Answer:
the rhythm of heart contractions.
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.
An electrocardiogram (ECG) provides information about the rhythm of heart contractions.
Additionally, 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.
Answer:
Children born to mothers with dark skin, living far from the equator.
Explanation:
I would say this is the answer but I'm not sure. This is just what I think. I asked my mom about it and she said the same thing I did. I hope this helps.
Answer:
A.
Explanation:
The arctic soil is so cold that the ground beneath the tundra surface remains frozen all year. This permanently frozen ground is called permafrost. Each summer, when the sun warms the tundra surface, the top few inches of soil thaw. This melted part is called the active layer.
Answer:
D
Explanation:
Hormones are bigger than the cell pores hence cannot pass through the cell membrane to influence biochemical processes. Therefore, hormones (such as glucagon and insulin) bind onto receptors on the cell membrane, then transmembrane proteins, such as the G-protein, change conformation activating the secondary messengers inside of the cell. Cyclic- AMP is a major secondary messenger significant in activating protein kinases.