Misc Flashcards
A bundle of hundreds to thousands of axons plus associated connective tissue and blood vessels that lies outside the brain and spinal cord
Nerve
Small masses of nervous tissue, consisting primarily of neuron bodies, located outside the brain and spinal cord
Ganglia
Extensive networks of neurons located in the walls of organs of the GI tract
Enteric plexuses
What neurons control voluntary skeletal muscles?
Somatic motor neurons
What neurons control smooth muscle, cardiac muscle, and glands?
Autonomic motor neurons
What neurons control smooth muscle, glands, and endocrine cells of the GI tract?
Enteric motor neurons
How many neurons are found in the enteric plexus?
100 million
The nervous system processes sensory information by analyzing and storing some of it and by making decisions for appropriate responses
Integrative function
Any change in the environment that is strong enough to initiate an action potential
Stimulus
Impulse, an electrical signal that propagates (travels) along the surface of the membrane of a neuron or muscle fiber
Action potential
Three parts of a neuron
1) a cell body
2) dendrites
3) an axon
Receiving/input part of a neuron
Dendrites
Conducts nerve impulses toward another neuron, a muscle, or a gland
Axon
The site where two neurons or a neuron and an effector cell can communicate
Synapse
Neurotransmitters are stored where in the neuron?
The synaptic end bulb (synaptic vesicles)
Usually have several dendrites and one axon.
Most neurons in the brain and spinal cord are this type.
Multipolar neuron
Have one main dendrite and one axon.
These are found in the retina of the eye, the inner ear, and in the olfactory area of the brain.
Bipolar
Have dendrites and one axon that are fused together to form a continuous process that emerges from the cell body.
These are sensory receptors for touch, pressure, pain, or thermal stimuli.
Unipolar neurons
Neurons that are located within the CNS between sensory and motor neurons.
They integrate incoming sensory information from sensory neurons and then elicit a motor response by activating appropriate motor neurons.
Interneurons
Interneurons and motor neurons are mostly what neuron type?
Multipolar
“Glue” that holds nervous tissue together
Neuroglia
Brain tumors derived from glia, tend to be highly malignant and grow rapidly
Gliomas
Astrocytes, oligodendrocytes, microglial cells, ependymal, Schwann and satellite are what?
Neuroglia
Myelin sheaths are composed of what?
Lipid and protein
Support neurons in PNS ganglia and regulate exchange of materials between neurons and interstitial fluid
Satellite cells
How many layers of myelin are wrapped around axons?
As many as 100 layers
Neuronal cell bodies grouped together are typically called?
Clusters
Axons of neurons grouped together are typically called?
Bundles
Cluster of neuronal cell bodies located in the PNS
Ganglion
Cluster of neuronal cell bodies located in the CNS
Nucleus
Bundle of axons in the PNS
Nerve
Bundle of axons in the CNS
Tract
A difference in the amount of electrical charge on the inside of the plasma membrane as compared to the outside
Membrane potential
How long does the depolarizing and repolarizing phases last?
One millisecond (1/1000 sec)
Action potential arises according to what principle?
All or nothing
A brief time after an action potential begins, a neuron cannot generate another action potential
Refractory period
Currents that flow across the membrane at the nodes, “leaps” from node to node.
Saltatory conduction
Electrical synapses, nerve impulses conduct directly between the plasma membranes of adjacent neurons through gap junctions are found where?
Visceral smooth muscle, cardiac muscle, and the brain
A typical neuron in the CNS receives input from how many synapses?
1,000 to 10,000
Neurotransmitters consisting of amino acids linked by peptide bonds
Nearuopeptides
Demyelinating disorder, microphages remove myelin from PNS axons. It is a common cause of sudden paralysis and may result from the immune system’s response to a bacterial infection. Most patients recover. 15% remain paralyzed.
Guillain-Barre Syndrome (GBS)
What vertebra does the spinal cord end?
L2
The tube of spinal dura mater ends at what vertebra?
S2
Space between the dura mater and vertebral column that contains fat and protective tissue
Epidural space
What is the length of the spinal cord?
16 to 18 inches
Spinal grey horns only present in the thoracic and upper lumbar, contain cell bodies of the autonomic motor neurons that regulate the activity of cardiac muscle, smooth muscle, and glands
Lateral gray horns
Groups of axons wrapped with endoneurium are arranged in bundles called:
Fascicles
Fascicles are wrapped in what layer?
