1. Cardiomyocytes contractile rate increases as Ca2 levels in cytosol rise.Releasing of Ca2+ to the cytosol from endoplasmic reticulum is regulated byCAMP-dependant transporters in ER membranes. Along with that, the CAMPconcentration in cytosol is regulated by two signal molecules- epinephrine andacetylcholine. Epinephrine, binding to B,-receptors, elevates the concentrationof CAMP in the cardiomyocytes and stimulates the cardiac output, andacctylcholine diminishes CAMP concentration and, therefore, depressmyocardial contractility. Explain why, using the same signal transductionpathway, these two primary messengers cause the different cellular responses inthe heart muscle. For that:a) draw the scheme of signal transduction for epinephrine and acetylcholine;b) point out the differences in the pathways for these two primary messengers;c) explain the opposite biological effects of these signal molecules.

Cells can respond to environmental signals via signal transduction pathways. A signal is amplified…

1. Cardiomyocytes contractile rate increases as Ca2+ levels in cytosol rise. Releasing of Ca²+ to the cytosol from endoplasmic reticulum is regulated by CAMP-dependant transporters in ER membranes. Along with that, the CAMP concentration in cytosol is regulated by two signal molecules-epinephrine and acetylcholine. Epinephrine, binding to B₂-receptors, elevates the concentration of CAMP in the cardiomyocytes and stimulates the cardiac output, and acetylcholine diminishes cAMP concentration and, therefore, depress myocardial contractility. Explain why, using the same signal transduction pathway, these two primary messengers cause the different cellular responses in the heart muscle. For that: a) draw the scheme of signal transduction for epinephrine and acetylcholine; b) point out the differences in the pathways for these two primary messengers; c) explain the opposite biological effects of these signal molecules.

1. Cardiomyocytes contractile rate increases as Ca2+ levels in cytosol rise. Releasing of Ca²+ to the cytosol from endoplasmic reticulum is regulated by CAMP-dependant transporters in ER membranes. Along with that, the CAMP concentration in cytosol is regulated by two signal molecules-epinephrine and acetylcholine. Epinephrine, binding to B₂-receptors, elevates the concentration of CAMP in the cardiomyocytes and stimulates the cardiac output, and acetylcholine diminishes cAMP concentration and, therefore, depress myocardial contractility. Explain why, using the same signal transduction pathway, these two primary messengers cause the different cellular responses in the heart muscle. For that: a) draw the scheme of signal transduction for epinephrine and acetylcholine; b) point out the differences in the pathways for these two primary messengers; c) explain the opposite biological effects of these signal molecules.

Biology: The Dynamic Science (MindTap Course List)

4th Edition

ISBN:9781305389892

Author:Peter J. Russell, Paul E. Hertz, Beverly McMillan

Publisher:Peter J. Russell, Paul E. Hertz, Beverly McMillan

Chapter44: The Circulatory System

Section: Chapter Questions

Problem 6TYK: Keeping the mammalian cardiac cycle balanced is/are: a. an AV node between the right atria atrium...

See similar textbooks

Similar questions

6. Which of the following statements concerning the differences between action potentials in skeletal muscle cells and in ventricular cardiac muscle cells is TRUE? A)The efflux of K+ repolarizes skeletal muscle cells after an action potential, while repolarization in cardiac muscle cells is due to the efflux of Ca2+ B)Unlike skeletal muscle cells, the initial depolarization of ventricular cells is mainly due to Ca2+ influx, not Na+ influx C)Action potentials in skeletal muscle cells are longer in duration than action potentials in cardiac muscle cells D)After sodium influx through voltage gated channels occurs in ventricular cells, prolong influx of calcium from the extracellular fluid occurs. No such calcium influx occurs in skeletal muscle cells. E)Like skeletal muscle cells, ventricular cardiac muscle cells have a resting potential primarily dependent on sodium.
Nodal (conductile) cells in the heart differ from other myocardiocytes (contractile cells) in that nodal cells have_____. A channels that allow Na+ to slowly leak in between action potentials B gap junctions while other myocardiocytes do not C more rapid depolarization in their action potentials due to voltage-gated Na+ channels D action potentials without plateau phases because they lack Ca+2 channels
In the myogenic response, ________. muscle contraction promotes venous return to the heart ventricular contraction strength is decreased vascular smooth muscle responds to stretch endothelins dilate muscular arteries
10. A ligand binds to a channel and opens it, resulting in the influx of sodium into a post-synaptic cell. The receptor and post synpatic response are... A) Ionotropic and neither excitatory nor inhibitory B) Metabotropic and inhibitory C) Metabotropic and excitatory D) Ionotropic and inhibitory E) Ionotropic and excitatory
Heart muscle cells ______. A will not contract unless acetylcholine is released at a neuromuscular junction B use glucose as their primary energy source and are easily damaged by hypoglycemia C have gap junctions that allow action potentials to be transmitted from one cell to the next D "are very long, with individual cells running the entire length of the heart"
In pacemaker cells the movement of __________ into the cell through voltage-gated channels is primarily responsible for the depolarization phase of the action potential. A Ca2+ ions B K+ ions C Na+ ions D Cl- ions
A rise in the intracellular Ca2+ concentration causes muscle cells to contract. in addition to an ATP- driven Ca2+ pump, muscle cells that contract quickly and regularly, such as those of the heart, have an additional type of Ca2+ pump—an antiport that exchanges Ca2+ for extracellular Na+ across the plasma membrane. The majority of the Ca2+ ions that have entered the cell during contraction are rapidly pumped back out of the cell by this antiport, thus allowing the cell to relax. ouabain and digitalis are used for treating patients with heart disease because they make heart muscle cells contract more strongly. both drugs function by partially inhibiting the Na+ pump in the plasma membrane of these cells. can you propose an explanation for the effects of the drugs in the patients? What will happen if too much of either drug is taken?
You give a drug intravenously that you think is a selective beta 1 receptoragonist to a patient. Which of the following effect would you expect toobserve?A)Increased heart rateB)Decreased renin secretionC)Increased central venous pressureD)Decreased contractilityE)Decreased cardiac output
1. What is a CAM that facilitates rolling of leukocytes on the surface of blood vessel's endothelium 2. What are the different types of CAM to CAM binding? 3. It is a calcium-dependent CAM that forms a dimer and binds to another CAM of an adjacent cell
Referring to the figure shown, the movement of glucose is from the lumen of the duodenum through an interstitial cell, out to the extracellular fluid, and into a capillary. What would happen if the action of the Na+–K+ pumps was reduced? A)The rate of flow of glucose into the interstitial cells would be increased. B)The direction of flow of glucose would be reversed. C)The rate of flow of glucose into the interstitial cells would be reduced. D)Nothing would differ: the movement of glucose would be the same as before the reversal.
A 32-year-old male is diagnosed with primary hypertension. His physician recommends a new drug for hypertension that acts by decreasing vascular smooth muscle contractile activity without affecting ventricular contractility. Which of the following is the most likely site of action for the new drug? a. -adrenergic receptors b. Calmodulin c. Troponin d. Tropomyosin e. Protein kinase A
why are cardiac muscle cells affected by hyperkalemia? A. All choices below are correct B. Resting membrane potential becomes less negative C. Voltage across the cardiac muscle cell cannot be maintained D. The cardiac muscle cell cannot respond to a nerve stimulus