Answer:
The charges inside and outside of the neuron before receiving a stimulus are negative and positive, respectively, which corresponds to the transmembrane rest potential.
Explanation:
Neuron is the specialized cell of the nervous system in charge of transmitting electrical impulses. The generation of a nerve impulse in the form of an electric current is due to a change in the transmembrane potential.
<u>Outside the neuron cell, electrical charges are predominantly positive, and the ion with the highest concentration is sodium. In the intracellular space, a great quantity of proteins provide negative charge, and there is a predominance of potassium ions</u>. Under these conditions, the ionic channels are closed.
For this reason, a neuron at rest, before receiving a stimulus, presents positive charges on the outside and negative charges on the inside, and the membrane potential in this condition is estimated at a value of -65 mV.
Once a stimulus is produced, the ionic channels open and Na+ ions enter the cytoplasm, exchanging them for K+, which implies a change in the membrane potential which, on reaching the threshold, produces an action potential and the nerve impulse is produced.
Answer:
Cellulose is a type of carbohydrate polymer is used for structural support in the cell wall within plants
Explanation:
Cellulose, for example, is a major component of plant cell walls, which are rigid structures that enclose the cells (and help make lettuce and other veggies crunchy). Wood and paper are mostly made of cellulose, and cellulose itself is made up of unbranched chains of glucose monomers linked by 1 4 glycosidic bonds
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Marie is experiencing the: Sympathomimetic effects (fight-or-flight state).
The sympathetic nervous system is a component of the autonomic nervous system, managing the activity of visceral organs and the automatic functions of the body, such as breathing or beating of the heart. The sympathetic nervous system is involved in many unconscious physiological activities through two neuromodulators of the catecholamine family: adrenaline, but especially norepinephrine (fight-or-flight hormones).
* It accelerates the metabolism and is activated for example in case of danger or fear, to prepare the individual to escape.
* It affects the cardiovascular system: it increases the heart rate and induces peripheral vasoconstriction, causing an increase in blood pressure.
* At the digestive level, it slows the muscular contractions of the intestines but promotes the release of glucose by the liver.
* It also has a bronchodilator effect, that is to say, it causes the increase of the diameter of the bronchi.
<span>Mosses receive their water from rainfall and most of their nutrients are dissolved in this water that has accumulated as dust on them. Their nutrient uptake is effected by the osmosis. Highly concentrated nutrients can kill them because they have no ability to regulate the absorption.</span>
