Oxygen-poor blood enters the heart through the right atrium. From there blood flows through the tricuspid valve into the right ventricle. When the heart contracts during the diastolic phase, this blood is pumped out through the pulmonary arteries that run toward the lungs. At the lungs, the blood is circulated through a series of progressively smaller arterioles until it flows through capillaries lining the lungs' alveolar sacs. It is here that gas exchange takes place as oxygen is taken up by the blood, and carbon dioxide is released into the waste air.After oxygenation, the fresh blood is circulated back through the bronchial veins and into the pulmonary veins. These run from the lungs and drain into the heart's left atrium. During the systolic phase of the heartbeat, the mitral valve under the left atrium opens and permits blood to pass into the left ventricle. This chamber is heavily muscled and it has the power to pump the oxygen-rich blood out through the aorta and into the rest of the body.
It is a measure of how acidic/basic a liquid is. The range goes from 0-14, with 7 being neutral. pHs less than 7 indicate acidity, whereas a pH of greater than 7 indicates a base.
A disturbance would be things like lava, flows, newly formed sand dunes, or rocks left from a retreating glacier. These are disturbances because Primary Successions happen in lifeless areas, which soil is incapable of sustaining life.
Answer: i think its 80 million years ago
Explanation:
A benign tumour is generally not dangerous as they grow usually within a membrane in one space. They can however grow really big in a short space of time and can cause pressure on neighbouring blood vessels which can be dangerous.
Metastatic or malignant tumours are dangerous and cancerous. After they grow, some cells break off and travel in the bloodstream to a different area of the body (usually the main organs) and forms a secondary tumour there. This keeps happening until the cancer has spread to all of the body.
**_hope this helps**
