Since the heart relies on aerobic respiration to supply its energy needs, cardiac muscle cells are richly supplied with mitochondria. Our hearts beat about once every second of every day of our lives or over 2.5 million times in an average life span. The only time the heart gets a rest in between beats. Position: […]
Regulation of Cardiac Activity: Normal activities of the heart are regulated in an essential or natural way, meaning it is autoregulated by specialized muscles or the nodal tissue, therefore the heart is called myogenic. A special neural center in the medulla oblongata can moderate the cardiac function through the autonomic nervous system (ANS). Neural signals can […]
In this article, we shall study the origin and measurement of blood pressure. Origin of Blood Pressure: Due to the contraction of the heart and by the muscles that surround our blood vessels, blood moves through our circulation system since it is under pressure by it. The measure of this force is blood pressure. In […]
In this article, we shall study blood vessels and their types: arteries, veins, and capillaries. Study of blood vessels is called Angiology. Blood vessels form a network of blood circulating vessels starting from the heart (left ventricle) arteries arterioles capillaries venules veins back to the heart (right auricle). Arteries and Arterioles: Arteries carry blood from […]
In this article, we shall study types of blood circulation in human body. Pattern of Circulation Our Blood moves through the body in an uninterrupted fashion in the following sequence: 1] Left ventricle 2] systemic circulation (body) 3] right atrium 4] right ventricle 5] pulmonary circulation (lungs) 6] left atrium left ventricle. Double Circulation: Double […]
In this article, we shall study heart-related disorders and heart surgeries Hypertension: Symptoms: A healthy adult has a blood pressure reading of about 120/80 mm Hg (120 mm Hg – systolic and 80 mm Hg – diastolic). This often rises normally with age to about 130/90 at 60. Abnormally high blood pressure is known as […]
Tissue Fluid and Lymphatic System: 10% of its fluid escape into the surrounding tissues, as blood proceeds through the capillaries and is known as tissue fluid. Chemicals such as glucose and hormones are carried by this fluid to the cells of the body that are not next to the capillary. It then removes the waste […]
Science > Biology > Digestion and absorption in Human > Salivary Glands There are two sources of digestive enzymes: The glandular cells of the lining of the stomach and intestine, which directly pour their secretion into the lumen of the gut or the alimentary canal. Special glands such as the salivary glands, the liver and the […]
In this article, we are going to study another important component of blood plasma i.e. White blood corpuscles, their types, structures, and functions. They are colourless, nucleated, amoeboid (irregular shape) and phagocytic cells larger than RBC’s. Their size ranges from 12 μm to 20 μm. They have mitochondria, Endoplasmic reticulum, Golgi complex, ribosomes, and centrioles. […]
Science > Biology > Digestion and absorption in Human > Alimentary Canal: Brief Idea The digestive system in humans consists of an alimentary canal and associated digestive glands. The human alimentary canal (aliment: nourish) is a continuous muscular digestive tube about 8 to 10 m long that runs through the body. It is open at two ends […]