Nerve 1 Flashcards
What are the two parts of the nervous system?
Central nervous system
Peripheral nervous system
What is the CNS composed of?
Brain
Spinal cord
What type of neurons does the CNS contain?
Relay neurons
What is the PNS composed of?
Cranial nerves
Spinal nerves
Peripheral nerves
What type of neurons does the PNS contain?
Sensory neurons
Motor neurons
What are the six types of neuroglial cells?
Schwann cells Astrocytes Oligodendrocytes Microglia Ependymal cells Satellite cells
What do all neurons consist of?
Cell body
axon
dendrites
What is the axon?
A long cytoplasmic extension specialised in generating or conducting nerve impulses to other cells that terminate in dilations known as end bulbs
What are dendrites?
Short processes specialised in receiving stimuli from other cells
What are the four different structural types of nerve cells?
Anaxonic
Bipolar
Unipolar
Multipolar
What does anaxonic mean?
Axon cannot be distinguished from dendrites
What does bipolar mean?
Axon and single dendrite on opposite ends of the soma
What does unipolar mean?
Dendrite and axon emerging from same process
What does multipolar mean?
Two or more dendrites, separate from the axon
What are Nissl bodies?
Combination of free ribosomes and RER
What is neuropil?
Mass of interwoven nerve endings and dendrites from other neurons
What is the membrane of the axon known as?
Axolemma
What is the cytoplasm of the axon known as?
Axoplasm
What are neurotubules?
Like conveyor belts to transport numerous substances along an axon between the soma and the axon terminal
What are neurofilaments?
Major component of the neuronal cytoskeleton, they provide structural support for the axon and regulate the axon diameter
What is myelin sheath made up of?
Schwann cells in PNS
Oligondendrocytes in CNS
What is the role of myelin?
To act as an insulator and allow for faster transmission of nerve signals and helps repair of axons
What happens during multiple sclerosis?
Myelin sheaths surrounding the axon is damaged by an autoimmune mechanism that t interferes with the activity of the affected neurons
What CT surrounds an individual axon?
Endoneurium
What CT surrounds a nerve fasicle?
Perineurium
What CT surrounds a nerve?
Epineurium
Where does the spinal cord begin?
The base of the medulla oblongata
Where does the spinal cord travel?
Inferiorly within the vertebral canal surrounded by the spinal meninges
How does the conus medullaris form?
At L2 vertebral level the spinal cord levels off
What is the name given to the spinal nerves that arise from the end of the spinal cord bundled together?
Cuada equina
What is the outer layer of the spinal cord known as?
white matter
What is the inner layer of the spinal cord known as?
grey matter
Label the spinal cord
Slide 20 nerve 1
What is the posterior side of the spinal cord?
Posterior - pointy - pointy things hurt - sensory
What are ganglia?
Ovoid structures containing neuronal cell bodies and their surrounding glial satellite cells supported by connective tissue and surrounded by delicate CT and surrounded by a denser capsule
What determines if it id a sensory or automatic ganglion?
the direction of the nerve impulse
How does neural regeneration occur?
Rare neural stem and progenitor cells (located near the ependyma) allow some replacement of neurons throughout life
