Mastication, or chewing, mixes food with salivary mucus. This action subdivides food and exposes ingested starch to salivary amylase to begin the digestive process. Mastication is not essential for normal GI function but facilitates the process. Swallowing propels food from the mouth into the esophagus. The initiation

Homeostasis Regulation – Positive and Negative Feedback Mechanism

Homeostasis, a term presented by W. B. Cannon, describes the mechanism by which the constancy of the internal environment is maintained and ensured Homeostasis is the maintenance of a fairly steady internal environment by self-regulating physiological processes Homeostasis keeps body temperature and the structure of blood and

Gastric Motility

Stomach The stomach is anatomically and functionally divided into the fundus, body, and antrum. The fundus and body are highly distensible and act as reservoir for the ingested meal. A 1.5 L volume increase causes only a small increase in pressure in the lumen of the stomach.

Excitation – Contraction Coupling

The action potential generated at the motor end plate region spreads along the membrane of skeletal muscle cell and into the T tubules. The T tubules contain dihydropyridine receptors that connect to the Ca++ channels of sarcoplasmic reticulum. Depolarization of T tubules opens the sarcoplasmic reticulum Ca++

Small Intestinal Motility

The small intestine is divided into duodenum, jejunum, and ileum, with the duodenum and jejunum being the major site of digestion and absorption. Chyme takes 2 to 4 hours to move through the 5 m of the small intestine. Segmentation, which mixes intestinal contents and enhances contact