Is like a big juicer of food that processes important materials needed for the function of the body
Main purpose of Digestive System
Grind and juice out our food and get its nutrients so that it can be used as a fuel of cell in our body
2 main processes of Digestion
Mechanical digestion
Chemical digestion
Mechanical digestion
Is the process in which food is broken down by means of chewing, biting and grinding to make it into smaller particles
Chemical digestion
Is the process of digesting food with the use of enzymes to make food soluble for it to be absorbed by the body and be transferred through the circulatory system
Four stages of food processing
Ingestion - taking in food that starts in the mouth
Digestion - breaking down of food into smaller particles in order to use its nutrients
Absorption - taking the nutrients from the digested food to be used by the body for different life processes
Egestion - removing any leftover wastes after the digestion process
Parts of the Alimentary Canal
Mouth
Esophagus
Stomach
Small intestine
Large intestine
Rectum
Anus
Saliva
Contains ptayalin, a.k.a salivary amylase, which softens and converts the starch in the food we eat into a simple sugar called maltose while chewing
Pharynx
Found at the region of the neck
Bolus
Function as a passageway of the ball of food mixed with saliva
3 main divisions of pharynx
Nasopharynx - near in the nasal cavity
Oropharynx - area of oral cavity
Hypopharynx - lowest part of the pharynx near the esophagus
Esophagus
A long, muscular tube that functions as a passageway of food from the pharynx to the stomach with the use of peristalsis
Peristalsis
Is a wave of muscular contractions that push the masticated food (bolus) down towards the stomach
Stomach
Is a J-shaped muscular bag where the food goes to be chemically digested
Cardiac sphincter
Is an opening in the stomach that allows the food to get inside the esophagus and closes to prevent backflow of food and digestive enzymes
Chyme
Semisolid form of digested food
Small intestine
20-30 feet long small intestine
Villi
Nutrients are mainly absorbed with the tiny hair like projections in the intestinal wall
Parts of the Large intestine
Cecum
Ascending colon
Transverse colon
Descending colon
Sigmoid colon
Mucus
Is also present in the large intestine to lubricate the food as it goes to the rectum and to the anus
Rectum and Anus
The waste product or feces from the large intestine is then temporarily stored to the rectum before it will be expelled by the anus. The rectum expands until it becomes full which then tells the brain to release it out with the use of the nerves in the rectum. This is called as bowel movement.
Accessory Organs
Salivary glands
Liver
Gallbladder
Pancreas
Salivary Gland
These are glands that produce saliva used for softening the food and breaking down carbohydrates into simple sugar
Liver
Found below the right side of the ribs. Main Functions: Produce bile, which breaks down or emulsify fat during digestion. Also detoxifies the blood as it circulates the body such as alcohol.
Gallbladder
Is a small sac located under the liver. Store bile- main purpose
Pancreas
Is a bumpy, leaf-shaped organ located below the stomach. It contains pancreatic duct, a tube that is located at the duodenum of the small intestine.