The muscle weakness of myasthenia gravis results from loss of acetylcholine receptors in the end-plate membrane. the motor neuron action potential being too small to shock the muscle fibers. insufficient acetylcholine release from presynaptic vesicles. excessive acetylcholinesterase that destroys the neurotransmitter. All of the answers probably contribute to the muscle weakness.

Answers

Answer 1

Answer:

The correct answer is ''loss of acetylcholine receptors in the end-plate membrane.''

Explanation:

Myasthenia gravis represents a human autoimmune disease. The neuromuscular junction abnormalities that occur in this disease are due to antibody-mediated processes. A reduction in the number of functional acetylcholine receptors on the postsynaptic membrane was established to contribute to the physiological abnormalities of myasthenia gravis. The reduction in receptors is due to immunological alterations directed against the acetylcholine receptor. Normally, when acetylcholine binds to its receptor, it opens allowing the rapid entry of cations, especially sodium. With this, the depolarization of the postsynaptic region of the muscle fiber occurs. Although acetylcholine is normally released in myasthenia gravis, it is not capable of causing an action potential in the muscle sufficient to initiate or weaken contraction. In patients with myasthenia gravis, failure to activate muscles is responsible for myasthenic fatigue. Most patients have elevated serum titers of antireceptor antibodies, which in turn accelerate receptor degradation.


Related Questions

which best describes a bacterium

Answers

a unicellular prokaryote

Answer:

Bacteria

Bacteria are a type of biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among the first life forms to appear on Earth, and are present in most of its habitats. Wikipedia

Explanation:

a member of a large group of unicellular microorganisms which have cell walls but lack organelles and an organized nucleus, including some that can cause disease.

What energy using-process helps to cool the body

Answers

Answer:

Convection

Explanation:

convection is the process of losing heat through the movement of air or water molecules

What type of unconformity did Hutton see at Siccar Point and how was this uniformity formed?

Answers

Answer:

Hutton's Unconformity

At Siccar Point, during the lower Silurian Llandovery epoch around 435 million years ago, thin beds of fine-grained mudstone were laid down gradually deep in the Iapetus Ocean, alternating with thicker layers of hard greywacke formed when torrents swept unsorted sandstone down the continental slope. Siccar Point is a rocky promontory in the county of Berwickshire on the east coast of Scotland. It is famous in the history of geology for Hutton's Unconformity found in 1788, which James Hutton regarded as conclusive proof of his uniformitarian theory of geological development.

Hyperscience is...
1. Genetically modifying plants.
2. quickly producing new plant varieties.
3. growing plants using new technology.
4. responding to the horticulture market.

Answers

Answer:

2

Explanation:

3. What is one thing that can be done to help improve areas that produce a lot of runoff?

Answers

Answer: hi, im here to help :3

so, you can either use plants, use pesticides and fertilizers less often or the one thing i know is consider a rain barrel.

list and explain the advantages of 5 farming systems

Answers

https://agriinfo.in/benefits-or-advantages-of-integrated-farming-system-670/

Determine if the following statement is true or false and why: All organisms make their own food, but plants are the only kind to do so using sunlight. A. False, not all organisms can make their own food, only plants and some bacteria. B. False, all organisms can use sunlight to make food. C. False, plants cannot make their own food. D. True

Answers

Answer:

A. False, not all organisms can make their own food, only plants and some bacteria.

Explanation:

It's right

The description of the statement whether it is true or false is described below:

All organisms make their own food, but plants are the only kind to do so using sunlight. (False).Not all organisms can make their own food, only plants, and some bacteria. (True). All organisms can use sunlight to make food. (False). Plants cannot make their own food. (False).

How do plants prepare their own food?

Plants prepare their own food with the process of photosynthesis which utilizes carbon dioxide and water and synthesizes glucose in the presence of sunlight.

Plants, some photosynthetic algae, and some bacteria prepare their own food with the help of sunlight. They have a photosystem that captures the energy of sunlight in the food production mechanism.

Therefore, it is well described above.

