The Ileum
Definition
The ileum is the last part of small intestine
It occupies the central and right lower abdomen and the pelvis
It ends by opening into the caecum where there may be a valve - ileocaecal valve
It forms 3/5 of the small intestine
Its wall is thinner than that of the jejunum
Microscopic Anatomy
The ileum consists of 4 layers
1. Mucosa - having three different layers:
- Columnar epithelial layer
- An underlying lamina propria - loose connective tissue - large aggregates of lymphoid tissue called Peyer's patches
- A thin layer of smooth muscle called muscularis mucosae.
2. submucosa - containing
- connective tissue
- blood vessels
- a nervous component called submucosal plexus
3. Muscular layer - containing
- inner circular -
- outer longitudinal smooth muscle bundles -
- myenteric plexus of nerves
4. Serosa - visceral peritoneum
Blood Supply
Arterial Supply
Multiple ileal branches arising from the left side of the Superior Mesenteric Arterty.
Ileocolic artery arising from the right side of the Superior Mesenteric Arterty
ileal, ileocolic veins drain into the Superior Mesenteric Vein
Nerve Supply
superior mesenteric plexus
Nerves are derived from the sympathetic and parasympathetic (vagus) nerves from the superior mesenteric plexus.
Applied Anatomy
Meckel's diverticulum
Crohn's disease
Tuberculosis
Lymphoma
Neuroendocrine tumours (carcinoid)
ILEUM = part of intestine
ILiUM = hip bone
