Lecture 4: PNS Flashcards
Nervous structures outside the brain and spinal cord with the exception of the dorsal root ganglia
Peripheral Nervous System
PNS allows the ____ to receive information and take action
CNS
All nervous system structures enclosed by bone are considered part of the ______
CNS
Spinal nerve lesions are expressed in what way?
Myotomal/dermatomal pattern
Peripheral nerve lesions are expressed in what way?
peripheral nerve pattern
What parts of the neuron are in the spinal region?
nerve root
dorsal ganglia
spinal nerve
What parts of the neuron are in the peripheral region?
rami, plexus
axons and nerve endings
Postganglionic ANS
Where are afferent neuron cell bodies located?
Dorsal Root Ganglia
What type of neurons carry sensory information from the outer body toward the CNS?
Afferent (sensory) Neurons
Where are efferent neuron cell bodies located?
Ventral horn of the spinal cord
What type of neurons relay commands from CNS to smooth and striated muscles and glands (effectors)?
Efferent (motor) Neurons
Where are interneurons located?
within the CNS in the brain and spinal cord
What do interneurons do?
Process information locally and convey information short distances
Another name for a bundle of peripheral axons
Nerves
Clusters of peripheral neuronal cell bodies
Ganglia
Pick up stimuli from inside of outside of the body
Sensory Endings
Axon terminals of motor neurons innervate effectors (muscle fibers and glands)
Motor Endings
Cable-like tissues in PNS
nerves
Nerve Trunk
a large cable like tissue grouped by numerous fascicles
Nerve fascicles
groups of axons bound into bundles
Small-diameter axons that share Schwann cells are referred to as:
unmyelinated
Large-diameter axons that are fully wrapped by individual Schwann cells are referred to as:
myelinated
___________ is a layer of delicate connective tissue surrounding the axon
endoneurium
___________ is a layer of connective tissue surrounding a nerve fascicle
perineurium
__________ is a tough fibrous sheath surrounding a whole nerve
epineurium
Nerve fibers with different diameters have different __________ ___________.
Conduction velocities
________ results in fascicle gliding within the nerve and the nerve gliding relative to other structures
Movement
somatic peripheral nerves are usually mixed, consisting of _______, __________, and ______ axons
sensory
autonomic
motor
Sensory input and motor output is divided into 4 main subdivisions:
somatic sensory
visceral sensory
somatic motor
visceral motor (autonomic nervous system)
Somatic Sensory General Somatic Senses (Skin)
touch, pain, vibration, pressure, temperature
Somatic Sensory Proprioceptive Senses (Skeletal muscle)
detect stretch in tendons and muscle
provide information on body position
orientation and movement of body in space
Somatic Sensory Special Senses
hearing, balance, vision