Structure and Function of Liver

The Structure and Functions of Liver 

The liver is the largest solid organ in the body. It removes toxins from the body's blood supply, maintains healthy blood sugar levels, regulates blood clotting, and performs hundreds of other vital functions. It is located beneath the rib cage in the right upper abdomen.

Key Facts

The liver filters all of the blood in the body and breaks down poisonous substances, such as alcohol and drugs.

• The liver also produces bile, a fluid that helps digest fats and carry away waste.

• The liver consists of four lobes, which are each made up of eight sections and thousands of lobules (or small lobes).

Structure

The liver consists of four lobes: the larger right lobe and left lobe, and the smaller caudate lobe and quadrate lobe. The left and right lobe are divided by the falciform ("sickle-shaped" in Latin) ligament, which connects the liver to the abdominal wall. The liver's lobes can be further divided into eight segments, which are made up of thousands of lobules (small lobes). Each of these lobules has a duct flowing toward the common hepatic duct, which drains bile from the liver.

Parts

The following are some of the most important individual parts of the liver:

• Common Hepatic Duct: A tube that carries bile out of the liver. It is formed from the intersection of the right and left hepatic ducts.

•Falciform Ligament: A thin, fibrous ligament that separates the two lobes of the liver and connects it to the abdominal wall.

• Glisson's Capsule: A layer of loose connective tissue that surrounds the liver and its related arteries and ducts.

•Hepatic Artery: The main blood vessel that supplies the liver with oxygenated blood.

• Hepatic Portal Vein: The blood vessel that carries blood from the gastrointestinal tract, gallbladder, pancreas, and spleen to the liver.

• Lobes: The anatomical sections of the liver.

• Lobules: Microscopic building blocks of the liver.

• Peritoneum: A membrane covering the liver that forms the exterior.

Functions of the Liver

The liver is an essential organ of the body that performs over 500 vital functions. These include removing waste products and foreign substances from the bloodstream, regulating blood sugar levels, and creating essential nutrients. Here are some of its most important functions:

•Albumin Production: Albumin is a protein that keeps fluids in the bloodstream from leaking into surrounding tissue. It also carries hormones, vitamins, and enzymes through the body.

• Bile Production: Bile is a fluid that is critical to the digestion and absorption of fats in the small intestine.

• Filters Blood: All the blood leaving the stomach and intestines passes through the liver, which removes toxins, byproducts, and other harmful substances.

• Regulates Amino Acids: The production of

proteins depend on amino acids. The liver

makes sure amino acid levels in the

bloodstream remain healthy.

•Regulates Blood Clotting: Blood clotting coagulants are created using vitamin K, which can only be absorbed with the help of bile, a fluid the liver produces.

•Resists Infections: As part of the filtering process, the liver also removes bacteria from the bloodstream.

• Stores Vitamins and Minerals: The liver stores significant amounts of vitamins A, D, E, K, and B12, as well as iron and copper.

• Processes Glucose: The liver removes excess glucose (sugar) from the bloodstream and stores it as glycogen. As needed, it can convert glycogen back into glucose.

Anatomy of the Liver

The liver is reddish-brown and shaped approximately like a cone or a wedge, with the small end above the spleen and stomach and the large end above the small intestine. The entire organ is located below the lungs in the right upper abdomen. It weighs between 3 and 3.5 pounds.

Structure and Function of Heart

Human heart is the main organ of your cardiovascular system, a network of blood vessels that pumps blood throughout the body. It also works with other body systems to control human heart rate and blood pressure.

The heart is a fist-sized organ that pumps blood throughout the body. It's the primary organ of human circulatory system.

Heart contains four main sections (chambers) made of muscle and powered by electrical impulses. The brain and nervous system direct the heart's function.

Chambers of the Heart 

The internal cavity of the heart is divided into four chambers:

-Right atrium

-Right ventricle

-Left atrium

-Left ventricle

The two atria are thin-walled chambers that receive blood from the veins. The two ventricles are thick-walled chambers that forcefully pump blood out of the heart. Differences in thickness of the heart chamber walls are due to variations in the amount of myocardium present, which reflects the amount of force each chamber is required to generate.

