Well , the humans have a closed double circulatory system as the blood passes by the heart twice per one cycle and doesn't leave the blood vessels like in insects.
》Pulmonary circulation : Blood is circulated to the lungs where it is oxygenated.
》Systemic circulation : Blood is circulated through all the other parts of the body where it unloads oxygen.
Oxygenated blood coming from the lungs enters the heart through the pulmonary vein which takes blood to the first chamber it meets ; the Left atrium. Left atrium pumps blood to the second chamber , which is left ventricle and during this time , the semi lunar valves are closed to prevent back flow of blood and the bicuspid valve will be open . Now , the left ventricle is filled with oxygenated blood so it will pump this blood to the whole body via the largest artery which is Aorta.
Oxygenated blood will unload oxygen to cells in need of it and will return back now to the heart as deoxygenated . This deoxygenated blood will enter the heart through superior and inferior vena cava which will take the blood to the third chamber , right atrium . Right atrium will pump blood to right ventricle so the semi lunar valves will be closed during this time and the tricuspid will remain open. Now that the fourth chamber is filled with deoxygenated blood , it will pump this blood through pulmonary artery when the semi lunar valves opens , to the lungs again to be oxygenated once more.
Notice that you have to know exactly the position of the valves that I have mentioned in the heart so that you could understand the blood flow better. You can refer to any heart labelled diagrams in your textbook or the internet.
Is there any multiple choice questions?
The answer is Tropical Rainforest Biome
The tropical rainforest has a moderate temperature with seasonal changes. The amount of rainfall in a tropical rainforest is high. It has a thick canopy of trees which filters out a majority of the sunlight which is why the forest floor is almost shaded.
Answer:
The given statement is True.
Explanation:
Scala media has endolymph as its constituent and endolymph is rich in Potassium ions (K+)
whereas
Scala tympani and scala vestibuli has in its composition Perilymph and Perilymph has sodium ions as their major constituent ions.
Therefore, scala media is Potassium ion rich while scala tympani and vestibuli are sodium ion rich.
Florida keys
The Florida keys is a coral cay archipelago in southeast United States.The Florida keys is an island which is near the gulf. The Florida keys is an archipelago landform.
Sea caves
<span>A sea cave,also known as a littoral cave,is a type of cave formed primarly by the wave action of the sea.Sea caves are a coastal and an oceanic landform.A sea cave causes by erosion because the rocks break down then terode all the materials to create sea caves.</span>
