Multiple sclerosis is a disease caused by the loss of the myelin sheath around the axons. What is
the expected effect of losing the myelin sheath on action potential transmission at the
neuromuscular junction?
a. The action potential from the motor neuron is normally transmitted across the synaptic cleft
and into the nearby muscle cell, eventually leading to muscle contraction
b. The action potential from the motor neuron is transmitted across the synaptic cleft and into the
nearby muscle cell, but it fails to propagate within the muscle cell
c. No action potential can be generated in the neuron itself, therefore no action potential ever
reaches the muscle cell
d. The action potential from the motor neuron cannot be transmitted across the synaptic cleft,
therefore the muscle cell never receives any signal from the neuron
e. The action potential, when triggered in the motor neuron, weakens as it propagates down the
axon, such that no signal ever reaches the neuromuscular junction
Solution
Ans: here iam discussing about myelin sheath potential transmission:
Myelin is a fatty white substance that surrounds the axon of some nerve cells, forming an
electrically insulating layer. It is essential for the proper functioning of the nervous system. It is
an outgrowth of a type ofglial cell.
The production of the myelin sheath is called myelination or myelinogenesis. In humans,
myelination begins in the 14th week of fetal development although little myelin exists in the
brain at the time of birth. During infancy, myelination occurs quickly, leading to a child\'s fast
development, including crawling and walking in the first year. Myelination continues through the
adolescent stage of life.
Schwann cells supply the myelin for the peripheral nervous system, whereas oligodendrocytes,
specifically of the interfascicular type, myelinate the axons of the central nervous system. Myelin
is considered a defining characteristic of the (gnathostome) vertebrates, but myelin-like sheaths
have also been seen in some invertebrates, although they are quite different from vertebrate
myelin at the molecular level. Myelin was discovered in 1854 by Rudolf Virchow
a)
b)
c)
Neurons receive information from sensory organs, send information to motor organs, or share
information with other neurons. The process of communicating information is very similar,
whether it is to another neuron or to a muscle or gland cell. However, by far the largest number
of neuronal connections is with other neurons. The rest of this tutorial therefore focuses on inter-
neuronal communication. The transmission of information is accomplished in two ways:
d)
Consequently, an understanding of this synapse leads to an understanding of the others.
Therefore, we will first discuss the process of synaptic transmission at the skeletal
neuromuscular junction.
e)
The somatic peripheral nervous system begins in the spinal chord where axons from peripheral
sensory neurons synapse on CNS sensory neurons and spina.
Multiple sclerosis is a disease caused by the loss of the myelin she.pdf
1. Multiple sclerosis is a disease caused by the loss of the myelin sheath around the axons. What is
the expected effect of losing the myelin sheath on action potential transmission at the
neuromuscular junction?
a. The action potential from the motor neuron is normally transmitted across the synaptic cleft
and into the nearby muscle cell, eventually leading to muscle contraction
b. The action potential from the motor neuron is transmitted across the synaptic cleft and into the
nearby muscle cell, but it fails to propagate within the muscle cell
c. No action potential can be generated in the neuron itself, therefore no action potential ever
reaches the muscle cell
d. The action potential from the motor neuron cannot be transmitted across the synaptic cleft,
therefore the muscle cell never receives any signal from the neuron
e. The action potential, when triggered in the motor neuron, weakens as it propagates down the
axon, such that no signal ever reaches the neuromuscular junction
Solution
Ans: here iam discussing about myelin sheath potential transmission:
Myelin is a fatty white substance that surrounds the axon of some nerve cells, forming an
electrically insulating layer. It is essential for the proper functioning of the nervous system. It is
an outgrowth of a type ofglial cell.
The production of the myelin sheath is called myelination or myelinogenesis. In humans,
myelination begins in the 14th week of fetal development although little myelin exists in the
brain at the time of birth. During infancy, myelination occurs quickly, leading to a child's fast
development, including crawling and walking in the first year. Myelination continues through the
adolescent stage of life.
Schwann cells supply the myelin for the peripheral nervous system, whereas oligodendrocytes,
specifically of the interfascicular type, myelinate the axons of the central nervous system. Myelin
is considered a defining characteristic of the (gnathostome) vertebrates, but myelin-like sheaths
have also been seen in some invertebrates, although they are quite different from vertebrate
myelin at the molecular level. Myelin was discovered in 1854 by Rudolf Virchow
a)
b)
c)
Neurons receive information from sensory organs, send information to motor organs, or share
information with other neurons. The process of communicating information is very similar,
2. whether it is to another neuron or to a muscle or gland cell. However, by far the largest number
of neuronal connections is with other neurons. The rest of this tutorial therefore focuses on inter-
neuronal communication. The transmission of information is accomplished in two ways:
d)
Consequently, an understanding of this synapse leads to an understanding of the others.
Therefore, we will first discuss the process of synaptic transmission at the skeletal
neuromuscular junction.
e)
The somatic peripheral nervous system begins in the spinal chord where axons from peripheral
sensory neurons synapse on CNS sensory neurons and spinal interneurons, and dendrites of
motor neurons receive inputs from descending CNS motor neurons and spinal interneuron
circuits.
