Nerve cells and Nerve impulses Flashcards
What are the two kinds of cells in the nervous system?
Neurons and Glia
Who is the pioneer of neuroscience?
Santiago Ramon Y Cajal
Neurons have much in common with the rest of the body’s cells are:
Membrane, Nucleus, Mitochondria, Ribosomes, Endoplasmic Reticulum.
Receives excitation through its dendrites and conducts impulses along its axon to a muscle.
Motor neuron.
Specialized at one end to be highly sensitive to a particular type of stimulation, such as light, sound, or touch.
Sensory neuron.
Branching fibers that gets narrower near their ends.
Dendrites.
Contains the nucleus, ribosomes, and mitochondria.
Cell body / Soma.
Thin fiber of constant diameter. It also conveys an impulse toward the other neurons, an organ, or a muscle.
Axon.
Insulating material.
Myelin sheath
End of each branch.
Presynaptic terminal.
Brings information into a structure.
Afferent axon.
Carries away information from a structure.
Efferent axon.
It remove dead neurons and waste products from the nervous system. It also nourish and insulate neurons, form a myelin, and it also play role in neural transmission messages.
Glia.
Dilate the blood vessels to bring more nutrients into brain areas that have heighted activity.
Astrocytes.
Contribute to learning by removing the weakest synapses.
Microglia.
Supply the axon with nutrients necessary for
proper functioning.
Oligodendrocytes.
Guide the migration of neurons and their axons and dendrites during embryonic development.
Radial glia.
- Electrical message that is transmitted down the axon of a neuron.
- Does not travel directly down the axon but is regenerated at points along the axon.
- Speed is approximately 1 m/s to 100 m/s.
Nerve impulses.
- state of the neuron prior to the sending of a nerve impulse.
- helps fire up.
- prepares the neuron to respond rapidly.
Resting potential.
- A difference in electrical charge between the inside and outside of the cell
- (How many Na+ or K+)
- The electrical potential inside the membrane is slightly negative with respect to the outside, mainly because of negatively charged proteins inside the cell
Electrical gradient (polarization).
- The process of transmitting nerve impulse.
- Messages sent by axons
Action-potential
The change which means increased polarization.
Hyperpolarization
The amplitude and velocity of an action potential are independent of the intensity of the stimulus that initiated it, provided that the stimulus reaches the threshold.
All-or-none law
A protein-mediated process that expends energy to pump chemicals from the blood into the brain.
Active transport
