eatwellgetwell – a nutrition and medicine study blog

Outer layer: Peritoneum  

= largest serous membrane of the body
(torso, map)
= Closed sac containing serous fluid
(serous fluid = watery fluid)

Supplied with many blood and lymph vessels

Barrier to local spread of infection

parietal layer: lines a cavity
visceral layer: surrounds organs

The organs are invaginated into the closed sac being at least partly covered
Greater ormentum

= fold enclosing the stomach.
It hangs in front like an apron
It stores fat

Middle layer: Muscle layer

Smooth, involuntary muscles

2 layers:
Circular muscle layer
Longitudinal muscle layer

In between:
Blood vessels, lymph vessels, a plexus
Myenteric or Auerbach’s plexus

= Network of sympathetic and
parasympathetic nerves

Movement

Contraction and relaxation in waves
= peristalsis

Moves food forward and mixes the food
Sphincters control movement

Sphincters

= increased numbers of circular muscle fibres

Act also as valves to prevent reflux

Submucosa

Connective tissue containing blood vessels, lymph vessels and nerves

Mucosa

mucous membrane
lamina propria
muscularis mucosa

Mucous membrane
In the intestinal tract: Columnar epithelial cells with mucus secreting goblet cells

Mucus lubricates and protects from digestive juices

Lamia propria
= Conncetive tissue with lymph tissue

Blood supply

The digestive organs are supplied form branches of the aorta.

Venous drainage

The portal vein drains the blood from the lower part of the oesophagus, the stomach, pancreas, small intestine, large intestine and part of the rectum.

Blood from the lower part of the rectum and the anal canal drains directly into the
iliac veins