BIO 161 EXAM 3 PSU QUESTIONS AND ANSWERS
A+ GRADED
Secretion
converting an electrical signal to a chemical signal
-allowing neurons to communicate with each other
presynaptic neuron
sending neuron
postsynaptic neuron
receiving neuron
Where are neurotransmitters synthesized?
How are they transported?
-cell body
-in vesicles to axon terminals
Neurotransmitters are derived from?
amino acids like dopamine or norepinephrine
-some can be gaseous or made of other chemicals (acetylcholine)
summation
total or sum of all local potential changes at the synapses of a postsynaptic cell
excitatory postsynaptic potential (EPSP)
neurotransmitters cause depolarization
inhibitory postsynaptic potential (IPSP)
neurotransmitters cause hyperpolarization
temporal summation
one presynaptic neuron sending multiple signals
spatial summation
multiple presynaptic neurons send signals
how does the brain detect the strength of a stimulus?
the frequency (how often action potentials fire per unit of time) is interpreted in the brain
as the strength of the stimulus
- stronger stimulus = more AP
CNS
brain and spinal cord
-houses cell bodies and axons
PNS
neurons traveling or leaving from the CNS
-100s of axons are grouped together in neurons
-ganglia
Ganglion
found in the sensory pathway; where the cell bodies of afferent neurons are located
PNS- Special Sensory
vision, hearing/balance, smell, tase
, PNS- somatic sensory
from muscles, bones, and skin
-monitored by receptors( specialized afferent neurons) or receptor cells (specialized
cells that synapse w afferent neurons)
-stimulus will cause gated-channels to open and depolarize the neuron
PNS- visceral sensory
from organs
PNS- somatic motor
voluntary control
-skeletal muscles
PNS- autonomic motor
involuntary control
-hear rate, breathing, smooth/cardiac muscle, glands
Proprioceptors
neurons that send signals to the brain about the stretch of muscles, tendons, and joints
(telling brain about movement of our body)
-EX dont need to look at toes to clench them
autonomic sensory receptors
- Also called "visceral sensory" receptors, because input is from viscera (internal
organs)
- Many of these receptors are chemoreceptors (sense chemicals)
dorsal horn
interneurons, synapse with sensory neurons
lateral horn
autonomic motor neuron cell bodies
ventral horn
somatic motor neuron cell bodies
dorsal root
axons of sensory neurons
ventral root
axons of motor neurons
Polio Virus
-Destroys ventral horn neurons
-Vaccine developed in 1955
-life threatening bc the diaphragm is voluntary control so polio goes after the sensory
neurons in ventral horn so that they cant breathe anymore on their own
Visceral motor division involves
2 efferent neurons, ganglia and multiple targets
-spinal cord to ganglion to target issue
somatic motor division involves
one efferent neuron traveling to a target
-axon terminal can branch to excite multiple parts of a muscle, but there is one main
target (effector)
divergence
one signal from CNS can alter the function of many organs
-one cell causes many outputs
A+ GRADED
Secretion
converting an electrical signal to a chemical signal
-allowing neurons to communicate with each other
presynaptic neuron
sending neuron
postsynaptic neuron
receiving neuron
Where are neurotransmitters synthesized?
How are they transported?
-cell body
-in vesicles to axon terminals
Neurotransmitters are derived from?
amino acids like dopamine or norepinephrine
-some can be gaseous or made of other chemicals (acetylcholine)
summation
total or sum of all local potential changes at the synapses of a postsynaptic cell
excitatory postsynaptic potential (EPSP)
neurotransmitters cause depolarization
inhibitory postsynaptic potential (IPSP)
neurotransmitters cause hyperpolarization
temporal summation
one presynaptic neuron sending multiple signals
spatial summation
multiple presynaptic neurons send signals
how does the brain detect the strength of a stimulus?
the frequency (how often action potentials fire per unit of time) is interpreted in the brain
as the strength of the stimulus
- stronger stimulus = more AP
CNS
brain and spinal cord
-houses cell bodies and axons
PNS
neurons traveling or leaving from the CNS
-100s of axons are grouped together in neurons
-ganglia
Ganglion
found in the sensory pathway; where the cell bodies of afferent neurons are located
PNS- Special Sensory
vision, hearing/balance, smell, tase
, PNS- somatic sensory
from muscles, bones, and skin
-monitored by receptors( specialized afferent neurons) or receptor cells (specialized
cells that synapse w afferent neurons)
-stimulus will cause gated-channels to open and depolarize the neuron
PNS- visceral sensory
from organs
PNS- somatic motor
voluntary control
-skeletal muscles
PNS- autonomic motor
involuntary control
-hear rate, breathing, smooth/cardiac muscle, glands
Proprioceptors
neurons that send signals to the brain about the stretch of muscles, tendons, and joints
(telling brain about movement of our body)
-EX dont need to look at toes to clench them
autonomic sensory receptors
- Also called "visceral sensory" receptors, because input is from viscera (internal
organs)
- Many of these receptors are chemoreceptors (sense chemicals)
dorsal horn
interneurons, synapse with sensory neurons
lateral horn
autonomic motor neuron cell bodies
ventral horn
somatic motor neuron cell bodies
dorsal root
axons of sensory neurons
ventral root
axons of motor neurons
Polio Virus
-Destroys ventral horn neurons
-Vaccine developed in 1955
-life threatening bc the diaphragm is voluntary control so polio goes after the sensory
neurons in ventral horn so that they cant breathe anymore on their own
Visceral motor division involves
2 efferent neurons, ganglia and multiple targets
-spinal cord to ganglion to target issue
somatic motor division involves
one efferent neuron traveling to a target
-axon terminal can branch to excite multiple parts of a muscle, but there is one main
target (effector)
divergence
one signal from CNS can alter the function of many organs
-one cell causes many outputs
