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The average distance that food travels through the body is about 8 m to 9 m.


The alimentary canal (or the digestive tract) covers the distance from the mouth to the anus.

Digestive System
(From lifespa.com)

However, the distance varies according to body type.

The intestinal distance in an ectomorph ("little fat or muscle") can be as little as 6 m and as much as 9 m for endomorphs ("much fat and muscle").

Here is a summary of the distances I found.

#color(white)(m)bb"Segment" color(white)(mm) bb"Length/m" color(white)(m)bb"Subsegment"color(white)(cm) bb"Length/cm"#
#color(white)(ll)"Mouth to"#
#color(white)(ll)"duodenum" color(white)(mmml)0.5 color(white)(mmmmmmmmmmmm)50#

#color(white)(mmmmmmmmmmmmml)"Jejunum"color(white)(mmmml) 250#

#color(white)(ll)"Intestine"color(white)(mmmml) 1.8color(white)(mmll) "Cecum" color(white)(mmmmmmll) 5#
#color(white)(mmmmmmmmmmmmmll)"Ascending" color(white)(mmmml)10#
#color(white)(mmmmmmmmmmmmmll)"Transverse" color(white)(mmmm) 65#
#color(white)(mmmmmmmmmmmmmll) "Descending" color(white)(mmmll) 10#
#color(white)(mmmmmmmmmmmmmll)"Sigmoid"color(white)(mmmmml) 65#
#color(white)(mmmmmmmmmmmmmll)"Rectum"color(white)(mmmmml) 20#
#color(white)(mmmmmmmmmmmmmll)"Anus" color(white)(mmmmmmml) 5#
#color(white)(mmm)"TOTAL ="color(white)(m) 8.6#


Mechanical digestion breaks the food into smaller pieces, so that digestive enzymes have a larger surface area to work on.


Mechanical digestion is the breakdown of food without the aid of chemicals.

Chemical digestion is the action of chemicals in the body to break large food molecules into smaller ones.

In the mouth

Chewing food breaks it into smaller pieces so they can be transported through the esophagus to the stomach.

Chewing also mixes the food particles with saliva, which contains enzymes for breaking down carbohydrates.

In the stomach

(From 2012 Book Archive)

The food travels to the stomach, where the food is mechanically churned by peristalsis (contraction of the stomach walls) and mixed with stomach acid and more digestive enzymes.

In the small intestine

Smooth muscle contractions called segmentation transport the food through the digestive system.

(From BC Open Textbooks)

Segmentation separates the food and then pushes it back together, mixing it with digestive juices and pushing it against the mucosa to be absorbed.

When most of the food has been absorbed, another type of peristalsis moves the remainder further along the small intestine to the large intestine for eventual evacuation.


Through the use of other scanning techniques.


While X-Rays are certainly the most widely known scans, they are not effective at revealing everything that goes on inside the body. A doctor would most likely use either an MRI or a CT to view an injured tendon.

Here are X-Rays and some other types of scans and what they are used for:

X-Rays - X-Ray scans beam X-Rays through your body revealing a two-dimensional image of what's inside. More dense materials, like bones, absorb X-Rays much better than less dense materials, like tissues. Therefore, X-Rays are the primary scan used to view the bones.

Also, air does not absorb X-Rays, so they can be used to diagnose lung tissue abnormalities as well, because there should be no image produced within the lungs because no X-Rays should be absorbed.

http://www.radiologyinfo.org/en/info.cfm?pg=bonerad http://www.radiologyinfo.org/en/info.cfm?pg=bonerad

CT: Computer Tomography scan also utilizes X-Rays, but CT scans shoot out X-Rays in layers or slices, and combines the slices to create a three-dimensional picture of the body.

The biggest advantage of CT scans is that they can be used to create detailed, 3-D images of many types of tissues.

This CT scan shows 23 slices of the brain. They give you a full picture of what every layer of the brain looks like.

MRI: Magnetic Resonance Imaging is another technique that, much like CT, creates detailed 3-D images of the inside of the body. Instead of radiation like CTs, MRIs uses magnetic fields and radio waves to create images.

MRIs are similar to CTs in that they are versatile in what they can be used for. However, CTs and MRIs often allow different details to be seen, so it is up to the medical professional to assess which would be most useful.

This is a brain MRI.

Ultrasound : A type of sonography, this method of imaging uses sound waves to create a live, real-time motion picture of what is happening inside the body. What ultrasound is probably most well known for is providing a look at what is happening in the uterus during pregnancy.

Here is a video of an expecting mother being talked through an ultrasound.

PET: Positron Emission tomography uses radioactive markers injected into a patient to track what is happening inside the body. PET scans are used to see what is happening inside the body at the cellular level.

Here is a PET scan of the brain!https://www.reference.com/health/pet-scan-cancer-28bd930602dd3766

To answer the initial question, a doctor would most likely use either an MRI or a CT to view an injured tendon.


Liver supplies emulsifying bile juice to duodenum.


Liver is a very important organ. It prduces bile juice which is not enzymatic but there are bile salts present in the juice. The juice is temporarily stored in a small sac like organ called gall bladder .

As the half digested food (chyme ) enters duodenum from stomach, the gall bladder is given signal to contract. Bile is thus poured in duodenal cavity through duct.



Bile salts present in the juice acts as emulsifier on dietary fat globules which has reached duodenum with chyme. Large fat droplets are transformed into microscopic aggregates called micelle. Fat digesting enzymes (lipases) can now act on large fat molecules and break them into absorbable smaller molecules (glycerol and fatty acids).




The digestive system extracts the usable chemical energy from food to power exercise.


Exercise is a very dynamic activity, requiring every body system to function properly. If one body system is not functioning properly, there will likely be a chain reaction leading to other body systems becoming impaired as well.

The digestive system's main role in exercise is to provide the necessary fuel. The purpose of eating is to extract chemical energy from the food and transform it into energy we can use to power our bodies. And exercise, and recovering from exercise, requires significant amounts of this energy, which the digestive system provides.

So to summarize, the main role of the digestive system in exercise is to provide the fuel we need to be able to physically perform exercise.


Complex food is converted to absorbable molecules in human digestive system


Food consists of complex carbohydrates, fat and proteins.
Digestive system is designed to convert complex food to absorbable, smaller molecules.


Food is first broken down mechanically when we chew it in our mouths. Some chemical digestion also occurs in our mouth as saliva breaks down food. Once food has reached the stomach, it is churned and broken down further with the aid of enzymes.

In the small intestine, some chemical digestion occurs, as enzymes break down food, but this is the main site where what remains of our food is absorbed into our body. In the small intestine, nutrients and minerals are absorbed through the villi. Nutrients absorbed through the cell wall of the villi enter the bloodstream and are then transported throughout the body. In the large intestine, more water is absorbed.

This short video covers the basics of the digestion system:

Only glucose can enter the cell membrane. Other monosaccharied absorbed are fructose and galactose.

Only individual amino acids are absorbed in digestive system. Complex proteins are degraded to amino acids.

Lipids are digested to free fatty acids are absorbed.
In short, digestive system degrades food in nutrients.

The reason is through cell membrane molecules of a certain size can be penetrated.

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