Mammalian Nutrition - Explain the role of longitudinal and circular muscle in the stomach and small intestines.(

Biology – Mammalian Nutrition

Explain the role of longitudinal and circular muscle in the stomach and small intestines.(6)

In the stomach the muscle tissue helps to churn the foods and acids up. This helps move the food get digested quicker as it moves it around, exposing more of the food to acids and enzymes. Sphincter muscles are required both at the bottom of the stomach to stop food proceeding onto the next part of the journey, and also at the top so that acid (or, less importantly, food) cannot be squeezed back up the oesophagus, which would itself be digested as it does not have the same mucus lining that the stomach does which protects it.

In the small intestines circular and longitudinal muscle is used as the means to enforce peristalsis along the gut. They make up the muscularis externa. The circular and longitudinal muscles contact behind a package of food which then squeezes that bit into the next little bit of the intestine.

Describe the role of the nervous system and hormones in controlling the secretion of saliva, gastric juice and pancreatic juice.(12)

Make a diagram to summarise what happens to cellulose in a cow’s rumen and reticulum.(6)