Answer:
D. All of the above
Explanation:
In Human anatomy, cardiac cycle can be defined as a complete heartbeat of the human heart which comprises of sequential alternating contraction and relaxation of the atria and ventricles, therefore causing blood to flow unidirectionally (one direction) throughout the human body.
Generally, the cardiac cycle occurs in two (2) stages;
1. Diastole : in this stage, the ventricles is relaxed and would be filled with blood.
2. Systole: at this stage, the muscles contracts and thus, allow blood to be pushed through the atria.
Cardiac output can be defined as the volume of blood that is being pumped by the mammalian heart through the left and right ventricle per unit time (minute).
The following conducting systems of the heart cause the ventricles to contract;
I. Atrioventricular (AV) node: it's a component of the electrical conduction system of the mammalian heart located in the Koch triangle which connect the ventricles and atria electrically.
II. Atrioventricular (AV) bundle: it's a specialized tissue that transmits electrical impulse from the atrioventricular (AV) node to the Purkinje fibres of the ventricles.
III. Purkinje fibers: it's a network of specialized cells that comprises of glycogen and they transmit cardiac action potentials in a rapid manner from the atrioventricular (AV) bundle to the myocardium of the ventricles.
Furthermore, the right atrioventricular valve (AV) also referred to as the tricuspid valve is located on the right dorsal side of the human heart. The right atrioventricular valve (AV) comprises of three (3) leaflets (flaps) which opens and closes in order to allow for the flow of blood from the right atrium of the human heart to the right ventricle. Also, the right atrioventricular valve is saddled with the responsibility of preventing blood from flowing backward in the mammalian heart.
Gg and Rr hope this helps:)
The correct answer is C. To store gastroliths that physically grind up food.
Explanation
The gizzards, are a special part of the digestive system of some animals such as birds, fish, and reptiles whose main function is to crush the food that the animal ingests, for this task, the gizzards contain in their interior gastroliths, a kind of polished stones, that grinds the food that the animal eats. The gizzards represent an important part for these animals because many of them do not have teeth to crush their food and feed on it. So, the correct answer is C. To store gastroliths that physically grind up food.
