HS 2300 Unit 2 Neuroanatomy Test With
Complete Solution
parts of the cns and pns - ANSWER cns: brain and spinal cord
pns: nerves
functions of the nervous system - ANSWER - Controls and integrates bodily activity
- Reacts to constant changes in external and internal environments
what are the two cells of the nervous system - ANSWER neruon and neuroglia
what are neurons - ANSWER basic unit of the nervous system
- Transmit electrical impulses to one another to communicate information to and from
different areas of the body
- Impulse will start in one neuron and be transmitted to the next neuron in the chain and
so forth until it reaches its target organ or area of the brain
list and describe the two types of neurons - ANSWER 1) multipolar motor neuron: two
poles, directional flow from cell body to periphery
2) pseudounipiolar sensory neuron: cell body in the middle and one pole receiving
information and sending to cell body to go to the cns
what are neuroglia - ANSWER - non-neuronal, non-excitable cells
- support for neurons (structural, nourishment, insulation, pathogen clearance)
- studies say they're involved in a lot of other processes as well
- 5x more abundant than neurons
list and describe the two types of neuroglia - ANSWER 1) oligodendrocyte (cns): several
myelin sheaths around multiple axons, gives structural support, bigger cell connected
to multiple axons
2) schwann cell (pns): forms one myelin sheath around one section of the axon, insulates
the nerve, causes difference in the conduction speed of a neuron `
list the parts of a multipolar motor neuron. what direction does flow occur? - ANSWER
cell body
dendrites
,trigger zone (axon hillock)
axon
axon terminal
myelin sheath + modes of ranvier
FLOW OCCURS FROM PROXIMAL TO DISTAL (CNS TO PNS)
purpose of dendrites - ANSWER - surrounds the cell body
- collects info from other neurons/cells
- other neurons synapse onto a dendrite to pass a signal
trigger zone and axon hillock - ANSWER - axon hillock is where signals summate to
reach threshold and cause action potential
- once threshold is hit, the action potential will travel down the axon
list the parts of a pseudo-unipolar sensory neuron. - ANSWER cell body
peripheral process
trigger zone/axon hillock
central process
axon terminals
peripheral and central processes - ANSWER peripheral: axon is distal to the cell body
and collecting information from receptor organs to bring it back to CNS
central: axon proximal to the cell body, carries away signals to CNS
ganglion - ANSWER collection of cell bodies that from multiple neurons within a nerve
multiple sclerosis (What causes it?) - ANSWER degradation of oligodendrocytes (cns)
- causes more spinal cord and brain related problems
- symptoms vary with no cure
- dying off so the myelin is degrading around the axons
Guillain-barre syndrome (what causes it) - ANSWER degradation of schwann cells (pns)
- causes weakness and paralysis
- causes more motor problems
- typically at younger ages and is reversible because Schwann cell shave ability to work
, on themselves
where is grey matter and white matter in the brain - ANSWER gray matter represents
the cell bodies and is in the cortex and nuclei of the brain (outside)
white mattter reprsents the axons and is more of the tracks, where axons are running,
highways of the brain
why is myelinization important (unmyelinated neuron v myelinated neuron) - ANSWER
myelin has a role in the signal speed
unmyelinated: polarization and movement of action potential is slow because you have
to depolarize at every point along the axon
myelinated: have pockets of myelin sheaths and nodes of ranvier between them, where
depolarization only happen at the nodes, leading to quick impulses
steps in a neuronal synapse - ANSWER 1) Nerve impulse arrives at axon terminal end
bulb of presynaptic neuron
2) Impulse causes calcium channels (voltage gated) to open and calcium ions rush into
end bulb
- Changes the polarization within the end bulb
3) Neurotransmitters are released from the end of the neuron and crosses the synaptic
cleft to trigger opening of sodium channels (voltage gated) on the postsynaptic neuron
- Sodium rushes into postsynaptic neuron and changes its polarization
4) Sodium ions flow into the dendrite of postsynaptic neuron to initiate new nerve
impulse
- Create summation and overwhelms threshold to send signals down
functional divisions of the PNS - ANSWER 1) autonomic
- peripheral innervations to visceral organs and glands, involuntary
- visceral afferent (sensory from organs) and efferent (motor to organs)
2) somatic
- peripheral innverations to other tissues, voluntary
- generally sensory and voluntary motor
autonomic nervous system is further divided into ___ and ___ nervous system - ANSWER
parasympathetic and sympathetic
parasympathetic nervous system - ANSWER - feed and breed, rest and digest
