Neuroscience Flashcards
(224 cards)
Name 3 divisions of the NS
Central NS
Peripheral NS
Enteric NS
What does the CNS consist of?
Brain and Spinal Cord
What does the PNS consist of?
Nerves and cell bodies protruding from the brain and spinal cord.
What is the Enteric nervous system?
Often percieved as being the PNS, the enteric nervous system is a system of interneurones, motorneurones and afferent neurones which form complexes called Plexuses that surround the gastrointestinal tract.
What is viscera?
The internal organs and main cavities of the body.
How many pairs of peripheral nerves are there?
43 pairs.
What is a neuron? what does it contain? what does it not contain?
Neurons are bundles of individual nerve processes. They contain axons. They DONT contain dendrites are dendrites are specialized for receiving inputs. They also don’t contain neuronal cell bodies.
What does it mean if a nerve is defined as being Mixed?
It contains both Sensory and Motor neurons.
Describe the composition of a nerve.
It begins with nerve fibers, each nerve fiber is surrounded by a coating called the Endoneurium. These nerve fibers are bundled together into Fascicles. individual fascicles bundle are surrounded by a protective coating called the Perineurium. Fascicles are bundled together and surrounded by another protective sheath called the Epineurium. The epineurium also encloses the fascicles with blood vessels.
Name the cranial nerves. in order 1 to 12.
1 - Olfactory 2 - Optic 3 - Oculomotor 4 -Trochlear 5 - Trigeminal 6 - Abducens 7 - Facial 8 - Vestibulocochlear 9 - Glossopharyngeal 10 - Vagus 11 - Accessory 12 - Hypoglossal
What % of PNS outflow id the vagus nerve responsible for?
80%
What is the function of an interneuron?
Act as relay neurons. Allow commuication between sensory and motor neurons and the CNS.
What is the function of a Motor neuron?
Carry impulses from the Brain/Spinal cord to the Muscles/Glands.
What is the function of a sensory neuron?
Carry sensory information to the brain/spinal cord.
How many spinal nerves are there?
31 pairs
What are RAMI?
Where the spinal cord nerves project out of the spine and begin to branch.
What is a dermatome?
An area of the skin which is mainly supplied by a single spinal nerve.
Is the somatic (afferent) division voluntary of involuntary? and what is it associated with?
Voluntary. Associated with pain.
Whats the difference in the transmission of signals in Somatic and Autonomic efferents?
In somatic efferents, the signal travels down motor axons from the spinal cord straight to the muscle.
In Autonomic efferents, the signal travels down motor axons to a synapse with another cell in a ganglion, this cell then innervates the muscle/gland.
In the Autonomic efferent pathway, what is the difference in the myelination of axons?
The axons between the spinal cord and the ganglion are myelinated. The axons between the ganglion and the muscle/gland are NOT myelinated.
What are the sympathetic ganglia near the spinal cord called and what do they form?
Paravertebral ganglia and form the sympathetic chain.
What are sympathetic ganglia close to the target called?
Collateral ganglia.
How many synapses can a single preganglionic sympathetic axon innervate?
20
How many synapses can a single preganglionic parasympathetic axon innervate?
4