Nervous System Flashcards
What are the 2 functions of the nervous system?
Receive and process info (stimuli) from the environment
Coordinate and carry out an appropriate action to respond to those stimuli.
Explain the difference between CNS and PNS.
CNS: brain and spinal cord, controls the PNS
PNS: all nerves outside CNS
Explain the difference between the somatic and autonomic (visceral) NS.
Somatic: stimuli largely external (touch, vibration) and internal (joint pain). responses voluntary (motor control over skeletal muscles)
Visceral: stimuli primarily internal (body temp, heart rate). Response involuntary (control over smooth muscle, visceral organs and their functions)
The ______ is the basic cellular unit of the NS.
Neuron
Neurons communicate through ___________ and information travels _______.
Chain-like connections, unidirectionally.
Name and describe the 5 components of a neuron.
Dendrite: receives short info
Cell body: processes info
Myelin: insulation - increases speed of electrical impulses
Axon: relays info as electricity, can be long
Synapse: passes info onto other nerves or effector organ chemically
Name and explain the difference between the 2 types of neurons.
Motor/efferent: unidirectional
Dendrites –> cell body –> axon –> PNS (target organ)
Pseudo-unipolar: sensory/afferent
Sensory receptors –> branched axon –> CNS
What is the posterior root ganglion?
group of cell bodies for the sensory neurons
What is the ventral horn?
Group of cell bodies for the motor neurons.
Name and describe the parts of the spinal nerve (6).
- Rootlets: axon bundles from sensory neurons (post.) and motor neurons (ant.) closest to spinal cord.
- Roots: convergence of rootlets. posterior root contains cell.
- Spinal nerve: convergence of roots, emerges from vertebral column
- Rami: first split of spinal nerve into
- Posterior ramus: to intrinsic back muscles and associated skin
- Anterior ramus: to everything else
How are skeletal muscle fibers stimulated to contract?
By the somatic NS via motor neurons.
Name the superior vertebrae and their quantity.
Thoracic (12), Lumbar (5), Sacral (5), coccygeal
Name the inferior vertebrae and their quantity.
cervical nerves (8)
Which vertebrae is the exception?
Spinal C8
Name the 6 elements of the inside of the spinal cord.
Central canal, posterior and anterior horn, lateral horn, gray matter, white matter.
