Biology Notes- Digestion & Nutrition

Digestion

The process of breaking down food into smaller components that the can be used by the body

Mechanical Digestion

Begins in the mouth ie; you chew

Oral Cavity

Multiple components

• Tongue- taste buds, moves for chewing and swallowing

• Teeth- for chewing and grinding

• Salivary Glands- release saliva, lubricates, contains digestive enzymes

Pharynx

A cavity that receives air from nasal cavities and food from the mouth

Swallowing occurs- sends the bolus to the esophagus

Bolus- chewed food mixed with saliva

Esophagus

Muscular tube that connects the pharynx to the stomach

Food moves down via peristalsis→ the rhythmic muscular contractions

Sphincter Muscle- acts as a valve, allows food to the stomach

Stomach

A J shaped organ that lies between the esophagus and the small intestines

Small intestines→ Nutrient Absorption

Small in diameter- roughly 20 feet long

Duodenum- roughly 1 foot in length, bile enters here

Bile- fluid made by the liver

Large Intestines→ Water Reabsorption

Large in diameter, roughly 5 feet long

Accessory Organs

Liver→ large gland in the body that detoxifies the blood

Pancreas→ acts as both an endocrine and exocrine gland

Gall Bladder→ aids digestion of fats