Unit 1 exam 1 Flashcards
Structurally the nervous system is divided into what?
Central Nervous System and Peripheral Nervous System
Functionally the nervous system is divided into what?
Somatic Nervous System and Autonomic Nervous System
Efferent (motor) and Afferent (sensory)
Nervous tissue consists of what two cell types?
Neurons (nerve cells)
Neuroglia (glial cells)
Another term for cell body
Soma
What two structures branch off the soma?
Dendrites
Axons (info Away)
What are myelin layers composed of?
Lipid and protein substances
Myelin sheath around some axons increase the velocity of what?
Impulse conduction
Neurons communicate with each other where?
At synapses
Chemical agents released or secreted by one neuron, which may excite or inhibit another neuron
Neurotransmitter
Neuroglia are how many times more abundant than neurons?
Five
Are neuroglia excitable, or non-excitable?
Non-excitable
What is the function of neuroglia?
Major component of nervous tissue, supporting, insulating, and nourishing the neurons
What neuroglia cells are from the CNS?
Oligodendroglia, astrocytes, ependymal cells, and microglia
What cells secrete CSF?
Ependymal cells
What neuroglia cells are in the PNS?
Satellite cells and Schwann (neurolemma) cells
What specific location are satellite cells found?
Around the neurons in the dorsal root ganglia and autonomic ganglia
What are the principal roles of the CNS?
Integrate and Coordinate incoming and outgoing neural signals as well as to carry out higher functions
A collection of nerve cell bodies in the CNS
Nucleus
A bundle of nerve fibers (axons/dendrites) connecting neighboring or distant nuclei of CNS
Tracts
What structure is purely white matter?
Corpus callosum
What constitutes gray matter?
Nerve cell bodies
The interconnecting fiber tract system forms what?
White matter
The struts of the H in gray matter are known as what?
Horns
What are the membranous layers in the CNS?
Pia, arachnoid, and dura mater
The collective term for pia, arachnoid, and dura mater
Meninges
What is the innermost meningeal layer?
Pia mater
Pia mater intimately covers what?
Brain and spinal cord
CSF is located between what layers?
Pia and arachnoid mater
What is the thick, tough external layer?
Dura mater
Peripheral nerve fiber consists of what?
Axon, neurolemma, and endoneurial connective tissue
This immediately surrounds the axon separating it from other axons.
Neurolemma (neurilemma)
In the PNS, neurolemma create two classes of what nerve fibers?
Myelinated and unmyelinated nerve fibers
Bundle of peripheral nerve fibers
Fascicles
Another term for blood vessels that nourish the nerve fibers and their coverings.
Vasa nervorum
What are the connective tissue coverings that support and protect the peripheral nerves?
Endoneurium, perineurium, and epineurium
This immediately surrounds the neurolemma cell and axon
Endoneurium
A layer of dense connective tissue that provides an effective barrier against penetration of the nerve fibers by foreign substances
Perineurium
Thick connective tissue that surrounds and encloses a bundle of fascicles forming the outermost covering
Epineurium
The epineurium is composed of what structures?
Fatty tissue, blood vessels, and lymphatics
Collection of nerve cell bodies outside the CNS
ganglion
These PNS fibers convey neural impulses to the CNS from sense organs and receptors throughout the body
Afferent (sensory)
These PNS fibers convey neural impulses from the CNS to effector organs
Efferent (motor)
Peripheral nerves can be what two types?
Cranial or Spinal nerves
Cranial nerves exit the cranial cavity through this
Foramina
Which CN does not arise from the brain, but rather the superior part of the spinal cord?
CN XI spinal accessory
The names of this type of ganglion match the name of the CN
Sensory ganglia
Spinal nerves arise from the spinal cord as what?
Rootlets
The ventral root contains what type of fibers?
Efferent (motor)
The dorsal root contains what type of fibers?
Afferent (sensory)
The ventral and dorsal nerve roots unite where?
Intervertebral foramen
When a ventral and dorsal nerve root unite, what is formed?
