GI Tract Flashcards
What is digestion?
The process of transforming the foods we eat into units for absorption.
Define absorption.
The movement of substances into or across tissues; particularly, the passage of nutrients into the gastrointestinal tract and then into the bloodstream.
What are cephalic phase responses?
The responses of the parasympathetic nervous system to the sight, smell, thought, and sound of food.
List the components of the gastrointestinal (GI) tract.
- Mouth
- Esophagus
- Stomach
- Small intestine
- Large intestine (colon)
- Rectum
- Anus
What is the mucosa?
The innermost layer of the gastrointestinal tract, composed of epithelial cells and glands.
What is the function of sphincters in the GI tract?
To control the flow of material between different parts of the GI tract.
What is chyme?
A mass of partially digested food and digestive juices moving from the stomach into the duodenum.
Define peristalsis.
The wavelike, rhythmic muscular contractions of the GI tract that propel its contents down the tract.
What is the role of enzymes in digestion?
Large proteins that accelerate the rate of chemical reactions without being altered in the process.
What is hydrolysis?
A reaction that breaks apart a compound through the addition of water.
Define passive diffusion.
The movement of substances into or out of cells without energy expenditure or transport proteins.
What is active transport?
The movement of substances into or out of cells against a concentration gradient, requiring energy (ATP).
What is endocytosis?
The uptake of material by a cell through membrane indentation and pinching off to form a vesicle.
What are emulsifiers?
Agents that blend fatty and watery liquids by promoting the breakdown of fat into small particles.
What is the function of the liver in digestion?
Produces and secretes bile, detoxifies harmful substances, and helps metabolise carbohydrates, lipids, proteins, and micronutrients.
What is bile?
An alkaline, yellow-green fluid produced in the liver that emulsifies dietary fats.
What is the role of cholecystokinin (CCK)?
A hormone that stimulates the release of digestive enzymes from the pancreas and bile from the gallbladder.
What is amylase?
A salivary enzyme that catalyses the hydrolysis of amylose, a starch.
What is the function of the pyloric sphincter?
Regulates the passage of food from the stomach into the duodenum.
What is the primary function of the small intestine?
Completion of digestion and absorption of nutrients.
What are villi?
Small, finger-like projections that blanket the folds in the lining of the small intestine.
Define the term ‘lymph’.
Fluid that travels through the lymphatic system, made up of fluid drained from between cells and large fat particles.
What is constipation?
Infrequent and difficult bowel movements, followed by a sensation of incomplete evacuation.
Describe diarrhea.
Loose, watery stools that occur more than three times in one day due to rapid movement through the large intestine.
What is gastro-oesophageal reflux disease (GERD)?
A condition in which gastric contents move backward into the oesophagus, causing pain and tissue damage.
What does the enteric nervous system refer to?
A network of nerves located in the gastrointestinal wall.
True or False: The central nervous system includes the brain and the spinal cord.
True
What is the function of gastric inhibitory peptide (GIP)?
Slows the release of stomach contents into the small intestine and stimulates insulin release from the pancreas.
What are the four basic processes of absorption in the GI tract?
- Passive diffusion
- Facilitated diffusion
- Active transport
- Endocytosis (phagocytosis or pinocytosis)
Define the term ‘flatus’.
Lower intestinal gas that is expelled through the rectum.
What are small pouches that bulge outward through weak spots on the digestive tract called?
Diverticula
Diverticula are associated with diverticulosis, a condition that can lead to complications.
What does GERD stand for?
Gastro-oesophageal reflux disease
GERD involves gastric contents moving backward into the esophagus.
What is a key symptom of GERD?
Pain and tissue damage
These symptoms arise from the reflux of gastric contents.
What is irritable bowel syndrome (IBS)?
A disruptive state of intestinal motility with no known cause
Symptoms include constipation, abdominal pain, and episodic diarrhea.
What does the term flatus refer to?
Lower intestinal gas expelled through the rectum
Flatus is a normal bodily function.
What is an ulcer?
A crater-like lesion in the lining of the stomach or duodenum
It is also called a peptic ulcer to distinguish it from a skin ulcer.
What is dyspepsia commonly known as?
Upset stomach or indigestion
Dyspepsia refers to difficulty with digestion.
What are common symptoms produced by GI disorders?
Abdominal pain, gas, bloating, and change in elimination patterns
These symptoms can indicate various gastrointestinal issues.
True or False: Diarrhea is generally a symptom of another illness.
True
Diarrhea often indicates an underlying condition.
What dietary changes can help treat many GI disorders?
Getting adequate fibre and fluids
These dietary modifications can reduce symptoms effectively.
