Catégories : Tous - symptoms

par hetal vithalani Il y a 11 années

475

Small Bowel by Hetal vithalani

Neuroendocrine tumors, particularly carcinoid tumors, are the most common neoplasms found in the small bowel. These tumors originate from neuroendocrine cells and often produce serotonin (

Small Bowel by Hetal vithalani

Small Bowel by Hetal vithalani

Mechanical obstruction

Small bowell infarction

Small bowel infarction

smll bowel is highly susceptible to ischemic injury

transmural infaction occurs with thrombois embolism of the superior mesentric artery or thrombosis of the mesentric vein

mucosal infarction occurs with marked hypotension

clinically fetures include abdominal pain

bloody dieariea and decresed bowel sounds.

Intussusception

telescoping of proximal segment of bowel forward in to distal segment

most common in infants and children.

in adults, intussusception may be associated with a mass or tumor

it present with intestinal obstruction

abdomianl pain

current jelly stool

it can get infacted

volvulus

Volvulus

twisting of a segment of bowel on its vascular mesentery, resulting in intestinal obstruction and infaction. volvulus is often associated with congential abnormalities such as inestinal malrotation.

common location include the signoid colon and small bowel

complication

infraction and peritonitis

Tumor

Carcinoid Tumor

malignant proliferation of neuroendocrine cells low grade maligancy

Neuroendocrine tumor, most common small bowel tumor (50%)

Common sites: appendix, small intestine, rectum, stomach, colon

Produce 5HT (serotonin), but asymptomatic unless 5HT gets beyond liver’s first-pass metabolism.

Generally, in order for symptoms to occur, the tumor must metastasize to the liver. Uncommonly, primary tumors in the bronchus can cause symptoms without

mets.

f carcinoid metastasizes to liver or beyond → carcinoid syndrome (symptomatic)

Carcinoid syndrome: paroxysmal wheezing, skin flushing, diarrhea, right-heart murmur

They are sometimes quite hard to rember, because they seem unrelated: diarrhea, flushing, diseases of the right heart valves and bronchospasm.









So imagine a toilet with this sign on it:


When in DIARRHEA:


Please FLUSH


using the RIGHT VALVE


to avoid BRONCHOSPASM


Malabsorption syndromes

Lectose Intolerance

Decresed function of the lactase enzyme found in the brush border of entrerocytes

Lactase normally breaks down lectose in to glucose and galactose

presents with abdominal distension and diarrhea upon consumption of milk products undeigested lactose is osmotically active

deficiency may be congetial or acquired

Whipple Disease

is a rare infectious disease involving many organs including small intestines

joints

lung

heart

liver

splean

central nervous system

Caucasian males aged 30 to 50

infecting organisam is

tropheryma whipplei - gram negative rod shaped bacilli

clinically

present with malbsorption weight loss and diarrhea

treatment

antibiotics

Topical Sprue

Tropical Sprue

Malabsorptive disease of unknown etiology

affecting travelers to tropical regions such as the caribean and south america

the microscopic apearance is similar to celiace sprue

treatment

Antibiotics

Vitamin B12

Folate

Celiac Disease

Celiac sprue

Gluten sensitive entrerophathy and nontropical sprue

is due to hypersensitivity to gluten resulting in loss of small bowel villi and malabsorption.

HLA B8 , DR3, and DQ have been linked to celiac sprue.

Microscopically

loss of villi

with increased inttraepithelial lymphocytes and increased plasma cell in the lamina propria

clinically

celiac sprue usally presents with childhood with malasorption.

Symptoms

Abdominal distention

blotting

dermatitis herpetiformis

Treatment

no gluten

Celiac sprue features

CELIAC:

Cell-mediated autoimmune disease

European descent

Lymphocytes in Lamina propria/ Lymphoma risk

Intolerance of gluten (wheat)

Atrophy of villi in small intestine/ Abnormal D-xylose test

Childhood presentation

(Atrophied villi cause less absorption, so diarrhea, weight loss, less energy.)

Congenital

Mechel Diverticulum

Meckel Diverticulum

Outpouching of all three layers of the bowel wall (true diverticulum)

arises due to failure of the vitelline duct to involute

Rule of 2nd

seen in 2% of the population

2inches long and located in the small bowel with in 2 feet of the ileocecal valve

can present during the first 2years of life with bleeding, volvulus, intussusception, or obstruction - mimic appendicitis however most causes are asymptomatic.

gastric metaplasia

Duodenal Atresia

congenital failure of a dudenum to canalize associated with Down syndrom

clinical features

polyhydrammions

Distension of stomach and lind loop of duodenum (double bubble)

Bilious vomiting

Duodenam observes nutrician from food

form in 6th week of pregnency

just below the stomuch

by 10 week of pregnancy - dudenum attresia forms