The Digestive System Flashcards
(35 cards)
What is the Digestive System?
The organ system with associated organs that take in food and liquids, breaking them down into substances that the body can use and discard as waste.
What are the organs and accessory organs involved in the digestive system?
- Oral Cavity
- Mouth
- Tongue
- Salivary Glands
- Pharynx
- Esophagus
- Stomach
- Gallbladder
- Liver
- Pancreas
- Large Intestine
- Small Intestine
- Rectum
- Anus
- Sphincter Muscles
How does the Digestive System Begin and End? Explain the process.
- Ingestion at the Mouth
Teeth (1): Aids Digestion via Mechanical Movement that physically breaks down the food.
Tongue (2): Helps churn food, allowing it to flow into the esophagus.
Salivary Glands: Performs chemical digestion by using the salivary amylase (enzymes found within the salivary glands), additionally breaks down food. - The esophagus then contract that force the food down
- The food travels from the esophagus and into the stomach where the acidic environment of the stomach breaks down food physically (peristalis- churning food) and chemically (hydrochloric acid).
- The body absorbs nutrients from the digested food is via the small intestine- the nutrients diffuse into the bloodstream to go to cells through the microvilli.
- It is during this time that the the liver creates bile and pancreas creates and releases more enzymes that speed up breakdown of proteins, lipids, and carbohydrates (i.e., the digested food in the small intestine mixes with the digestive enzymes from the pancreas and bile from the liver, efficiently quickening digestion).
- The gallbladder also stores the bile and transport it to the small intestine when it is ready to emulsify fat.
- Afterwards, the food passes to the large intestine (colon) for further digestion and water absorption- this process turns the food into solid waste.
- The Anus is an orfice that then allows waste to exit the body.
Define Peristalis
Peristalsis is a series of wave-like muscle contractions that move food through the digestive tract.
Physical Digestion
What are the parts of the Large Intestine?
Cecum: The first part of the large intestine, which looks like a pouch
Colon: The main part of the large intestine, which includes the ascending colon, transverse colon, and descending colon
Rectum: Stores feces until they are expelled through the anus as a bowel movement
Enzymes
How does the amylase enzyme work for digestion?
It turns starch and carbohydrates into small sugars.
Enzymes
Where are amylase enzymes found in the body?
In the salivary glands of the mouth (starch into small sugars) and the small intestine (carbohydrates into small sugars).
Enzymes
How does the pepsin enzyme work for digestion?
It breaks down proteins.
Enzymes
Where are the pepsin enzyme located?
Stomach
Enzymes
How does the trypsin enzyme work for digestion?
Breaks down proteins into amino acids.
Enzymes
Where are the trypsin enzymes located?
Small intestine
Enzymes
How does the lipase enzyme work for digestion?
Turns lipids into fatty acids and glycerol.
Enzymes
Where are the lipase enzymes located?
Small intestine
Specialized Cells of the Digestive System
What are absorptive cells?
A dense array of microvilli, visible microscopically as the brush border.
Specialized Cells of the Digestive System
What are goblet cells?
Scattered among the absorptive cells in the epithelium of the small intestine and colon. These epithelial cells are specialized for the secretion of mucus which facilitates a passage of material through the bowel.
Goblet refers to the cell’s shape, narrow-based and apically bulging
Specialized Cells of the Digestive System
What are taste cells?
The sensation of taste is mediated by columnar epithelial sensory cells.
- sensory cells are normally replaced every 10-14 days by division and differentiation of stem cells, which is handy since they are exposed and easily damaged
Clarification
Epithelial cells are?
Type of Tissue cells that make up the epithelium (tissue made up of tightly bound epithelial cells that form sheets which ocver the body’s surfaces.
Clarification
What are hepatocytes?
Cells that predominantly make up the liver.
80% to be specific
Clarification
Functions of Hepatocytes:
- form and secrete bile
- store glycogen and buffer blood glucose
- synthesize urea (colourless substance formbed by the breakdown of protein in the liver)
- metabolize cholesterol and fat
- synthesize plasma proteins
- detoxify many drugs and other poisons
- process several steroid hormones and vitamin D
- offer splendid and numerous examples of most cellular organelles.
Difference between Villi and Microvilli
Villi are covered with even smaller hairlike structures called microvilli. Microvilli are projections smaller than villi. Their job is to also increase the surface area so each villus can absorb the maximum amount of nutrients.
What is the brush border?
Specialized structure that lines the small intestine- made up of tightly packed microvilli.
Function of the Oral Cavity?
Mouth, Tongue, Salivary Glands, etc.
The mouth is where food enters- its teeth chew food (a physical component of digestion)
Its tongue aids in breaking down food into smaller parts.
The Salivary Glands employs enzymes contained in the glands that break down food
What is the function of the pharynx?
Swallows food, muscle contractions push food into the esophagus.
What is the function of the esophagus?
Tubular structure that leads food into the stomach through peristalsis (muscle contractions).
