There are 4 types of movements of small intestine
- Mixing movements
- Propulsive movements
- Peristalsis in fasting – Migratory Motor Complex
- Movements of villi
I. Mixing movements
They are responsible for breakdown of chyme and mixing them with
the digestive juices.
There two types of mixing movements
- Segmentation contractions
- Pendular movements
1) Segmentation contractions
- They are rhythmic contractions of contraction and relaxation of a segment of small intestine alternately
- They chop the chyme and mix them with the digestive juices.
2) Pendular movement
- These are sweeping movement of small intestine resembling the movements of pendulum of clock.
- They help in mixing of chyme with digestive juices.
II. Propulsive movements
These movements push the chyme in the aboral direction
There are 2 types of propulsive movements
- Peristalsis
- Peristaltic rush
1) Peristalsis
- Peristalsis is a wave of contraction followed by wave of relaxation of smooth muscles of small intestine in aboral direction.
- These movement push the chyme in the aboral direction.
2) Peristaltic Rush
They are powerful peristaltic contraction due to excessive
irritation or distension of intestinal
It Sweeps the contents of intestine into colon there by
relieving the small intestine off either irritants or excessive distention
III. Peristalsis in fasting - Migrating Motor Complex (MMC)
It occurs in stomach & small intestine during periods of
fasting
Significance of Migratory Motor Complex
- It sweeps the excess digestive secretions there by prevents its accumulation in stomach and intestine
- It also sweeps residual indigested materials
IV. Movements of Villi
Movements are shortening and elongation of villi occurring
alternatively as well as sidewards swaying of the villi.
- It helps in emptying lymph from the into the lymphatic system.
- Elongation of villi increase in surface area which helps absorption of food molecules.
