Featured Answers

Active contributors today


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#


You look for the side where the capitulum is located.


First, you must be able to recognize a humerus.


The humerus is the long bone in the arm that runs from the shoulder to the elbow.

The upper end has a rounded head.

The lower end has two processes (projections) in the front.

(From bio.sunyorange.edu)

One is the trochlea (Latin for pulley, referring to the groove in a pulley).

The other is the capitulum (little head).

A distinguishing characteristic in the posterior view is the olecranon fossa (head of elbow trench).

(From bio.sunyorange.edu)

Right or left?

Orient the bones so that the rounded head is up.

Look for the deep olecranon fossa on the lower (distal) end.

Rotate the humerus so that the capitulum and trochlea face YOU.

If the capitulum is on the left side of the bone, it is a left humerus. If the capitulum is on the right side, it is a right humerus.

Just to make it clear, the rotating image at the top of this page represents a left humerus and the image below it is of a right humerus.


I don’t know about veins, but the whole circulatory system can stretch up to 160 000 km.


The human circulatory system consists of arteries, veins, and capillaries.

They can stretch up to 160 000 km when laid end to end.

This is enough to stretch four times around the Earth's circumference (40 000 km).


Most of the blood vessels in the human body are capillaries.

They are short but there are billions of them.

Thus, even though they are small, they are so numerous they make up most the body's 160 000 km of blood vessels.


The nephrons in desert mammal Camel are equipped with well developed Henle's loop and number of juxtamedullary nephrons in kidneys is very high, about 35% (in man this number is about 15%).


Desert mammals do not readily find water, hence they must excrete very less amount of water. They are able to produce highly concentrated urine.



From the accompanying diagram you would be able to see that the Henle's loop of juxtamedullary ( =adjacent to medulla of kidney) nephron goes deep down into the medulla. This is why medulla of camel's kidney is thicker than that of other mammals, but it is most well developed in another desert mammal, the kangaroo rats.

The Henle's loops of juxtamedullary nephrons along with counter flowing blood vessels, called vasa recta, help in conservation of water.



Blood first flows along ascending limb of Henle, which is impermeable to water. Solutes can leave the filtrate and enter the blood along this stretch. When this blood flows along descending limb, water is reabsorbed from filtrate but not the solutes. Longer the Henle's loop, more amount of solute will be reabsorbed and hence more amount of water could be removed from filtrate.


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.

View more
Ask a question Filters
This filter has no results, see all questions.
Question type

Use these controls to find questions to answer

Need double-checking
Practice problems
Conceptual questions