Neurons, Glia, & CNS Histology Flashcards
Neural cell differentiation involves the actions of growth and transcription factors that up-regulate the expression of _____-_________ genes.
Pro-neural
If one progenitor cell responds to pro-neural growth factor it will begin to differentiate as a neuron. Simultaneously, it will begin producing proteins that inhibit pro-neural gene expression in adjacent cells.
This process is called ______ ____________, and involves the ______ signaling pathway.
Lateral Inhibition
Notch
Microglia originate from ____ ______ precursor cells.
Bone marrow
Structure of a Neuron
The cell body is also called ____. It contains cellular organelles. Typical characteristics of a neural cell are: (3 answers)
(Soma)
Multiple mitochondria
Abundant rough ER and Golgi for producing proteins
Nissl granulation
Structure of a Neuron
This structure (from a few up to 1.5 million)?:
Arises from a hillock Initial segment Devoid of ribosomes Multiple mitochondria,microtubules, and neurofilaments Do not branch proximally Terminal arbor with terminal boutons
Axon
Structure of a Neuron
This structure (?):
Usually multiple
Can branch
Neurofilaments and microtubules
May contain mitochondria
Dendrites
Morphologically, Neurons can be divided into 3 classes:
Multipolar
Pseudounipolar
Bipolar
Functionally, neurons can be divided into:
Motor - somatic and visceral
Sensory - somatic and visceral
Integrative - connective
Neuroendocrine- releases peptide hormones
The process of converting sensory input into a form interpretable by the nervous system is called __________.
Transduction
List examples of ‘zones’ of neurons where synapses can occur…4 possible
Axodendritic
Axospinous
Axosomatic
Axoaxonic
Neurons produce and transport various substances and cellular organelles throughout intraneural transport system. Name the 5 steps in transmission…
- Synthesis
- Storage
- Transport
- Release
- Reuptake/destruction
This location on a neuron is the site of where most transcription and translation occurs: ____
Soma (cell body)
Neurotransmitters and other substances are transported along ____________ of the axons in both directions:
1) ___________ transport (away from the cell body) through ________.
2) __________ transport (toward the cell) via _______.
Microtubules Anterograde Kinesins Retrograde Dyneins
(Video showed in class of little feet walking along carrying stuff)
The term neuroglia (glia, “glue”) includes several cell types that are not ___________.
Cell types include (4):
Excitable
Astrocytes
Oligodendrocytes
Microglia
Ependimal
Protoplasmic astrocytes are located in the ____ ______.
While Fibrous astrocytes are located in _____ ______.
Gray matter
White matter
_________ are highly branched with multiple processes that give these cells their star-like appearance.
Astrocytes
Astrocytes contact neuronal ________, cell bodies, _____ and ________ with their processes.
Dendrites
Axons
Synapses
These cells provide structural and functional support to neurons, maintain a constant pH, lower extracellular K+, secrete growth factors and cytokines, remove glutamate from synapses, and help neuronal metabolism.
Astrocytes
Astrocytes retain the ability to ___________ in the mature brain.
Proliferate
When injury to the CNS results in destruction of neurons, the space created by the breakdown of debris is filled by proliferation and/or hypertrophy of astrocytes, resulting in the formation of an __________ ____.
Astrocytic scar
Other astrocytes have a process that end in expansions called ___-____.
End-feet
Astrocytes end-feet join together and insulate the ___ from other tissues.
CNS
_____ ________ ________ - the surface of the brain and spinal cord, adjacent to the pia mater is covered with several layers of joined end-feet called the ____ ________.
Glial limiting membrane
Glia limitans
Similarly, every capillary in the CNS is jacketed by a layer of end-feet that separates it from the neural tissue forming the _____-_____ _______.
Blood-Brain Barrier
