Meet John Watson
Former army doctor and Sherlock's closest friend, John Watson is here to talk to you about the digestive system. Trained at St. Bartholomew's Hospital, John is an expert in the digestive area. At his office, you'll get to explore the various parts and functions of the system
After living with the know-at-all Sherlock for so long, he finally gets to show his expertise to anyone who's interested to learn about the digestive system.
Look below for a brief overview of the things you'll learn with John.
After living with the know-at-all Sherlock for so long, he finally gets to show his expertise to anyone who's interested to learn about the digestive system.
Look below for a brief overview of the things you'll learn with John.
Parts of the digestive system
The mouth:
The mouth perform mechanical digestion, which is the break down of food through physical movement. In this case, using the teeth and tongue to break apart large food particles into smaller ones which are easy to swallow. The epiglottis is an elastic cartilage covered in mucous that guards the entrance of the glottis. Also, salivary glands can be found in the mouth and throat, which secretes saliva containing the protein amylase that breaks down carbohydrates (Starch into maltose). This is an example of chemical digestion, which converts polymers into monomers through digestive enzymes. The esophagus: It transports bolus and liquids to the stomach which passes through the upper and lower sphincters which are pinched to prevent back flow. Peristalsis, a rhythmic waves of contraction, help the food down into the stomach. |
The liver:
Located on the top right side of the belly, the liver filters blood and removes toxic substances and waste via bile. The bile produced by the liver is stored in the gallbladder, which secretes the bile into the small intestine when the food enters. Bile neutralises stomach acid and provides a larger surface area for enzymes to use to break apart lipids. The Pancreas: Located underneath the stomach, above the spine, and connected to the small intestine, the pancreas carries abundant blood supply. Also, it regulates glucose metabolism and digests carbohydrates and proteins. Lipase, an enzyme that breaks down fasts and lipids, and amylase is also secreted from the pancreas. Enzymes secreted by the pancreas play a vital role in digestion in the stomach. The Stomach: A small round organ found on the left side of the body that digests food, mainly proteins through hydrochloric acid, which is measured by pH levels. When the food is acidified, chief cells release pepsin which is a digestive protease (breaks down protein into amino acids). |
The small intestine:
Made up of three parts: the duodenum, jejunum, and the ileum. Most of the digestion happens in the duodenum, which is the first part of the small intestine, while the nutrient absorption happens in the jejunum and ileum. When chyme (HCL acid + water +digested food) enters the duodenum, the pancreas secretes sodium bicarbonate to make the solution basic. Small protrusions called villi in the small intestine help increase internal surface area and well as absorb nutrients through its capillaries and lacteals. The large intestine: Absorbs water and vitamins from remaining food before excretion. It is made up of six parts: the cecum, rising colon, slanting colon, downward colon, sigmoid colon, and the rectum. Egestion takes place at the end, which is the passing out of food as feces through the anus. |