Gradual changes in the frequency of diseases over long periods are known as SECULAR TIME TRENDS. For example, the rate of mortality in USA due to coronary heart diseases over a period of time. Onset of puberty in girls is also a secular time trend.
Secular time trend is also referred as Secular Variation and Secular Drift.
In the heart, the valves are located between atria and ventricles and between ventricles and arteries (option D).
<h3>What are valves in the heart?</h3>
Valves are membranous partitions which permit the passage of the contents of a vessel or cavity in one direction, but stop or control the flow in the opposite direction.
Valves in the heart enforce a one-way blood flow through the heart and separate atria from ventricles, and ventricles from the large arteries that leave them.
The four valves in the heart and their location is as follows:
- tricuspid valve: located between the right atrium and the right ventricle
- pulmonary valve: located between the right ventricle and the pulmonary artery
- mitral valve: located between the left atrium and the left ventricle
- aortic valve: located between the left ventricle and the aorta.
The valves between the atria and ventricles are called atrioventricular valves or cuspid valves while those at the bases of the large vessels leaving the ventricles are called semilunar valves.
Therefore, it can be said that the valves of the heart are located between atria and ventricles and between ventricles and arteries.
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Answer:
Listen to pronunciation. (al-VEE-oh-ly) Tiny air sacs at the end of the bronchioles (tiny branches of air tubes in the lungs). The alveoli are where the lungs and the blood exchange oxygen and carbon dioxide during the process of breathing in and breathing out.
The relevant questions are number 2, 3, and 4.
a because its all living things
