Fantastic Voyage Essay Example for Free

Fantastic Voyage EssayOnce again my mini sub and I will be miniaturized making us 8 microns long and witnessing an early(a)wise(prenominal) Fantastic Voyage in a human clay. This time I will be swallowed by a 55 year old man, while he is eating his meal consisting of a hamburger, French fries, and a root beer. I will be piloting my sub through his gastrointestinal parcel to monitor the canion of his meal, I will be describing all major structures I go through. Digestion begins in the mouth. A brain reflex triggers the flow of saliva when we see or even think of nutrient. Saliva moistens the diet while the teeth chew it up and make it easier to swallow.Amylase, which is the digestive enzyme, found in saliva, starts to break dash off starch into simpler sugars before the sustenance even leave the mouth. The nervous pathway involved in salivary excretion requires stimulation of receptors in the mouth, sensory impulses to the brain stem and parasympathetic impulses to saliv ary glands. Swallowing his nourishment happens when the muscles in his tongue and mouth move the food into his pharynx. The pharynx, which is the passage way for food and air, a pocket-size hassle of skin called the epiglottis closes over the pharynx to prevent food from entering the trachea and causing choking.For swallowing to happen suitable a combination of 25 muscles must all work together at the same time. afterwards being chewed and swallowed the food enters the esophagus or gullet is the muscular tube in vertebrates through which ingested food passes from the throat to the raise. It connects the pharynx, which is the body cavity that is common to both the digestive and respiratory systems behind the mouth, with the carry, where the second exemplify of digestion is initiated. The esophagus is a long tube that runs from the mouth to the stomach.It uses rhythmic wave like muscle movements called vermiculation to force food from the throat into the stomach. At the b lock off of the esophagus there is a sphincter that allows food into the stomach thus closes ski binding up so the food can not travel back up into the esophagus. The distal end of the esophagus is slightly narrowed because of the thickened circular muscles. This part of the esophagus is called the lower esophageal sphincter. Now I follow the food down the esophagus into the stomach. The stomach is a hallow saclike organ enclosed in a muscular wall.These flexible muscles allow the stomach to expand when you eat. The stomach has three tasks in digestion. Mixing foods with gastric juices, gastric juices are secretions from the stomach cladding that contains hydrochloric acid and pepsin, an enzyme that digests protein. Hydrochloric acid I nteh stomach kills bacteria taken in with food and creates an acidic environment. Storing swallowed food and liquids, the stomach holds food and liquids Next is the pancreas, liver and gallbladder. The pancreas liver and gallbladder are essential f or digestion.The pancreas produces enzymes that help digest proteins, fats, and carbohydrates, the liver produces bile that helps the body absorb fat, and the gallbladder stores the bile until it is needed. The enzymes and bile travel through special(prenominal) channels called ducts and into the small catgut where they help break down the food. afterwards being in the stomach food enters the duodenum. The duodenum is a hollow jointed tube connecting the stomach to the jejunum. It is the first and shortest part of the small intestine.This is too where the bile and pancreatic juices enter the intestine. The jejunum is a part of the small bowel, located between the distal end of the duodenum and the proximal part of the ileum. The inner surface of the jejunum its mucous membrane, is covered in projections called villi, which increase the surface sweep of weave available to absorb nutrients from the gut contents. The ileum its function is to absorb vitamin B12 and bile salts. The three main sections of the small intestine is the duodenum, the jejunum, the ileum.In the small intestine bile produced in the liver and stored in the gallbladder, pancreatic enzymes and other digestive enzymes produced by the inner wall of the small intestine help in the breakdown of food. After passing through the small intestine, food passes into the large intestine in the large intestine well-nigh of the piddle and electrolytes are removed from the food many microbes in the large intestine help in the digestion process. The first part of the large intestine is called cecum. The superior mesenteric vein drains blood from the small intestine jejunum and ileum.At its termination behind the neck of the pancreas the superior mesenteric vein combines with the splenic vein to take form the hepatic portal vein. Before joining with the splenic vein, it lies next to the superior mesenteric arteria wich arises from ab aorta. The portal vein drains blood to capillary beds in the liver. From here the hepatic vein arises and drains into the inferior cava where it enters the right atrium of the heart. From here he deoxygenated blood enters the right ventricle via the tricuspid valve. From the right ventricle it enters the pulmonary artery via the pulmonary valve and enters the lungs.From here the deoxygenated blood enters the left atrium of heart via the pulmonary vein and then the left ventricle via the mitral valve. From the left ventricle blood enters he aorta the ascending aorta. Thoracic aorta and ultimately abdominal aorta. The abdominal aorta divides into the left renal artery which enters the kidneys and supplies blood over there. Each renal artery divides into segmental arteries dividing except into interlobar arteries which penetrate the renal capsule and extend through the renal columns between the renal pyramids.These interlobular arteries tot blood to the accurate arteries that run through the boundary of the cortex and the medulla. Each arcuate art ery supplies some(prenominal) interlobular arteries that feed into the afferent arterioles that supply the glomeruli and hence the kidneys. The urinary tract from bowmans capsule is, the blood then enters the kidney via glomerular membrane in the nephrons. The blood trickles from bowmans capsule to renal tubule, that is proximal knobbed tubule, loop of Henley, distal convoluted tubule and then into collecting duct system.The blood from the cortex is passed to medulla of kidneys. The water supply formed is collected via ureter. The urine from the ureter then passes to urinary bladder and leaves the body from the urethra. Homeostasis in the body is just possible if the cardiovascular system is working properly. This means that the system needs to deliver oxygen and nutrients to the tissue silver that surrounds the cells and also take away the metabolic waste, the heart is composed of arteries that take blood from the heart, and vessels that relent blood to the heart.Blood is pum ped by the heart into two turns the pulmonary and systemic circuits. The pulmonary circuit carries blood through the lungs where gas exchange occurs and the systemic system transports blood to all parts of the body where exchange with tissue fluid takes place. The cardiovascular system works together with all other systems to concord homeostasis. Homeostasis and the urinary system, toxic nitrogenous wastes accumulate as proteins and nucleic acids are broken down and used for other purposes.The urinary system rids the body of these wastes. The urinary system is also directly involved in maintaining proper blood volume and ion concentration within the blood. One other contribution is that the kidneys produce a internal secretion that stimulates red blood cell production. The kidneys also play an important role in maintaining the correct water content of the body and the correct salt composition of extracellular fluid. External changes that lead to excess fluid loss trigger feedback mechanisms that act to inhibit fluid loss.