The right atrium receives deoxygenated blood from systemic veins; the left atrium receives oxygenated blood from the pulmonary veins.

Valves of the Heart

Pumps need a set of valves to keep the fluid flowing in one direction and the heart is no exception. The heart has two types of valves that keep the blood flowing in the correct direction. The valves between the atria and ventricles are called atrioventricular valves (also called cuspid valves), while those at the bases of the large vessels leaving the ventricles are called semilunar valves.

The right atrioventricular valve is the tricuspid valve. The left atrioventricular valve is the bicuspid, or mitral, valve. The valve between the right ventricle and pulmonary trunk is the pulmonary semilunar valve. The valve between the left ventricle and the aorta is the aortic semilunar valve.

When the ventricles contract, atrioventricular valves close to prevent blood from flowing back into the atria. When the ventricles relax, semilunar valves close to prevent blood from flowing back into the ventricles.

Pathway of Blood through the Heart

While it is convenient to describe the flow of blood through the right side of the heart and then through the left side, it is important to realize that both atria and ventricles contract at the same time. The heart works as two pumps, one on the right and one on the left, working simultaneously. Blood flows from the right atrium to the right ventricle, and then is pumped to the lungs to receive oxygen. From the lungs, the blood flows to the left atrium, then to the left ventricle. From there it is pumped to the systemic circulation.

Blood Supply to the Myocardium

The myocardium of the heart wall is a working muscle that needs a continuous supply of oxygen and nutrients to function efficiently. For this reason, cardiac muscle has an extensive network of blood vessels to bring oxygen to the contracting cells and to remove waste products.

The right and left coronary arteries, branches of the ascending aorta, supply blood to the walls of the myocardium. After blood passes through the capillaries in the myocardium, it enters a system of cardiac (coronary) veins. Most of the cardiac veins drain into the coronary sinus, which opens into the right atrium.

Diarrhoea

Loose, watery stools that occur more frequently than usual.

Diarrhoea is usually caused by a virus, or sometimes, contaminated food. Less frequently, it can be a sign of another disorder, such as inflammatory bowel disease or irritable bowel syndrome.

COMMON CAUSES

Diarrhoea can have causes that aren't due to underlying disease. Examples include a liquid diet, food intolerance, stress, anxiety or use of laxatives.

For informational purposes only. Consult your local medical authority for advice.

Types of diarrhoea

There are three clinical types of diarrhoea: acute watery diarrhoea - lasts several hours or days, and includes cholera; acute bloody diarrhoea - also called dysentery; and. persistent diarrhoea - lasts 14 days or longer.

Prevention 

Interventions to prevent diarrhoea, including safe drinking-water, use of improved sanitation and hand washing with soap can reduce disease risk. Diarrhoea should be treated with oral rehydration solution (ORS), a solution of clean water, sugar and salt.

Monkeypox

Monkeypox is a viral infection that manifests a week or two after exposure with fever and other non-specific symptoms, and then produces a rash with lesions that usually last for 2-4 weeks before drying up, crusting and falling off [15] While monkeypox can cause large numbers of lesions, in the current outbreak, some patients experience only a single lesion in the mouth or on the genitals, making it more difficult to differentiate from other infections.[26] In infections before the current outbreak, 1-3 percent of people with known infections have died (without treatment). Cases in children and immunocompromised people are more likely to be severe.[6]

Monkeypox spreads through close, personal, often skin-to-skin contact. The disease can spread through direct contact with rashes, or body fluids from an infected person, by touching objects and fabrics that have been used by someone with monkeypox or through respiratory secretions.1271 Given the unexpected and vast geographical spread of the disease, the actual number of cases is likely to be underestimated [28] While anyone can get monkeypox, to date the vast majority of confirmed cases outside of the endemic regions in Africa occurred in young or middle aged men who have sex with men (MSM) who had recent sexual contact with new or multiple partners. [29][30] On 28 July, the WHO Director General advised MSM to limit exposure by reducing the number of sexual partners, reconsidering sex with new partners, and maintaining contact details to allow for epidemiological follow-up.[31] The Centers for Disease Control and Prevention has

emphasized the importance of reducing stigma in communicating about the demographic aspects of monkeypox, specifically with regards to gay and bisexual men.[32]