Nerve Systems (From input to output) Flashcards
Fascicles
Contain numerous axons
endoneurium, perineurium, epineurium
connective tissues that surround axons
Nerves
Nourished by blood vessels and bathed in cerebrospinal fluid on the other side of blood brain barrier
Peripheral nervous system
sensory inputs and motor outputs. voluntary and involuntary divisions
Neural Plasticity
changes in growth or connectivity of interacting neurons.
Central Pattern Generators
Moves the body in semi-automated fashion
2 neuron reflex
involving afferent and efferent neuron
Afferent neurons have … cell body
centrally positioned
spatiotemporal summation
determines whether an action potential will be fired or not
Convergent reflex arcs
Many receptors on a single efferent neuron
Divergent reflex arcs
One receptor signaling many efferent neurons
Central Nervous System
Consists of a main centralized nerve chord and a brain
Afferent neurons
Lead from PNS to CNS. Convert stimuli to electrical signal.
Efferent neurons
Lead from CNS to PNS
The CNS contains … that act as a middle ground between afferent and efferent neurons
interneurons
An interneuron modulates the signal …
stronger or weaker
Polysynaptic reflex arc
afferent to interneuron to efferent to action
Afferent neurons enter the spinal cords …. In the spinal cord the … is exterior to the …
grey matter, white matter (myelinated axons) , grey matter (nerve cell bodies)
Interneurons are located within the
grey matter
Axons of efferent (motor) neurons run back out of the spine through the … of the spinal nerve to the …
ventral root, tissues
Central Nervous System
Brain + Spinal Cord
Peripheral Nervous System
Afferent and efferent neural pathways
Motor division
Voluntary control
Autonomic division
Involuntary and subdivided into 3 categories. Sympathetic, parasympathetic, and enteric.
Under stress the … system is involuntarily told to … (peristalas)
enteric, stop digestion
Most organs are dually innervated by … and … nerves
sympathetic, parasympathetic
Why are sympathetic and parasympathetic nerves called antagonistic pairs?
Because they enact opposite physiological functions
Sympathetic nervous system
Speeds things up. Increases metabolic, heart, and breathing rate. Fight or Flight response. Short pre and long postganglionic neurons.
Catabolic sympathetic nervous system
Burn nutrient stores for energy. Release glucose from the liver.
Adrenal medulla
Inner part of adrenal gland that acts like a specialized ganglion. Innervated by a sympathetic nerve called the splanchnic nerve.
Adrenal medulla contains … which secrete … and … when activated by this nerve during the stress response
chromaffin cells, epinephrine, norepinphrine
Adrenal cortex
secretes catecholamines by adrenocorticotropic hormone (ACTH) secreted by the anterior pituitary.
Parasympathetic Nervous System
Slows things down. Decrease metabolic heart and breathing rate. Rest and Digest. Long pre and short post ganglionic neurons
Anabolic Parasympathetic Nervous System
Absorb nutrients and store energy. Maintenance and repair.
The 4 nerves of the parasympathetic nervous system
Oculomotor, Facial, Glossopharyngeal, Vagus
Both para and sympathetic nervous systems release … during pre ganglionic neurons. However the sympathetic nervous system release … to target effector proteins
acetylcholine, norepinephrine
Sensory Nerves
Olfactory, Optic, Acoustic/Vestibulocochlear
Motor Nerves
Oculomotor (Eye AND Iris), Trochlear (Eye), Adbucens (Eye /external rectus, abducts the eye), Accessory (Neck) ,Hypoglossal (Tongue)
Sensory AND Motor Nerves
Trigeminal (Taste, teeth, facial touch, jaw muscles), Facial (Tongue and palate, salivary glands, facial muscles), Glossopharyngeal (Posterior tongue and pharynx muscles), Vagus (Heart, lungs, GI tract, larynx)
Parasympathetic nervous system has which nerves
Oculomotor, Facial, Glossopharyngeal, and Vagus
Which nerves involved in gag reflex?
