Concept explainers
Introduction:
The concentration of potassium ions (K+) is high in the intracellular fluid (ICF). It determines volume and intracellular osmolarity of the cell. It regulates resting membrane potential and depolarization of nervous and muscular systems with sodium. It serves as a co-factor for translation and is involved in other
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- T-type calcium channels inactive rapidly. True Falsearrow_forwardThe resting membrane potential (RMP) is the voltage measured in a cell during resting state. It is particularly critical for the proper functioning highly excitable cells such as neurons and skeletal muscle cells. Identify the major ionic player then describe how it gives rise to and maintains RMP.arrow_forwardHigh Potassium can cause the symptoms seen in hyperkalemia. What about low potassium, known as hypokalemia? What affectwould hypokalemia have on the resting membrane potential and action potentials?arrow_forward
- Every cell in the body requires oxygen for respiration so that sufficient energy can be produced. Carbon dioxide a waste product in the process, is also produced and needs to be removed from the cells. Therefore, the levels of both gases should be regulated. How does this physiological mechanism explain the changes observed and noted in the increase of pulse rate during running?arrow_forwardSevere burns, particularly third-degree burns that damage a significant portion of the body surface, can result in the release of sodium from damaged cells into the bloodstream leading to hypernatremia. Note: Words with the suffix '-emia' generally indicate a presence of a substance or condition in the blood. Question: Based on this information, which of the following statement/s is/are true? ☐ Hypernatremia would lead to a greater Na* influx through voltage-gated Na* channels. This increased Na* influx would cause the cell to reach threshold faster and increase cell excitability. ☐ Hypernatremia can result in more negative resting membrane potential due to the reduced efflux of Na+ ions. Consequently, this may lead to a decrease in the rate of action potential generation in excitable cells. Hypernatremia can result in a more positive resting membrane potential due to the increased influx of K+ ions. Consequently, this may lead to a decrease in the rate of action potential generation…arrow_forwardSarin gas is an inhibitor of acetylcholinesterase used in chemical warfare. Briefly (in 1 sentence or less) explain how sarin causes: a) increased urination b) tachycardia (rapid heartrate)arrow_forward
- Please fill in the blanks: A(n) ["action potential", "muscle twitch", "contraction"] consists of a wave of depolarization that moves along the plasma membrane of a neuron or a muscle fiber. This wave of depolarization is immediately followed by repolarization. Depolarization is when the cell's membrane potential becomes more ["resting", "negative", "positive"] . Depolarization occurs when calcium channels open in the plasma membrane. Repolarization is when the cell's membrane potential becomes more ["resting", "positive", "negative"] , returning the cell to its resting potential. Repolarization occurs when ["calcium", "sodium", "potassium"] channels close and ["sodium", "calcium", "potassium"] channels open.arrow_forwardWhich of the following occurs at this point of the membrane potential (marked by the black arrow) in autorhythmic cells? (A) A (B) B (C) C (D) Darrow_forwardThe resting membrane potential is a negative value because of:arrow_forward
- A patient has been exposed to the organophosphate pesticide malathion,which inactivates acetylcholinesterase. Which of the following symptoms would you predict: blurring of vision, excess tear formation, frequent or involuntary urination, pallor (pale skin), muscle twitching, orcramps? Would atropine be an effective drug to treat the symptoms?(See Clinical Impact 16.2 for the action of atropine.) Explain.arrow_forwardDescribe the ion movement across the cell membrane during the following stages: resting potential, threshold potential, depolarization, repolarization.arrow_forwardare these True or False? Receptors on the post-synaptic cell membrane that bind the acetylcholine are voltage-gated channels (channels that open in response to a change in the electrical charge of the membrane). When a muscle cell is not contracting its cell membrane is negative on the inner surface. The effect of a neurotransmitter on the muscle cell membrane is to modify its ion permeability properties temporarily.arrow_forward
- Human Physiology: From Cells to Systems (MindTap ...BiologyISBN:9781285866932Author:Lauralee SherwoodPublisher:Cengage Learning