digestive system

What’s it made up of:

  • Mouth: where digestion begins with chewing (Teeth) and saliva softens food for it to be swallowed

  • Pharynx: the passage that connects the mouth to the esophagus, allowing the movement of food and liquids towards the stomach as well as air to pass through.

  • Esophagus: the tube that connects the mouth to the stomach (moves food to stomach with a invoulntary smooth muscle contraction called peristalsis) (

  • Stomach: a muscular organ that squishes down food using acids and enzymes

  • Small intestine:long,twisty tube that breaks down food even more and where most nutrient absorption occurs. repeated folds called villi and microvilli.

  • Large intestine: absorbs water and forms waste for elimination

  • Liver: produces bile to help breaks down lipids in small intestine

  • Gallbladder: stores bile produced by liver

  • Pancreas: produces enzymes that aid in digestion and regulates blood sugar levels

  • Rectum/anus: Rectum hold the poop; Anus is the exit where the poop leaves from

The functions of the digestive system

brief summery:

The steps are:

Ingestion: Taking in food

1.) Breaking down food (digestion)

  • starts in the mouth where teeth/saliva mash food into smaller pieces

  • Your stomach and intestines break the food down into smaller parts

2.) Getting nutrients (absorption)

Starts in the small intestine .

  • In the small intestine food turns into nutrients like vitamins/energy

  • Nutrients go into the blood throughout the body

3.) Getting rid of waste (elimination)

  • Parts of food body doesn’t need go to large intestine

  • It then turns into poop which your body gets rid of

Difference between chemical and mechanical (also known as digestion)

Mechanical:

What it does: physically breaks the food into smaller pieces

Where it happens:

  • mouth: Teeth chew/grind food

  • Stomach: Muscles squeeze/churn food

Chemical:

What its does: uses special chemicals (enzymes/acids) to break food into tiny molecules

Where it happens:

  • Mouth: Saliva breaks down carbs

  • Stomach: acids break down proteins

Small intestine: enzymes finish breaking down fats, proteins and carbs

The steps of the digestive system:

  • Begins in the Mouth where saliva is secreted that contains Amylase an enzyme that begins carbohydrate digestion in the mouth.

  • This is where mechanical digestion takes place and with chewing and grinding of food well also mixing it with enzymes and saliva.

  • Then Chemical digestion takes place making the food into smaller pieces. As food is made smaller it is formed into a bolus and moved to the pharynx

  • The bolus is then swallowed and the epiglottis then closes of the opening to trachea so food only enters the esophagus.

  • when food reaches the distal portion of the esophagus the sphincter between esophagus and stomach relaxes to let food pass into the stomach

  • Mechanical digestion occurs again as the stomach mixes food with gastric juices to form a partially digested liquid called chyme. the gastric juices will continuing to aid in chemical breakdown of food particles.

  • The chief cells secrete pepsinogen a form of pepsin used in protein digestion and enzyme gastric lipase, which digest fat.

Hydrochloric acid then takes pepsinogen and makes it into a in active form of pepsin

Small intestine has three sections

  1. Duodenum: shortest section attached to pyloric sphincter (sphincter is like a valve) of stomach

  2. Jejunum: Middle segment; absorption of nutrients of carbohydrates and protein absorption into the bloodstream

  3. ileum: