S2_L1: The Neuron Flashcards
What forms the plasma membrane of the axon?
Axolemma
What part of the neuron receives stimulus from the another neurons?
Dendrites
What is the myelin sheath made of?
Schwann cells
Where does protein synthesis occur in a neuron?
Nissl substance
What carries impulses away from the cell body?
Axon
Where are the neurotransmitters found?
Synapse
Dopamine, serotonin, acetylcholine are types of?
Neurotransmitters
What do you call the spaces in between myelin sheaths?
Nodes of Ranvier
TRUE OR FALSE: Neurons only have one shape.
False
TRUE OR FALSE: Like neurons, glial cells are excitable.
False
TRUE OR FALSE: All nerves can regenerate after injury
True
TRUE OR FALSE: Peripheral nerves can re-innervate.
True
TRUE OR FALSE: Nerves in the CNS can regenerate, but not re-innervate.
True
What do you call the process of nerve damage?
Wallerian degeneration
What glial cell/s form scaffolds for immature neurons?
Astrocytes, radial glial cells
What glial cell provides myelin to the CNS?
Oligodendrocytes
What cells support neurons?
Glial cells
Association neuron that acts as connections in between big neurons
Interneurons
Group of cell bodies outside the CNS
Ganglion
Group of cell bodies in the CNS
Nucleus
Neuron that has one process but it divides into 2 (2 goes out of the main stem). It is found in extremities, skin of fingers and an example of it is the posterior root ganglion
Pseudounipolar
Longest cranial nerve
vagus nerve
start from cranium and innervates the heart, stomach until it
reaches the transverse half of the large intestine
Exhibits the fluid mosaic model and site of protein ribosome synthesis
Neurolemma
For ribosomal subunit assembly and rRNA synthesis
Nucleolus
Breakdown of colors. This happens when you injure, denervate or cut the nerve. The Nissl substance is lost.
Chromatolysis
TRUE OR FALSE: The dura matter is the covering that supports the brain and does not have neurons.
True
TRUE OR FALSE: Since the Nissl substance is absent in the axons, it is not present in the Schwann cells and myelin sheath.
True
External boundary of the cell and the site of initiation and conduction of impulses.
Plasma membrane
These increase the surface area to 90% and are numerous in areas for precise tactile discrimination.
Dendrites
The ___ is the most excitable part of the motor nerve
Initial segment of the axon
The ___ is the most excitable part of the sensory nerve
First node of Ranvier
Also called lockjaw. Open wounds, lacerations, punctured wounds, and animal bites may cause this.
Tetanus
Determine the corresponding descriptions of the types of axon transport
- Guided by microtubules
- For membrane bound organelles, mitochondria, and synaptic vesicles
- Needs metabolic energy and Ca++
- For proteins dissolved in cytoplasm
- Cannot communicate with others without neurotransmitters
A. Slow axonal transport
B. Fast axonal transport
- A
- B
- A
- A
- B
Axon transport from soma to axon terminal. It is for the replenishment of synaptic vesicles and enzymes
for neurotransmission.
Anterograde / orthograde
Axon transport from axon terminal to soma. It returns all synaptic vesicles back to the soma for lysosomal degradation.
Retrograde
Glial cell that acts as the first line of protection and electrical insulators on synaptic contacts. This absorbs GABA and glutamic acid and takes up excess K+. It also acts as a barrier for the spread of neurotransmitter at synapses.
Astrocytes
The formation of myelin sheaths in the CNS begins on the ___ week of gestation to walking.
16th
Glial cell that controls hormone production of the anterior pituitary gland.
Ependymal cells
Glial cells active during development and serves as guide posts & scaffoldings to the immature neurons.
Radial glial cells
In stroke, neurons undergo wallerian degeneration and there is a golden period when interventions must be given to the patient so that the neuronal buds will be forced to look at its previous innervation which will receive nerve growth factor (NGF) and innervation will happen.
How long is the golden period?
For the first 6 months (when the patient is safe)
In nerve regeneration, the damaged neuron will create ___ at about 3-5 mm per day. Then, these will be guided by the Schwann cells until it reaches the destination, the axons will be reformed and Schwann cells will wrap around the axon.
Neuronal buds
When a nerve is cut, severed, or injured, what changes occur in the nerve cell body?
Becomes inflamed or circular and Nissl substance disappears (Chromatolysis)
When a nerve is cut, severed, or injured, what changes occur in the proximal axon?
Disintegrates within 7 days, nerve becomes wavy, Schwann cells will retract its processes or unwrap itself from axon
When a nerve is cut, severed, or injured, what changes occur in the distal axon?
Disintegrates after 5-7 days, nerve
becomes wavy and synapse will
slightly be inflated. Schwann cells will retract its processes or unwrap itself from axon.
Determine the corresponding descriptions of the Seddon-Sunderland Classification of Nerve Compression
- Focal conduction block
- Epineurium is intact
- Disruption of axonal continuity
- Loss of axonal continuity and endoneural tubes
- Motor and proprioceptors affected, local compression only
A. Type 1 (Neuropraxia)
B. Type 2 (Axonotmesis)
C. Type 3 (Axonotmesis)
D. Type 4 (Axonotmesis)
E. Type 5 (Neurotmesis)
- A
- D
- B
- C
- A
Determine the corresponding descriptions of the Seddon-Sunderland Classification of Nerve Compression
- Endoneural tubes, perineurium, and epineurium intact
- Severance of entire nerve
- Perineurium and epineurium are preserved
- No Wallerian degeneration
- Loss of axonal continuity, endoneural tubes, & perineurium
A. Type 1 (Neuropraxia)
B. Type 2 (Axonotmesis)
C. Type 3 (Axonotmesis)
D. Type 4 (Axonotmesis)
E. Type 5 (Neurotmesis)
- B
- E
- C
- A
- D
