Chapter 44
1) What are the two main types of cells in the nervous system?
a) Glial Cells: Act to help protect the nervous system.
b) Neurons: Send and receive signals throughout the body.
2) What are action potentials and which cells use them?
a) An action potential is a signal that is sent down a neuron. Glial cells do not use
action potentials.
3) What are the general structural features of a neuron and what is the overall function of
each structure?
a) Dendrites: receive information from other neurons
b) Cell Body: contains nucleus and most cell organelles
c) Axon Hillock: integrates information and generates AP
d) Axon: conducts AP away from cell body
e) Axon Terminal: synapse of target cell
4) What is a synapse?
a) Synapse is the transfer of information between a presynaptic and postsynaptic
cell.
5) What is the difference between a presynaptic cell and a postsynaptic cell?
a) A presynaptic cell is a neuron which send a signal and the postsynaptic cell is a
neuron which receives the signal. Both types of cells have the ability to send and
receive signals, however, in relation to each other, they act as described above.
6) What two types of synapses are there?
a) Electrical: AP passes between 2 neurons (does not have synapse)
b) Chemical: neurotransmitters is as a chemical messenger molecules (has
synapse)
7) What function do oligodendrocytes and Schwann cells share?
a) Myelin sheath is made up of oligodendrocytes wrapped around the CNS axons
and Schwann cells wrapped around the PNS axons.
8) How are these glial cells different?
a) Glial cells do not have chemical synapses and cannot conduct AP.
9) What is the function of myelin?
a) Myelin acts to speed up the AP moving down the axon,
10) What is the blood brain barrier and why is it important?
a) Blood brain barrier is a barrier between the blood in brain which makes it very
difficult for chemicals and cells to move between the blood and brain in order to
, protect the brain. The capillaries in the brain (CNS) do not have pores for ions to
move through.
11) What are 6 specific functions of an astrocyte?
a) Regulate environment through blood brain barriers (BBB)
b) Nourish neurons with glycogen
c) Signaling (release of NT)
d) Reuptake of NT
e) Repair and regenerate neurons
f) Communicate changes in blood
g) Regulation of potassium in extracellular brain
12) What is meant by a tripartite synapse?
a) Regulating the signal by NT release
13) What are the 3 functional categories of neurons in the neural network and what is the
function of each?
a) Sensory (afferent)
b) Motor (efferent)
c) Interneuron
14) What is the general organization of a vertebrate nervous system?
In order:
- Nerve net (can only perform simple actions of contraction and relaxation
- Ganglia (forms bundles of nervous cells that form a brain like structure at the
head)
- Brain (sends information to neurons received from PNS
15) What is membrane potential and how is this potential maintained?
a) Membrane potential is the charge of the membrane of the axon of neurons.
16) What is the resting potential?
a) Resting potential in neuron is between -40mV and -90mV which is controlled by
the sodium potassium pump.
17) How does the resting potential provide the necessary force to cause action potentials?
a) The resting potential is negative because there are more sodium outside of the
cell than inside. Slowly, sodium ions will start to gradually move into the cell, until
threshold is reached. Then, they flood in, causing the membrane potential to
increase dramatically, thus creating an AP.
18) What is voltage and how is this accomplished in cells?
a) Voltage is a charge in the membrane. Voltage is created in cells from the proton
gradient created from the sodium potassium pump.
1) What are the two main types of cells in the nervous system?
a) Glial Cells: Act to help protect the nervous system.
b) Neurons: Send and receive signals throughout the body.
2) What are action potentials and which cells use them?
a) An action potential is a signal that is sent down a neuron. Glial cells do not use
action potentials.
3) What are the general structural features of a neuron and what is the overall function of
each structure?
a) Dendrites: receive information from other neurons
b) Cell Body: contains nucleus and most cell organelles
c) Axon Hillock: integrates information and generates AP
d) Axon: conducts AP away from cell body
e) Axon Terminal: synapse of target cell
4) What is a synapse?
a) Synapse is the transfer of information between a presynaptic and postsynaptic
cell.
5) What is the difference between a presynaptic cell and a postsynaptic cell?
a) A presynaptic cell is a neuron which send a signal and the postsynaptic cell is a
neuron which receives the signal. Both types of cells have the ability to send and
receive signals, however, in relation to each other, they act as described above.
6) What two types of synapses are there?
a) Electrical: AP passes between 2 neurons (does not have synapse)
b) Chemical: neurotransmitters is as a chemical messenger molecules (has
synapse)
7) What function do oligodendrocytes and Schwann cells share?
a) Myelin sheath is made up of oligodendrocytes wrapped around the CNS axons
and Schwann cells wrapped around the PNS axons.
8) How are these glial cells different?
a) Glial cells do not have chemical synapses and cannot conduct AP.
9) What is the function of myelin?
a) Myelin acts to speed up the AP moving down the axon,
10) What is the blood brain barrier and why is it important?
a) Blood brain barrier is a barrier between the blood in brain which makes it very
difficult for chemicals and cells to move between the blood and brain in order to
, protect the brain. The capillaries in the brain (CNS) do not have pores for ions to
move through.
11) What are 6 specific functions of an astrocyte?
a) Regulate environment through blood brain barriers (BBB)
b) Nourish neurons with glycogen
c) Signaling (release of NT)
d) Reuptake of NT
e) Repair and regenerate neurons
f) Communicate changes in blood
g) Regulation of potassium in extracellular brain
12) What is meant by a tripartite synapse?
a) Regulating the signal by NT release
13) What are the 3 functional categories of neurons in the neural network and what is the
function of each?
a) Sensory (afferent)
b) Motor (efferent)
c) Interneuron
14) What is the general organization of a vertebrate nervous system?
In order:
- Nerve net (can only perform simple actions of contraction and relaxation
- Ganglia (forms bundles of nervous cells that form a brain like structure at the
head)
- Brain (sends information to neurons received from PNS
15) What is membrane potential and how is this potential maintained?
a) Membrane potential is the charge of the membrane of the axon of neurons.
16) What is the resting potential?
a) Resting potential in neuron is between -40mV and -90mV which is controlled by
the sodium potassium pump.
17) How does the resting potential provide the necessary force to cause action potentials?
a) The resting potential is negative because there are more sodium outside of the
cell than inside. Slowly, sodium ions will start to gradually move into the cell, until
threshold is reached. Then, they flood in, causing the membrane potential to
increase dramatically, thus creating an AP.
18) What is voltage and how is this accomplished in cells?
a) Voltage is a charge in the membrane. Voltage is created in cells from the proton
gradient created from the sodium potassium pump.
