Cells To The NS Flashcards
Nerve tissue consists of:
Neurons and nueroglia(glial cells)
Name the five functions of neuroglia. Hint:M_2p’s_2r’s
- Maintain physical structure of the tissues
- Perform phagocytosis
- Provide nutrients to neurons
- Repair tissue framework after injury
- Regulate the composition of the interstitial fluid
Name 3 parts of a neuron.
- Dendrites
- Cell body
- Axon
Towards where do the dendrites signal?
Cell body
Cell body contains of what and also produces what which is stored in what?
Nucleus( containing genetic info) and other things found in most cells.
Neurotransmitters
Synaptic vesicles
Explain what is an axon hillock.
Is the 1st part of the axon plus the part of the cell body where the axon exits.
It has the lowest threshold for AP.
Part where AP are initiated
Towards where does the axon signal?
Away from cell body
Other name for axon.
Nerve fiber
An axon is a single tube like fiber that is shorter/longer and thicker/slimmer than dendrites.
Longer,thicker
Neurons use axons to transmit an electrical/chemical l impulse to other neurons?
Electrical impulse
Is an axon terminal the BEGINNING/END of an axon?
End
Which neuron sends information from the sensory organs, through the spinal nerves, into the CNS?
Sensory (afferent) neuron
Which neuron carries messages from the CNS, through spinal nerves, to operate muscles and glands?
Motor(efferent) neuron
Which neuron exists only within the CNS, that carry messages from 1 set of neurons to the other. They can bring information from different sources together into one location in the CNS.
Interneurons
Give the types of CNS neuroglia. Hint: Aw’O ME
Astrocytes
Oligodendroglia
Microglia
Ependymal
Name the types of neuroglia cells that “ digest parts of dead neurons “ phagocytic cells.
Astrocytes and Microglia(only function)
Give the types of PNS neuroglia. Hint:SS
Schwann and Satellite
Which neuroglia cells “provide insulation(myelin) to neurons in the CNS AND THE OTHER IN THE PNS?
CNS- oligodendroglia
PNS- Schwann
Satellite gives “physical support to neurons in the CNS/PNS?
PNS (peripheral nervous system)
Ependymal cells line the____of the brain and produce____.
Ventricles and CSF
Name the two kinds of signaling mechanisms.
Electrical and chemical signals
Explain what is an electrical signal?
Is an INTRAneuronal signal that transmits Action
Potential along the axon and Graded Potentials
in the postsynaptic membrane , which cause an
Action Potential, stimulated by Resting Membrane
Potential.
Name the components of the basic reflex arch.
E.g Patellar tendon
- Stimulus
- Receptors
- Sensory neuron
- Spinal cord
- Motor neuron
- Effector muscle
- Response
Give the whole scenario when stimulus is stretched muscle. Hint:5 steps
- Graded potentials in the stretch receptor ending
- Action potentials conducted to CNS
- Action potentials converted to graded transmitters release.
- Graded postsynaptic potentials in motor neuron
- Action potentials conducted to muscle
Which then response in muscle contracting
What is membrane potential?
Is the voltage across membrane.
How are neurons polarized?
They are electrical polarized more negative on the inside and positive outside, this is due to uneven ion distribution =RMP.
Step by step explain membrane potential. Hint: 4 steps (4a-c)
- RMP = -70mV
- Ion distribution across membrane (more + ions outside, more - ions inside)
- Role of Na+/K+ pump is to keep Na+ outside and K+ inside.
- Ion channels
A. Voltage gated ion channels open when membrane voltage changes to reach threshold.
B. Chemical gated ion channels open when certain chemical binds. E.g acetylcholine
C. Mechanical gated ion channels open due to distortion.
Define ion channels.
Are pore or “gates” to regulate ion flow inside and outside of cells.
What are action potentials?
They are nerve impulses.
Name the two events of AP.
Summation and Threshold potential (-55mV)
What is summation?
When all incoming signals from dendrites are added up at the cell body membrane.
What is threshold potential?
When lots of excitatory signals arrive at cell from dendrites.
The AP acts on an___________.Has to reach______ before it will fire, and then it will fire completely.
All or none principle, threshold
The process of AP occurs repeatedly about (100/200) many times per (second/minute).
100, second
What is the chemical signaling mechanism?
Is an international, involved with synapses for neurotransmitters.
