Unit 8 Flashcards
Neuron job
-Collect information, monitor and change stimuli
-Process and evaluate info: determine response
-initiate response through effectors
What is involved in the nervous system
Brain, spinal cord, nerves, ganglia
Cell body
the core of the cell that surrounds and protects
Axon
where electrical impulses from the neuron travel away to be received by other neurons. This where propagation happens.
Dendrites
receive information. Transmit graded potential along the plasma membrane
Synaptic Knob
Contains neurotransmitters
Axon Hillock
the region of a neuron that controls the initiation of an electrical impulse based on the inputs from other neurons or the environment. The electrical part of the electrochemical signal is called an action potential.
Synapse
transmission of nervous impulses from one neuron to another. Neurons are specialized to pass signals to individual target cells, and synapses are the means by which they do so.
Synaptic cleft
The space between two neurons across which the impulse is transmitted by a neurotransmitter is known as synaptic cleft
Myelin
an insulating layer, or sheath that forms around nerves, including those in the brain and spinal cord
Nodes of Ranvier (nerurofibrial node)
specialized regions in the axonal membrane that are not insulated by myelin.
Multipolar neurons
has multiple processes extending from the cell
Bipolar neurons
has 2 processes extending directly from the cell
unicellular neuron
dingle process extends directly from the cell and looks like a T
Sensory (afferent) neurons
Conduct sensory input from both somatic sensory and visceral sensory, Most are unipolar
Motor neurons
neurons of the motor nervous system. Conducts motor output away from the CNS to both somatic effectors and autonomic effectors. All are multipolar
Interneurons
Lie entirely within the CNS, they receive stimulation from neurons recieve, process, and store infant decide how the body responds to stimuli. Facilitated communication between sensory and motor neurons
Resting Membrane Potential
A resting (non-signaling) neuron has a voltage across its membrane called the resting membrane potential, or simply the resting potential. The resting potential is determined by concentration gradients of ions across the membrane and by membrane permeability to each type of ion.although the inactivation gate is open, the activation is closed and entry of Na+ is prevented
Electrochemical gradient
The electrochemical gradient determines the direction that ions will flow through an open ion channel and is a combination of two types of gradients: a concentration gradient and an electrical field gradient
Ligand-gated ion channels
channels respond to a neurotransmitter and are concentrated in the synapse
Voltage-gated ion channels
Respond to changes in the transmembrane electrical potential and are mainly located along the neuronal axal
Mechano-gated ion channels
respond to mechanical deformation
Graded potentials
primarily generated by sensory input, causing a change in the conductance of the membrane of the sensory receptor cell. Causes voltage gated Na+ channels to open.
Depolarizing graded potential
Depolarizing graded potentials are often the result of Na+ or Ca2+ entering the cell. Both of these ions have higher concentrations outside the cell than inside; because they have a positive charge, they will move into the cell causing it to become less negative relative to the outside.
