Digestive System Flashcards
What is the primary function of the digestive system?
To bring essential nutrients into the internal environment so that they are available to each cell of the body.
What does the digestive system do to food?
Breaks down food so that it can be absorbed and utilized in the body.
What does the digestive system absorb?
Absorbs water, minerals, and vitamins.
What does the digestive system process and eliminate?
Processes and eliminates waste.
What are the two main groups of the digestive system?
Mouth (oral cavity), Tongue, Esophagus, Liver, Gallbladder, Small intestine, Anus, Pharynx, Stomach, Pancreas, Large intestine, Appendix, Anal canal.
What are the parts of the small intestine?
Duodenum, Jejunum, Ileum.
What are the parts of the large intestine?
Transverse colon, Descending colon, Ascending colon, Cecum, Sigmoid colon.
What is the alimentary canal?
A continuous coiled hollow tube; pathway that food takes from mouth to anus.
What are accessory digestive organs?
Organs that help the organs of the alimentary canal carry out their digestive role.
What glands are considered salivary glands?
Parotid gland, Sublingual gland, Submandibular glands.
What are the organs of the gastrointestinal tract?
Mouth, Pharynx, Oesophagus, Stomach, Small intestine, Large intestine, Anus
What are the parts of the small intestine?
Duodenum, Jejunum, Ileum
What are the parts of the large intestine?
Transverse colon, Descending colon, Ascending colon, Sigmoid colon, Appendix
What are the salivary glands?
Parotid gland, Sublingual gland, Submandibular gland
What is the function of the liver?
The liver processes nutrients and detoxifies harmful substances.
What is the role of the pancreas?
The pancreas produces digestive enzymes and hormones.
What is the function of the gallbladder?
The gallbladder stores and concentrates bile.
What is the anal canal?
The anal canal is the terminal part of the digestive tract.
Assessors digestive organs?
Salivary glands
Teeth
Pancreas
Liver
Gall bladder
What is ingestion in the digestive system?
Ingestion is getting food and liquids into the mouth.
What is secretion in the digestive system?
Secretion involves the release of water, acid, buffers, and enzymes by accessory digestive organs and specialized epithelial cells lining the GI tract.
What does motility/propulsion refer to?
Motility/propulsion refers to moving foods from one region of the digestive system to another.
What is peristalsis?
Peristalsis is characterized by alternating waves of contraction.
What is segmentation in the digestive system?
Segmentation is the process of moving materials back and forth to aid in mixing.
What is digestion?
The process by which food is broken down into absorbable molecules.
What is mechanical digestion?
The mixing of food in the mouth by the tongue, churning of food in the stomach, and segmentation in the small intestine.
What occurs during mechanical digestion?
Food molecules are dissolved and mixed with digestive enzymes.
What is chemical digestion?
The breakdown of large molecules such as carbohydrates, lipids, and proteins into smaller absorbable molecules.
What catalyzes chemical digestion?
Digestive enzymes produced by salivary glands, stomach, pancreas, and small intestine.
What is absorption in digestion?
End products of digestion move from the lumen of the gastrointestinal tract into blood or lymph (via epithelial cells).
What substances can be absorbed without digestion?
Vitamins, ions, cholesterol, and water can be absorbed without first undergoing digestion.
What is defecation?
Elimination of indigestible substances, dead cells, and bacteria as faeces.
What is the generalised structure of the gastrointestinal tract?
The gastrointestinal tract consists of the following layers: Epithelium, Lamina Propria, Muscularis mucosa, MUCOSA, SUBMUCOSA, Circular muscle, MUSCULARIS, Longitudinal muscle EXTERNA, SEROSA (or adventitia).
What is the mucosal layer of the gastrointestinal tract composed of?
The mucosal layer is composed of Epithelium, Lamina Propria, and Muscularis mucosa.
What is found in the submucosal layer?
The submucosal layer contains submucosal glands.
What are the two types of muscle in the muscularis layer?
The muscularis layer contains Circular muscle and Longitudinal muscle EXTERNA.
What is the outermost layer of the gastrointestinal tract?
The outermost layer is called SEROSA (or adventitia).
What is an example of a mesentery?
An example of a mesentery is the Peritoneum.
What is associated with large accessory digestive organs?
The duct of large accessory digestive organs is associated with them.
What is the innermost layer of the gastrointestinal tract?
The Mucosa.
What is the surface epithelium?
It is part of the mucosa.
What is the submucosal plexus also known as?
Meissner’s plexus.
What is the lamina propria?
Areolar connective tissue that is rich in blood and lymphatic vessels, containing immune cells and mucosa-associated lymphoid tissue (MALT).
What does the submucosa contain?
Glands in submucosa.
What is the muscularis mucosae?
A thin layer of smooth muscle fibers.
What are the two types of muscle in the muscularis layer?
Circular muscle and longitudinal muscle.
What is the serosa composed of?
Areolar connective tissue and epithelium.
What is the function of the myenteric plexus?
Also known as Auerbach’s plexus, it is involved in the regulation of gastrointestinal motility.
What type of epithelium is found in the oral cavity?
Stratified squamous epithelium, partially keratinized (e.g. gums, hard palate).
Absent muscularis mucosae.
What type of epithelium is found in the esophagus?
Stratified squamous, non-keratinized.
What are the types of epithelium?
Transitional, Simple squamous, Simple cuboidal, Simple columnar, Stratified squamous, Stratified cuboidal, Pseudostratified columnar.
What is the primary function of the stomach?
The stomach is specialized for the production of digestive acid and enzymes.
What type of epithelium is found in the stomach?
The stomach has an abrupt transition to simple-columnar epithelium, containing mucus-secreting cells.
What is the role of mucus-secreting cells in the stomach?
Mucus-secreting cells protect the gastric mucosa from acid and enzymes.
What are gastric pits?
Gastric pits are invaginations in the stomach that open into gastric glands.
What do gastric glands contain?
Gastric glands contain acid-secreting cells and enzyme-secreting cells.
What type of epithelium is the mucosa of the stomach?
The mucosa of the stomach is made up of stratified squamous epithelium.
What is the primary function of the small intestine?
Specialised for absorption of nutrients.
What type of epithelium lines the small intestine?
Simple columnar epithelium (absorptive & secretory lineages).
How is the small intestine organised to increase absorption?
Organised into crypt-villus structures.
What does the lamina propria contain?
A prominent population of immune cells including some organised lymphoid tissue.
What are lacteals?
Blind-ended lymphatic capillaries extending into villi.
What is the structure of the colon?
The colon has crypts but no villi, which are flattened at birth.
What type of epithelium is found in the anal canal?
The anal canal is lined with non-keratinized stratified squamous epithelium.
