Tag: digestion and absorption

• The liver receives blood supply from two sources. 
• The first is the hepatic artery which delivers oxygenated blood from the general circulation. 
• The second is the hepatic portal vein delivering deoxygenated blood from the small intestine containing nutrients. Hence, Deoxygenated blood is processed by hepatocytes.

• An arteriole is a small-diameter blood vessel in the microcirculation that extends and branches out from an artery and leads to capillaries.
• The liver receives blood from two major blood vessels. The hepatic arterioles bring oxygen-rich blood from the heart.
• The hepatic portal vein brings blood rich in digested nutrients from the intestine. This means excess nutrients can be removed and stored before blood circulates around the body. Hence Arterioles provides oxygen to the liver.

Blood is carried to the liver via two large vessels: the hepatic artery carries oxygen-rich blood from the aorta, and the portal vein carries blood containing digested food from the small intestine. The hepatic portal vein is a blood vessel that conducts blood from the gastrointestinal tract and spleen to the liver. This blood is rich in nutrients that have been extracted from food, and the liver processes these nutrients; it also filters toxins that may have been ingested with the food. The liver receives about 75% of its blood through the hepatic portal vein, with the remainder coming from the hepatic artery proper. The blood leaves the liver to the heart in the hepatic veins.

Capillaries are essential for the delivery of oxygen to the tissues and the exchange of nutrients between blood and interstitial fluid surrounding the cells. This function is well supported by the anatomy of the vessels. The thin walls of the capillaries are composed of a single layer of endothelial cells. As a result, gasses such as oxygen and carbon dioxide can diffuse through their walls, as can lipid soluble substances.
Capillaries also play an important role in regulating the relative volume of the blood and interstitial fluid by allowing a bulk flow through their walls. This exchange of water and solutes occurs in response to the pressure gradient across the capillary wall.
Therefore, the correct answer is option B.

The endothelium is a type of epithelium that lines the interior surface of organs. It is present in the inner lining of blood vessels and lymphatic vessels, forming an interface between circulating blood or lymph in the lumen and the rest of the vessel wall. It is a thin layer of simple squamous cells called endothelial cells. Whereas hemocyte is a blood cell, especially in an invertebrate, parietal cells (also known as oxyntic or delomorphous cells), are the epithelial cells that secrete hydrochloric acid (HCl) and intrinsic factor and chondrocyte is a cell that has secreted the matrix of cartilage and become embedded in it. Thus, option D is correct.

In order for blood to perform its essential functions of bringing nutrients and oxygen to the cells of the body, and carrying waste materials away from those cells, the chemical composition of the blood must be carefully controlled. Blood contains particles of many different sizes and types, including cells, proteins, dissolved ions, and organic waste products. Some of these particles, such as proteins like hemoglobin, are essential for the body. Others, such as urea (a waste product from protein metabolism), must be removed from the blood or they will accumulate and interfere with normal metabolic processes. But the largest responsibility for maintaining the chemistry of the blood falls to the kidneys, a pair of organs located just behind the lining of the abdominal cavity. It is the job of the kidneys to remove the harmful particles from the blood and to regulate the blood's ionic concentrations, while keeping the essential particles in the blood. Dialysis is a process for removing waste and excess water from the blood and is used primarily as an artificial replacement for lost kidney function in people with kidney failure.

• Digestion of protein is initiated in the stomach by the enzyme pepsin.
  
• In the small intestine, further digestion is done by trypsin, chymotrypsin, and carboxypeptidase into dipeptidase that releases from the pancreas.
• Dipeptidase are broken into amino acids by intestinal dipeptidase.
  
• These amino acids are absorbed actively by walls of intestine and release in the bloodstream.
• These are utilized by tissues and broken down into carbon dioxide and ammonia.
• Proteins require maximum energy to digest.

 Parietal cells of stomach secrets hydrochloric acid which convert inactive pepsinogen to partially active pepsinogen, partially activates pepsinogen then cleaves the peptide from other pepsinogen molecules to form active pepsin which converts protein into proteases and peptides.