Once again, these lectures aren't super well organised, but I'll try and talk about them as best I can.
"Dumping" Syndrome
"Dumping" Syndrome is a functional disorder of the stomach where the stomach empties too fast, thus "dumping" all of its contents into the poor, overworked duodenum. It is usually idiopathic (that is, has no known cause), but bariatric surgery (which Google Chrome seems to want to correct to "barbaric surgery") seems to be a risk factor. Which leads us to our next topic...
Obesity and Bariatric Surgery
As you should know, being obese usually comes with a host of other health problems. (If you've gotten this far without knowing that, then I suggest you change majors.) Bariatric surgery was developed to combat obesity. There are two main goals of bariatric surgery: restrictive operations reduce the size of the stomach, whereas malabsorptive operations bypass parts of the small intestine so that not as many calories are absorbed. Some types of surgery may address both parts, whereas others might only address one.
One common type of bariatric surgery that addresses both parts is called Roux-en-Y. Roux-en-Y separates off most of the stomach, leaving only a little bit attached to the rest of the GI tract. (The rest of the stomach still stays inside the patient, but doesn't receive any food.) Parts of the small intestine are bypassed, forming a Y-shaped structure, hence the name of the operation. Roux-en-Y can also help with co-morbidities of obesity, such as diabetes, and patients who undergo this surgery are less likely to require repeated operations. It is, however, major surgery, and as such can be risky.
A less invasive type of bariatric surgery that is commonly done is adjustable gastric banding. In adjustable gastric banding, a band is wrapped around part of the stomach, restricting the amount of food that can pass through. It's much safer than Roux-en-Y and patients can typically walk out of the hospital following surgery.
A third type of bariatric surgery is sleeve gastrectomy where part of the stomach is removed permanently. This isn't so common throughout the world any more, however.
Gastroparesis
Back to other functional disorders of the stomach! Gastroparesis is kind of the opposite to "dumping" syndrome- instead of the stomach emptying too quickly, in gastroparesis it empties too slowly. Usually, a balance of neuronal, hormonal and luminal signals work together to regulate gastric emptying. If this goes awry, then the stomach might take longer to get rid of its stuff. Diabetics are particularly prone to this- remember how I mentioned that diabetics were at risk of neuropathy? Well, the enteric nervous system is not immune to this, and if this system is affected, gastroparesis may result.
Pyloric Stenosis
Pyloric stenosis is another functional disorder in which the pyloric sphincter, between the stomach and duodenum, does not open at all. This is usually due to some abnormality in the enteric nervous system, meaning that the pyloric sphincter never gets inhibitory signals telling it to relax. Symptoms of this include projectile vomiting and failure to thrive (since pyloric stenosis is something that kids have from birth). To treat this, the pyloric sphincter is cut.
Liver and Gallbladder Problems
Now we're moving onto some organs that are a little bit different, in that the food doesn't pass through them, but they secrete lots of juices and stuff that are important in digestion. Hopefully you know a little bit about these organs- if not, check out the posts that I linked to in my previous post.
Biliary Colic
Biliary colic is the blockage of bile outflow. True to its name, it results in colicky pain, which is pain that comes and goes. A common cause of biliary colic is gallstones, which many adults (10-20%) have, but very few of these actually get symptoms. Aside from pain, there are a range of complications that can result from gallstones: they can perforate the bile duct, or simply cause things to back up, resulting in jaundice and/or liver cirrhosis. Not pleasant, especially since these complications can dramatically increase mortality rates.
Fortunately, there are ways of treating gallstones before they get too bad. They can be surgically removed, be broken up via lithotripsy (shockwaves) or dissolved with certain medications.
Jaundice
I mentioned jaundice just now, but I didn't really explain what it was. Well, jaundice is essentially when your skin and eyes turn yellow. It is essentially the symptom that results from having very high levels of bilirubin in the blood, bilirubin being a product from the breakdown of old red blood cells. High levels of bilirubin could mean two things: that you are producing too much (which might happen in the case of a haemolytic disorder) or you are getting rid of too little (which might happen in the case of an obstructive disorder, such as biliary colic). A common cause of jaundice is...
Hepatitis
Hepatitis is inflammation of the liver (hopefully you realise by now that "-itis" means "inflammation"). It is caused by viruses (helpfully named Hepatitis A, B, C, D and E) as well as cancer and some chemicals such as paracetamol/acetaminophen and ethanol. Here's a handy little table about the viral forms of hepatitis:
| Virus | Fun facts (not really) | Where found | Duration |
| A | a.k.a. "Infectious Hepatitis" | Contaminated water, food etc. | Acute |
| B | a.k.a. "Serum Hepatitis" | Blood and other secretions | Chronic. Can be an asymptomatic carrier. |
| C | Was known as the one that was "non-A and non-B" for a while. May leave you at risk of cancer. | Blood | Chronic |
| D | Can only occur with Hep B | Blood, environment | Can be acute or chronic |
| E | Essentially just the acute form of D | Blood, environment | Acute |
Thankfully, there is some protection available against viral hepatitis! There are vaccinations available against Hep A and Hep B, and since D requires B (D's defective and needs to hang onto B in order to exist), being vaccinated against Hep B essentially vaccinates you against Hep D as well. Handy!
Cirrhosis
Cirrhosis, or scarring of the liver, can develop as a consequence of hepatitis. Just like with any other scar tissue, cirrhosis results in a loss of function. When the liver is scarred, a whole lot of things happen: bilirubin increases, less bile is produced, less fat is absorbed, less glucose is converted to glycogen, detoxification is impaired, and so on. These can lead to jaundice (see above) and even encephalopathy (brain damage). Cirrhosis can also restrict blood flow, causing pressure in the hepatic portal vein to increase. This can have a downstream effect on other veins that drain into the hepatic portal vein, such as the splenic vein, superior and inferior mesenteric veins, gastric vein etc. In turn, this can lead to complications such as rupture of the spleen and ascites (fluid in the peritoneal cavity). Pretty nasty stuff- cirrhosis can be lethal!
And on that note, sweet dreams!
Cirrhosis
Cirrhosis, or scarring of the liver, can develop as a consequence of hepatitis. Just like with any other scar tissue, cirrhosis results in a loss of function. When the liver is scarred, a whole lot of things happen: bilirubin increases, less bile is produced, less fat is absorbed, less glucose is converted to glycogen, detoxification is impaired, and so on. These can lead to jaundice (see above) and even encephalopathy (brain damage). Cirrhosis can also restrict blood flow, causing pressure in the hepatic portal vein to increase. This can have a downstream effect on other veins that drain into the hepatic portal vein, such as the splenic vein, superior and inferior mesenteric veins, gastric vein etc. In turn, this can lead to complications such as rupture of the spleen and ascites (fluid in the peritoneal cavity). Pretty nasty stuff- cirrhosis can be lethal!
And on that note, sweet dreams!
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