Anooshka's Blog

Whenever we hear the phrase "blood vessels", we always think of arteries and how they distribute blood to cells and tissues. However, we hardly think about the billions of microscopic capillaries, the real vessels that supply cells and tissues with blood and nutrients. It is no doubt that arteries branch into arterioles and capillaries, but it is mainly through capillary walls that gases, nutrients, and metabolic wastes diffuse. The tiniest blood vessels, capillaries have a diameter ranging from .008 to .01 mm, roughly 1/1000 the diameter of arteries and 1/18th the diameter of a strand of hair.  Capillaries lack a both a tunica adventitia and tunica media, and consist of a tunica intima so small in diameter that they can fit only one red blood cell at a time, forcing the RBCs to move in a single file. Although capillaries are found in most tissues, some tissues lack these vessels. For instance, the cornea of the eye does not contain many capillaries. It acquires oxygen and nu

How do cells in different regions of the body acquire the nutrients you digest from your sandwich? The answer lies in a long network of blood vessels approximately 62,000 miles long, nearly 2.5 times the circumference of Earth! Blood vessels are integral components of the circulatory system, which serves as a group of "highways" for oxygen and nutrients to travel to various organs of the body. Arteries transport oxygen and nutrients to bodily organs , whereas veins transport deoxygenated blood from cells back to the heart . Blood that contains metabolic wastes from cells is filtered by the renal arteries, and these metabolic wastes leave the body through urine. Anatomy and Physiology of Blood Vessels All blood vessels, except the smallest arterioles, capillaries, and venules, contain three main layers referred to as  tunics .  Figure 2: Anatomy of Blood Vessels Tunica Externa  The outermost layer of a blood vessel is known as the tunica externa  and is formally referred to

On a hot summer day, you go jogging outside and notice that your cheeks are gradually turning red. What causes them to become red? It is the arteries in your cheeks dilating in an attempt to release the heat in your body. Not only do arteries help regulate body temperature, but they also play a crucial role in delivering blood to organs, keeping you alive. Damage to arteries can have life-threatening consequences. For instance, cerebral arteries that are ruptured or obstructed in a stroke can block blood supply to the brain, resulting in death if immediate action to restore blood supply is not taken. To recap, arteries transport blood (rich in oxygen and nutrients) from the heart to bodily organs. As arteries carry blood away from the heart, they branch into smaller vessels. Arteries are classified into three types based on their size and proximity to the heart: elastic, muscular, and arterioles. Elastic Arteries Elastic arteries are closest to the heart and have the largest diameter,

Homeostatic Imbalances with the Heart Heart disease refers to diseases that interfere with the proper functioning or supply of blood to the heart. Genetic predispositions, lack of physical activity, and certain foods are few of the many factors that can lead to heart disease. However,  lifestyle changes can reduce  its risk. Exercise improves blood circulation to cells, tissues, and organs, enhancing their function. If organs are deprived of blood, they do not receive an ample supp ly of oxygen, which could have severe consequences including death.  A blood clot, known as a thrombus, and a cholesterol deposit, known as a plaque, can obstruct arteries, which prevents blood flow. If a thrombus and a plaque obstruct the coronary arteries, the myocardium of the heart will not receive enough blood to contract, resulting in a heart attack . During physical activity, the high velocity by which blood moves through arteries removes thrombi and plaques, lowering the risk of heart disea

DNA: The Molecule That Defines Us You, your parents, and your siblings have similar traits. But why do you still not closely resemble each other? The answer lies in a tiny, but long molecule that is unique to every living organism (except for identical twins)* on this planet : DNA, or deoxyribonucleic acid.  DNA serves as a template for the production of proteins, affecting our traits and carrying out functions in the body.  The Nucleotide       DNA consists of repeating subunits called nucleotides. A nucleotide consists of a pentose (five carbon) sugar, phosphate group, and a nitrogenous base. The sugar is known as deoxyribose, and it forms a covalent bond with the phosphate group. This covalent bond is called a phosphodiester linkage . The repeating bonds between deoxyribose and the phosphate group form the sugar-phosphate backbone of DNA. A hydrogen bond joins the nitrogenous base pairs. This hydrogen bond is weak so that it can easily be broken for DNA replication.  

"The best and most beautiful things in the world cannot be seen or even touched - they must be felt with the heart"   - Hellen Keller            We often treat the heart as an emotional object inside us, but there's way more to the heart than that! It is one of the primary organs in the body that keeps us alive. The heart is a muscular organ that pumps blood to the other organs of the body every nanosecond of your life. This allows every cell, tissue and organ to get a fresh supply of blood and oxygen. It enhances their respective functions, keeping you alive.              The heart pumps oxygenated blood in the body. The organs of the body use the oxygen from the blood.  There are two ways in which blood circulates throughout the body - p ulmonary circulation   and systematic circulation . Pulmonary circulation refers to blood going from the heart to the lungs to get oxygenated before being sent to the rest of the body. Systematic circulation refers to  fresh, oxy