Glossopharyngeal and Vagus
Trigeminal Nerve has 3 large branches. One is … the other …. and the last one ….
Opthalmic (sensory), Maxillary (Sensory), and Mandibular (Sensory/Mandibular)
Trigeminal Neuralgia
Painful compression or damage to the nerve
The enteric nervous system uses …. to communicate its needs to the brain.
the vagus nerve
A decrease in blood pressure is detected by the …. in the hindbrain
medulla oblangata
Cardiomyocytes
Control heart contractability
The medulla communicates with the heart using the … and …. nerves.
sympathetic cardiac (increases), parasympathetic vagus (decreases)
The medulla can also tell the heart to speed up using the … nerve
cardiac spinal
RAAS
Just know it involves the kidneys and an important regulator of bp
Baroflex
How the CNS can detect changes in blood pressure. Autonomic corrective response to bp fluctuations.
The 2 bp sensors on arteries near the left heart that detect pressure are the … and …
aortic body in aortic arch, and carotid body in the carotid sinus. Both are innervated with with sensory receptors that fire (depolarize) when stretched by higher bp
Action potentials are sent to the … about hypertension stimulating the … to … heart rate
medulla, vagus, decrease
Synaptic plasticity
neural plasticity by how the neuron changes after a prolonged stimulus
Synaptic facilitation
Greater levels of calcium influx through voltage-gated calcium channels at the axon terminal leads to more neurotransmitter (NTM) release from synaptic vesicles, which excites the postsynaptic neuron.
As a secondary messenger the calcium binds to … on the … facilitating their movement into the “active zone” of the
axon terminal
Calcium also helps vesicles bind to docking proteins on … and then release NTMS into the synaptic cleft via …
presynaptic membrane, exocytosis
Post tetanic potentiation (PTP)
When the depolarization is stronger the second time. (memory recall)
Facilitating interneurons
Gets sensitized by another sensory neuron which facilitates reaction by sending other neurotransmitters like serotonin to the presynaptic axon terminal.
Serotonin binds to … on the presynaptic neuron which active … to make …
GPCR, adenylate cyclase, cAMP
cAMP activates … which … voltage gated K+ channels preventing potassium ….. Positive charge then ….
PKA, inactivates, efflux, accumulates
During the process in which cAMP deactivates K+ channels, … can stay open leading to prolonged exocytosis of …
voltage gated calcium channels, neurotransmitters
When the snail recieves an electric shock to the tail its habituation to siphon touch goes away because …
of the interneuron (GPCR, cAMP, PKA) that connects between the tail and siphon
sinosoidal undulations
the movements that nematodes make such as the c elegans in which touching the creature causes it to make a sudden stop reverse motion
Predacious fungal hyphae have … which trap nematodes
snares. The inflation fo these hyphal rings keeps the nematode from escaping. If they back out instead of twitching their head they will survive
Swim oscillator (Central patter generate CPG)
Alternatively contracts dorsal and ventral axial muscles via two motor neurons in leeches. Touching it will release a thigmotropic response. The brain makes the final decision as to where the leech wants to go. Brain stimulates swim excitor interneuron rather than swim gating interneuron .
In the fish that turn their bodies into a C shape, sound waves detected by the labyrinth trigger an extremely long … that synapses with motor neurons
Mauthner neuron (M)
Commissural interneurons
inhibit the left side of the fish from moving when it hears a sound of the left side
Motor neurons extend from the … to a … in the …
motor cortex, ventral root, spinal cord
Pyramidal tract
Voluntary limb movement. Connects motor cortex and spinal cord. Its faster because their are less synapses.
Extrapyramidal tract
Balance and posture. Proprioceptors (stretch muscles or spindle neurons) give the cerebellum information about the animal’s 3D limb position in space.
The cerebellum connects to the motor cortex via nerve projections in the …
thalamus
The cerebellum also receives input from the vestibule the semicircular canals and maculae about
spacial equilibrium
