Body Systems Bio 20 AP Ingestion

The digestive tract, from the mouth to the anus.

The act of eating.

The process of breaking down food (enzymatic hydrolysis).

Cells take in small molecules (monomers).

Removal of undigested material.

• - Is part of the mouth
• - Produces amylase enzymes which digest carbohydrates
• - Produces saliva, which helps form bolus, lubricate the esophagus/digestive tract, and activate taste buds

An enzyme produced by the salivary glands that break down carbohydrates in the mouth.

Produced by the salivary glands and works to form bolus, lubricate the esophagus/digestive tract, and activate the taste buds.

A ball of food.

• Physically digests food. There are 3 types. 
• Incisors - Cut (Front 4)
• Canine - Tear  (Middle Teeth, like fangs)
• Premolars & Molars - Grind (Back teeth, flat-shaped)

Transports bolus from the mouth to the stomach by muscle contractions called peristalsis.

A gate that keeps food from getting into the lungs by covering the top of the trachea whenever the process of ingestion is occurring.

Muscle contractions that move the bolus down the esophagus. The muscles tightly and fully contract together behind the food, which moves it forward. This also keeps food from going back up the esophagus.

• - Connects the esophagus to the duodenum of the S.I. 
• - Stores food and secretes the enzyme that starts protein digestion (pepsin)
• - Physically digests food by mixing it/muscle contractions
• - Chemically digests food with the hydrochloric acid (HCl) and pepsin it produces
•           - The HCl also kills bacteria
•           - A mucous layer keeps the HCl and pepsin from digesting the stomach 
• - Holds 1.5 L that empties every 2-6 hours and has a pH of 2-3
• - Has two sphincters: Lower esophageal (entrance to stomach;connected to the esophagus) & Pyloric (exit from stomach; connected to the duodenum)

An enzyme secreted by and functions in the stomach and digests proteins. Its inactive form is pepsinogen, which is awakened by the HCl acid produced by the stomach. When the pepsin enters the small intestine, it is deactivated by bicarbonate ions (HCO3-).

• Ulcers 
• - The mucous lining breaks down, which leaves the stomach and capillary network exposed to the HCl acid
• - Histamine is released, which increases blood flow, and acid secretion
• - This then causes more tissue to be burned, so more histamine is released
• - It becomes a cycle
• - H. pylori- bacteria that can cause infections that can destroy the mucous lining

• - HCl
• - has a ph of 2-3
• - kills bacteria
• - activates pepsin from pepsinogen

• Endoscope
• - A tube-shaped instrument with a lens and light source that can be fitted with a laser to diagnose problems and/or perform surgery.
•         - Burns ulcer until it turns into a scab

Breaking the food into smaller pieces, which increases surface area and makes it easier for the enzymes to work on it.

Break the bonds of the polymer to make something new/release its monomers.