pg 1 of digestion

what are the 2 types of digestion

mechanical and chemical

Mechanical breakdown

breaks large pieces into smaller ones without altering composition.

Chemical breakdown

breaks food into nutrient molecules

Alimentary Canal

mouth, pharynx, Esophagus,Stomach, Small intestine,Large intestine (semples)

Mixing movements

smooth muscle

contracts rhythmically in small sections

Stomach

mix foods with digestive juices

Small intestine

segmentation alternates contractions and relaxations of the smooth muscle in segments.

Propelling movements

Peristalsis

wavelike motion in which a ring of contraction occurs in the wall and moves progressively along its length

receptive relaxation

Muscles in the wall just ahead of the ring relax

As the contraction moves along the tube,

it pushes the contents of the tube ahead of it

innervations of the tube

Branches of the

sympathetic and parasympathetic autonomic nervous system innervate the alimentary canal

Parasympathetic impulses

increase the activities.

Sympathetic impulses

inhibit activities

Submucosal plexus controls

secretions by the gastrointestinal tract

Myenteric plexus controls

gastrointestinal motility