1.2.3: Toxicology & The Digestive System

Added: 2026-05-27

[00:00:00]hey everybody this is a short video about toxicology and the digestive system so during the lab in 1 two three you guys are going to be doing a forensic Toxicology presumptive test so let's talk a little bit about what we mean by these things well toxicology is the field of science that studies the effects of chemicals such as drugs alcohols poisons metals and gases on the human body and forensic toxicologists of course are analyzing biological samples to detect the presence of toxic substances in the human body so looking for toxic substances is because toxic substances of course could contribute to somebody's death so in a forensic autopsy you need the work of forensic toxicology in order to determine if possibly some sort of toxic substance chemical poison drug Etc might have contributed to somebody's death forensic chemists are similar to forensic toxicologists but are generally going to test non-biological samples so two different kind of types of um people who would work with these sorts of substances looking for these kinds of chemicals uh forensic toxicology is kind of like a more specialized version of a forensic chemist except that they're um you know toxicologists are more working with biological samples whereas chemists are not so a partially digestive pill was found in an a stomach contents during the autopsy and that's why we're talking about forensic toxicology and also while we're talking about the digestive system so major subdivisions of the digestive tract are going to be the parts of the digestive tract through which food and other nutrients are entering and passing through the body so it's going to start with the mouth also known as oral cavity here the teeth the tongue right and this is where a lot of the mechanical processing the chewing moistening saliva is going to be introduced the ferx is going to propel uh food items uh from the oral cavity down into the esophagus so the tongue action is going to push food through the fings and down to the opening of the esophagus the esophagus then of course is that muscular tube that goes from the mouth and the fairings down to the stomach right and so there is mus smooth muscle within that esophagus that is going to uh push that food down through an action that's called peristalsis the stomach then is where you have uh further chemical breakdown this is a very uh acidic region of the digestive tract there's a lot of acid there's a lot of enzymes um enzymes like pepsin for example that break down protein and other enzymes that break down other types of um biological stuff right U biological molecules food stuff uh and then once the stomach is done digesting both through that chemical digestion and mechanical digestion then food's going to be moving into the small intestine and small intestine is where you're going to have a little bit further digestion a little bit further breakdown but the main purpose of the small intestine is for the absorption of those nutrients into the bloodstream so water organic substrates vitamins ions uh carbohydrates proteins Etc all these things are going to be going uh into the bloodstream mostly through the small intestine there's a small amount of absorption that happens in the stomach but it's mostly going to happen in the small intestine then you have your large intestine and the large intestine there's a little bit more uh digestion absorption but mostly it's going to be of water the large intestines main purpose is going to be reabsorbing water that was introduced into the small intestine and the stomach through in order to help digest things uh and then so the large intestines main thing is to reclaim that water for the body so that you don't get dehydrated if your large intestin doesn't do that very well you have diarrhea and that's no fun uh so those are the main subdivisions that dig just subtract now there are also other organs that are going to be contributing to digestion but are not actually going to be something that food passes through so those are called the accessory organs of the digestive system uh and they include your salivary glands contribute saliva uh into the mouth uh the liver liver secretes bile which is a really important thing for helping you uh break down and digest fats or lipids also helps store nutrients does a whole bunch of other things uh for the digestive system that the contribution of bile is the main thing that's it's going to be doing the gallbladder is a little storage stck basically that stores concentrated bile that's produced by the liver uh that can be used when when it's needed so kind of plays a similar role kind of Step by Step there with the liver and then you also have the pancreas and the pancreas uh secretes um buffers and digestive enzymes uh into the small intestine especially and uh it also plays an important role with how we actually process our food later on um playing a role in like um blood sugar h stasis and that sort of thing so there's a bit of introduction to uh the basics of Toxicology and the digestive system uh the next video will be more about the specifics of the lab that we're going to be doing in 1 two 3