BIOD 152 Module 1 Exam with verified questions and
answers latest updated
true/false: axons can't regenerate in pns - false
true/false: myelin sheath is continuous and has no gaps - false
types of support neuroglial in cns - ependymal, oligodendrocytes, astrocytes, microglial
ependymal cells - produce cerebrospinal fluid
Oligodendrocytes - insulation
Astrocytes - form blood brain barrier
_____ neurons send messages from the central nervous system to the peripheral. -
motor
neuroglia cells - support neurons
PNS neuroglia - satellite cells and schwann cells
microglial cells - remove waste products
action potential - a neural impulse; a brief electrical charge that travels down an axon
steps of action potential - resting state, depolarization, repolarization, hyperpolarization
Describe what happens to the charges on the axon cell membrane during depolarization
and what causes this to happen. - Sodium gates open and sodium rushes into the axon
and the inside becomes more positive than the outside causing the membrane potential
to become more positive.
Describe what happens to the charges on the axon cell membrane during repolarization
and what causes this to happen. - The sodium gates close and potassium gates open
, allowing potassium to rush out of the axon. This returns a negative charge to the inside
of the axon re-establishing the negative potential.
describe what happens during afterpolarization - The potassium gates that open during
repolarization are slow to close and there is an afterpolarization undershoot of the
potential.
What causes the difference in intensity of a sensation? - Due to the number of neurons
stimulated and the frequency with which they are stimulated.
True or False: An impulse from a neuron moves in both directions. - false
What is meant by neuron signals being electrochemical in nature? - The signal moves
from electrical (through the neuron) to chemical (in the synapse) to electrical again once
the signal reaches the next neuron.
What is the chemical portion of neuron signal transmission? - neurotransmitters
How is an impulse passed from one nerve cell to another? - There is a minute fluid-filled
space, called a synapse, between the axon terminal of the sending neuron and the
dendrite of the receiving neuron. When a nerve impulse reaches the end of an axon,
neurotransmitters are released into the synapse.
What prevents continuous stimulation of a nerve synapse and how is this
accomplished? - The short existence of neurotransmitters in the synapse prevents
continuous stimulation.
What neurotransmitter helps regulate emotional responses and muscle tone? -
dopamine
What neurotransmitter is found at the neuromuscular junctions? - acetylcholine
Once ACh is released in the NMJ, what happens to cause muscle contraction to occur?
- Acetylcholine binds to receptors on the muscle fiber that cause sodium channels to
open. Sodium rushes into the muscle cell, triggering an action potential which reaches
the sarcoplasmic reticulum
reflex - a simple, automatic response to a sensory stimulus, such as the knee-jerk
response
Sensory information travels into the spinal cord via the _______ of a nerve - dorsal root
answers latest updated
true/false: axons can't regenerate in pns - false
true/false: myelin sheath is continuous and has no gaps - false
types of support neuroglial in cns - ependymal, oligodendrocytes, astrocytes, microglial
ependymal cells - produce cerebrospinal fluid
Oligodendrocytes - insulation
Astrocytes - form blood brain barrier
_____ neurons send messages from the central nervous system to the peripheral. -
motor
neuroglia cells - support neurons
PNS neuroglia - satellite cells and schwann cells
microglial cells - remove waste products
action potential - a neural impulse; a brief electrical charge that travels down an axon
steps of action potential - resting state, depolarization, repolarization, hyperpolarization
Describe what happens to the charges on the axon cell membrane during depolarization
and what causes this to happen. - Sodium gates open and sodium rushes into the axon
and the inside becomes more positive than the outside causing the membrane potential
to become more positive.
Describe what happens to the charges on the axon cell membrane during repolarization
and what causes this to happen. - The sodium gates close and potassium gates open
, allowing potassium to rush out of the axon. This returns a negative charge to the inside
of the axon re-establishing the negative potential.
describe what happens during afterpolarization - The potassium gates that open during
repolarization are slow to close and there is an afterpolarization undershoot of the
potential.
What causes the difference in intensity of a sensation? - Due to the number of neurons
stimulated and the frequency with which they are stimulated.
True or False: An impulse from a neuron moves in both directions. - false
What is meant by neuron signals being electrochemical in nature? - The signal moves
from electrical (through the neuron) to chemical (in the synapse) to electrical again once
the signal reaches the next neuron.
What is the chemical portion of neuron signal transmission? - neurotransmitters
How is an impulse passed from one nerve cell to another? - There is a minute fluid-filled
space, called a synapse, between the axon terminal of the sending neuron and the
dendrite of the receiving neuron. When a nerve impulse reaches the end of an axon,
neurotransmitters are released into the synapse.
What prevents continuous stimulation of a nerve synapse and how is this
accomplished? - The short existence of neurotransmitters in the synapse prevents
continuous stimulation.
What neurotransmitter helps regulate emotional responses and muscle tone? -
dopamine
What neurotransmitter is found at the neuromuscular junctions? - acetylcholine
Once ACh is released in the NMJ, what happens to cause muscle contraction to occur?
- Acetylcholine binds to receptors on the muscle fiber that cause sodium channels to
open. Sodium rushes into the muscle cell, triggering an action potential which reaches
the sarcoplasmic reticulum
reflex - a simple, automatic response to a sensory stimulus, such as the knee-jerk
response
Sensory information travels into the spinal cord via the _______ of a nerve - dorsal root
