Flashcards in Exam 1 Unit 2 Deck (84):
Neuroepithelial cells gives rise to:
Give rise to astrocytes & the oligodendrocytes
Maintain some mobility potential
Most numerous cell of the adult central nervous system
2 types of astrocytes
Protoplasmic - grey matter
Fibrous - white matter
______ found b/t blood vessel capillaries & neuron cell bodies
Store what little excess glucose can be held by CNS tissue
Play a dominate role in forming "scar- like" tissue following CNS injury
Neurotransmitters such as _________, _______, _________ may be influenced directly by astrocytes at synaptic gaps.
Glutamate, dopamine, serotonin
Types of oliodendrocytes:
Perineuronal satellites - grey matter
Interfascicular- white matter(form myelin sheaths around most axons in CNS)
Serve as a"leaky" barrier b/t the CSF and the CNS parenchyma
Most ependymal cells are classified as
Tanycytes in 3rd ventricle
Transporting some compounds from CSF to hypophyseal- portal system
Most common, primary brain tumor
Most lethal, primary brain tumor
Restrict the flow of CSF- result in increase in intracranial pressure
medodermally derived. Arise from fetal macrophages & invade from the bloodstream during embryonic & fetal development
Become active when neural tissue is injured
Microglia have _______ function -responsible for clearing dead & damaged tissue & may even wall off damaged areas along with the astrocytes
Also mediate immune responses w/in CNS
Have a neuroepithelial origins (along neural tube)
Neuroeithelial cells in the neural crest give rise to _____ of the PNS
Show little mitotic activity but do undergo growth/masturation & adaptation
Anatomical vs. Physiological
Based on appearance & generally designated as unipolar, bipolar, and mulitpolat
based on function & position & generally designated as sensory, motor, & internuncial
- AKA Pseudounipolar: w/ central & peripheral extensions.
- Found in Dorsal Root Ganglion
Smell, vision, hearing, taste, & equilibrium
ONE & ONLY ONE axon. but can have multiple denrites
Multipolar has 2 types:
Golgi Type 1; Long axon
Golgi Type 2: Short axon
Carry info. toward CNS
Carry info. away from CNS
An internuncial neuron that runs b/t equivalent structures on OPPOSITE sides of the CNS
An internuncial neuron that begins in one structure & terminates in a different structure
Projection neurons has 2 types:
Ipsilateral- stays on the SAME side
Contralateral- Crosses to the OPPOSTIE side
An internuncial neuron in the spinal cord that begins & ends at the same cord level
Internuncial neuron in the spinal cord that begins at one cord level & terminates at another cord level
Bilaminar disc is the ectoderm and the endoderm, the Ectoderm gives rise to what system
Neural crest cells give rise to what system
Rhombencepalon is made up of the:
Myelencephalon & the Metencephalon
Prosencephalon is made up of the:
Diencephalon and the telencephalon
Myelencephalon gives rise to the:
Metencephalon gives rise to the:
Cerebellum and the pons
Secrete cerebrospinal fluid and form the "choroid plexus" in each ventricle
What structures meet to form a synapse in the CNS?
Synapse w/ axon - least common
Axon synapses with another dendrite- Most common
Synapse b/t axon & cell body
Where are mitochondria most abundant?
- Cell body
- Telodendritic endings
Mitochondria produce what?
What are nissl bodies?
Clumps of RER
Nissl bodies are also known as?
When present nissl bodies are found in the:
Dendrites and cell body
New names for neurofibrils?
Tubules help maintain cell shape and have a diameter b/t 20-30 nm (largest)
They run longitudinally and circinferentially and are often associated with axolemma (3-5 nm smallest)
Moderate in diameter filaments (9-10nm middle in size)
What is axoplasmic (cell) transport?
Movement of "raw materials" within the cell (NOT nerve impulse)
- Movement of protein building blocks for the neurofibrils and mitochondria.
- Occurs in an anterograde direction (away from the cell body)
Slow transport (DOES NOT REQUIRE ATP)
-Movement of synaptic vesicles, lysosomes, and certain enzymes.
- Moves in either anterograde or retrograde
Fast transport (REQUIRES ATP)
The anatomical & functional unit of the nervous system (single nerve cell)
Extension of the neuron AWAY from its cell body (can be an axon or a dendrite)
Neuron process conducting an impulse TOWARD the cell body, Can be several
Single neuron process carrying the impulse AWAY from the cell body toward a synaptic or neuromuscular junction
Raised area of the cell body from which an axon arises, In the CNS most action potential are initiated here
Dominantly long process, if present, of a neuron. Usually an axon but can be a dendrite
Myelin is composed of ________/________ and neurokeratin (protein) accumulations. Myelin is made by surrounding cells
Schwann cells wraps around the:
Schwann cells become:
There is no myelin over the _______, ________ or ______. when present myelin is only over the long process. (fiber)
Telodendria, Perkaryon or hillock
Schwann cells cover nerve fibers in the
Where one Schwann covering meets another a tiny exposed area is created and is called:
Node of Ranvier
Where the Schwann cell exists, you have an:
Additional coverings in the PNS
Highly vascular, fibrous and cellular matrix is around each neurilemma. It continues even out along the finest telodendritic branches.
- This coat wraps around groups of fibers (fasciculi).
- The most elastic of the mesodermal covers
- it is continuous with the pia and the arachnoid maters as it approaches the CNS structures
-Outer coat of a nerve
- Virtually inelastic and adds protection, strength and support to the fasciculi w/in.
Continuous with the dura mater as it approaches the CNS structures
Myelin will be found covering what structures in the CNS?
Axons > 1micron in diameter
Is the myelin associated with a Schwann cell?
No, interfassicular oliodendrocytes
Guillain - Barre syndrome
Affects the PNS / affects Schwann cells
Affects the CNS
Axons grouped together in the CNS
Midline white matter connectors inside the CNS