Unit 7 Study Review Flashcards
What two systems can the nervous system be divided into?
Central nervous system and Peripheral nervous system.
Central contain brain and spinal cord.
Peripheral nervous system contains sensory and motor divisions.
Sensory division is divided into ____ and ____ sensory division.
Visceral sensory and Somatic sensory.
Motor division is divided into ___ and ____ division.
Visceral motor and somatic motor.
Visceral motor division is divided into ______ and ____ division.
Sympathetic and parasympathetic division.
What are the two inputs to sensory nervous systems?
Somatic sensory(eyes) and visceral sensory(blood vessels).
What are the two outputs of the motor nervous system?
Somatic motor(skeletal muscle) and automatic motor(cardiac muscle).
The cell in the nervous system is called _____.
Neuron.
Function of the neuron?
Generating electrical signals and releasing neurotransmitters.
What are the cells that are responsible for supporting neurons?
Glial cells.
What are the fingers that surround the neuron’s head? Function?
Dendrites. Area where they receive inputs from other neurons and form neuron networks.
What is the small area between the cell body and axon?
Axon hillock.
Where does the output start and end?
Axon hillock to axon terminals.
Where do the axon terminals attach to another neuron?
Dendrites.
What is the neural impulse?
Electrical signal traveling down the axon.
What is the myelin sheath?
Covers the axon of some neurons and helps speed neural impulses.
What are the four segments of a neuron?
Receptive segment, Initial segment, Conductive segment and Transmissive segment.
Where are the areas of each segment?
Receptive-Cell body and dendrites, Initial-Axon hillock, Conductive-Axon and Transmissive-Axon terminals.
What are the functions of each segment?
Receptive-productions of graded potentials/bind neurotransmitters.
Initial-summation of graded potentials and initiation of action potentials.
Conducive-propagation of action potential.
Transmission-action potential causes release of neurotransmitters.
What is the difference between presynaptic and postsynaptic neurons?
Before synapse and after synapse.
When the axon terminal innervates to dendrites or to another cell body, what is it called?
Synapse.
What are the four types of neurons?
Multipolar, bipolar, unipolar and anaxonic neuron.
What type of neuron is most motor and some interneuron? Explain what it looks like?
Multipolar neuron, it has dendrites connected directly to the cell body and one long axon with many axon terminals.
What is the special sense neuron that is uncommon and found in the olfactory? Explain what it looks like?
Bipolar neuron, two processes extend from the cell body of one dendrite and one axon.
What type of neuron is most types of sensory neurons? Explain what it looks like?
Unipolar, single short process that extends directly from the cell body. Looks like a T.
What are the three classifications of the function class of neurons?
(input)Sensory: five senses. (output)Motor: Innervates skeletal muscle. Interneuron: Connects neuron to neuron.
What are the 6 types of glial cells?
Astrocyte, microglia, ependymal, oligodendrocyte, satellite cells and schwann cells.
What are the functions of the 6 types of glial cells?
Astrocyte-forms blood brain barrier, microglia-kill bacteria/defends cells, ependymal-cover ventricle and whole CNS/produces CSF(liquid between cell and cell),
oligodendrocyte-covers the axon in CNS/produces myelin,
satellite cells-supporters of ganglia cells/covers cell body
schwann cells-same job as oligodendrocyte(forms myelin sheath) in PNS.
What is the space between each myelinated axon?
Node of ranvier.
What jumpers between nodes of ranvier?
Action potential.
What is the action potential jump between nodes of ranvier?
Saltatory conduction.
How does myelin sheath grow on the PNS axons by schwann cells?
Layers will be built over under each other and continuously overlap.
The surrounding connective tissue of the outer layer of a single axon is called _____.
Endoneurium.
The collection of bundled axons is called ___.
Fascicle.
The collection of multiple bundles of axons(fascicles) is called _____.
Nerve.
The nerve is surrounded by _____.
Epineurium.
The connective tissue between each fascicle/cover the fascicle is called ____.
Perineurium.
What is the cluster of cell bodies in the PNS(peripheral nervous system)?
Ganglia.
What is the cluster of cell bodies in the CNS?
Nucleus.
A nerve is?
Group of axons in PNS.
A tract is?
Group of axons in the CNS.
Gray matter is made of?
Cell bodies, dendrites, synapse and unmyelinated axons.
White matter is made out of?
Myelinated axon.
__ percent of the brain is made out of fat.
70%
What are the two pumps in neurons?
Ca2+ pump and Na+/K+ pumps.
What are the two leak channels?
K+ and Cl- leak channels.
What does the leak and pump channels cause?
Electrical gradient of the cell.
What are the three chemically graded channels?
Na+, K+ and Cl- channels.
What are the three voltage gated channels?
Na+, K+ and Ca2+ channels.
The dendrites contain what two chemically gated channels?
Na+ and Cl- chemically gated channels.
The two gated channels in the dendrites are opened by?
Neurotransmitters of other axon terminals.
When the sodium chemically gated channels open and the body cell becomes positive creating a potential it is called?
Excitatory postsynaptic potential(EPSP).
The axon contains what channels?
Voltage gated K+ and Na+ channels.
What is the resting membrane potential?
70 mV
When the voltage gated channels open on the axon hillock and whole axon what happens?
Action potential.
What voltage gated channels open on the axon terminal?
Voltage gated Ca2+(neurotransmitters).
When the voltage gated Ca2+ opens in the axon terminal what happens?
Ca2+ will cause induced exocytosis, where neurotransmitters will be released.
___ leak channels mainly contribute to resting membrane potential.
K+(and K+/Na+ pump restores the balance to resting potential).
Definition of voltage?
Difference in electrical charge across plasma membranes.
Definition of Current?
Movement of ions across membranes.
Definition of resistance?
Opposition to movement of ions, plasma membrane resitis ion movement. Resistance changes when ion channels open or close.
What is chemical synapse? Example?
Where neurotransmitters are released(12 total). Ligand gated ion channel or Na+.
What is an excitatory synapse?
A ligand gated channel of Na+ causes depolarization aka makes the inside more positive(EPSP).
What is an inhibitory synapse?
A ligand gated ion channel of Cl- causes hyperpolarization aka makes the inside more negative.
What are graded potentials?
Short lived changes in resting membrane potential.
Na+ causes _____ and Cl- causes _____.
EPSP(depolarization/peak of highest peak of membrane potential only) and IPSP(hyperpolarization/lowest dip of membrane potential only) before it will return to resting membrane potential(-70mV)
What are the two postsynaptic potentials?
EPSP(excitatory depolarization) and IPSP(inhibitory hyperpolarization).
What is summation?
Additive effects of EPSP and IPSP on membrane potentials.
What is spatial summation?
Multiple presynaptic neurons release neurotransmitters at the same time.
What is temporal summation?
One presynaptic neuron releases a neurotransmitter several times within a few milliseconds.
What is a subthreshold stimulus?
Not enough to generate AP at axon hillock.
What is the threshold stimulus?
Enough to generate AP at axon hillock.
How does hyperpolarization occur?
When voltage after K+ channels stay open longer than the time needed to reach the resting membrane potential, makes it becomes below -70mV.
How many stages are there in creating AP?
- 1 is resting, 2 is initial segment, 3 is depolarization, 4 is repolarization, 5 is hyperpolarization, 6 is voltage gated K+ are closed and returned to resting potential.
What is the absolute refractory period?
Time during AP when a second AP cannot be generated(between steps 2 and 4).