Renal & GI Disorders Mini Medical School

Overview of the Kidney The Kidney’s main function is to maintain the homeostasis of

blood. It does this by filtering the blood contents and by releasing hormones into the blood stream. A Nephrologist is a physician who studies kidney diseases.

Kidney Function Initially, blood enters in through the renal artery, the blood

then passes through the nephron and some of its contents are filtered out. This filtrate eventually becomes the urine and is passed through the renal pelvis and down the ureter. The clean blood is returned into circulation via the renal vein. The nephron is the functional unit of the Kidney it is where a

series of pores cause osmotic changes and filter the blood.

Kidney Diagram.

Nephron…

Other functions of the Kidney In addition to filtration of blood the kidneys can release

hormones such as erythropoietin, calcitrol, and renin. For example, if the blood volume coming to the kidney is low

the kidney will think that blood volume and pressure is low and try to raise it by releasing renin. Renin works as part of the Renin-angiotensin system and

causes a variety of changes such as vasoconstriction, sodium and water reabsorption, eventually raising blood pressure and volume.

Gastrointestinal Overview The Gastrointestinal system is responsible for the digestion

and processing of food, it does this through mechanical movement, secreted enzymes, acid and hormones. Today, we will focus on the Stomach and the Lower

Gastrointestinal tract.

The Stomach The main function of the stomach is to store and break down

food. The stomach releases HCL and proteases to break down

protein and other food products with in itself. These along with protective factors are released from the gastric pits. In order to make sure this dangerous mixture does not leave

the stomach has several protections. First it has two sphincters that close tightly, the esophageal

sphincter (cardiac sphincter) at the top and the pyloric sphincter, which connects to the intestines. It also has several layers of mucus secretions to protect the

stomach lining from being digested. The stomach is also very muscular which is protective and

allows it to stretch.

The Small Intestine The Small Intestine has three sections: Duodenum This is the first section where digestive enzymes and bile

mix. This mixture breaks down proteins and emulsifies fat into micelles. Micelles are small spheres of fat which can be easily transported. The duodenum also produces and releases bicarbonate to help neutralize stomach acid.

Jejunum This is the middle portion of the Intestine, much of the

digested food is absorbed here through the villi. The villi are finger like projections that stick into the intestines and increase the surface area of absorption.

Ileum The Ileum comes last and mainly absorbs vitamin B12

along with some of the remaining nutrients missed by the Jejunum

The Large Intestine The large intestine makes up the last part of the GI system it

is about 5 ft long. It connects the small intestine to the anus. Its main function is the remove water from the excess waste

products of the body. It also helps to absorb a few vitamins. It can lead to many pathologies such as IBS, colon polyps,

colon cancer, diverticulitis, etc.

Case Study I 43 year old male comes into the ED at University hospital. He

is diaphoretic and complains of a sharp stabbing pain in his abdomen. He states that he feels nauseous and that the pain is unbearable. He says “ he can feel his pulse where the pain is.” He collapses on floor and is rushed to radiology for an abdominal x-ray.

X Ray Findings…

What is the diagnosis?

Kidney Stones Kidney stones form as a result of chemicals that build up

during the filtration process in the kidneys. They can result from many different things The biggest risk factor for kidney stones is dehydration Stones may not produce symptoms until they begin to move

down the ureters Stones can block the flow of urine out of the kidneys→

swelling of kidneys → severe pain!

Symptoms The main symptom is severe pain that starts suddenly

and may go away suddenly Pain may be felt in the belly area or side of the back Pain may move to groin area (groin pain) or testicles

(testicle pain) Other symptoms can include: Abnormal urine color Blood in the urine Chills Fever Nausea Vomiting

Types of Kidney Stones Calcium stones: oxalate, phosphate, or carbonate Most common type Often in men than women Ages 20-30 Calcium Stones are often Recurring

Cystine: Cystinuria Runs in families Men and women

Struvite: Women with UTI

Uric acid stones: More often in men than women Occur with gout or chemotherapy.

Treatment Treatment varies based on the severity/size and type of the

stone. Some stones are small and pass on their own. Pain relievers are used during the passing of stones, for

chronic pain narcotic and/or non-steroidal anti-inflammatory drugs (NSAIDS) are used. Surgery can be used in some cases. Extracorporeal shock-wave lithotripsy. Percutaneous nephrolithotomy. Ureteroscopy.

Case Study II Arnold a 60 year old store manager comes in complaining of

abdominal pain in the middle of the night for several nights. Arnold had stopped eating as much because he was afraid of the pain. He was referred to a different physician to get an endoscopy.

Findings on Endoscopy

What is the DDx ?

Peptic Ulcer A peptic ulcer is a sore that occurs in the lining of the

stomach or the duodenum. Most ulcers occur as a result of infection by Helicobacter Pylori. H.Pylori are bacteria that can survive in the stomach, by

converting urea to ammonia, thus raising the pH around them. They also move through the mucous layers. This movement allows HCL, pepsin, and other stomach contents to break through the lining. Infection with H.Pylori can also lead to adenocarcinoma. If stomach and or duodenal contents leak into the body,

major consequences result.

Symptoms Dyspepsia Heartburn Chest Discomfort Rarely, Haematochezia

Treatment Treatment includes anti-secretory therapy and avoidance of

NSAIDS. Surgery maybe required if ulcer is too large and bleeding

can’t be controlled by endoscopy. Extreme cases can be treated by vagotomy, antrectomy with

gastro duodenal reconstruction.

Case Study III A 46 year old woman goes to her Primary care physician

complaining of belly and back pain that has been getting worse over the past day. She has a fever of 101 degrees F. She noticed a little bit of blood in her stool. She has the chills and feels like vomiting. She has a history

of constipation. The lower left side of her abdomen is tender. She has no history of heart burn or stomach pain so she is

sent for a colonoscopy.

The colonoscopy revealed….

What is the diagnosis?

Diverticulosis Diverticulosis: presence of small outpouchings (diverticula)

in the muscular wall of the large intestine that form in weakened areas of the bowel. usually occur in the sigmoid colon, the high-pressure

area of the lower large intestine. Very common: occurs in 10 percent of people over age 40

and in 50 percent of people over age 60 in Western cultures.

Cause: Too little roughage (fiber) in the diet

Symptoms By itself diverticulosis doesn’t cause symptoms. It is when

these outpouchings trap feces and cause infection Symptoms often start suddenly, but they may become worse

over a few days. Tenderness, usually in the left lower side of the abdomen

due to infection in the sigmoid colon. Bloating or gas Fever and chills Nausea and Vomiting. Not feeling hungry and not eating

Treatment Rest in bed and possibly use a heating pad on your belly Pain medications maybe used. Antibiotics maybe used. Patients are instructed to drink only fluids for a day or two,

and then slowly begin drinking thicker liquids and then eating foods. Fiber can prevent future episodes and initial occurrence. Serious complications like perforation, or narrowing of the

colon may require surgery.

End.