Anatomy and Functions of Salivary Glands, Pancreas and Liver

Anatomy of salivary glands

The salivary glands secrete saliva into the mouth through ducts. This allows you to swallow and chew food. Saliva can also protect you from oral and pharyngeal infections.

Salivary glands can be divided into two groups:

• Minor salivary glands
• Major salivary glands

Major salivary glands

There are several large and important salivary glands, but the major ones are the largest and most important of them. The largest amount of saliva is produced by these glands. The three major salivary glands are the parotid gland, the submandibular gland, and the sublingual gland.

Parotid glands

A parotid gland is one of the largest salivary glands. Their size is quite large, and they are located behind the ear. A duct near your upper second molar allows saliva to flow into your mouth from these glands. The shallow lobe and deep lobe of the parotid gland are separate. The facial nerve lies between these two parts. This nerve controls a variety of facial functions, including the ability to close your eyes, raise your brows, and smile. A major artery in the head and neck region, the external carotid artery, and a branch vein of the jugular vein, the retromandibular vein, are also nearby. A parotidectomy is the procedure used to remove a parotid gland tumor. Due to these important structures, the surgeon must locate them and operate around them with great precision.

Submandibular glands

Submandibular glands are located below the jaw and measure about the size of a walnut. They produce saliva, which is then secreted from under the tongue into the mouth. The submandibular glands also have superficial and deep lobes, like the parotid glands. They are located near:

• Nerves that help you smile, called marginal mandibular nerves
• You can move your lower lip because of the muscle called platysma muscle.
• The sensation in your togue is allowed by lingual nerve
• As your tongue moves, the hypoglossal nerve allows you to speak and swallow

All of these structures must be protected during treatment to avoid causing damage.

Sublingual glands

One of the smallest of the main salivary glands is the sublingual gland. Under the tongue and under the mouth floor are structures with almond-like shapes. These structures are very rarely affected by tumors.

Minor salivary gland

Small salivary glands are distributed all over the mouth and aerodigestive tract. It is impossible to see these glands without a microscope because they are much smaller than the major salivary glands. The majority of them are found in the walls of the mouth, on the tongue, inside the cheeks, in the nose, in the sinuses, and in the larynx (voice box). It is extremely rare for salivary glands to develop small tumors. The likelihood of malignant tumors is higher than benign ones. The cancers that affect the roof of the mouth are most likely to affect the minor salivary glands.

Functions of salivary glands

Many different purposes are served by saliva. Saliva forms the finely packed ball of food we roll in our mouths, as well as being the only secretion of our salivary glands. The shape of this food ball allows it to pass through our alimentary canal with ease. Saliva also has protective properties that make it an effective lubricant. While swallowing a bolus, our saliva protects our mouths, teeth, and throats from bacteria. Aside from that, it helps cleanse the mouth after meals and gives food a taste by converting fat into chemical compounds.

Anatomy of pancreas

Location - As a horizontal organ (15 cm long) lying obliquely across the posterior abdominal wall, the pancreas is elongated and horizontal, lying between the L1 and L2 vertebral bodies. The oblique positioning of the pancreas makes it impossible to see the entire organ in a single transverse section in the clinical context. During its travel through the epigastric and left hypochondriac regions of the abdomen, the pancreas comes into contact with several neighbouring structures. Besides the tail, the pancreas is located in the retroperitoneum, behind the peritoneum, in the abdominal cavity.

Parts - It is now time to move on to exploring the anatomy of the pancreas, since you know now where it is located. The body, the uncinate process, the neck, the body, and the tail make up the five anatomical sections of the parenchymatous organ. Pancreas expands medially at the head. The duodenum extends downwards and horizontally around the pancreatic head. On the inferior surface of the head, we see the uncinate process, which extends in a posterior direction towards the inferior mesenteric artery. In addition to the head, the neck continues laterally from it, a short extension of around 2 cm that joins the head to the body. As well as the origins of the hepatic portal vein and superior mesenteric artery, the superior mesenteric artery is posterior to the neck. Upon merging with the splenic vein, the superior mesenteric vein is present. Besides their surfaces (anteroposterior and posterior) and borders (superior and inferior), pancreatic bodies also have two integral lobes. The bursa of the L2 vertebra is located anteriorly. A smaller bursa called the omental bursa is located near it. The pancreatic body has several vessels and glands posterior to it, including the superior mesenteric artery, left kidney vessels, left suprarenal gland, and left renal vessels. Lastly, the pancreas is composed of the intraperitoneal tail. Splenic vessels run along the splenorenal ligament and the splenic hilum is closely related to it.

