Biology News
Anatomy and physiology of ageing 10: the musculoskeletal system - Nursing Times


Nursing Times
This is the penultimate article in our series on the anatomy and physiology of ageing. Citation: Knight J et al (2017) Anatomy and physiology of ageing 10: the musculoskeletal system. Nursing Times [online]; 113: 11, 60-63. Authors: John Knight is ...

Using planes and lasers for a biodiversity checkup - SWI swissinfo.ch - swissinfo.ch


swissinfo.ch
Researchers at the University of Zurich have developed a new system to measure the diversity and health of forests with a laser scanner mounted on ...

Visualizing Anatomy Unseen - Science Friday


Science Friday
We live at a time where medicine can offer face transplants and build prosthetic hands that provide the sense of touch. But it's surprising what we still don't know about basic anatomy, such as the veins and capillaries that make up the vascular system ...

ThinkQuest: Human Digestive System

Redwood Shores, California - United States

The human body needs fuel to live. We eat food for fuel. But just getting the food into the body is only a small part of the process. The food must be broken down into chemicals that the body can use. This whole process is called digestion. Some of the organs involved in digestion are the mouth, esophagus, stomach, small and large intestines, gallbladder, pancreas and liver. Follow the process to find out how the body uses the food we eat.
Mouth and Teeth: The mouth and teeth are the first step in breaking food down. During the process of chewing, food is shredded and ground. Powerful muscles move the mandible, or lower jaw, while the food is chewed. The front teeth cut the food and the back teeth grind the food.
There are three main parts to the tooth: the root, the neck and the crown. The root is the part inside the jaw. The neck is a narrow connection between the root and the crown. The crown of the tooth is above the gum.
First teeth come in between 6 and 8 months. By age 6, baby teeth are gradually replaced by permanent teeth. There are 32 permanent teeth.
When food is being chewed, saliva is squirted into the mouth. Saliva helps to soften the food. It contains an enzyme that helps break down the starch in the food.
After chewing, the food is swallowed and passes down the esophagus to the stomach. The esophagus is about ten inches long. The tongue helps push the food to the back of the mouth, and the muscles in the esophagus move the food down the tube.
Traveling Food: The stomach is a sac shaped like a "j" and is about eight inches long. In the stomach, food is mixed with acids. The muscles in the stomach move, which helps break down the food. The stomach is protected from the acid by a lining. From the stomach, the food pulp is sent to the small intestine. Food leaves the stomach a little bit at a time.
The small intestine is the final place for digestion. Measuring about twenty feet in length, the small intestine is one inch in diameter. Digestive juices released in the small intestine finish breaking down the food.
The food is moved along the small intestine in a squeezing motion known as peristalsis. This motion is much the same as squeezing a tube of toothpaste. All of this movement causes the noise when we say our stomach is "growling."
Lining the small intestine are millions of fingers called villi. These absorb the chemicals that we need from the food into the body. It is at this point the food is actually in the body.
Waste products and food that are not absorbed in the small intestine pass into the large intestine. This waste material is called feces. The large intestine is only five feet long but is larger in diameter than the small intestine. The large intestine includes the colon.
In the large intestine, feces are formed from water, undigested food and bacteria. Water is absorbed back into the body so the waste material becomes more solid as it travels through the colon. It may take as long as twenty hours for food to pass completely through the large intestine.
Gall Bladder Pancreas and Liver:The pancreas is an elongated gland that is below the stomach. It produces pancreatic juice that contains digestive enzymes. The pancreas also secrets insulin into the blood. Insulin is needed to allow glucose or sugar from food to get into the bloodstream. People who cannot produce insulin are diabetics.
The largest gland in the body is the liver. It is on the right side of the body underneath the ribs. It weighs about three pounds and is eight inches long. The liver stores a form of glucose called glycogen. Vitamin A is manufactured in the liver. Bile which is needed to breakdown fat, is made in the liver. This organ is also where alcohol, drugs, bacteria and old blood cells are broken down and removed from the body. Damage to the liver can be serious because this organ is extremely necessary to life.
The gallbladder is a small sac on the underside of the right lobe of the liver. It stores bile that is made by the liver. Bile travels from the liver through the hepatic ducts to the gallbladder. It holds about two ounces of bile. Bile is needed to breakdown the fat that is in food.

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Muscles are responsible for your body's every move. Muscles keep your gut from sagging and your lungs pounding. Muscles are more than movers. Muscles make the heat that keep you warm. If you leap, bend, or reach, this is a result of a muscle action. A muscle makes itself smaller when it contracts and larger when it relaxes. Types of Muscles: Skeletal Smooth Cardiac

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The integumantary system contains the largest organ in the human body, the skin. It is also comprised of such extensions of the skin as hair and fingernails. The skin, however, is the most important of these. The skin protects and cushions the body's delicate organs. It also provides the body a physical barrier to keep out foreign materials and to prevent the body from drying out. The skin is made of three separate layers, each with its own parti

Digestive System - KidsHealth
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The digestive system is made up of the alimentary canal and the other abdominal organs that play a part in digestion, such as the liver and pancreas. The alimentary canal (also called the digestive tract) is the long tube of organs - including the esophagus, the stomach, and the intestines - that runs from the mouth to the anus. An adult's digestive tract is about 30 feet long.

Your Digestive System and How It Works
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Describes the digestive process and the organs involved.

InnerBody:  Digestive System
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The digestive system is a group of organs working together to convert food into energy and basic nutrients to feed the entire body. Food passes through a long tube inside the body known as the alimentary canal or the gastrointestinal tract (GI tract).

Pathophysiology of the Digestive System
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Voyage through the digestive tract.

The Ruminant Digestive System
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Information on this system which is very different to that of non-ruminants, featuring a fermentation chamber housing millions of micro-organisms.

Medpedia:Digestive System
United States

The digestive system consists of the organs involved in ingestion, digestion and absorption of food. Thus it is composed of the digestive tract from the mouth to the anus, and its associated glands and organs (salivary glands, liver, gall bladder and pancreas). Other roles of the organs of the digestive system include the metabolic functions of the liver and the endocrine functions of the pancreas.

Digestive System Disorders
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The function of the digestive system is to take the food and liquids that we put into our mouths and then either turn these foods and liquids into nutrients or energy needed by the cells of our body, or alternatively turn them into waste products that are then expelled by our body as bowel movements.

Finland

Describes important discoveries related to human origin as well as various theories and theorists.