Physiology Flashcards
What are the four functions of the digestive system?
Digestion
Secretion
Absorption
Motility
What are the four layers (tunics) of the alimentary canal?
Mucosa
Submucosa
Muscularis externa
Serosa/Adventitia
What are the three layers of mucosa?
Epithelium
Lamina propria
Muscularis mucosae
What type of epithelium lines the mouth, oesophagus and anal canal?
Stratified squamous
What type of epithelium lines the stomach, small and large intestine?
Simple columnar
What is the function of the submucosa?
Supports mucosa
Contains submucosal plexus
Contains submucosal glands in oesophagus and duodenum
What is the difference between serosa and adventitia?
Serosa surrounds stomach, small and large intestines (inside peritoneal cavity)
Adventitia attaches oesophagus and rectum to surrounding structures (outside peritoneal cavity)
What are the two layers of the muscularis externa?
Inner layer = circular muscle (constricts lumen)
Outer layer = longitudinal muscle (shortens tube)
What nerve supplies parasympathetic stimulation of the gut? (Except for salivation)
Vagus (CN X)
Increases secretion and motility
What nerve supplies sympathetic inhibtion of the gut? (Except for salivation)
Splanchnic nerve
Decreases secretion and motility
What nerves stimulate salivation?
Facial (CN VII) and Glossopharyngeal (CN IX)
What organs does the celiac trunk supply?
Stomach
Small intestine
Pancreas
Liver
What organs does the superior mesenteric artery supply?
Small intestine
Caecum
Ascending colon
Transverse colon
What organs does the inferior mesenteric artery supply?
Descending colon
Sigmoid colon
Rectum
Which veins drain the stomach?
Gastric veins
