Central nervous system and Peripheral nervous system | What are the two main divisions of the nervous system? |
brain and spinal cord | What parts of the body does the CNS cover/control? |
everything BUT the spinal cord and brain. | What parts of the body does PNS control/control? |
Somatic Nervous System and Autonomic Nervous System | What are the two main divisions of the peripheral nervous system? |
voluntary - afferent (from senses) - Efferent (to voluntary muscles) | What parts of the body does the Somatic Nervous System cover? |
involuntary - Afferent ( from things like stomach, lungs) Efferent (to involuntary muscles like gut and blood vessels) | What parts of the body does the Autonomic Nervous Systemcover? |
Sympathetic - fight or flight response (stress) Parasympathetic - rest and digest (opposite of sympathetic) | What are the differences between the sympathetic and parasympathetic nervous systems? |
dendrites, cell body, axon | What are the three main parts of a neuron? |
afferent - sensory nerves, move toward the CNS efferent - motor nerves, move away from the CNS | The difference between afferent and efferent neurons? |
sensory nerves, move toward the CNS | Function of: Afferent Neuron |
motor nerves, move away from the CNS | Function of: Efferent Neuron |
glial cells that support functions of neurons, and help form myelin | What are/is Neuroglia? |
astrocytes, oligodendrocytes, microglia and ependyma | What are the four types of Neuroglia seen in the CNS? |
help maintain BBB Blood Brain Barrier and scar tissue in CNS | What are the functions of astrocytes? |
maintain myelin sheath | What are the functions of oligodendrocytes? |
phagocytes that help clean out bacteria | What are the functions of microglia? |
ciliated cells that help regulate/circulate cerebrospinal fluid | What are the functions of ependyma? |
BBB filters blood going in to the brain and keeps bad things out | What is the blood/brain barrier? |
the electric insulator on the axon | What is myelin? |
keeps the nerve signal in the axon | What is the function of Myelin? |
gaps in the myelin sheath | What is a node of Ranvier? |
the space between one neuron's axon and the neighboring neurons dendrite | What is a synapse? |
multiple sclerosis (MS) | well-known disease is the result of damage to myelin sheaths? |
fluid that fills space between arachnoid membrane and pia mater | What is cerebro-spinal fluid? |
schwann cells | What cells maintain myelin in the PNS? |
they can help damaged axons repair themselves | What can schwann cells do that myelin-maintaining cells in the CNS cannot? |
nerve signal traveling down a neuron | What is an action potential? |
1. ungated channel 2. voltage gated channel 3. chemically gated channel 4. mechanically gated channel | What are the four types of ion channels used in transmitting nerve signals? |
Allows Na+ and K+ to leak across channel AND it's always OPEN | Functions of: Ungated channel? |
open when relative chargers on each side of membrane change (during action potential) | Functions of: Voltage gated channel? |
opens or closes when a specific chemical binds to it | Functions of: Chemically gated channel? |
opens or closes in response to a mechanical stimuli like sound waves, pressure of touch, or stretching | Functions of: Mechanically gated channel? |
all channels allow for passive movement via diffusion down gradient | Do ion channels allow for the passive diffusion of ions, or active transport? |
up gradient via active transport | Sodium potassium pump moves ions ____? |
-70mV | What is the resting potential of a nerve cell? |
Na+ is more common outside | A neuron at rest, are Na+ ions more common inside or outside the cell? |
K+ is more common on the inside | Are K+ ions more common inside or outside the cell? |
a small change in resting potential | What is a graded potential? |
moving TOWARD magic number (55mV) makes you Excitatory (depolarizing) | What is an excitatory graded potential and is it depolarizing or hyperpolarizing? |
moving AWAY from the magic number makes it Inhibitory (hyperpolarizing) | What is an inhibitory graded potential and is it depolarizing or hyperpolarizing? |
-55mV | What is the cell’s potential when it hits the threshold causing it to fire an action potential? |
hyperpolarization | Would membrane potentials greater than -70mV (that is, values like -75 or -80mV)represent hyperpolarization or depolarization? |
less likely AND inhibited | Would a neuron with a potential greater than -70mV be more likely or less likely to fire than a neuron at rest? Would it be excited or inhibited? |
depolarizing | Would membrane potentials between -70mV and -55mV represent hyperpolarization or depolarization? |
more likely AND excited | Would a neuron with a potential between -70mV and -55mV be more likely or less likely to fire than a neuron at rest? Would it be excited or inhibited? |
70 resting potential | What do the values –70mV represent? |
-55 magic number, threshold | What do the values -55 mV represent? |
30mV | What do the values +30 mV represent? |
more negative on the inside | A neuron has a membrane potential of -70mV, is it more negative inside the cell or outside? |
first part of action potential | What is the depolarization phase of the action potential? |
the start of depolarization the potential is -55mV | What is the membrane potential at the start depolarization? |
the end of depolarization the potential is 30 | What is the potential at the end of the depolarization phase? |
at the end of depolarization the voltage gated sodium channels close | Which ion channels close at the end of depolarization phase? |
sodium ions are flowing into the cell while potassium ions are leaving | Which ions enter or leave the neuron during the depolarization phase? |
repolarization happens at +30 mV | What is the repolarization phase of the action potential? |
voltage gated potassium channels open however they are are slow (they open as sodium ones start to close) | Which ion channels open at the start of repolarization? |
+30mV | What is the membrane potential at the start of the repolarization phase? |
at the end of depolarization of the membrane potential is -70mV | What is the membrane potential at the end of the depolarization phase? |
from 30mV to -55mV | What is the absolute refractory period? |
No. no neuron can fire during this period | Can a neuron fire an action potential during the absolute refractory period? |
an action potential at one node of Ranvier causing inward currents that depolarize the membrane at the next node , provoking a new action potential there. | Describe saltatory conduction? |
action potentials occur at nodes of ranvier | Where on the neuron do action potentials occur in saltatory conduction? |
The big advantage is that this is much faster | What is the big advantage of saltatory conduction? |