Perineurium
Plexus that supplies the skin and muscles of the posterior head, neck, upper part of the shoulders, and diaphragm
Cervical plexus
What nerve stimulates the diaphragm to contract?
Phrenic nerve (from the cervical plexus)
Plexus that supplies the upper limbs, several neck and shoulder muscles.
Contains musculocutaneous, axillary, median, radial, and ulnar nerves.
Brachial plexus
Plexus that supplies the abdominal wall, external genitals, part of the lower limbs.
Arising from this plexus are the ilioinguinal, femoral, and obturator nerves.
Lumbar plexus
Plexus that supplies the buttocks, perineum, and lower limbs.
Arising from this plexus are the gluteal, sciatic, and pudendal nerves.
Sacral plexus
What spinal nerves do not form a plexus and are called “intercostal nerves”?
T2-T11
Pathway followed by nerve impulses that produce a reflex
Reflex arc
What does the diencephalon consist of?
1) Thalamus
2) Hypothalamus
3) Pineal Gland
CSF primarily drains into what vein?
Superior sagittal sinus
What is the volume of CSF in the body?
80 to 150 mL (3 to 5 oz)
Where does the gray and white matter intermingle in the brain stem?
Reticular formation
Masses of gray matter where neurons form synapses with one another
Nuclei
Nuclei associated with cranial nerves V, VI, VII, and VIII are located in the:
Pons
Nuclei associated with cranial nerves III and IV are located where?
Midbrain
Stimulation of the reticular activating system (RAS) produces what?
Consciousness
Deactivation of the reticular activating system (RAS) produces what?
Sleep
The major relay station for most sensory impulses that reach the cerebral cortex from the spinal cord and brain stem
Thalamus
Part of the brain that controls many functions related to homeostasis.
Control of the ANS, Pituitary gland, regulation of emotions & behavior, eating & drinking, body temperature, Circadian rhythms
Hypothalamus
Secretes melatonin
Pineal gland
Part of the brain that regulates posture, balance, skilled motor activities, and helps with equilibrium.
Cerebellum
Folds in the cerebrum
Gyri
Deep grooves of the cerebrum
Fissues
Shallow grooves of the cerebrum
Sulci
What connects the cerebrum’s hemispheres, is a broad band of white matter containing axons that extend between the hemispheres?
Corpus callosum
Primary motor area of the cerebral cortex
Precentral gyrus
Primary somatosensory area of the cerebral cortex
Postcentral gyrus
Nuclei that helps initiate and terminate movements. Help with movements such as automatic arm swings while walking.
Basal Nuclei
“Emotional brain”, Primary role in range of emotions. Controls most of its involuntary aspects related to survival.
Limbic System
Parts of the brain that help with memory
Limbic system
Cerebrum
Primary gustatory area, located at the base of the postcentral gyrus, is responsible for what?
Taste
Broad region in the left temporal and parietal loves, interprets the meaning of speech by recognizing spoken words
Wernicke’s area
Somatic sensory pathway responsible for touch, pressure, vibration, and conscious proprioception
Posterior Column-Medial Lemniscus
Anosmia (loss of smell) can be caused by trauma to what?
Olfactory tract lesion or trauma to the cribriform plate
First CN to lose function with increased ICP
6
Who may have a diminished corneal reflex?
Patient who wears contact lenses
Upper Neuron Disease, such as stroke or brain attack, patients are still able to what?
Show emotional movement
Most patients who have a loss of taste actually have a dysfunction with what sensation?
Olfactory
Another name for Heel-to-Toe walking
Tandem Gait
When would you test for temperature and deep pressure?
Only done if superficial pain is not intact
Inability to recognize objects by touch, suggests a parietal lobe lesion
Tactile agnosia
Dorsiflexion of the great toe, with or without fanning of the other toes. Indicates a pyramidal tract or upper motor neuron disorder.
Babinski sign
Absent reflexes indicate what?
Lower motor neuron disorder
Hyperactive reflexes indicate what?
Upper motor neuron disorder
Sustained clonus is associated with what?
Upper motor neuron disorder
What size monofilament is used in the protective sensation?
5.07
