Week 1: Neural Tissue Flashcards
The basic functional unit of the nervous system.
Neuron
Perform all of the communication, information processing, and control functions of the nervous system.
Function of Neurons
Cells that support neurons and have functions essential to the survival and functionality of neurons.
Neuroglia
- Separate and protect neurons
- Provide a supportive framework
- Act as phagocytes
- Regulate the composition of interstitial fluid
Function of Neuroglia
Cytoplasm that surrounds the nucleus.
Perikaryon (Component of a Neuron)
(of the perikaryon) contains neuro filaments, and neurotubules.
Cytoskeleton (Component of a Neuron)
Bundles of neurofilaments.
Neurofibrils
Are clusters of rough endoplasmic reticulum (RER) and free ribosomes (responsible in the “gray” in gray matter).
Nissl Bodies (Component of a Neuron)
Extend from the cell body and are responsible for communication.
Dendrites (Component of a Neuron)
Extend out from dendrites.
Dendritic Spines (Component of a Neuron)
Receive information from both external and internal stimuli, process information, and send signals to initiate any necessary response.
Function of the Nervous System
Are long cytoplasmic processes capable of propagating action potentials.
Axons (Component of a Neuron)
The cytoplasm of an axon.
Axoplasm (Component of a Neuron)
The cell membrane of an axon.
Axolemma (Component of a Neuron)
aka Axon Hillock; where the axon and the cell body meet.
Initial Segment (Component of a Neuron)
An axon may branch along its length, producing side branches called ________________.
Collaterals (Component of a Neuron)
Are where telodendria end.
Synaptic (Axon) Terminal (Component of a Neuron)
A specialized site where neurons communicate with another cell.
Synapse
Sends a message.
Presynaptic Cell
Receives message.
Postsynaptic Cell.
The axon terminal of the presynaptic cell communicates with the postsynaptic cell using chemicals called __________________.
Neurotransmitters
A synapse between a nerve and a muscle.
Neuro-muscular Synapse
A synapse between a nerve and a gland.
Neuro-glandular Synapse
A synapse between a nerve and another nerve.
Neuro-neuronal Synapse
Space between presynaptic and postsynaptic cells.
Synaptic Cleft
Neurotransmitters are stored in tiny vesicles in the ________________ and release their contents into the synaptic cleft when an __________________ arrives at the axon terminal.
Axon terminals, Action potential
Neurotransmitters that are captured back in pieces from the synaptic cleft.
Resynthesized Neurotransmitters
Neurotransmitters from the cell body.
Synthesized Neurotransmitters
Transport away from body and toward distal axon.
Anterograde Transport
Transport toward the body.
Retrograde Transport
Are small neurons with no distinguishing feature.
Anaxonic Neurons (Classified by Structure)
Rare neurons, and occur in special senses of sight, smell, hearing.
Bipolar Neurons (Classified by Structure)
Represent most sensory neurons.
Unipolar Neurons (Classified by Structure)
Represent all motor neurons controlling skeletal muscle.
Multipolar Neurons (Classified by Structure)
Afferent, intero, extero, proprioceptors.
Sensory Neurons (Classified by Function)
Somatic and visceral motor.
Motor Neurons (Classified by Function)
Most abundant neuron, responsible for higher order functions.
Interneurons (Classified by Function)
- Ependymal cells
- Astrocytes
- Oligodendrocytes
- Microglia
Contents of CNS Glia
- Schwann cells
- Satellite cells
Contents of PNS Glia
Line the cerebral ventricles and central canal producing Cerebral Spinal Fluid (CSF).
Ependymal Cells
- Maintain the blood brain barrier
- Create 3D framework for CNS
- Repair neural damage
- Guide neuron development
- Control the interstitial environment
Astrocytes
Cooperate in forming a myelin sheath along the lengths of CNS axons.
Oligodendrocytes
Phagocytic cells acting as wandering macrophage, acting as both “police” and “janitor”.
Microglia
Responsible for myelinating axons in the peripheral nervous system.
Schwann Cells
Schwann cells can only myelinate ______ segment of a _________ axon unlike _________________.
1, single, oligodendrocytes.
Like astrocytes, maintain blood brain barrier helping to regulate neuron interstitial fluid.
Satellite Cells
Most neurons lack ___________, important organelles involved during mitosis. For this reason, they cannot be replaced if lost to injury or disease.
Centrioles
A series of fine extensions at the end of an axon.
Telodendria (Component of a Neuron)
Monitor the digestive, respiratory, cardiovascular, urinary, and reproductive systems, and provide sensations of distension (stretch), deep pressure, and pain.
(intero-, inside)
Interoceptors
Provide information about the external environment in the form of touch, temperature or pressure sensation and the more complex senses of taste, smell, sight, equillibrium (balance), and hearing.
(extero-, outside)
Exteroceptors
Monitor the position and movement of skeletal muscles and joints.
Proprioceptors
