kidney
right atrium
Right auricle which receives deoxygenated blood from all parts of the body from veins.
The definition of a right atrium of a pig is the upper chamber of the heart which receives deoxygenated blood from the body. The right and left atrium are collective called the atria.
The receiving chambers are the atria (singular atrium). The right atrium receives deoxygenated blood from the body, and the left atrium receives oxygenated blood from the lungs. The right atria receives blood from the veins (systemic). The left atria receives blood from the lungs (pulmonary).
The atria allow the blood to move from the body into the heart.
the atria only pump blood to the ventricles
the atria pump blood only to the ventricles.
Right atrium then right ventricle.
Some terminology first: The upper chambers = atria (singular atrium) The lower chambers = ventricles The atria are responsible for receiving blood: the right atrium receives deoxygenated blood from the body and the left atrium receives oxygenated blood from the lungs. The atria only pump this blood into the ventricles and therefore do not need particularly thick muscular walls. The ventricles on the other hand are responsible for pumping the blood received from the atria to the body. The right ventricle pumps the deoxygenated blood it receives from the right atrium out of the heart and into the lungs. On the other hand, the left ventricle is responsible for pumping the oxygenated blood received by the left atrium to the rest of the body. It is because of the this that the walls on the side of left ventricle are the thickest. The left ventricle requires "more muscle" than the right ventricle as the distance it has to pump the blood is far greater. So, SHORT ANSWER: The walls of the lower chambers/ventricles are thicker and more muscular than the walls of the upper chambers/atria because they have to pump blood out of the heart and to the body as opposed to the atria which only receive blood from the body and then pump into the ventricles.
The right ventricle receives blood that has circulated through the body via the right atria. it then pumps the blood through the pulmonic valve to the lungs where the blood becomes reoxygenated for circulation. :)
Function of the Atria The atria of the heart receive blood returning to the heart from other areas of the body. Right Atrium: Receives blood returning to the heart from the superior and inferior venae cavae. The superior vena cava returns de-oxygenated blood from the head, neck, arm and chest regions of the body to the right atrium. The inferior vena cava returns de-oxygenated blood from the lower body regions (legs, back, abdomen and pelvis) to the right atrium. Left Atrium: Receives blood returning to the heart from the pulmonary veins. The pulmonary veins extend from the left atrium to the lungs and bring oxygen-rich blood back to the heart.
Your lungs don't have ventricles. However your heart has two (a left one and a right one). The right ventricle receives deoxygenated blood from the body through the right atria and sends it up to the lungs to become oxygenated. The left ventricle receives oxygenated blood from the lungs through the left atria and sends it out the the systemic circulation to supply the tissues with oxygen.