C<span>ommon names can be confusing because they vary among languages and from place to place , SO (D) hope this helps:)</span>
Answer:
by the sarcoplasmic reticulum's calcium ion pumps
Explanation:
Rigor mortis or postmortem rigidity, is a state caused by chemical changes in the muscles that occur post mortem and cause the limbs of the corpse to stiffen.
This occurs because after death, there is no cellular respiration and consequently, no oxygen nor ATP (ATP is required for the muscle relaxation).
Calcium enters the cytosol after death because it is released due to the deterioration of the sarcoplasmic reticulum and due to the breakdown of the sarcolemma. Ca2+ ions activate the formation of actin-myosin cross-bridging necessary for the contraction. Muscles are unable to relax, because myosin heads continue to bind with the active sites of actin and there is no ATP to destabilize the myosin-actin bond.
Answer
Ventricular systole begins during the <u>isovolumetric contraction </u>phase of the cardiac cycle.
Explanation
1. Ventricular ejection
The forceful expulsion of blood from the ventricles into the aorta and the pulmonary arteries.
2. Isovolumetric contraction
The interval between the closing of the AV valves and the opening of the semilunar valves (aortic and pulmonary valves) is known as isovolumetric contraction. it is the beginig of systole. it is the first chamber systolic event. The myocardial muscle fibers have begun to shorten but have not developed enough pressure in the ventricles to overcome the aortic and pulmonary end-diastolic pressures and open the aortic and pulmonary valves. During this period of muscle fiber contraction, the ventricular volumes do not change.
3. Ventricular filling
In this stage AV valve is opened and the blood that has accumulated in atria flow rapidly into ventricles. The ventricular volume increase rapidly. A third heart sound known as S3 is heared during this stage.
4. Isovolumetric relaxation
It is the beginning of diastole. The AV valve are closed at beginig. The atrium in diastole has been filling with blood on top of the closed AV valve, causing atrial pressure to rise gradually. The pressure in the ventricles continues to drop. Ventricular volume is at a minimum and is ready to be filled again with blood.
Answer:
d) passage of a solute against its concentration gradient
Explanation:
When a solute is transported against its concentration gradient, the cells use metabolic energy. To move a substance from the region of its lower concentration to that of its higher concentration, the energy of ATP hydrolysis is utilized. These types of transport mechanisms are called active transports. If ATP hydrolysis is inhibited in a cell, it would not be able to perform the uphill movement of solutes due to the lack of any source of energy to drive the process.
<span>Diffusion is the process by which particles tend to move from an area where they are more concentrated to an area where they are less concentrated.
Facilitated diffusion is the process in which molecules pass across the membrane through cell membrane channels.</span>
