Intro- Nervous System Flashcards
What are the meninges?
Membranous layers called pia mater, arachnoid mater, and dura mater. Surround and protect the CNS.
What are the collection of nerve cell bodies located outside of the CNS?
The ganglion
What is the somatic nervous system?
Voluntary nervous system
Somatic sensory fibers- touch, pain, and temperature
Somatic motor fibers- stimulate skeletal muscle exclusively
Anterior ( ventral) root
Motor ( efferent ) fibers pass through this to effector organs located peripherally
Posterior ( dorsal ) root
Consists of sensory ( afferent ) fibers that send neural impulses to the CNS
Posterior rami
Supply nerve fibers to synovial joints of the vertebral column, deep muscles of the back, and the overlying skin
Anterior rami
Supply nerve fibers to a large remaining portion of the body, anterior and lateral regions of the trunk, and the upper and lower limbs arising from them
Dermatone
The unilateral area of skin that is innervated by the general sensory fibers of a single spinal nerve
What are cutaneous nerves?
Nerves that supply sensation to the skin
What does the autonomic nervous system consist of?
Visceral efferent motor fibers- stimulate smooth involuntary muscle
Visceral afferent sensory fibers
What are the two systems of efferent nerve fibers in the ANS?
Sympathetic (thoracolumbar) division
Parasympathetic (craniosacral) division
Sympathetic division
Stimulation is catabolic, preparing body for fight or flight
Parasympathetic division
Stimulation is anabolic, promotion normal function and conserving energy
Presynaptic neuron
Preganglionic neuron located in the gray matter of the CNS. Conducts impulses from CNS to the effector organs in both sympathetic and parasympathetic systems.
Postsynaptic neuron
Postganglionic neuron. The fiber or axon of the presynaptic neuron synapses here. These cell bodies of this second neuron are located in ganglia outside of the CNS. These fibers terminate on the effector organ such as smooth muscle or glands.
Where are the presynaptic and postsynaptic neurons of the sympathetic division located?
Presynaptic- intermediolateral cell columns or nuclei of the spinal cord, the IMLs are part of the gray matter extending between the 1st thoracic and second or third lumbar
Postsynaptic neurons- paravertebral ganglion and prevertebral ganglion
What are the horns of the gray matter?
Posterior dorsal gray horn
Anterior ventral gray horn
What are the primary curvatures of the vertebral column?
thoracic anterior concavity and sacral anterior concavity
What are the secondary curvatures of the spine?
cervical anterior convexity
lumbar anterior convexity
What is unique about the C1 vertebrae?
atlas- no body or spinous process, articulates with axis via superior articular facets and the dens of axis
What is unique about the C2 vertebrae?
axis- dens, large superior facets for C1
What is the sacral hiatus?
it is the termination of the sacral canal; it contains the filum terminale
what is the conus medullaris?
the termination of the spinal cord… typically ends at L2
What are the cauda equina?
bundle of nerve roots after the conus medullaris
What are the distinctive features of the thoracic vertebrae?
heart shaped bodies; long spinous processes; costal facets for rib articulation on bodies and transverse processes
What are the distinctive features of the lumbar vertebrae?
large kidney-bean shaped bodies; sturdy laminae; thick and short spinous processes
What are the distinctive features of the cervical vertebrae?
small bodies; large vertebral foramina; transverse foramina; anterior and posterior tubercles; bifid spinous processes
What are the Zygapophysial joints or facets?
synovial joints between the superior and inferior articular processes; permit gliding movement between vertebrae
What are the atlanto-occipital joints?
synovial joints between the lateral masses of atlas and occipital condyles; permit flexion and extension (some lateral bending and rotation)
What are the atlanto-axial joints?
the three synovial joints between inferior lateral masses of C1 and superior facets of C2; also between anterior arch of C1 and dens of C2; permits rotation of C1 (and head)