Mixed spinal nerve
A posterior and anterior rami carry what?
Both motor and sensory fibers
Unilateral area of skin innervated by the fibers of a single spinal nerve
Dermatome
Unilateral muscle mass receiving innervations from the fibers of a single spinal nerve
Myotome
Do innervations from cranial nerves or spinal nerves have little overlap in innervation zones of skin?
Cranial nerves
Which fibers transmit sensations from the body to the CNS?
General sensory or general somatic afferent
Pain, temp, touch , and pressure are this type of sensations from the skin.
Exteroceptive sensations
These type of sensations are from muscles, tendons, and joints.
Proprioceptive sensations
What combines resulting in awareness of the orientation of the body and limbs in space independent of visual input?
Proprioceptive sensations and vestibular apparatus of inner ear
What type of fibers transmit impulses to skeletal muscles?
Somatic motor or general somatic efferent fibers
What type of fibers transmit pain or subconscious visceral reflex sensations?
Visceral sensory or general visceral afferent
Visceral afferent fibers measure what specifically?
Distension, blood gas and blood pressure levels
What type of fibers transmit impulses to smooth, cardiac muscles and glandular tissue?
Visceral motor or general visceral efferent
Visceral efferent fibers have what two varieties of fibers?
Presynaptic and postsynaptic
Sensory and visceral fibers in spinal or cranial sensory ganglia are what type of neurons?
Pseudounipolar
Motor fibers of the PNS are what type of neurons?
Multipolar
What specific cell bodies are located in the gray matter?
Somatic motor and presynaptic visceral motor
What specific cell bodies are located in autonomic ganglia?
Postsynaptic visceral motor
What are the special senses?
Smell, sight, hearing, taste, and balance
Branchial motor fibers refer to muscle tissue derived from what?
Pharyngeal arches in the embryo
The somatic motor pathways are composed of what two essential neurons?
Upper motor neuron
Lower motor neuron
In UMN, where are the cell bodies located?
Precentral gyrus (Brodmann #4)
Brodmann #4 forms what>
Motor homunculus
The axons of UMN project caudally through what?
Corona radiata and genu of internal capsule
Most of UMN terminate where?
Brainstem and project bilaterally to synapse with LMN
LMN neuronal bodies of cranial nerves are located where?
Brainstem and upper cervical spinal cord
LMN of spinal nerves are located where?
Anterior gray column of spinal cord
List 5 clinical manifestations of UMNL
Spastic paralysis Hyper-reflexia Hyper-tonicity Clonus Positive Babinski sign
List 4 clinical manifestations of LMNL
Flaccid paralysis
Hypo-reflexia
Hypo-tonicity
Atrophy
In regards to somatic motor pathways, what restrains what?
UMN restrain LMN
Somatic sensory pathway involves at least how many neurons?
Three
What are the primary somaesthetic neurons?
Pseudounipolar neurons
In sensory ganglion of PNS
What are the secondary sensory neurons?
Nuclei of termination in the dorsal gray matter of brainstem
The secondary sensory neurons join what tract?
Spinothalamic
What are the tertiary sensory neurons?
Located in ventral thalamic nucleus and send fibers through the posterior limb of the internal capsule and then the corona radiata to postcentral gyrus
What happens in the postcentral gyrus?
Brodmann #1, 2, and 3 conscious interpretation
The conscious correlation between motor and sensory pathways and memorization is achieved in the cerebral cortex by what cells?
Interneurons and neuroglia
Motor or efferent cranial nerves arise from what?
Nucleus of origin
Sensory or afferent cranial nerves arise from what?
Neuron cell bodies in sensory ganglia or special sense organs
Sensory CN primary somaesthetic neurons are what type?
Unipolar
Describe a sensory primary somaesthetic neuron
Long peripheral process or dendrite
Short central process or axon
Describe a primary special sense neuron
Short peripheral
Long central process
Mixed CN carry what?
Both efferent and afferent neurons
What are the minimum requirements of a mixed CN
One nucleus of origin
One nucleus of termination
One sensory ganglion