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Why the leading and lagging strand of DNA synthesize through different mechanism?What factor determine these differences

Answers

Answer:

ناسحتصس حساب سكسوسشت كمسنصو م٩سس

A common genetic mutation that lowers levels of the enzyme cathepsin C severely reduces a person’s ability to ward off periodontitis, or gum disease. The enzyme triggers immunological reactions that destroy diseased cells and eliminate infections
in the mouth. But researchers are developing ways to restore the enzyme to normal levels. Once that happens, we will be able to eliminate periodontitis.
Which one of the following is an assumption on which the argument depends?
(A) Restoring cathepsin C to normal levels is the only way to eliminate periodontitis.
(B) Genetic mutation is the only cause of lowered levels of cathepsin C.
(C) Researchers will soon succeed in finding means of restoring cathepsin C to normal levels.
(D) Persons who do not have the genetic mutation that lowers levels of cathepsin C do not get gum disease.
(E) A person whose cathepsin C level has been restored to normal will not suffer from periodontitis.

Answers

Answer:

(E) A person whose cathepsin C level has been restored to normal will not suffer from periodontitis.

Explanation:

Considering the fact that there may be some other causes of periodontitis aside from the lowered levels of the enzyme.

Therefore, should there be some other causes of periodontitis, hence, it can be concluded the process of restoring the enzyme to normal levels might not be sufficient for eliminating periodontitis.

Hence, the author's argument is solely based on this assumption, and option. Hence, option (E) is the correct answer.

The teacher was unaware of the difference between suspension feeding and predation. The teacher thought that providing live copepods (2 mm long) and feeder fish (2 cm long) would satisfy the dietary needs of all of the organisms. Consequently, which two organisms would have been among the first to starve to death (assuming they lack photosynthetic endosymbionts)

Answers

Answer:

The correct answer is - Biwalves and sponges.

Explanation:

Suspension feeders are the organisms that depend on, for the dietary needs or nutriton, materials suspended in the water. The materials that are suspended are living organisms such as phytoplankton and zooplankton.

Biwalves and sponges are suspended or filter feeders and not predators like other organisms so providing copepods will not complete their food requirement and they will starve to death.

The correct answer is - Biwalves and sponges.

What connections are there between the changing surface of the Earth and the evolution of life?

Please help!!

Answers

New research has uncovered a direct link between changes in the earth's crust three billion years ago and the introduction of free oxygen to the atmosphere. Without these changes, oxygen could have been suppressed in earth's crust forever, so the findings help explain the emergence of life on our planet.

Evolution is the modification of heritable traits. The change in the earth's surface is directly linked to evolution as the formation of the species, abiotic factors, and gases happened due to changes.

What is evolution?

Evolution is the adaptation and survival of the modified organism due to changes in favorable environmental conditions. It is an important factor governed by natural selection.

The evolution and the change in the earth's surface are interconnected as the changes in the earth's crust made the presence of the living beings possible. The conditions at early times were unfavorable that underwent many changes till the present scenario.

The atmosphere and crust were unfavorable for the living beings that got changed and improved with oxygen quality, water, and the crust for the organism to exist, survive and reproduce to continue their lineage.

Therefore, evolution is linked to changing the earth's surface.

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What is the difference between sediments deposited in outwash and sediments deposited in moraines?

1. Sediments in the outwash are larger.
2. Sediments in the outwash are sorted
3. Sediments in the outwash are more angular
4. Sediments in the outwash are older.

Answers

Answer:

2. Sediments in the outwash are sorted

The difference between sediments deposited in outwash and sediments deposited in moraines is that-Sediments in the outwash are sorted. Therefore, the correct option is 2.

What is the sediment of outwash and moraines?

Outwash is the sediment that is carried away from a glacier by meltwater and deposited in streams and rivers. This sediment is typically well-sorted, which means that particles are relatively uniform in size, shape, and composition.

Moraines are piles of unsorted sediment that are left behind by a glacier as it retreats. This sediment is typically a mix of different particle sizes, shapes, and compositions.

The glacier's movement is not strong enough to sort the sediment of moraines, so it remains unsorted. Therefore, the correct option is 2.

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Which correctly describes Earth's population over the centuries?
O A. It has risen steadily.
B. It has remained steady overall.
C. It has risen at an increasing rate.
O D. It has declined in some places due to migration.
SUBM

Answers

C

It has risen at an increasing rate throughout time. This rate hasn’t been steady due to many reasons. See the attached photo for details.

Hope this helps! Please make me the brainliest, it’s not necessary but appreciated, I put a lot of effort and research into my answers. Have a good day, stay safe and stay healthy.

Earth's population over the centuries has risen at an increasing rate. So, the correct option is C.

