Science quiz: The digestion system

What is the digestion system?

Organ system that:

• takes in food

• breaks down food (mechanically and chemically)

• digests and absorbs nutrients

• eliminates waste

Digestion system is separated by two parts:

• Digestive tract

• Accessory organs

Digestive tract

• food and waste travel though these organs

• entire legnth of tract is covered in epithelial tissue which includes goblet cells

• also has nerve and muscle tissue

Organs:

• mouth

• esophagus

• stomach

• intestines

• rectum

• anus

Goblet cells

• secrete mucus that has two functions:

1. protects the digestion tube from digestive enzymes

2. allows for material to pass smoothly through the tube

Mouth

Function: The process of breaking down food starts here and happens two ways

1. Mechanically (teeth and tongue)

2. Chemically (saliva)

• Saliva is produced to help break up food , which is then swallowed into the esophagus

Esophagus

Function: Muscular tube , lined with smooth muscle tissue, which connects your mouth and your stomach

• involuntarily , these muscles contract and relax which move the food towards the stomach which are called peristalsis

Peristalsis

• the involuntary contraction and relaxation of smooth muscles in sections to push food through your digestive tract

Stomach

Function: to churn food in order to continue the process of digestion

• is lined with cells that produce enzymes, to help break down food and produce Hydrochloric acid

• hydrochloric acid helps break down food

• lined with smooth muscle tissue which contracts and expands to help mix stomach contents

• nerve cells in the stomach send signals to the brain to tell it when it is full

The intestine

• lined with cells that produce mucus

• also has smooth muscles that contract and relax to push food though the digestive tract, involuntarily (Peristalsis)

Small intestine:

Function: cells secrete mucus for nutrients to make their way to the blood stream through diffusion

• where most digestion and absorption occurs

• has numerous folds which allow for greater surface area for absorption

• contains projections called Villi that increase surface area for absorption of nutrients

• relatively long, approx. 6 meters long but known as small becuase the diameter is small

Large intestine:

Function: water absorption from the indigestible food

large is 1.5 meters long but has a larger diameter than the small intestine

Rectum

• remaining stool matter will come from large intestine to be stored in the rectum

Anus

• when rectum is full the anus will excrete the undigestible stool matter

Accessory organs

• organs that assist in the digestion process

• all accessory organs help the digestive tract by producing digestive enzymes

Organs:

1. Liver

2. Gallbladder

3. pancreas

Liver

• produces bile which helps break down fat

Gallbladder

• bile is stored in the gallbladder and released into the intestine when required

Pancreas

• the pancreas produces enzymes called INSULIN which is responsible for regulating the amount of sugar in the blood

• diease known as diabetes is when the pancreas produces too much or too little insulin