Lecture 2 nervous ppt Flashcards
What are the 5 elements of neurons?
1) Cell body
2) Dendrites
3) Axons
4) Myelin sheath around some axons
5) Synapse
What is the mnemonic to help remember the order of the cranial nerves?
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1) What type of neuron cell bodies tend to be in the CNS?
2) What about the PNS?
1) Motor tend to be in CNS (UMN, LMN)
2) Sensory tend to be in PNS (DRG)
1) What do dendrites do?
2) What do axons do?
1) Dendrites: impulses from receptors to neuron
2) Axons: impulses from neuron to site of action
What do synapses do?
Communicate with neurotransmitters (excite or inhibit)
What do neuroglia do?
Support, insulate, & nourish neurons
What are the 3 functions of myelin?
1) It acts as an electrical insulator for the neuron
2) Prevents depolarization
3) It speeds up conduction/ transmission of an electrical impulse
What does the CNS do?
Integrate and coordinate signals to and from soma (body) & central nervous system
1) Define nucleus and give an example
2) Define ganglia and give an example
3) Define tracts and give 2 examples
1) Nucleus: collection of nerve cell bodies within CNS (lateral geniculate nucleus in thalamus)
2) Ganglia: collection of nerve cell bodies outside of the CNS (paravertebral sympathetic ganglia)
3) Tracts: bundle of nerve fibers (axons) connecting nuclei in CNS.
-Ex: corticospinal tract or corticobulbar tract
1) Define gray matter
2) Where’s it’s located?
3) What are the parts of this location?
1) Nerve cell bodies
2) The brain and grey matter horn (H) in spinal cord
3) Parts of horn: anterior (motor), dorsal (sensory), lateral (sympathetic and parasympathetic)
1) What is white matter?
2) What are the 3 layers of meninges?
3) Where is the CSF?
1) Fiber tracts
2) Pia, arachnoid, dura mater (split in cranium)
3) Subarachnoid space
1) A collection of nerve cell bodies within CNS is called?
2) A collection of nerve cell bodies outside of the CNS is called?
3) A bundle of nerve fibers (axons) connecting nuclei in CNS is called?
1) Nerves
2) Ganglia
3) A tract
How many cranial nerves are there?
12 pairs
List the order of the spinal nerve sections and how many nerve are in each section
Cervical-8
T-12
L-5
S-5
Coccygeal-1
What are the functional components of the nervous system? Define each.
What may both have?
1) Sensory (afferent): toward brain
2) Motor (efferent): away from brain
3) Somatic (voluntary) and visceral (involuntary) components
What are the two structural categories of the nervous system? Define each
1) CNS: brain and spinal cord
2) PNS: cranial and peripheral nerves “outside” the CNS
1) What is the gray matter of the CNS made of?
2) What is the white matter of the CNS made of?
3) What are the nerve cell bodies of the PNS called?
4) Does the PNS have fiber tracks?
1) Nerve cells, nuclei
2) Fiber tracks
3) Ganglia
4) Yes
1) Define the somatic nervous system
2) What does it provide, and what to? What are the exceptions?
3) What 4 things does it transmit?
4) What does it stimulate?
1) Somatic parts of CNS and PNS
2) General sensory and motor to all parts of body (soma)
-Except: viscera in body cavities, smooth muscle, and glands
3) Touch, pain, temperature, proprioception
4) Skeletal (voluntary) muscle contraction
1) Define visceral nervous system
2) What does it provide? To where?
3) What are its 3 functions?
4) What 3 things does it stimulate?
1) Visceral (autonomic) parts of CNS and PNS
2) Visceral sensory and motor innervation to viscera, smooth muscle, and glands
3) Visceral sensory pain, reflexes, regulates visceral function
4) Smooth muscle in walls of vessels and organs, modified cardiac muscle (intrinsic stimulating and conducting tissue), and glands
What is the mnemonic to help remember whether a cranial nerve is sensory, motor, or both?
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1) What CN nerve(s) arise from the brain?
2) Which CN nerve(s) arise from the spinal cord? What part of the spinal cord and where does it/they go?
1) CN I-X and XII arise from brain
2) CN XI (spinal accessory n.) from cervical spinal cord to transverse foramen magnum into skull
1) What are the 2 types of cranial motor nerves?
2) What are the 3 types of cranial sensory nerves?
1) Somatic and visceral (aka autonomic)
2) Somatic, visceral, special (vision, hearing, taste, balance)
1) How many pairs of spinal nerves are there?
2) List the number in each section of the spine
3) Where do they originate and emerge?
4) What does each nerve do?
1) 31 pairs
2) C8, T12, L5, S5, Co1 (differ than vertebral count)
3) From the spinal cord
4) Follows a defined path and serves a specific region of the body
1) The specific region innervated by each somatic spinal nerve is called what?
2) Where are dermatomes guaranteed to end?
3) Why is this important?
1) A dermatome
2) The midline
3) Meningitis sometimes will remain on one side because of dermatomes
Give 4 examples of what special cranial sensory nerves are responsible for
Vision, hearing, taste, balance
1) Are spinal nerve roots sensory, motor, or both?
2) What does is the posterior ramus innervate?
1) Both sensory and motor
2) Mid back
What 3 things are found within the anterior ramus of a spinal nerve?
1) White ramus communicans
2) Sympathetic truck (also runs through posterior)
3) Gray ramus communicans
1) Where does the anterior ramus go?
2) True or false: Peripheral nerves are mixture of modalities
1) Continues to remainder of soma (body)
2) True
What are the 3 types of fibers found within peripheral nerves?
Afferent, efferent, and postsynaptic sympathetic fibers
If you feel touch just above your mid back, what ramus is this going to?
Posterior ramus of spinal nerve
If you feel touch in your arm, what ramus is this going to?
Anterior ramus of spinal nerve
1) What type of ganglia are closer to their target organ?
2) What kind is further?
1) Parasympathetic
2) Sympathetic
What is the difference in origin between an upper motor neuron (UMN) and a lower motor neuron (LMN)?
1) UMNs: originate in the cerebral cortex, travel down to the spinal cord or brainstem
2) LMNs: begin in the spinal cord.
1) If there’s a peripheral nerve injury, what do you know has survived if function is able to be restored?
2) What happens around the lesion? Why?
1) Neurons
2) Axons degenerate distal to the lesion because of loss of “life support”
1) Describe how healing peripheral nerves from a crush injury works
2) Describe how healing peripheral nerves from a severed (cut) nerve injury works
3) What may a vasa nervorum injury result in?
1) If nerve cell body survives and connective tissue coverings of nerve intact, they guide regenerating axon to their destination
2) Surgical repair often needed for apposition of the severed ends of the connective tissue “guide” to direct axons growth to their correct destination
3) Ischemia may result in damage to nerves