How the population of Earth is increasing?

This sharp increase in population has been primarily caused by an increase in the proportion of individuals reaching breeding age, the gradual extension of human life expectancy, growing urbanization, and quickening migration. This expansion has been accompanied by significant changes in the fertility rate.

One of the key reasons for India's population expansion is a drop in death rates brought on by better medical services and a steady birth rate. The widespread illiteracy in India makes people believe that "children are god's blessings," which makes them opposed to the idea of "family planning." Earth's population over the centuries has risen at an increasing rate.

Therefore, the correct option is C.

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Where do convection currents occur atmophere

Answers

Answer:

Convection takes place in the atmosphere, in the oceans, and in Earth's molten subcrustal asthenosphere.

Explanation:

According to the cell theory, which describes cells?

Answers

Answer:

Living organisms are not created spontaneously

Explanation:

All living organisms are made out of cells, cells are the basic unit of life, and cells come from preexisting cells

To test how fertilizer affects tomato plants, a farmer divided a field of young
tomato plants into 10 plots of equal size. The farmer then put fertilizer on half
of the plots and no fertilizer on the other half of the plots. What is the control
group in this experiment?

Answers

Answer:

The plots with no fertilizer

Explanation:

In an experiment, the control group is used as a comparison for the experimental group (the group being actively changed and observed).

So, in this experiment, the control group is the plots with no fertilizer.

This acts as a good control group because it provides a normal standard to show the effect of fertilizer on the tomato plants.

So, the control group in this experiment are the plots with no fertilizer.

What element is commonly used to date archaeological or geological materials?

Select one:
a. Phosphorus
b. Nitrogen
c. Hydrogen
d. Carbon

Answers

Answer:

D. Carbon

Explanation:

Carbon is the element that is commonly used to date fossils and ancient materials.

This is called carbon dating, where the concentrations of different carbon isotopes are used to determine the age of ancient materials.

Carbon dating has been used for almost 70 years and is still commonly used to date fossils.

So, the correct answer is D. Carbon

Geologists commonly use radiometric dating methods, based on the natural radioactive decay of certain elements such as potassium and carbon, as reliable clocks to date ancient events.
Answer:
Carbon
Hope it helps

ruth is presenting the feedback model to her class help her complete the statements

Answers

Answer:

Feedback models are tools that provides specific, concise, and clear feedback for a particular thing.

Explanation:

Feedback models are tools that provides specific, concise, and clear feedback for the organization so that an organization can make useful changes which is necessary for the organization growth and development. There is high need of this feedback model which helps us to know about the specific areas where one needs to improve performances in order to work more effectively.

If you were running an experiment to determine the color of light at which beans grew best, what would be the variable?
Group of answer choices

the number of beans plants in the experiment

the amount of water you give the beans

the color of the light under which each bean is grown

the height to which you let the sprouts grow

Answers

Answer:

The number of beans in the experiment

Explanation:

I hope it helps choose me the brainer

Two populations of frog species are separated by a group of mountains. A tunnel is built through the mountains, through which some of the frogs are able to safely navigate, and attempt mating with frogs on the other side of the tunnel. However, their heroic feat is for nothing, because their offspring all produce sterile young. This scenario is an example of

Answers

Answer:

Post reproductive isolation → Hybrid sterility

Explanation:

The biological concept of species states that individuals of a species can not mate and reproduce with individuals of another species. But if they get to reproduce, the progeny will not be viable or fertile. There will not be any reproductive success.

There are different reproductive isolation mechanisms, which are barriers that inhibit or interrupt the genetic flow between different species.

Reproductive barriers are isolation mechanisms that prevent mating between two or more species. The prezygotic mechanism avoids fertilization between individuals of different species, while the postzygotic mechanism impedes the zygote to develop and reach the adult stage.

Postzygotic mechanisms or barriers include

Hybrid inviability,  Hybrid sterility, Hybrid decreased viability or fertility, Cytoplasmic interactions.

In the exposed example, it seems that the mountains separating the frogs´ populations made a place for the development of postzygotic barriers, specifically hybrid sterility. Frogs from one population get to mate and produce offspring with the frogs of the other population, but their progeny is sterile.  

