Flashcards in Lecture notes Nervous system Deck (73):
What is the order of muscle conduction?
1) Motor neuron action potential
2) Synaptic knob & neuromuscular junction
3) Sarcolemma action potential
4) T-tubule action potential
5) Release of Ca++from terminal cisternae
What are the next events after the 5 first muscle conduction events?
1 )Ca++ bonds to troponin causing shift in
2) Bonding site is exposed on actin
3) Myosin head bonds to actin
4) Stored energy is released as “power stroke”
5) Actin moves relative to myosin
6 )ATP used to detach head and bend myosin back to resting position (energy loaded)
7 )Cycle repeated
What is the structural and functional unit of the nervous system?
• Assist the neuron
• Do not conduct an impulse
• 4 types in CNS
• 2 types in PNS
* Produce CSF (Cerebral spinal fluid)
* Concentrated in choroid plexus
* Most common
* Structural, Blood Brain Barrier, Regulate AP
For CNS Defense- think of WBC’s
Produce myelin sheath
Produce myelin sheath
Separate cell bodies of ganglia and homeostasis of ganglion environment
What are the two structural divisions of the
CNS and PNS
What are the two functional divisions?
Sensory and Motor
What is the involuntary system called?
Which part of a neuron can have more than one branch coming off the cell body?
What are the 3 structural neurons?
Unipolar, bipolar, multipolar
What are the parts of a polysynaptic reflex?
What is the voltage for the resting potential of a neuron?
-70mv inside v outside
What is the impulse?
Reversal of charge transferred to adjacent areas (+30mv)
If stimulated anywhere along a neuron the impulse will travel in the dendrite to axon direction. True or False?
False! It will travel in BOTH directions
What maintains the resting potential?
Ion pumps and diffusion
What kind of molecules are the ion pumps?
Where are they located?
In the cell membrane of neurons and muscles
A “strong enough” stimulus has to be above the _____ to cause an action potential?
What are the “helper” cells of the nervous
Which produces CSF?
Which fights disease?
Which produces myelin sheath?
Oligodendrocytes and Neurolemmocytes
Which isolates cell bodies in the spinal ganglia?
A waxy membranous wrapping that Insulates the axon
the myelinating cell of the PNS
Neurolemmocyte (Schwann Cell)
Neurilemma is the
The outermost part
Neurofibril node (Nodes of Ranvier) are
Small gaps between each myelinating cell. The axon is exposed
The myelinating cell of the CNS myelinate several axons
Speeds up impulses
Two factors effect speed of conduction
1. Size of the axon
2. Insulation with myelin sheath, Large, insulated axons are faster
A bundle of neuron fibers
* ￼￼￼￼￼￼Fibers bundled as tracts
* Cell bodies in nucleus
* Myelin by oligodendrocytes
Central nervous system
* Fibers bundled as nerves
* Cell bodies in ganglion
* Myelin by neurolemmocytes
Peripheral Nervous System
Describe chemical synapse
*The axon ending (of the pre-synaptic neuron) has many synaptic vesicles filled with
neurotransmitter (acetylcholine, serotonin, norepinephrine, dopamine, GABA)
* When the action potential reaches the synaptic knob, the synaptic vesicles release their contents into the synaptic cleft
* The neurotransmitters cross this synaptic cleft and bind to receptor sites on the post-synaptic neuron (2nd neuron) or effector (muscle or gland)
Why have a synapse?
Keeps impulse unidirectional
Synapse and memory
* They also play a role in memory
* As signals cross a synapse the association is strengthened
* This is how memories are “built"
Neurons can synapse with?
* Other neurons
Sympathetic deals with
Parasympathetic deals with
Sympathetic nerves: Summary, origin, specific responses, neurotransmitter
Summary: Fight or flight
Specific responses: Gland secretions decrease (saliva gets thick), GI tract inhibited, sphincters contract, pupils dilate, increased pulse rate
Parasympathetic nerves: Summary, origin, specific responses, neurotransmitter
Specific responses: Gland secretions increase (saliva gets watery), GI tract stimulated, sphincters relax, pupils constrict, decreased pulse rate Neurotransmitter: acetylcholine
* Glands are closer to CNS
* Short preganglionic neurons
* Long post ganglionic neurons
Sympathetic trunk is
Ganglion and synapse
*Preganglion neurons arise from cranial or pelvic nerves
* Ganglion are closer to organs
* Long preganglion neurons and short postganglionic neurons
Primitive brain comes from
What germ layer does the brain from the neural tube derive from?
What if it doesn’t close at the caudal end?
The cephalons short version
The cephalons long version
• Thalamus and hypothalmus
• Peduncles and Colliculi
• Pons and Cerebellum
• Medulla oblongata
For the brain, Gray is located on
Cell bodies & unmyelinated axons
Funiculus is the spinal cord is
What is the communication between left and right hemispheres in the brain?
How much energy does the brain use?
The human brain takes up 2% of human body weight but uses 20% of its energy
* Odor detection
Oculomotor, Trochlear & abducens
To the eye. eye muscles
* Three branches
* Motor to face
* Sensory from tongue
* Hearing and balance
* Tongue sensory
* Visceral- sensory
* Throat- motor
* Neck and upper back
What happens when a neuro damaged?
• Depends on the damage
• If cell body is damaged the neuron is lost and is not replaced
• If axon is in PNS it may repair
• If axon is in CNS usually no repair
• Depends upon the neurolemma