Neuro Flashcards
What are the three inter functions of the nervous system?
- Sensory input.
- Integration (interpreting sensory.)
- Motor Output.
What does the Central Nervous Consist of?
Brain and spinal cord.
Can do all functions (Sensory Input, Integration, & Motor Output.)
What are the two primary functions of the Peripheral Nervous system?
To send and receive signals.
What are the two divisions of the PNS?
The Sensory/ Afferent division and the Afferent Division.
Division of PNS Which carries information to the central nervous system?
The Afferent Division (Action perceived to CNS.)
Division of the PNS which carries information from the CNS to the motor organs (Think muscles, glands etc.)
Efferent (effect from the CNS.)
What are the two divisions of the afferent/ sensory nervous system, what are their functions?
PNS
Visceral: Innervation of inner body, think heart, lungs, GI.
Somatic: Innervation of outer body, think skeletal muscles and skin.
What are the two divisions of the Somatic Afferent/ Sensory system?
Functions?
PNS
General Somatic Senses: Receptors spread widely throughout the outer body- intakes Pain, Temp, Touch, Stretch of muscles/ joints/ tendons, etc.
Special Somatic Senses: Receptors concentrated in specialized area of outer body- Echolocation, magnetoception, electroception, equilibrium, also normal ones like vision, aural, olfaction etc. NOT TASTE.
What are the two divisions of the Visceral Sensory/ Afferent System?
PNS
General Visceral Senses: Receptors located widely throughout the inner body- intakes Pain, Nausea, irritation, hunger, chemical changes.
Special Visceral Senses: Receptors Concentrated in specialized area- TASTE -not in cat fish.
What are the two divisions of the Motor/ Efferent division.
PNS
Somatic Motor: Motor innervation of most skeletal Muscle (not pharyngeal arches.) -No subdivision. (you don’t have outer/ inner skeletal muscle.)
Visceral Motor/ Autonomic system: Motor innervation of the inner body.
What are the two divisions of the Visceral Motor/ efferent division?
PNS
General visceral motor: Motor innervation of involuntary muscles, and glands.
special Visceral motor: pharyngeal arches- Specialized group of skeletal muscles.
Rate on understanding.
See it, know it plz.
What are the two physiological traits of a neuron?
Irritability and conductivity.
Capacity to generate a nervous impulse in response to
various stimuli.
Irritability.
Ability to transmit impulses along its cellular processes.
Conductivity.
Soma/ Perikaryon
The Nerve Cell body.
Receptive structures on the nerve cell (usually) Conduct impulses towards perikaryon.
Dendrites.
What is it called when an axon branches along it’s length?
An Axon Collateral. (Always branch at a 90º angle to the axon.) (Rare.)
Branches at the end of an axon name?
Telodendria.
Swollen area at the end of Telodendria?
Axon Terminal/ Axonal Buoton.
Type of neuron most common in embryonic state with only one process?
Where is it most common?
Unipolar Neuron/ pseudounipolar.
Most abundant in embryo before differing into bipolar and multipolar neurons.
Adult: Located in the sensory ganglia of the spinal cord- at the dorsal roots and more “true” ones exist in the cerebellum.
Collection of neuronal bodies within the PNS (Usually occurs when a bunch of axons begin at the same area.)
Ganglia.
Type of neuron with two processes?
Where is it most common?
Bipolar Neuron.
Most common in olfactory (smell) mucosa, retina, and inner ear. (Sensory Role.)
Neuron with three or more radiating processes?
Where is it most common?
Multipolar Neuron.
Most abundant within the body. Serve all three roles of the nervous system: Integration, Motor, Sensory.
Specialized intermediate filaments within a neuron?
Neurofilaments.
Bundle of Neurofilaments?
Neurofibril -Visible within cytoplasm.
Role of Neurofibrils?
The give strength, resiliency and may play a role in the movement of neurotransmitters/ Axonal Transport.
Where are the two types of endoplasmic reticulum found within a neuron?
Smooth endoplasmic reticulum is found throughout the cell.
Rough endoplasmic reticulum is found everywhere but the axon.
Since the Axon does not have RER/ Ribosomes it relies on the soma for protein synthesis and axonal transport.
Rough endoplasmic reticulum absorbs lots of which dye and is called what in it’s visible state under the scope?
Hematoxylin- A basophilic stain.
The RER + Ribosomes form visible bodies under the scope called Nissl/ Chromatophilic Bodies.
What are the three cytoplasmic inclusions common in a neuron?
Lipid drops
Pigments: Melanin ( Some CNS) and Lipofuschin (Some Ganglions).
Glycogen
What are the 5 types of synapse connections of neurons?
Components?
- Axodendritic (Most Abundant): Presynaptic Axon, Postsynaptic Dendrite/ Neuron.
Rest way less common- Usually amniote brain regions. - Axoaxonic: Presynaptic Axon, Postsynaptic Axon.
- Dendrodenritic: Presynaptic Dendrite, Postsynaptic Dendrite
- Axosomatic: Presynaptic Axon, Postsynaptic Soma.
- Dendrosomatic: Presynaptic Dendrite, Postsynaptic Soma.
What occurs at the Synapse?
Synaptic Transmission.
What are the two physiological types of synapses?
Chemical and Electrical (Really only present in amniote brain.).
Why are chemical Synapses more common within the nervous system?
The electrical signals of the neurons are converted into chemical signal in between the synapses, in electrical synapses they use 2 connexon hemichannels.
Synaptic vesicles (Only on one side of synapse- Axon) allow for unidirectional impulse. Electric may “backfire”.
What contain Neurotransmitters?
Synaptic Vesicles- Membrane bound. Release contents into the synaptic cleft.
The space between synapse?
Synaptic cleft.
What occurs after synaptic vesicles have been released into the synaptic cleft?
They will attach to receptor proteins on the target (usually dendrite) This will trigger the opening of the associated ion gateways, this initiates/ propagates a wave of depolarization. This conducts/ generates an electrical impulse that will carry towards the perikaryon.
What is the neurotransmitter of the neuromuscular junction?
Acetylcholine.
What makes up the specialized gap junction of an electric neuron synaptic cleft?
The membranes of the cleft are connected through a channel made from two half units called connexons. The connexons are made of six subunits called connexins. The depolarization is mediated directly to the connecting cell, however this allows for bi-directional travel.
What produces myelin in the PNS?
Schwann cells.
All axons in the PNS have what?
Myelin. Even covers some dendrites in the PNS.
Differences: Myelinated Vs Unmyelinated- Both still use myelin.
Another name for sheath of Schwann?
Neurilemma.
Where are Schwann cells derived from?
Neural Crest Cells.
What are the three functions of myelin?
- Insulation.
- Speed of depolarization.
- Intact Structures can be used a model for nerve repair in the body albeit slow; ~ 1in/ Month.
Schwann cell which has axons invaginated into it, but leaves some portions not totally covered?
Unmyelinated.
Slower conduction.
Schwann cells which wrap their membrane multiple times around a singular axon.
Myelinated.
Term for the nerve impulse leaping over the myelins sheath through the nodes of Ranvier?
Saltatory Conduction.
What are the narrow channels of cytoplasm that connect the revolutions of the Schwann cell plasmalemma?
Schmidt-Lanterman clefts.
