GI Flashcards
What two groups of organs make up the digestive system
Gastrointestinal tract (alimentary)
Accessory digestive organs
The gastrointestinal tract extends from the __________ to the _________
Mouth to the anus
What anatomy is considered the GI tract
Mouth
Pharynx
Esophagus
Stomach
Small intestine
Large intestine
What are the accessory digestive organs
Teeth
tongue
salivary gland
liver
gallbladder
Pancreas
What is the function of accessory digestive organs
Aid in digestion
What are the three regions of the abdomen
Intrathoracic
True abdomen
Retroperitoneal
What defines an organ as intrathoracic
Enclosed by the lower ribs and immediately distal to the diaphragm
Intrathoracic organs
Liver
Gallbladder
Spleen
Stomach
Transverse
What is contained in the true abdomen
Large and small intestines, portion of the liver, and the bladder
Females: uterus, Fallopian tubes, ovaries
How is retroperitoneal defined
Lies behind the thoracic and true portions, separated by the retroperitoneal membrane
Retroperitoneal organs
Kidneys
Urters
Pancreas
Posterior duodenum
Ascending and descending colon
Inferior vena cava
What are the six basic functions of digestion
Ingestion
Secretion
Mixing and propulsion
Digestion
Absorption
Defecation
What is ingestion
Taking in food and liquid through the mouth
What is secretion
Cells lining the GI tract produce water, acid, buffers and enzymes to aid digestion
What is Mixing and propulsion
Continuous contraction and relaxation moving food along the tract.
What is digestion
Mechanical and chemical process that breaks down food
What is absorption
Small molecules produced in digestion move into spaces to be used by cells
What is defecation
Elimination of materials not absorbed by our body
What are the layers of the GI tract
Mucosa
Submucosa
Muscularis
Serosa
Mucosa in the GI tract is the ________
Innermost lining in direct contact with the substances passing through
What is the submucosa within the GI tract
Areolar connective tissue that connects the mucosa and the muscularis. Contains blood and lymph vessels
What does the muscularis contain within the GI tract
Skeletal and smooth muscles
What are the layers of the serosa
Visceral peritoneum
Parietal peritoneum
What is the visceral peritoneum
Outmost layer around the organs
What is the parietal peritoneum
Lines the walls of the abdominal cavity
Define the greater omentum
Fatty apron that drapes over transverse colon and small intestine
What is mesentery
Binds the small intestine to the posterior abdominal wall
Name the salivary glands
Parotid
Submandibular
Sublingual
What is the function of salivary glands
Dissolve food and begin digestion
Contain lysosomes that kill bacteria
Mucous produced to lubricate food
Amylase begins digestion of starches in mouth
What percentage of saliva is water
99.5% water
0.5% solutes
The tongue is what type of organ
Accessory digestive organ
Define the frenulum
Fold of mucous membrane in the midline underneath tongue that limits posterior movement
What is the function of teeth
Perform mechanical digestion (chewing and breaking down food)
What is the pharynx
Funnel shape tube, located posterior end of oral cavity and comprised of skeletal muscle
Name the branches of the pharynx
Nasopharynx
Oropharynx
Laryngopharynx
Where is the esophagus located
Posterior to the trachea
Where the esophagus begins and ends
Begins at the end of the pharynx
Ends at the superior aspect of the stomach
What are the sphincters of the esophagus
Upper esophageal - skeletal muscle
Lower esophageal - smooth muscle
Define the function of esophagus
Transport food along its path, mixing it with mucous
Phases of swallowing
Voluntary
Pharyngeal
Esophageal
What is voluntary swallowing
Bolus forced into oropharynx from upward movement of tongue against palate
What is pharyngeal swallowing
Breathing is temporarily stopped, soft palate and uvula move up to close of nasopharynx, epiglottis closes off larynx and UES relaxes to allow bolus to move into esophagus
What is esophageal swallowing
Good is pushed through esophagus via peristalsis, LES relaxes and bolus moves to stomach
Describe the stomach
J shaped organ which serves as a mixing chamber for food. Aids in digestion
What is the pH of stomach
2 (acidic, < 7)
The stomach can accommodate up to _____ liters of food
6.4 liters