Although now it causes more harm than good because it doesn't really have a purpose, it is believed it once was used for humans to digest bone.
The troposphere is shallowest or narrowest at the poles, and deepest or thickest at the equator. At the geographic North and South Poles, the troposphere reaches only 4 miles high, while at the equator, it extends nearly 12 miles high.
Answer:
The ventricles of the heart have thicker muscular walls than the atria. This is because blood is pumped out of the heart at greater pressure from these chambers compared to the atria. ... This is due to the higher forces needed to pump blood through the systemic circuit (around the body) compared to the pulmonary circuit.
Explanation:
The Human Heart — PT Direct
The lymphatic system includes areas of high concentrations of APCs, T and B cells.
<h3>What is the lymphatic system?</h3>
The lymphatic system is a branch of the circulatory system which consists of a system of organs , tissues, cells and vessels known as lymphatic vessels, which help transport the fluid, lymph around the body.
The lymphatic system contains high concentration of immune cells.
Therefore, the lymphatic system includes areas of high concentrations of APCs, T and B cells.
Learn more about lymphatic system at: brainly.com/question/3318384
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