Midterm 1 Flashcards
What is the difference between afferent and efferent neurons?
Afferent carries info toward CNS and efferent carries info away from CNS
What is functional neuroanatomy?
Defining language and concepts needed to describe nervous system and it’s function
What makes up the CNS?
Brain and spinal cord
What makes up the PNS?
Cranial and spinal nerve fibers, ganglia
What are the functional divisions of the PNS?
Autonomic, somatic
What does the somatic NS control?
Voluntary and conscious movement
What does the autonomic control?
Unconscious or involuntary movements
What does the enteric NS control?
GI tract, works without intervention from CNS
What are to parts of the autonomic NS?
Sympathetic, parasympathetic, enteric
What is the sympathetic NS associated with?
Fight/flight
What is the parasympathetic NS associated with?
Rest/digest
Are sensory neurons afferent or efferent? Motor neurons?
Sensory is afferent
Motor is efferent
What part of the neuron receives input?
Dendrites
What direction do axons send signals?
Away from soma
Where is white matter and grey matter in the brain?
Grey matter is on outside of white matter
Where is white matter and grey matter in spinal cord?
White matter is on outside of grey matter
What do ependymal cells do?
Line the ventricles in brain and central canal in spinal cord and make CSF via making the choiroid plexus
What are the 3 major subtypes of macroglia?
protoplasmic astrocytes, oligodendrocytes, fibrous astrocytes
What are protoplasmic astrocytes?
primarily found in grey matter, support blood brain barrier
What are fibrous astrocytes?
support neruons and their functions, primarily found in white matter (similar function to protoplasmic)
What are oligodendrocytes?
found in CNS, myelinate multiple axons
What are schwann cells?
found in PNS, myelinate axon
How many places can be myelinated by 1 schwann cell?
1
What is the function of microglia?
macrophages, immune response
What are the primary division of the spine?
cervical, thoracic, lumbar, saccral
What are columns in the spinal cord? Where are they found?
long connections up and down the spinal cord, in white matter
What parts of the NS help maintain homeostasis?
Sympathetic, parasympathetic, enteric
What are the effector organs?
Skeletal, smooth, and cardiac muscle and glands
Where are ependymal cells and macroglia derived from?
Cells of the neural tube
Where are microglial cells derived from?
Monocyte precursors of the bone marrow
How do astrocytes assist neurons in transmitting impulses?
Regulating the presence of neurotransmitter substances as well as releasing gliotransmitter substances
What are gliotransmitters?
Chemicals released from glial cells that modulate synaptic transmission and neural excitability
Ex. ATP and glutamate
What is the telencephalon?
Cerebral hemispheres of brain
What is the diencephalon?
Epithalamus, thalamus, hypothalamus, subthalamus
What is the mesencephalon?
Cerebral peduncles and tectum
What is the metencephalon?
Pons and cerebellum
What is the myelencephalon?
Medulla oblangata
Where are the nerves responsible for somatic motor function in the spinal cord located?
Ventral horn, their axons leave via the ventral rootlets, inner area skeletal muscle
What regions is the lateral horn found in?
Thoracic, upper lumbar and sacral regions
What is the function of lateral horn?
Central component of the sympathetic division of autonomic NS
What is the function of the dorsal horn?
Where sensory info is brought in by dorsal root ganglia
What do interneurons do?
Connect two types of neurons to each other
What is an example of a connection interneurons make? Hint motor and sensory
Unipolar sensory neurons of DRG to motor neurons of ventral horn
What are the two major categories of neurons?
Those with axons that leave the CNS and those whose axons remain in CNS
How many pairs of spinal nerves are there?
31
8 cervical, 12 thoracic, 5 sacral, 5 lumbar, 1 coccygeal
Where is the boundary between sensory and motor more ambiguous the CNS or PNS?