Complete Solution
parts of the cns and pns - ANSWER cns: brain and spinal cord
pns: nerves
functions of the nervous system - ANSWER - Controls and integrates bodily activity
- Reacts to constant changes in external and internal environments
what are the two cells of the nervous system - ANSWER neruon and neuroglia
what are neurons - ANSWER basic unit of the nervous system
- Transmit electrical impulses to one another to communicate information to and from
different areas of the body
- Impulse will start in one neuron and be transmitted to the next neuron in the chain and
so forth until it reaches its target organ or area of the brain
list and describe the two types of neurons - ANSWER 1) multipolar motor neuron: two
poles, directional flow from cell body to periphery
2) pseudounipiolar sensory neuron: cell body in the middle and one pole receiving
information and sending to cell body to go to the cns
what are neuroglia - ANSWER - non-neuronal, non-excitable cells
- support for neurons (structural, nourishment, insulation, pathogen clearance)
- studies say they're involved in a lot of other processes as well
- 5x more abundant than neurons
list and describe the two types of neuroglia - ANSWER 1) oligodendrocyte (cns): several
myelin sheaths around multiple axons, gives structural support, bigger cell connected
to multiple axons
2) schwann cell (pns): forms one myelin sheath around one section of the axon, insulates
the nerve, causes difference in the conduction speed of a neuron `
list the parts of a multipolar motor neuron. what direction does flow occur? - ANSWER
cell body
dendrites
,trigger zone (axon hillock)
axon
axon terminal
myelin sheath + modes of ranvier
FLOW OCCURS FROM PROXIMAL TO DISTAL (CNS TO PNS)
purpose of dendrites - ANSWER - surrounds the cell body
- collects info from other neurons/cells
- other neurons synapse onto a dendrite to pass a signal
trigger zone and axon hillock - ANSWER - axon hillock is where signals summate to
reach threshold and cause action potential
- once threshold is hit, the action potential will travel down the axon
list the parts of a pseudo-unipolar sensory neuron. - ANSWER cell body
peripheral process
trigger zone/axon hillock
central process
axon terminals
peripheral and central processes - ANSWER peripheral: axon is distal to the cell body
and collecting information from receptor organs to bring it back to CNS
central: axon proximal to the cell body, carries away signals to CNS
ganglion - ANSWER collection of cell bodies that from multiple neurons within a nerve
multiple sclerosis (What causes it?) - ANSWER degradation of oligodendrocytes (cns)
- causes more spinal cord and brain related problems
- symptoms vary with no cure
- dying off so the myelin is degrading around the axons
Guillain-barre syndrome (what causes it) - ANSWER degradation of schwann cells (pns)
- causes weakness and paralysis
- causes more motor problems
- typically at younger ages and is reversible because Schwann cell shave ability to work
, on themselves
where is grey matter and white matter in the brain - ANSWER gray matter represents
the cell bodies and is in the cortex and nuclei of the brain (outside)
white mattter reprsents the axons and is more of the tracks, where axons are running,
highways of the brain
why is myelinization important (unmyelinated neuron v myelinated neuron) - ANSWER
myelin has a role in the signal speed
unmyelinated: polarization and movement of action potential is slow because you have
to depolarize at every point along the axon
myelinated: have pockets of myelin sheaths and nodes of ranvier between them, where
depolarization only happen at the nodes, leading to quick impulses
steps in a neuronal synapse - ANSWER 1) Nerve impulse arrives at axon terminal end
bulb of presynaptic neuron
2) Impulse causes calcium channels (voltage gated) to open and calcium ions rush into
end bulb
- Changes the polarization within the end bulb
3) Neurotransmitters are released from the end of the neuron and crosses the synaptic
cleft to trigger opening of sodium channels (voltage gated) on the postsynaptic neuron
- Sodium rushes into postsynaptic neuron and changes its polarization
4) Sodium ions flow into the dendrite of postsynaptic neuron to initiate new nerve
impulse
- Create summation and overwhelms threshold to send signals down
functional divisions of the PNS - ANSWER 1) autonomic
- peripheral innervations to visceral organs and glands, involuntary
- visceral afferent (sensory from organs) and efferent (motor to organs)
2) somatic
- peripheral innverations to other tissues, voluntary
- generally sensory and voluntary motor
autonomic nervous system is further divided into ___ and ___ nervous system - ANSWER
parasympathetic and sympathetic
parasympathetic nervous system - ANSWER - feed and breed, rest and digest