If something is tucked in, this means it is
covered with shells
folded up and small
immersed in water
in a snug or hidden place

Answers

Answer:

in a snug or hidden place

A pesticide tolerance refers to the a. amount of a pesticide that can be applied to a food and how much of the pesticide that is permitted to remain on the food in the marketplace. b. ability of the liver to detoxify a pesticide c. toxicity of the pesticide in the laboratory d. number of pests that are killed by a selected dose of the pesticide

Answers

Answer:

a. amount of a pesticide that can be applied to a food and how much of the pesticide that is permitted to remain on the food in the marketplace.

Explanation:

Pesticides are chemical substances used to get rid of or kill pests that attack crops on farmlands. These pesticides, although help the farmer to get rid of his pest problem and likely have an increase in yield, are dangerous to human and animal health if consumed.

As set up by the Environmental Protection Agency (EPA), pesticide tolerance is the amount or quantity of pesticide chemical that can be applied to a food and how much of the pesticide that is permitted to remain on the food in the marketplace.

Which of the following is NOT an argument used against genectically modified food?
(A) It is new technology that unnaturally breaks genetic barriers between species
(B) It might cause allergic reactions
(C) Humans should not be designers of life
(D) All of these arguments are used

Answers

Answer:

(D) All of these arguments are used

Which concept is illustrated in the flowchart below?

Overproduction arrow pointing Struggle for survival arrow pointing Survival of the fittest arrow pointing Changes in traits of species

Dynamic equilibrium
Genetic manipulation
Material cycles
Natural selection

Answers

Answer:

Natrual selection

Explanation:

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The concept illustrated in the flowchart is Natural selection. The correct option is 4.

What is natural selection?

Natural selection is the process by which species evolve over time as the prevalence of certain traits increases or decreases in a population.

Natural selection, the mechanism by which species evolve over time, is depicted in the flowchart.

Overproduction of offspring causes competition for limited resources, resulting in a struggle for survival.

Based on their inherited characteristics, some people are better equipped to survive and reproduce than others.

These people are said to be "fit," and they are more likely to pass on their positive traits to their children. These advantageous traits become more common in the population over time, causing changes in the species as a whole.

Thus, the correct option is 4.

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Your question seems incomplete, the probable complete question is:

A person who has allergies has a compromised immune system because the body's immune system

attacks its healthy cells.

overreacts to an antigen.

steals nutrients from healthy cells.

responds to mutagens.

Answers

Answer:

overreacts to an antigen

the answer is overreacts to an antigen

The purpose of Mendel's experiments with dihybrid crosses was to determine
whether:
A. an F2 generation could be produced from the Fi offspring.
B. one of two traits could be transformed by DNA.
O c. one trait would affect how another is inherited.
D. traits are controlled by more than one gene.

Answers

Answer:

C. one trait would affect how another is inherited

Explanation:

If there is a high concentration of carbon dioxide in the blood stream, it will diffuse into the _______
A. Hemoglobin
B. Alveolus
C. Capillary
D. Protein Channel

Answers

If there is a high concentration of carbon dioxide in the bloodstream, it will diffuse into the Capillary (Option C).

What are pulmonary capillaries?

Pulmonary capillaries are small blood vessels that are able to perform gas exchange.

The process of gas exchange in the respiratory system is fundamental for carrying out cellular respiration by obtaining oxygen from the air.

In conclusion, the high concentration of CO2 in the bloodstream diffuses into the capillaries (Option C).

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What is the control for “which bait works best for a homemade fly trap?”

Answers

Answer:

A glass of water or an empty cup

Explanation:

If no flies are attracted, that means your experiment is not flawed.

Name two organs that are made up of all four tissues?

Answers

i believe the heart and lungs are 2 organs made up of 2 or more tissues

Heart and lungs are the  two organs that are made up of all four tissues.     secretion, movement, strength, excretion and communication are the main functions of tissues.

What are tissues in human body?

Tissues are the same type of group of cells which have the same structure and functions together in a unit. Connective tissue, epithelial tissue, muscular tissue, and nerve tissue are the four fundamental forms of tissue. Other tissues are held together and supported by connective tissue bone, blood, and lymph tissues.

All body surfaces are covered in epithelial tissues, which also line bodily cavities and hollow organs and make up the majority of glandular tissue. Connective tissues are presents in the blood cells in the human body. Loose connective tissue, adipose tissue, dense fibrous connective tissue, elastic connective tissue, cartilage, osseous tissue, and blood are further more tissues in the body.

