Lecture 16 Flashcards
Purpose of the nervous system
Integrates and coordinates processes in our body, essentially matching the sensory environment with our body’s needs.
Integration, coordination and response
Integration: letting our body know there’s a problem coordination: preparing a valid response response: doing the chosen response
Our nervous system is subdivided into two systems, what are they called and what do they consist of?
Central nervous system and peripheral nervous system, the CNS consists of nerves within your brain and spinal cord while the PNS consists of peripheral nerves (ones which aren’t in the brain or spinal cord.
Cells of the nervous system and their general function
Glia: support neurons and come in 5 basic types (4 in CNS and 1 in PNS)
Neurons: transmit information of varying types and come in thousands of different types.
4 types of CNS glia and their specific functions
What is the PNS glia and its function
Schwann cell, supports peripheral nerve fibers and wraps around them to insulate in myelin sheath (similar to oligodendrocytes)
The 6 parts of a typical myelinated neuron
also, what is myelin sheath made of?
dendrites (receive input), cell body, axon (carries the action potential), axon terminal (synapse with next neuron), myelin sheath and nodes of ranvier.
consequence of shit myelin and a possible cause?
nerves can’t transmit signals as well due to decreased conduction, possible causes could be autoimmunity
zones of a neuron and functions that occur there
input zone: dendrites and cell body, signals generally enter here.
summation zone: axon hillock, where it is chosen whether a signal will keep going.
conduction zone: axon, action potentials travel through here
output zone: axon terminals, generally makes contact with contact neurons input zone releases neurotransmitter, forming a chemical signal.
what are the morphological neuron types?
multipolar: multiple processes emanate from cell body (one axon, many dendrites)
bipolar: two processes emanate from cell body (one axon, one dendrite)
unipolar: one process from cell body which branches into a dendrite and an axon
What is the junction between neurons? What is the signal generally through this junction?
Synapse, most commonly the electrical signal is transformed into a chemical signal.
What are the neurons before and after the synapse refered to as? What do they each have/do?
pre-synaptic is before the synapse, it contains vesicles to release neurotransmitter. The post-synaptic contains receptors for the neurotransmitter.
What synapse types are there?
Axodendritic (synapse on post synaptic dendrite, the most common), axosomatic (synapse on post synaptic cell body), axoaxonic (synapse on post synaptic cell body).
names of signals in regard to direction from brain
afferent (or ascending) is towards the brain.
efferent (or descending) is away from the brain.
What are the names for organisations of cell bodies/axons in the CNS and PNS?
CNS: cell bodies are grouped into nuclei while axons are grouped into tracts, an exception is in the cerebral cortex where cell bodies are grouped into grey matter and axons into white matter.
PNS: cell bodies are grouped into ganglia(ganglion) and axons are grouped into nerves.