Pancreatic duct - There are two main pancreatic ducts (Wirsung) in the pancreatic parenchyma: one in the tail and one in the head. The hepatopancreatic duct, or ampulla of Vater, connects the liver with the pancreatic head. On the major duodenal papilla, it opens into the duodenum descending part. Flow through smooth muscle is controlled by the sphincter of Oddi through the ampulla of Vater. Hepatopancreatic duct resorption is also prevented due to this device. A sphincter sets up at the end of the main pancreatic and bile ducts to regulate the flow of these fluids. Pancreatic accessory ducts are in addition to the main duct. In the duodenum, in the descending part of the pancreatic neck, the main pancreatic duct opens.

Functions of pancreas

In addition to its exocrine functions, the pancreas plays an endocrine role as well. A function of the exocrine system is to produce digestive enzymes that are released into the small intestine called the duodenum. Endocrine glands release hormones such as insulin and glucagon into the bloodstream to regulate glucose, lipids, and protein metabolism. Exocrine and endocrine glands play major roles in pancreatic function. Eventually, these enzymes (zymogens) will be released into the glandular and pancreatic ductal systems, where they will act as digestive enzymes. As the zymogens reach the duodenum, these enzymes are activated by proteolytic enzymes that then act as active peptidases, amylases, lipases and nucleases in the small intestine to further digest the food. As part of the pancreas' endocrine function, the Langerhans islets produce hormones. Alpha, beta, and delta types of cells make up these endocrine glands. These glands make hormones directly available to the body. Alpha cells produce glucagon, while beta cells produce insulin, and delta cells produce somatostatin. The hormones act to regulate sugar metabolism and digestion.

Anatomy of liver

In your belly (abdomen) top right corner is the liver. There is a cavity beneath the diaphragm above the stomach, right kidney, intestines, and the right kidney. It performs a variety of functions.

Blood is supplied to the liver from two distinct sources:

• By way of the hepatic artery, blood is supplied with oxygen to the liver.
• Hepatic portal veins bring nutrient-rich blood into the liver.

The liver consists of two lobes. Each lobe contains eight segments. Segments are divided into thousands of small lobes (lobules). There are tiny ducts (tubes) connecting the lobules that connect with the larger ducts to form the hepatic duct. As bile is made in the liver, it travels through the common hepatic duct and on to the gallbladder and the duodenum. Bile aids digestion by being yellow or orange and helping to break down food.

Functions of liver

The liver is responsible for controlling the majority of chemical levels in the blood. The liver secretes this yellow or orange liquid. By breaking down fats, it makes them easier to digest and absorb. As the blood leaves the stomach and intestines, it is filtered by the liver. In the liver, blood is broken down, balanced, and nutrient-rich nutrients are created for the body. As well as breaking down the medicines in the blood to make them easier to use by the body, it metabolizes them. This liver performs several important functions, including:

• Bile helps transport waste away from the small intestine and break down fat during digestion.
• It is also responsible for producing proteins for blood plasma
• Produces cholesterol and special proteins for carrying fat around the body
• Glucose is stored and released as necessary
• The liver uses the iron in hemoglobin to produce hemoglobin.
• Produces urea (one of the materials excreted in the urine as a result of protein metabolism) that is harmful.
• Blood is cleansed of harmful substances and medicines
• Aids clotting of the blood
• By making immune factors, it removes bacteria from the bloodstream and protects the body against infections
• Bilirubin is cleared by this medication (high levels of bilirubin cause yellowing of the skin and eyes).

The liver excretes harmful substances into the bile or blood after they have been broken down by the liver. As bowel movements leave the body, bile by-products enter the intestineBy excreting blood by-products as urine; the kidneys eliminate these substances from the body.

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