. macrophages
b. schwann cells c. axons |
|
|
What do the macrophages do?
|
remove debris
|
|
|
What do the schwann cells do?
|
from regeneration tube and secrete growth factors
|
|
|
What do the axons do?
|
regenerate damaged part
|
|
|
What is the soma of the nerve?
|
cell body
|
|
|
What is cranial nerve I?
|
olfactory nerve
|
|
|
Where does the olfactory nerve arise from?
|
from the olfactory epithelium
|
|
|
What does the olfactory nerve pass through?
|
the cribriform plate of the ethmoid bone
|
|
|
Where does the olfactory nerves fibers run through?
|
the olfactory bulb and terminate in the primary olfactory nerves
|
|
|
What is the function of the olfactory nerve?
|
carrying afferent impulses for smell
|
|
|
What is cranial nerve II?
|
optic nerve
|
|
|
Where does the optic nerve pass through?
|
the optic canals and converge at the optic chiasm, the continue to the thalamus where they synapse
|
|
|
What is the function of the optic nerve?
|
carrying afferent impulses for vision
|
