Intro & Basics Flashcards
Neurons
Primary processors of neural signals
What do Neuroglia support?
Support the electrical and chemical functions of neurons
Vascular endothelium
Provides for the supply of blood to brain tissue
Fundamental unit of function in the CNS
Neurons
3 zones of functional microanatomy of neurons
Input zone: Dendrites, Cell Body
Conducting Zone: Axon
Output Zone: Synapses, Axon Terminal
Dendrite
A neuronal process arising from the nerve cell body that receives synaptic input.
Morphology of the dendrite gives some insight into…
The functional properties of those cells and the class of neuron
Example: the absence of dendritic spines (smoothness) is evidence of an inhibitory effect on the cells that they make synaptic connections to.
Axon
The neuronal process that carries the action potential from the nerve cell body to a target.
electrical synapses
Synapses that transmit information via the direct flow of electrical current at gap junctions.
chemical synapses
Synapses that transmit information via the secretion of chemical signals (neurotransmitters).
gray matter refers to
any accumulation of cell bodies and neuropil in the brain and spinal cord (e.g., nuclei or cortices)
What is white matter
refers to areas of the central nervous system (CNS) that are mainly made up of myelinated axons
Give 4 examples of different classes of neurons
Cortical pyramidal cell
Retinal bipolar cell
Cerebellar Purkinje cells
Retinal Ganglion cells
Afferent
A neuron or axon that conducts action potentials from the periphery toward the central nervous system (coming in to CNS)
Efferent
A neuron or axon that conducts information away from the central nervous system toward the periphery
Interneuron
AKA: local circuit neuron.
Technically, a neuron in the pathway between primary sensory and primary effector neurons;
more generally, a neuron whose relatively short axons branch locally to innervate other neurons.
Brainstem is comprised of
Midbrain
Pons
Medulla
diencephalon
(location)
(Comprises)
Portion of the brain that lies just rostral to the midbrain; comprises the thalamus and hypothalamus
Rostral
Anterior, or “headward.”
anterior
Toward the front;
sometimes used as a synonym for rostral, and sometimes as a synonym for ventral.
caudal
Posterior, or “tailward.”
Posterior
Toward the back;
sometimes used as a synonym for caudal or dorsal.
Neuroglia provides these functions for the brain:
- Support the metabolic and signaling functions of neurons
- Participates in neuron circuit formation and synaptic plasticity
- Make myelin (axonal insulation)
- Contribute to formation of blood-brain barrier
- Participate in inflammatory response in injured neural tissue
- Contribute to the formation of scar tissue in damaged brain and spinal cord
Types of glial cells
Astrocyte
Oligodendrocyte
Microglial Cells
Astrocyte
(Found in)
(Assists with)
(Contributes to)
Found
+in gray matter
Assists with
+ionic balance of extracellular fluids,
+Take-up and process neurotransmitters from synaptic clefts
+formation of new synapses and circuits
Contributes to
+formation of blood-brain barrier and brain-ependymal barrier
+scar formation in necrotic neural tissue following injury
Oligodendrocyte
(Found in)
(Present)
(Subject to)
- Found in white matter and form myelin
- Present antigens that influence the outgrowth of axons in developing and recovering brain
- Subject to immunological attack in diseases of the CNS (e.g., multiple sclerosis)
Myelin
- Insulate axons by with layers of membrane that wrap around axon segments
- Decreases “leakiness” of the membrane, making the current more efficient
Nodes of Ranvier
Gaps between myelin segments that allow for the economical concentration of ion channels and ion pumps that are necessary for electrical signaling in axons.