BIO 241 Ch 25 - Oral Cavity

why do we need a digestive system?

food is essential to life

provides energy

supplies building blocks for metabolic processes (growth and maintenance)

5 processes involved in digestion

1. ingestion

2. peristalsis

3. digestion

4. absorption

5. compaction and defection

what is peristalsis

movement of food

2 types of digestion

mechanical

chemical

mechanical digestion

physical

ex: chewing in mouth, churning in stomach, segmentation in small intestine

chemical digestion

aid of enzymes

absorption

nutrients and water to blood vessels and lymph vessels in small intestine

water to blood vessels in large intestine

organs of alimentary canal

mouth, pharynx, esophagus, stomach, small intestine, large intestine/colon, anus

organs part of gastrointestinal tract (GI)

stomach, small intestine, large intestine/colon

accessory organs

teeth, tongue, salivary glands, gallbladder, liver, pancreas

anatomy of oral cavity

known as mouth

stratified squamous epithelium 

boundaries are cheeks, lips, tongue, palate

what type of digestion occurs in the oral cavity?

mechanical and chemical

what enzymes are produced in oral cavity? (chemical digestion)

salivary amylase and lingual lipase

salivary amylase 

breaks down starch into oligosaccharides (pH is 6.8-7.0)

lingual lipase

very small amount of fat digested

no protein is digested

accomplishments of digestion in the mouth (1)

teeth shredded/ground food, easier to swallow, higher surface area for chemical digestion

accomplishments of digestion in the mouth (2)

starch digestion has begun

accomplishments of digestion in the mouth (3)

mucus bound food particle together which creates a bolus

bolus 

soft, slippery, easily swallowed mass

mechanical digestion of oral cavity

chewing (mastication)