Module 1.1 Flashcards
Neurons
One of two type of cells in the nervous system. Neurons receive info and transmit it to other cells.
All neurons have a soma (cell body), and most have dendrites, axon, and presynaptic terminals.
Membrane
Separates the inside of the cell from the outside environment. Most chemicals cannot cross the membrane. However, protein channels in the membrane allow for controlled flow of water, oxygen, sodium, potassium, calcium, chloride, etc.
Nucleus
The structure in the cell that contains chromosomes. All animal cells have a nucleus except for mammalian red blood cells.
Mitochondria
The structure of the cell that performs metabolic activities. Mitochondria has genes separate from the nucleus and they differ from eachother genetically.
Overactive mitochondria cause burning fuel rapidly and overheating. Under active mitochondria cause predisposition for depression and pain.
Ribosomes
The sites within a cell that synthesizes new protein molecules.
Endoplasmic reticulum
A network of thin tubes that transport newly synthesized proteins to other locations.
Dendrite
The branching fibres that come off the soma. It’s surface is lined with synaptic receptors that receive info from other neurons. The more surface area, the more information it can receive.
Soma
Cell body that contains the nucleus, ribosomes, and mitochondria.
Axon
A thin fibre that conveys impulses towards other neurons, organs, or muscles. Can be more than a meter long.
Presynaptic terminal
The bulb at the end of each axon branch. Where chemicals are released that cross from the neuron to another cell.
Motor neuron
The soma is in the spinal cord. It receives excitation through its dendrites and conducts impulses along its axon to the muscle.
Sensory neuron
Specialized at one end to be highly sensitive to one type of stimulation (light, sound, touch, etc).
Myelin sheath
The insulating material around axons
Nodes of ranvier
Afferent axon
Brings information into a structure. Sensory neurons.
A for admit
Efferent axon
Carries info away from a structured. Motor neurons.
E for exit
Interneuron
The cell’s dendrites and axons are entirely contained within a single structure.
Glia
Cells that enhance and modify the activity of neurons
Astrocytes
They wrap around the synapses of axons that perform similar functions to help synchronize the neurons, and send messages in waves. This creates rhythms such a breathing.
Microglia
Tiny cells that act as part of the immune system, removing fungi and virus’s from the brain. They proliferate after brain damage to remove dead or damaged nerves. They also remove weakest synapses.
Oligodendrocytes
Schwann cells
Glia cells in the periphery of the body that builds myelin sheath
Radial glia
Guide the migration of neurons, axons, and dendrites during embryonic development.
Blood- brain barrier
Keeps most chemicals from the vertebrate brain.
To prevent the immune system from killing off infected neurons, as they cannot be replaced like other cells in the body.
Some viruses that evade the blood-brain barrier infect the brain and lead to death (rabies). Others are controlled by the microglia but not eliminated (herpes).
Santiago Ramón y Cajal
Discovered that the nervous system is composed of separate cells
