Heart Health Basics

Heart Health Basics62-70

  • Every cell in the human body requires oxygen and nutrients for its survival and blood is the biological medium which vitally supplies these survival-essentials to the cells.
  • The heart is a hollow muscular organ that pumps blood and circulates it through blood vessels to the various body parts by repeated, rhythmic contractions.
  • Heart and the blood vessels which constitute the cardiovascular system are also responsible for mobilizing hormones and cellular waste products to their respective target sites.

The CardioVascular Sysytem In A Nutshell

  • The heart has four chambers of which the two top chambers are known as the left and right atria, while the bottom two chambers are known as the left and right ventricles.
  • Blood vessels are channels which transport blood across the heart and various body parts.
  • Among blood vessels, arteries supply oxygen and nutrient-rich blood from the heart to various parts of the body while veins bring back the used up deoxygenated blood from the various body parts to the heart (pulmonary arteries & veins are exceptions).

Cycle of circulation

  • The right atrium receives deoxygenated blood from various parts of the body, which is pumped into the right ventricle.
  • The right ventricle pumps the deoxygenated blood to the lungs for oxygenation through pulmonary artery.
  • Once the blood becomes oxygenated (oxygen-rich), it reaches the left atrium through the pulmonary veins.
  • It is then pumped into the left ventricle, and from the left ventricle it is pumped to various parts of the body through aorta (the largest artery).
  • The contraction of the ventricle begins at the apex of the heart and moves superiorly, forcing the blood upward toward the arteries.
  • This is important because the large arteries are located superiorly and the blood has to be rung from the bottom of the heart up.

Heart valves….

  • Valves are fibrous flaps of tissue found between the heart chambers and also in the blood vessels.
  • They are rather like gates which prevent blood from flowing in the wrong direction.
  • Each heart valve has two important functions, namely-
    • To open correctly & fully so that blood can empty from the chamber
    • To close properly (tightly) so that blood cannot flow the wrong way
    • This is important because the large arteries are located superiorly and the blood has to be rung from the bottom of the heart up.
  • Here are the four heart valves in the order of circulation
    • Tricuspid valve- opens to allow blood to flow from the right atrium to the right ventricle. Prevents back flow of blood from the right ventricle to the right atrium when blood is pumped out of the ventricle into the pulmonary artery.
    • Pulmonary valve (or Pulmonic valve)- opens to allow blood to be pumped from the heart (right ventricle) to the lungs (through the pulmonary artery) where it will receive oxygen. Prevents back flow of blood from the pulmonary artery to the right ventricle.
    • Mitral valve (Bicuspid valve)- opens to allow blood to flow from the left atrium to the left ventricle. Prevents back flow of blood from the left ventricle to the left atrium when blood is pumped out of the ventricle into the Aorta.
    • Aortic valve- opens to allow blood to be pumped from the left ventricle of the heart to the various body parts (through aorta). Prevents back flow of blood from aorta to the left ventricle.

Heart septum….

  • Septum is the muscular wall dividing the chambers on the heart's left side from the chambers on the right.
  • The portion of the septum that separates the right and left atria is termed as atrial/interatrial septum, whereas the portion of the septum that lies between the right and left ventricles is called the ventricular/interventricular septum.

Heart wall or layers…

  • The heart is securely anchored in its place by a thick, fibrous layer called pericardium.
  • Pericardium is organized into three main layers, namely epicardium, myocardium and endocardium.
  • Myocardium, being the muscular layer is responsible for systematic contractionsthat assist in pumping blood throughout the body.
  • The endocardium is the thin innermost layer of tissue that makes direct contact with the blood pumping through the heart chambers.
  • The layers of the pericardium fuse to form a space around the heart called the pericardial cavity.
  • Pericardial cavity produces a serous fluid which helps lubricate your heart and decrease friction against other organs as it pumps.