Free Essay Example: Anatomy - Digestive System

The digestive system, which in other words is referred to as the gastrointestinal tract is a lengthy coiled, hollow continuous muscle duct that runs from the oral cavity through the stomach and ends in the anus. The main organs that are within the digestive system include the mouth, pharynx, gullet, stomach, ileum, and colon which leads to an opening referred to as the anus (Hightower & Sircus, 2020). It additionally comprises accessory organs such as the pancreas, liver, and gallbladder.

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Anatomical Functions

The mouth or the oral cavity is described by Pearson (2018) as a lubricated membrane lined opening which is comprised of the lip, cheeks tongue, plates, teeth as well as the salivary glands, which are paramount in the digestion process (Miller & Leavell, 1972).

• The Lips protect the anterior of the opening
• Checks from the lateral wall
• Palates are divided into both the hard and soft palate, and these are responsible for the formation of the anterior as well as the posterior roofs, respectively.
• The tongue is the muscles that occupy the floor of the mouth
• The vestibule is the spacer between the teeth and the gums, as well as the space between the lips and the cheeks forming the internal and external vestibule, respectively.
• The teeth are born like substances commonly referred to as the dentin, and they are covered by enamel.
• There are three groups of salivary glands, and they produce a soggy secretion referred to as saliva, and the saliva is responsible for softening the food.
• Throat or pharynx is a tube-like funnel that connects to the back of the oral cavity (Miller & Leavell, 1972).
• The pharynx is equipped with two skeletal muscles, and it allows the food to pass the posterior of the mouth or oropharynx, as well as the laryngopharynx, which is continuous with esophagus.
• Esophagus, commonly referred to as the gullet, connects the pharynx to the stomach, and it conveys the chewed and swallowed balls of nutriment. The esophagus has four layers of tissues (Hightower & Sircus, 2020).
• Mucosa which the innermost layer; it is moistened, and it lines the cavity.
• The second layer is the submucosa, which lies underneath the mucosa. It is mainly a soft connective muscle which has a high concentration of blood vessels as well as the nerve endings
• The muscularis externa is the other layer, and it is comprised of the inner circular layer as well as the outer longitudinal layers of even muscles.
• The serosa is the outermost layer. It is a Single fat layer, and it is responsible for producing serous cells.
• The stomach is usually c-shaped, and it is mainly located on the left of the gut cavity and almost concealed by the liver (Hightower & Sircus, 2020).
• Important to note is that the stomach is between 15 to 25 inches long and holds upon four liters of food
• The cardia is the area surrounding the cardioephageal sphincter through which the food balls enter the stomach from esophagus.
• The stomach is, therefore, a provisional storage tank that encompasses the digestive enzymes and the hydrochloric acid, which aid in the digestion process.
• The small intestine is an essential digestive organ, and it is a powerful funnel or tube that connects the pyloric sphincter to the colon (Miller & Leavell, 1972).
• The small intestine is two to four meters long, and I inch in diameter
• It is further divided into three sections that are the duodenum, which is the first part, the jejunum, “which is among the duodenum and the ileum, and the ileum, which is the terminal part of the small intestines between the jejunum and the cecum of the large intestines.” (Hightower & Sircus, 2020).
• By the time the food exists the small intestines, the nutrients of around 90 percent are already extracted.
• The large intestine is in charge for drying the indigestible foods by absorbing a large about of water as well as eliminating the residues (Hightower & Sircus, 2020).
• the large intestine is shorter than the small intestine but broader. It is 1.5 to 5 feet and 2.5 in circumference.
• It connects the ileocecal valve to anus
• It is additionally divided into five subsections, including the cecum, which is the pouch beginning in the large intestines, an appendix which is a worm-like protraction of the large intestines, the colon, rectum, and the anal canal.
• The liver, which is located beneath the diaphragm, is a major gland in the body.
• It additionally lies on the right side of the body superimposes or almost covering the stomach completely.
• The liver is composed of four lobes, namely left, right, quadrate, and caudate.
• It is responsible for the production of bile juice.
• The gallbladder is a small “green sac that snuggles in a shallow fossa in the inferior of the liver” (Miller & Leavell, 1972).
• It is responsible for storing the indigested food
• The pancreas is a huge gland that is both positioned at the inferior as well as the posterior of the stomach.
• It is approximately six inches in length.
• “It is responsible for secreting the digestive enzymes into the small intestine to complete the digestion procedure” (Miller & Leavell, 1972).

The Physiological Functions

Ingestion

It is the initial purpose of the digestive structure (Miller & Leavell, 1972).

The intake of food and this functio0n is carried out in the mouth.

Propulsion

This function is carried out by more than a single organ

The peristalsis is the involuntary contractions and the relaxation of the muscles on the walls of an organ that compel the food along a tube or tract.

Digestion. The larger food particles are broken into smaller digestible molecules, both mechanically and chemically, by the use of enzymes (Miller & Leavell, 1972).

Mechanical digestion includes the mixing of the food in the mouth, chewing, and mixing.

The chemical digestion includes the use of saliva, enzymes, acids, and pepsin

Absorption

It is the transportation of nutrient from the lumen to the blood vessels and therefore enters the mucosal cells

The absorption mainly takes place in the large intestine

However, “water and both vitamin K and B are absorbed in the large intestine” (Miller & Leavell, 1972).

Excretion

It is the exclusion of the indigestible foods from the digestive system through the anus inform of feces

it is the last purpose of the digestive scheme, and it is controlled entirely by the brain, and it is accomplished regularly to stop back up.

Interesting Facts

It takes only seven seconds for food ball to reach the stomach from the mouth.

The intestines of adult females are longer or more extensive than those of male adults

An individual can eat upside down

The stomach is not accountable for complete digestion of food instead this is done in the ileum.

Reference

Hightower, N., & Sircus, W. (2020, February 04). Human digestive system. Retrieved July 10, 2020, from https://www.britannica.com/science/human-digestive-system

Miller, M. A., & Leavell, L. C. (1972). Anatomy and Physiology. New Delhi: Amerind Pub. Pvt. Retrieved July 10, 2020, from https://opentextbc.ca/anatomyandphysiology/