definition layers of the small intestine parts of the small intestine functions of the small intestine types of enteritis signs and symptoms complications diagnose treatment

1. Enteritis
Dr.Sami

2. Definition:
 Entero: Small Intestine
 Itis: Inflammation
 Enteritis is inflammation of the small intestine. It is most commonly caused
by food or drink contaminated with pathogenic microbes, such as serratia, but
may have other causes such as NSAIDs, cocaine, radiation therapy as well as
autoimmune conditions like Crohn's disease and celiac disease. Symptoms
include abdominal pain, cramping, diarrhea, dehydration, and fever

3.  Coeliac disease or celiac disease
 is a long-term autoimmune disorder, primarily affecting the small intestine,
where individuals develop intolerance to gluten, present in foods such as
wheat, rye and barley
 Crohn's disease
 is a type of inflammatory bowel disease (IBD) that may affect any segment of
the gastrointestinal tract from the mouth to the anus

4. Small Intestine:
 The small intestine or small bowel is an organ in the gastrointestinal tract
where most of the absorption of nutrients from food takes place. It lies
between the stomach and large intestine, and receives bile and pancreatic
juice through the pancreatic duct to aid in digestion.
 it is longer than the large intestine, it is called the small intestine because it
is narrower in width.
 Width of Large Intestine: 7.5 cm (3 in.)
 Width of Small Intestine: 2.5 cm (1 in.)

5. Structure:
 Size:
 The length of the small intestine can vary greatly, from as short as 3.00 m
(9.84 ft) to as long as 10.49 m (34.4 ft),
 It is approximately 1.5 cm in diameter in newborns and 2.5–3 cm (1 inch) in
diameter in adults. On abdominal X-rays,

6. Small intestine Mucosa:
 The small intestine is similar to the other organs in the digestive tract. There
are four main layers:
 Mucosa (Innermost layer) – Contains the epithelium, lamina propria and
muscularis mucosae.
 Submucosa – Connective tissue layer, which contains blood vessels,
lymphatics and the submucosal plexus.
 Muscularis externa – Consists of two smooth muscle layers; the outer
longitudinal layer and inner circular layer. The myenteric plexus lies between
them.

7.  Adventitia (Outermost layer) – Comprised of loosely arranged fibroblasts and
collagen, with the vessels and nerves passing through it. The majority of
the small intestine adventitia is covered by mesothelium and is commonly
called the serosa.

8. Parts:
 The duodenum
 is a short structure ranging from 20 cm (7.9 inches) to 25 cm (9.8 inches) in
length, and shaped like a "C".
 It receives gastric chyme from the stomach, together with digestive juices
from the pancreas (digestive enzymes) and the liver (bile).
 The digestive enzymes break down proteins and bile emulsifies fats into
micelles. The duodenum contains Brunner's glands, which produce a mucus-
rich alkaline secretion containing bicarbonate. These secretions, in
combination with bicarbonate from the pancreas, neutralize the stomach
acids contained in gastric chyme.

9.  The jejunum
 is the midsection of the small intestine, connecting the duodenum to the
ileum.
 It is about 2.5 m long, and contains the plicae circulares, and villi that
increase its surface area. Products of digestion (sugars, amino acids, and
fatty acids) are absorbed into the bloodstream here.

10.  The ileum:
 The final section of the small intestine.
 It is about 3 m long, and contains villi similar to the jejunum.
 It absorbs mainly vitamin B12 and bile acids, as well as any other remaining
nutrients.
 The ileum joins to the cecum of the large intestine at the ileocecal junction.

11. Blood supply
 The small intestine receives a blood supply from the celiac trunk and the
superior mesenteric artery. These are both branches of the aorta.
 The duodenum
 receives blood from the coeliac trunk via the superior pancreaticoduodenal
artery and from the superior mesenteric artery via the inferior
pancreaticoduodenal artery.
 The jejunum and ileum receive blood from the superior mesenteric artery

12. Enteritis
 Enteritis is inflammation of the small intestine.
 Duodenitis, jejunitis and ileitis are subtypes of enteritis which are localised
to a specific part of the small intestine.
 Inflammation of both the stomach and small intestine is referred to as
gastroenteritis
 colitis large intestine
 enterocolitis large and small intestine

13. Causes and Types:
 Autoimmune
 Crohn's disease – also known as regional enteritis, it can occur along any
surface of the gastrointestinal tract. In 40% of cases, it is limited to the small
intestine.
 Coeliac disease – caused by an autoimmune reaction to gluten by genetically
predisposed individuals. where individuals develop intolerance to gluten,
present in foods such as wheat, rye and barley.
 Eosinophilic enteropathy – a condition where eosinophils build up in the
gastrointestinal tract and blood vessels, leading to polyp formation,
necrosis, inflammation and ulcers. It is most commonly seen in patients with
a history of atopy, however is overall relatively uncommon

14. Infectious enteritis
 In 90% of cases of infectious enteritis are caused by four pathogens,
Norovirus, Rotavirus, Campylobacter and Salmonella. Other common causes
of infectious enteritis include bacteria such as Shigella and E. coli, as well as
viruses such as adenovirus, astrovirus and calicivirus.
 Campylobacter jejuni is one of the most common sources of infectious
enteritis, and the most common bacterial pathogen found in 2 year old and
smaller children with diarrhoea

15. Vascular disease
 Ischemic enteritis is uncommon compared to ischemic colitis due to the
highly vascularised nature of the small intestine, allowing for sufficient blood
flow in most situations.
 It develops due to circulatory shock of mesenteric vessels in the absence of
major vessel occlusion, often associated with an underlying condition such as
hypertension, arrhythmia or diabetes.
 Thus it has been considered to be associated with atherosclerosis
 Ischemic damage can range from mucosal infarction

16. Radiation enteritis
 This type of enteritis canoccur after radiation therapy. Radiation works by
killing rapidly dividing cells. This kills cancer cells, but also healthy cells.
This includes mouth, stomach, and bowel cells.
 Radiation enteritis develops when your normal, healthy intestinal cells are
damaged by radiation and become inflamed. This condition usually goes
away several weeks after you finish your treatment. However, symptoms can
sometimes be chronic and last for months or years after you have finished
your treatment.

17.  Symptoms may include abdominal
 pain,
 cramping,
 diarrhea,
 dehydration,
 fever,
 nausea, vomiting
 weight loss.
 Bleeding and mucus discharge from rectum

18. Complications:
 excessive thirst
 Dehydration
 weakness
 fatigue
 lethargy
 poor urine output
 dark urine with strong odor
 dizziness especially when standing up

19. Diagnose:
 Medical history
 Physical examination
 Tests
 blood counts,
 stool cultures
 CT scans, MRIs,colonoscopies and upper endoscopies.
 biopsy

20. TREATMENT
 For mild cases treatment is not need, it recovers within two to three days
 In cases where symptoms persist or severe cases treatment is needed
 Oral rehydration solution(ORS) is used in cases of diarrhea
 In infectious enteritis Antibiotics are taken.