Thus, Heart and lungs are the  two organs that are made up of all four tissues.    

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Whats a hypothesis for “Which bait works better for a homemade fly trap?”

Answers

Answer:

If I use the correct bait, then I will have a successful homemade fly trap.

Explanation:

A hypothesis is always an "if, then" statement

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Please help asap!!!!! At Sarah's cafe, customers can choose one of the following entrees: burrito, pasta, soup or taco. They can also order a side dish. They have a choice of french fries, salad, potato salad or coleslaw. Finally customers get to choose one of the following drinks and a choice of soda, coffee, water, milk or juice.For dinner, the cafe offers diners a special, customers can order 2 sides with their entree. In how many different ways can dinner be ordered? Which of the following BEST describes the rule of four?A.The Supreme Court uses the rule of four after they have heard a case to decide whether they will issue an opinion on the case.B.The Supreme Court uses the rule of four to determine whether a case will be granted a writ of certiorari.C.It refers to the number of votes required to make a majority decision on the Court.D.The rule of four refers to the number of justices it takes to form a minority opinion on a case it often takes you .... to climb up to the top of mount kinabalu Please enter the missing number: 4, 5, 8, 17, 44, ? Which excerpts contain examples of epic similes? Select 3 options."its crackling roots blazed and hissed as a blacksmith plunges a glowing ax or adzein an ice-cold bath and the metal screeches steamand its temper hardens that's the iron's strength so the eye of Cyclops sizzled round that stake."Or are you wandering rogues, who cast your liveslike dice, and ravage other folk by sea?'Then he dismembered them and made his meal,gaping and crunching like a mountain lioneverything: innards, flesh, and marrow bones.When the young Dawn with finger tips of roselit up the world, the Cyclops built a fireand milked his handsome ewes, all in due order, putting the sucklings to the mothers. Below are the times (in days) it takes for a sample of 6 customers from Sarah's computer store to pay their invoices.33, 16, 29, 41, 36, 37Find the standard deviation of this sample of times. Round your answer to two decimal places.=___ HELP ME PLEASE I NEED HELP what is velocity give its SI unit A company's managers should almost always give serious consideration to making significant adjustments in its camera/drone strategies and competitive approaches when: a. all or most of its competitors are using mostly different competitive approaches and therefore the marketplace is not big enough to accommodate all of the competitors. b. all or most of its competitors are using mostly copycat competitive approaches that make it difficult for any of these companies to capture sales volumes and revenues big enough to earn profits large enough to meet investor-expected EPS, ROE, and stock price appreciation targets. c. the number of camera and drone workstations the company has installed is NOT well above the industry-averages (as reported on pages 6 and 7 of the most recent Camera & Drone Journal). d. the company's market share for action cameras has not been the largest for two straight years and when its EPS and ROE have also not been the highest in the industry for two straight years. e. the company's operating profits per action camera sold are not substantially above the industry-average benchmarks in at least three geographic regions (as reported on p. 6 of the most recent Camera & Drone Journal), In what quadrant would the triangle be if rotated 90 degrees Which of the lists of letters all have line symmetry? 1. (A, B, C, D)2. (W, X, Y, Z) 3. (L, M, N, O)4. (S, T, U, V) la couleur de la maison de M. Vincent est ......verterougeblanche ! !please translate it into japanese or English. About 6% of the population of a large country is math phobic. If two people are randomly selected, what is the probability both are math phobic? 9. The scatter plot below shows the average yearly consumption ofbottled water by people in the United States starting in 1990.181614Gallons ofBottledWater perPerson12101990 1992 1994 1996 1998 2000YearUsing the line of best fit, predict the average consumption of bottledwater in the year 2000?B) 18 gallonsA) 20 gallonsC) 20 gallonsD) 19 gallons What happens if a cell goes through metastasis? Si la fuerza de friccin cinetica es 250N Qu fuerza se necesita para mantener a la caja deslizndose a una velocidad constante Is someone who is xenophobic considered racist? Grace bought a property valued at $200,00.00 and 20% down and a mortgage amortized over 10 years. She makes equal payments due at the end of every months. Interest on the mortgage is 4% compounded semi-annually and the mortgage is renewable after five years. a) What is the size of each monthly payment? b) What is the outstanding principal at the end of the five-year term? c) What is the cost of the mortgage for the first five years? SEE QUESTION IN IMAGE