Digestive System Flashcards
What does the GI tract include?
Oral Cavity Pharynx Esophogus Stomach Small Intestines Large Intestine Rectum Anus
Accessory organs include?
Salivary glands
Liver
Gallbladder
Pancreas
What are the layers of the GI tract deep to superficial?
- Mucosa
- Submucosa
- Muscularis externa
- Serosa/adventitia
What are the layers of the mucosa? Deep to superficial
- Epithelial - direct contact with food matter
- Lamina Propria - basement membrane
- Muscularis mucosa - contains many nerves
What type of tissue is submucosa?
Connective tissue
- full of lymphatics, nerves and blood vessels
Layers of muscularis externa Deep to superficial
- Inner - circular muscle fibers
2. Outer - longitudinal muscle fibers
Serosa/adventitia type of tissue
Serosa - prevent friction
Adventitia - outer layer made of fibrous CT
How many deciduous (baby) teeth are there?
20
- including (half) 2 incisors, 1 canine, 0 premolar, and 2 molar
How many permanent teeth are there?
32
- including (half) 2 incisors, 1 canine, 2 premolar, and 3 molar
What is the enamel made of?
Calcium mostly
What is the dentin made of?
Living cells
What is contained in the pulp?
Veins, arteries, and nerves
What is contained within saliva?
Water, digestive enzymes, antibacterial enzymes, salts
What digestive enzymes are in saliva?
Salivary amylase - digestion of starch
Salivary lipase - digestion of lipids
What is the function of the parotid gland?
Anterior to the ear
- Secretes serous fluid
What is the function of the submandibular gland?
Inferior to the mandible
- Secretes 50/50 mucous/serous fluid
What is the function of the sublingual gland?
Inferior to the tongue
- mostly mucous
What is an acinus?
Any berry shaped gland
What is the esophagus?
Muscular tube that connects the oral cavity/pharynx to the stomach
What is the gastroesophageal sphinter?
Where the esophogus enters the stomach
What does the stomach do?
Mixes food, rugae mix food, protein digestion breaks down food
What is the pyloric sphincter?
Anatomical sphincter guarding the entrance to the small intestine
What is unique about the muscularis externa in the stomach?
One extra layer (oblique) adds to the mixing ability
What attaches to the greater and lesser curvatures of the stomach respectively?
Greater - greater omentum, large fatty flap
Lesser - Lesser omentum, supports and connects stomach and liver
What is the function of mucous cells?
Produces mucous to protect against highly acidic stomach contents
What is the function of chief cells?
Produce pepsinogen (precursor to pepsin) to break down proteins
What is the function of parietal cells?
Produce HCl which is necessary to activate pepsinogen
What is the function of endocrine cells?
Produce gastrin
What is the duodenum shaped like? And what is its function?
C-shaped
- where secretions from the pancreas and gallbladder are added to the chyme that has moved from the stomach to the small intestine through the pyloric sphincter
What enzymes does the pancreas release?
Trypsinogen, amylase, lipase, and ribonuclease
What is the digestive function of the liver?
Make bile, glycogen, and dispose of RBC
What makes up the portal triad?
Hepatic vein
Hepatic artery
Bile Duct
What type of blood is located in a sinusoid?
Mixed - 70% portal vein, 30% hepatic artery
What is cholecystitis?
Inflammation of gallbladder results in a cholisistectomy
What are the three sections of the small intestine?
Duodenum, jejunum, and ileum
Characteristics of the duodenum
Where the ingredients for digestion are added
- fixed against the posterior abdominal wall
Characteristics of the jejunum
Absorbs nutrients
- Both jejunum and ileum are suspended by mesentery that allows for mobility during digestion
What do intestinal cells include?
Enterocytes - absorb nutrients
Goblet cells - secrete mucous
Paneth cells - secrete antimicrobial enzymes
Large intestine characteristics
Shorter and wider diameter than the small intestine
- Consists of the cecum, colon, rectum, and anal canal
- Haustra - puches of muscularis externa
Characteristics of the rectum
Does not have haustra
- instead has continuous layers of circular and longitudinal muscle in the muscularis externa
Characteristics of the anal canal
Has 2 sphincters - internal (involuntary) and external (voluntary)