Neurons + Brain + EEG Flashcards
Two major systems of nervous system
- Central nervous system (CNS)
- Peripheral nervous system (PNS)
The main parts of the central nervous system (4 - think CBC radio)
- Cerebrum - brain
- Brain stem
- Cerebellum
- Spinal cord
Main part of the PNS
The remaining nerves outside the CNS (outside the cerebrum)
Main role of the PNS system
Connects the brain to the outside world
Name the number : spinal nerves and cranial nerves
- Spinal : 31 pairs
- Cranial : 12 pairs
T/F : The PNS system is the primary processing center
F : it is the CNS
Say “u-u-u-u-u”!
You probably used your facial nerve (aka the seventh cranial nerve or CN VII) for moving the lips while producing the sound. Cranial Nerve VII most likely belongs to:
A. CNS
B. PNS
C. Not sure
B. PNS
T/F : the fundamental unit of the nervous system is the axon, because it is responsible for the transmission/speed of the signal
F : the neuron is the fundamental unit
T/F : the affective neuron transmits electrical signals and the motor neuron transmits chemical signals
F : a neuron transmits both kinds of signals
Name all parts of the neuron
- Dendrites
- Cell body
- Axon
- Myelin sheath
- Nodes of Ranvier
- Axon terminal
- Synapse
Primary function of nodes of Ranvier + what they are
gaps in between segments of myelin sheath along the axon
they allow signal to accelerate the signal by skipping over certain distances
What is the synapse
the space where chemicals in neurotransmitters will transfer info to neighbouring neurons
Function of dendrites + what they are
tree like extensions that receive signals from other neurons
They increase the surface area for receiving incoming signals
During the depolarization phase of an action potential, which statement is true?
- Both sodium and potassium ions flow into the neuron, neutralizing the resting potential.
- Sodium channels open, allowing sodium ions to enter the neuron, making the interior more positive.
- Potassium ions enter the neuron, causing the interior to become less negative.
- Sodium-potassium pumps actively depolarize the neuron by expelling potassium ions.
- Sodium channels open, allowing sodium ions to enter the neuron, making the interior more positive.
The transmission speed of an action potential along an axon is directly influenced by axonal diameter and myelination. According to the information provided, which of the following statements accurately describes this relationship?
A. Thinner axons, whether myelinated or unmyelinated, transmit impulses faster due to reduced internal resistance.
B. Thicker axons transmit impulses faster than thinner axons, and myelination further increases this speed through saltatory conduction.
C. Myelination decreases transmission speed in thicker axons by increasing the capacitance of the axonal membrane.
D. Axonal diameter only affects transmission speed in unmyelinated axons; myelinated axons transmit impulses at a constant rate regardless of diameter.
B. Thicker axons transmit impulses faster than thinner axons, and myelination further increases this speed through saltatory conduction.
The establishment and maintenance of the resting membrane potential are critical for neuronal excitability. Which of the following contributes most significantly to the negative resting membrane potential of a neuron, as described in the slides?
A. The equilibrium potential of sodium ions (Na+) due to high permeability at rest.
B. The equal distribution of sodium (Na+) and potassium (K+) ions across the cell membrane.
C. The action of the sodium-potassium pump, which actively transports ions against their concentration gradients.
D. The passive diffusion of chloride ions (Cl-) into the cell, driven by their concentration gradient.
C. The action of the sodium-potassium pump, which actively transports ions against their concentration gradients.
During neural impulse transmission, the transition from depolarization to repolarization is crucial for the generation of an action potential. According to the slides, what is the primary mechanism responsible for initiating repolarization?
A. The continued influx of sodium ions (Na+) through voltage-gated channels.
B. The inactivation of voltage-gated sodium channels combined with the opening of voltage-gated potassium channels.
C. The activation of the sodium-potassium pump to restore ion balance.
D. The influx of chloride ions (Cl-) to counteract the positive charge inside the cell.
B. The inactivation of voltage-gated sodium channels combined with the opening of voltage-gated potassium channels.
T/F : the soma will combine electrical signals received from dendrites to bring them down the axon.
True
Function of axon + what it is
- long, slender projection that conducts electrical impulses away from soma
- responsible for transmitting the neuron’s electrical signals to other cells, either neurons or muscles
Thicker axons transmit ______ signals than thinner signals, which transmit _____ signals.
faster; slower
T/F : the Myelin sheath is made up of chemicals and fat, where the chemicals will further get secreted into the signal
F - just a fatty layer
Two functions of myelin sheath
- Increases electrical impulse speed
- Protects nerve fiber
Name the difference between a motor neuron and a sensory neuron
- Motor - signals from CNS to muscles (voluntary + involuntary)
- Sensory - sensory info from sensory organs –> CNS
T/F : the motor neurons going from CNS to our arms ONLY transmit voluntary actions
False - motor neurons play key role in movement, both involuntary or voluntary