16.2 Digestive System

The process of removing waste and excess water from the blood is called Dialysis.

The body of fluids and waste must be removed when the kidneys fail.
This is important to keep patients alive.
In some cases, the patients have to go through artificialalysis until they are ready for a transplant.
In people who aren't candidates for a transplant, it's a necessity.

The technicians work in hospitals and clinics.

Some roles in this field include equipment development and maintenance, but most work in direct patient care.
Under the direct supervision of a registered nurse, their on-the-job duties typically include providing dialysis treatments.
This can include reviewing patient history and current condition, assessing and responding to patient needs before and during treatment, and monitoring the process.
Taking and reporting a patient's vital signs may be part of the treatment.

All living organisms need food.

Animals are able to get their nutrition from the consumption of other organisms than from the roots of plants.
The animal's function at the cellular level is dependent on a number of biological molecules.
The food is made up of fat, and complexCarbohydrates.
Animals need to convert macromolecules into simple molecule for cellular function.
The absorption and digestion of food is a multistep process.
Food particles are broken down during digestion and absorbed by the body.

This can be done by both physical and chemical means.

Maintaining a balance between food intake, storage, and energy expenditure is one of the challenges in human nutrition.

Storage of the excess in the form of fat deposits is caused by taking in more food energy than is used in activity.

Understanding the role of diet and nutrition in maintaining good health is more important now that there is a rise in obese people.

The teeth break food into smaller particles in the process of digestion.

saliva begins to break down food.
A tube that connects the mouth to the stomach is called a long tube.
The stomach's pH is between 1.5 and 2.5.
This acidity kills organisms and breaks down food.
Further breakdown of food takes place in the small intestine, where bile andamylases are produced by the pancreas and small intestine.
The small molecule enters the blood stream through the cells of the small intestine.
The waste material travels on to the large intestine where water is absorbed and the drier waste material is compressed into feces, which is stored until it is excrete through the anus.

The components of the human body are shown.

The mastication of the teeth breaks the food into smaller particles.

All mammals have teeth and can chew their food to break it down into smaller particles.

lysozyme has antibacterial action.

Cells in the tongue produce lipase to break down fats.
The tongue helps in swallowing.
The pharynx opens to two different parts of the body.
The trachea leads to the lungs.
The epiglottis is a flap of tissue that covers the tracheal opening during swallowing to prevent food from entering the lungs.

The saliva begins to digest fats and starches.

With the help of the tongue, the result is moved into the stomach.

The mouth and stomach are connected by the esophagus.

The food is chewed and swallowed.
The food is pushed toward the stomach by the smooth muscles of the esophagus.
There is no reverse movement of the peristaltic wave except in the case of the vomit reflexample.

The sphinxes form valves in the GI tract.

The cardiac sphincter is located at the stomach end of the esophagus.
In response to swallowing, the sphinx opens and the food enters the stomach.
The contents of the stomach are not allowed to travel up the esophagus when there is no swallowing action.
When the acidic juices escape into the esophagus, acid reflux occurs.

The acidic environment kills many organisms in the food and the action of the pepsin results in the catabolism of the food.

The stomach is churned by contraction and relaxation of smooth muscles to facilitate chemical digestion.
Within two to six hours after a meal, gastric emptying occurs.
A small amount of chyme is released into the small intestine.
The movement of chyme from the stomach into the small intestine is regulated by hormones, stomach distension and muscular reflexes.

The stomach has a thick mucus lining and is unaffected by pepsin and the acidity.

From the stomach to the small intestine is where chyme goes.

The small intestine is a long tube-like organ with a folded surface.
Microvilli are small projections on the top surface of each villus.
The cells of these structures absorb food and release it to the bloodstream on the other side.
The villi and microvilli have many folds and increase the surface area of the small intestine.

The duodenum, jejunum and ileum are the three parts of the small intestine.

The duodenum is in the stomach.
The chyme is mixed with juices that have an alkaline solution in them.
Pancreatic juices have several digestive enzymes that break down food.
The water-soluble enzymes can be reached by bile salts.
The cells of the intestinal lining absorb monosaccharides, amino acids, bile salts, vitamins, and other nutrients.

The food is sent from the ileum to the colon.

The large intestine begins at the ileocecal valve.
The ileocecal valve contains the vermiform appendix.
Humans have a small role in immunity.

The large intestine is larger in diameter than the small one.

The cecum, colon and rectum are part of it.
The cecum joins the ileum to the colon and is the receiving pouch.

The colon is home to many types of flora that aid in the digestion.

The colon is used to store waste material and to extract water and mineral salts from undigested food.

The large intestine stores waste until it is eliminated.

During elimination, the feces are propelled.

The outer and inner sphinxes regulate the exit of feces.

The organs of the bicyle are what passes food through.

There are accessory organs that break down food.
The salivary glands are one of the accessory organs.
The hormones that regulate the secretions of the three organs are related to food consumption.

The duodenum contains bile that is needed for the breakdown of fats.

The absorbed vitamins and fatty acids are processed by the liver.

The stomach has an acidic environment.

The human diet needs to be balanced to provide the necessary vitamins and minerals for good health and reproductive capability.

A balanced diet for humans includes fruits, vegetables, grains, and dairy.

You can learn more about the recommended daily amounts for each food group.

Food is required for the building of cellular material and tissues.

Carbohydrates are broken down into sugars and used to provide energy in the cells of the body.
Humans don't produce theidase necessary to digest cellulose, which can be broken down into sugars through biochemical modification.
The plant fibers in the human gut can provide some nutrition.
The plant fibers are an important part of the diet.
The excess sugars in the body are stored in the body for later use.

Long-distance running and providing energy during a food shortage can be done with genogen stores.

mammals store fat under their skin for insulation and energy reserves.

During the process of digestion, the resulting amino acids are absorbed.

All of the proteins in the body have to be formed from these amino-acids.

Fats add flavor to food.

Saturated foods are important sources of energy and are required for the construction of the sphinx.
The production of fat-soluble hormones and the absorption of fat-soluble vitamins are aided by fat in the diet.

The animal body can synthesise many of the molecules required for function, but there are some that need to be obtained from food.

Omega 3 alpha-linolenic acid and Omega 6 linoleic acid are essential for making some types oflipids.

Many of these help the enzymes in their function and are called coenzymes.

Absence or low levels of vitamins can affect health.
Minerals act as cofactors and perform many functions.
The body can't synthesise certain amino acids from food.
The "essential" amino acids are these.
The human body can only synthesise 11 of the 20 required acids from food.