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- Lyrics are right below the video
They say you are what you eat, which leaves me with a question
‘Bout this food on my plate and its impending digestion.
How this protein, fat and carbohydrate that you see
Is gonna get broken down and rebuilt into me?
Ingestion’s the start, it’s when you take the food in
Breaking down the food, that’s digestion
And then the food gets absorbed or assimilated
What you can’t absorb, it’s gotta be eliminated
Chewing and grinding food to forms so little
That kind of digestion is mechanical
And enzymes breaking polymers to monomers so simple
That kind of digestion is chemical
In ‘most animals, earthworms, gnats or rats,
There’s a tube that’s called the digestive tract.
Attached to the tract are parts that secrete,
Enzymes and juices to break down what you eat
Breaking food down in your digestive tract
Polymers to monomers enzyme attack
Food becomes chyme, disassembly line
You are what you eat so watch how you dine!
Liver and pancreas keep on secreting
Juices for treating the food you’ve been eating
Mouth to esophagus, stomach, intestine,
Colon to rectum to anus digestion!
The teeth grind food increasing surface area,
Of any food you’d find, in any cafeteria
The salivary glands release salivary amylase
Which chemically digests starch, a carbohydrate
Then swallowing moves mood to the esophagus
Choking is prevented by the epiglottis
Which covers the up the windpipe so you won’t choke or cough
The epiglottis seals the trachea off!
Peristalsis moves food through the digestive tract,
In waves smooth muscles contract and relax
So it’s not gravity that moves the food from place to place,
You can eat upside down, or in outer space.
The stomach’s the next place your food will go,
Hydrochloric acid makes the pH low
The low pH makes proteins relax
Setting them up for enzyme attack
Pepsinogen’s an enzyme that the stomach secretes,
Acid makes it into pepsin which breaks apart proteins
A soupy mixture known as acid chyme forms in your tummy
It’s what you vomit when you’re sick it’s anything but yummy
The stomach sends the chyme on the next step on this trip,
Pyloric sphincter opens, allowing chyme to drip
Into the duodenum, the start of the intestine,
Leading us into another moment in digestion
Now it’s time for bile, that bitter green secretion
Whose job is to emulsify the fat that you’ve been eatin’
The gall bladder stores bile that the liver synthesizes
Fat gobs are split into digestible sizes
The duodenum gets the bile from the bile duct,
And more secretions come in through the pancreatic duct
Bicarbonate is one, it’s job is to neutralize
The acid from the stomach so intestines will be alkaline.
This pancreatic juice, it’s an enzymatic brew
With amylase and protease and lipase in that stew
As food moves along, enzymes break down each polymer
‘Til nothing’s left of food but the simplest monomers
We’re ready for absorption: no cause for confusion
Food moves from intestines to the bloodstream by diffusion
The intestine’s villi, increase surface for absorption
Food diffuses into the blood, no matter what the portion!
After this absorption, the system ain’t restin’
What’s left moves to the colon, the large intestine
Feces forms from indigestible food and fiber
It’s the same in earthworms, or antelopes or tigers.
Reabsorbing water, it’s a main colonic function,
Its flows from the colon to the blood without compunction.
And you can thank the bacteria in your colon,
For synthesizing vitamin K and Biotin
But other colonic things ain’t so cute
The gases, farts, that make us toot
Nitrogen, hydrogen, CO2 and methane,
The last one’s a cause of climate change.
The appendix is a little pouch that sometimes can excite us,
When it’s inflamed it causes pain it’s called appendicitis
It’s functionless, vestigial so you can take mine out of me
Its surgical removal is called an appendectomy
The rectum’s the last stop on this pathway within us,
The feces is stored ‘til it exits out the anus,
What started as food, now meets its final fate
As it exits out our body as we eliminate.