CNS, especially in brain
PNS is defined and also spinal cord
If someone injured their C6 dorsal root ganglion what would happen to them?
loss of sensation in the area of C6 dermatome (arm, thumb, index finger)
b/c dorsal is sensory
What is the function of the dorsal root ganglion?
contains the cell bodies of sensory neurons
What is the function of the dorsal column?
aka. dorsal column medial lemniscus pathway (DCML)
deals with fine touch, proprioception, two-point discrimination, and vibration sensations from everywhere but head
If patient injures their left dorsal column which leg will show symptoms?
left leg, damage is ipsilateral
if it was right leg, right side is damaged
What is the lateral funiculus?
aka. lateral white column
contains lateral spinothalamic tract and the lateral corticospinal tract
What is the function of the lateral spinothalamic tract?
an ascending sensory pathway that transmits pain sensations, temperature, and potentially itching
damage typically is contralateral
What is the function of the lateral corticospinal tract?
largest descending motor pathway in body, responsible for voluntary movement of the contralateral (opposite) upper and lower limbs
What is the function of myelin?
speeds up transmission of nerve impulses
What part of the spinal cord contains motor neurons?
ventral horn
What is contained in the anterior root of spinal cord?
the axons of motor neurons that exit that spinal cord
What is contained in the lateral horn?
neurons involved in the autonomic nervous system
What is anterograde transport?
movement of materials (neurotransmitters, proteins, organelles) from the soma to the axon terminal
What is retrograde transport?
movement of materials (neurotransmitters, proteins, organlles) from the axon terminals to the soma
What is the vestibulospinal tract involved with?
balance and posture
What is the conus medullaris?
tapered end of the spinal cord
What is the coccyx?
bone at base of spinal cord
aka. tailbone
Who is Ian Waterman?
contracted a viral illness which attacked his NS, leaving him without proprioception from neck down
despite his motor neurons being unaffected he couldn’t move, pain and temperature was intact
managed to relearn to walk
What is sacrum?
shield shaped bone located between hipbones, base of lumbar vertebrae and connected to pelvis
What is a three neuron reflex arc?
made up of receptor sensory, interneuron, motor
reflex can be overidden when interneurons receive input from brain
What is a two neuron reflex arc?
made up of sensory and motor neuron, automatic and only involve part of body
ex. patellar reflex
Where do action potentials originate?
axon hillock
Collectively, anterograde and retrograde transport are referred to as?
axonal transport
What is axodendritic?
one of the potential synapse configurations
where axon of 1 neuron synpases w/dendrites of another
What is axon proper?
long part of axon that you usually think of when thinking of axons
Why is the axon hillock where actiona potentials start?
high density of Na+ channels
What are bipolar neurons?
possess an axon and dendrites
found in retina, roof of nasal cavity, inner ear
What is cilia? Where is it found in the NS and why?
short hairlike filaments
spinal canal and ventricles, b/c they help circulate CSF
How do presynaptic membranes stay the same size when vesicles have to fuse with it to deliver their contents?
form clathrin coated pits, which eventually form clathrin coated vesicles, then recycled by SER to be used in forming new vesicles
What are schmidt-lantermann clefts/incisures?
small pockets of cytoplasm in myelin sheaths made by schwann cells
What is the function of shcmidt-lantermann clefts/incisures?
believed to help sustain the growth and function of compact myelin
What are dendritic spines?
tiny protrusions from dendrities, form contacts with axons of other neurons
very plastic, have diff shapes and size
(filopodia, mushroom, etc)
What are docking complexes?
oblong electron dense, protein structures located at presynaptic membrane, form presynaptic grid
What is the purpose of docking complexes?
some synaptic vesicles are bound by them near the active site so they are ready when an action potnetial comes
What type of synapse is faster?
electrical
Are electrical synapses found in mammals?
only in retina, cerebral cortex, and brainstem
What is a type I synapse?
aka. asymmetric synapse b/c postsynaptic density is thicker than presynaptic density, round vesicles, excitatory