We digest our meals utilizing our gastrointestinal tract, additionally referred to as the GI tract. Meals strikes from the mouth to the esophagus, by way of the decrease esophageal sphincter, to the abdomen, by way of the pyloric sphincter, to the small gut, after which to the big gut. Accent organs embrace the liver, gall bladder, and pancreas.
What occurs in your mouth? A number of issues. These embrace mechanical digestion as you bodily chew your meals, chemical digestion utilizing lingual amylase (additionally referred to as salivary amylase) lingual lipase, and lubrication of our meals to allow simple swallowing. Though our nostril does the primary job of detecting flavors, we are able to additionally detect flavors from the meals aromas that journey from the again of our mouth up into the nasal cavity. Do not forget that we mentioned we style with our tongue and detect flavors with our nostril. The instrument for tasting is our style buds. These “buddies” of ours detect sure chemical compounds on our tongue and ship a sign to our mind to inform us what we’re tasting. The 5 tastes embrace: salty, bitter, umami, bitter, and candy.
As soon as we’re achieved chewing, we swallow. We didn’t discuss this however you will need to observe that as we swallow, a valve referred to as the epiglottis covers the doorway to our windpipe in order that meals or drinks don’t get into our respiratory system. That’s why we are able to’t breathe and swallow on the similar time.
After swallowing, the meals strikes rapidly in direction of the abdomen by highly effective muscle tissues that loosen up and contract within the esophagus, permitting meals to get to the abdomen in seconds. Simply earlier than going into the abdomen there’s a valve or you could say gate, referred to as the decrease esophageal sphincter. The well being of this gate is essential. Folks affected by disfunction of the LES will expertise acid reflux disease, that’s, meals shifting again up into the esophagus. In case you have ever skilled this, the burning sensation that it causes – not stunning given the acidic nature of the abdomen.
The abdomen is a strong muscle designed to churn the meals we eat right into a soupy mass referred to as chyme. Digestive juices together with hydrochloric acid (HCl), gastric lipase, pepsin (a protease), and intrinsic issue (for B12 absorption) ensures that our meals is sufficiently damaged down in order that the remainder of the manufacturing line can deal with the job.
After digestion within the abdomen, chyme is handed off to the small gut. As you possibly can think about, meals from the abdomen may be very acidic. The small gut can not deal with this stage of acidity, in order meals enters, sensors within the duodenum ship a message to the pancreas to launch bicarbonate ions which it makes use of to neutralize the acid. Additionally secreted from the pancreas are varied enzymes which can be wanted to complete up digestion e.g., amylase, lipases, and proteases. A few of these enzymes are additionally produced within the lining of the small gut. Since fat have a tendency to stay collectively, bile salts saved within the gall bladder are launched to interrupt the fat aside and stop them from associating. That is very similar to the perform of cleaning soap which disperses oil and grease out of your plate as you do the dishes.
The small gut is the place we full the digestion course of, and the place we additionally start to soak up vitamins which will get transported to its varied locations through the liver. Two of the essential options we talked about at school in regards to the small gut is that it’s lengthy (about 20 ft) and has a tough floor. This facilitates most absorption of vitamins. What are the tiny projections within the small gut referred to as that provides it its tough texture? When you mentioned villi, you might be completely appropriate. As soon as digested, vitamins are absorbed by way of the cells lining the villi referred to as enterocytes. Every villus has tiny capillaries that enables the absorption of amino acids, sugars, and small fatty acids. The villi even have one other transportation line referred to as lacteals that are hooked as much as our lymphatic system. That’s the place giant fatty acids and fat-soluble nutritional vitamins are absorbed as these molecules are too giant and hydrophobic (water hating) to be absorbed into the blood through the tiny capillaries within the villi.
Subsequent cease, we go to the big gut, in any other case generally known as the colon. Right here is the place water and electrolytes (dissolved minerals) remaining within the meals is absorbed. This will increase effectivity and little question prevents your stool from being too watery – in any other case you’ll have a everlasting diarrhea. Who needs that? Aside from absorption, the big gut is the place you’ve one other cool factor taking place, i.e., fermentation. Right here, good micro organism (additionally referred to as probiotics) break down fiber (additionally referred to as prebiotics) to provide essential byproducts for our well being. For instance, they produce vitamin Okay and B nutritional vitamins, and brief chain fatty acids (SCFA) which have been discovered to have a number of useful results on the mind, immune and intestine well being.
Undigested meals is quickly saved within the rectum and finally eradicated through the anus.
Courtney Simons
Administrator
Dr. Simons is a meals science educator. He earned his bachelor’s diploma in meals science, and Ph.D. in cereal science at North Dakota State College.
