During the transmission of signals across a neuromuscular junction, which of the following happens last?

1 answer:

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A neuromuscular junction (or myoneural junction) is a chemical synapse formed by the contact between a motor neuron and a muscle fiber.[1] It is at the neuromuscular junction that a motor neuron is able to transmit a signal to the muscle fiber, causing muscle contraction.

Muscles require innervation to function—and even just to maintain muscle tone, avoiding atrophy. Synaptic transmission at the neuromuscular junction begins when an action potential reaches the presynaptic terminal of a motor neuron, which activates voltage-dependent calcium channels to allow calcium ions to enter the neuron. Calcium ions bind to sensor proteins (synaptotagmin) on synaptic vesicles, triggering vesicle fusion with the cell membrane and subsequent neurotransmitter release from the motor neuron into the synaptic cleft. In vertebrates, motor neurons release acetylcholine (ACh), a small molecule neurotransmitter, which diffuses across the synaptic cleft and binds to nicotinic acetylcholine receptors (nAChRs) on the cell membrane of the muscle fiber, also known as the sarcolemma. nAChRs are ionotropic receptors, meaning they serve as ligand-gated ion channels. The binding of ACh to the receptor can depolarize the muscle fiber, causing a cascade that eventually results in muscle contraction.

Neuromuscular junction diseases can be of genetic and autoimmune origin. Genetic disorders, such as Duchenne muscular dystrophy, can arise from mutated structural proteins that comprise the neuromuscular junction, whereas autoimmune diseases, such as myasthenia gravis, occur when antibodies are produced against nicotinic acetylcholine receptors on the sarcolemma.

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Which of the following is often used to remove poisonous gases from industrial emissions before they are released into the atmos

Alenkinab [10]

Answer:

B.) Scrubbers

Explanation:

Scrubbers are used to remove poisonous gases from industrial emissions before they are released into the atmosphere.

These devices are air pollution control units in industrial power plants that uses liquids to absorb harmful gaseous industrial gases.

Some of these gases are carbon monoxide, nitrogen oxides.
This atomized liquid removes harmful gases
The waste gas is brought into close contact with the liquid.
Some of the gases will pass into the liquid.
They are very effective in removing polluting gases from wastes.

3 0

3 years ago

What kind of lab equipment would you use to conduct a small chemical experiment

Alexandra [31]

Answer:

Beaker - A beaker is a glass container with a flat bottom and a small spout for pouring. It is used in the chemistry lab for mixing, heating, and stirring liquids. Beakers come in various sizes and are shaped like a cylinder.

Chemistry lab beakers Beakers

Bunsen burner - The Bunsen burner is a metal tube that produces a flame from gas such as methane, propane, or butane. It is used in the lab for heating and sterilizing. The Bunsen burner is named after German chemist Robert Bunsen.

Bunsen burner

Crucible - Crucibles are containers used for heating substances to very high temperatures. They are generally made from materials such as porcelain, nickel, and alumina.

Erlenmeyer flask - This is a type of chemistry flask with a conical shaped body, a cylindrically shaped neck, and a flat bottom. It generally has measurement marks on the side. It is similar to a beaker, but has the cone shaped body. The cone shape reduces losses from evaporation and helps to prevent spills when stirring the liquid.

Erlenmeyer flask

Funnel - A funnel is a pipe with a wide mouth that helps to pour substances into a container without spilling. In a chemistry lab, funnels are often used together with filters to separate a mixture.

Funnel and flask

Gloves - Laboratory gloves are important to wear in order to protect the skin from chemical substances. Always listen to your teacher and make sure to wear gloves when performing experiments.

Always wear gloves

Goggles - Goggles are very important when performing experiments of any kind. They can keep dangerous chemicals and other substances from damaging your eyes. Always wear your goggles in the lab!

Always wear goggles

Graduated cylinder - A tall skinny cylinder used to measure volumes. It is generally a more accurate way to measure volume than a typical beaker or flask.

Graduated cylinder

Mortar and pestle - A mortar and pestle are used to crush and grind solids into a powder. The mortar is a bowl and the pestle is a small club-shaped tool. They are typically made from ceramic or stone.

Mortar and pestle

Pipette - A narrow glass tube used to transfer liquids from one place to another. Pipettes sometimes are used for measurement. The accuracy of different pipettes varies widely.

Pipette

Scoopula - A scoopula is a metal spatula-type utensil used to scoop up solids such as powders in a chemistry lab.

Stirring rod - A skinny solid glass rod used in chemistry to mix chemicals and liquids. A stirring rod is typically about the length of a long straw and has rounded ends.

Test tube - A test tube is a glass or plastic tube used for holding, mixing, and heating small quantities of liquid chemicals. Test tubes often have a flared top to help with pouring. They come in a variety of sizes.

Test tube holder - A stand built for holding multiple test tubes.

Test tube brush - A brush designed to help clean out test tubes.

Test tube clamps - Clamps that hold test tubes while using them to heat up chemicals during a lab experiment.

Test tubes in a holder

Thermometer - A device used for measuring the temperature of a substance.

Triangle - A triangle made of clay pipes and wire that can withstand high temperatures. It is often used to hold a crucible.

Wire gauze - A wire gauze is used to support a beaker or flask when heating. The wire gauze helps to spread the heat evenly.

7 0

3 years ago

Which of the following is an advantage of sexual reproduction? A. It increases genetic variety. B. Less energy is required. C. L

Rashid [163]

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