(8) Nervous System Flashcards
● Consists of the brain, the spinal cord, and the peripheral nerves, which connect various parts of the body to either the brain or spinal cord
Nervous System
primary functional cell of the nervous system
Neuron
other cells types that functions to maintain the cellular environment to support the activity of the neurons
Glia
this system is the control center consisting of the brain and the spinal cord
Central Nervous System
this system has all the nerve processes connecting to the CNS, consisting of cranial and spinal nerves
Peripheral Nervous System
conducts sensory (afferent) information from the periphery to the CNS
Sensory (afferent) system
sensory fibers in the spinal cord that travel toward the brain
Ascending tracts
consists of motor (efferent) nerves that conduct from higher to lower levels of the CNS and from the CNS to the periphery
Motor (efferent) system
extend from the brain down the descending tracts in the cord to synapse on lower motor neurons (LMN)
Upper motor neurons (UMN)
What motor neuron extend away from the spinal cord and brain to the muscles and glands of the body
Lower motor neurons (LMN)
bundles of upper motor neuron fibers that move caudally in the spinal cord
Descending tracts
This system carries conscious voluntary information from the CNS to the skeletal muscles along cranial and spinal nerves
Somatic nervous system (soma, body)
This system carries involuntary information (sensory and motor) to and from smooth muscle, cardiac muscle, and glands of the body along cranial and spinal nerves to the spinal cord and brain
Autonomic nervous system (ANS)
● An artificial classification because many of the nerves of the body are partly in both divisions
Structural Classification
● Takes into account the impulses (sensory or motor) carried by nerves and the directions they travel
Impulse Classification
● Takes into account the activities that are directed by the nervous system
Functional Classification
from nerves of the somatic nervous system to skeletal muscles; and from skin and deeper somatic structures
Somatic fibers (motor and sensory)
supply skeletal (somatic) muscles, no matter what the branchial arch origin
Somatic motor (efferent) fibers
carry sensory information from skin and deeper somatic structures (skeletal muscle, skin, tendons, joint capsules, bones, etc)
Somatic sensory (afferent) fibers
from nerves of the ANS
ANS fibers
These fibers are carried by branches of all spinal and most cranial nerves
Sympathetic fibers
These fibers are restricted to some sacral spinal nerves (pelvic nerve) and only a few cranial nerves
Parasympathetic fibers
these fibers can be further divided into sympathetic and parasympathetic fibers
ANS motor (efferent) fibers
These fibers carry sensory fibers from blood vessels and viscera throughout the body
ANS sensory (afferent) fibers