Chapter 25 - Digestive System Flashcards
What is digestion?
Process whereby food is changed into a form that can be absorbed, breakdown of ingested food, and absorption of nutrients into blood.
What is metabolism?
Production of ATP and anabolic & catabolic cellular activities.
What are the 2 parts of the digestive system?
Alimentary canal and accessory glands.
What makes up the alimentary canal?
Mouth, pharynx, esophagus, stomach, intestines, rectum, and anus.
What are the accessory glands?
Salivary glands, liver, gallbladder, and pancreas.
What are the layers of the digestive wall?
INSIDE TO OUTSIDE
Mucosa, submucosa, muscularis, and serosa.
What are the 3 layers of the mucosa?
Mucosal epithelium, lamina propria, and muscularis mucosa.
What does the lamina propria contain?
BVs, sensory nerves, lymph vessels, and MALT.
What does the mucosa muscularis contain?
Smooth muscle and elastic fibers.
What are the layers of the muscularis?
Circular and longitudinal.
Can the mucosa have folds?
YES!!!!
What do folds do?
Increase surface area.
What glands can be in the mucosa?
Mucous and digestive enzymes.
What are the functions or the mucosa?
Protection, absorption, and secretion.
What does the submucosa contain?
Loose CT, glands, BVs, lymph vessels and nerves.
What are the functions of the submucosa?
Nourish surrounding tissues and carry away absorbed materials.
What are the layers of the muscularis?
Inner and outer.
What is the inner layer?
Circular smooth muscle.
What is the outer layer?
longitudinal smooth muscle.
What is the function of the circular smooth muscle?
Decrease the diameter when contracted.
What is the function of the longitudinal muscle?
Shorten tube when contracted.
What is another name for the serosa?
Visceral peritoneum.
Does the serosa exist superior to the diaphragm?
NEGATIVE!!
What replaces the serosa above the diaphragm?
Adventitia.
What is the function of the serosa?
Protection and secrete serous fluid.
What is the peritoneum?
A series of membranes in the abdominal cavity.
What are the layers?
Visceral peritoneum and parietal peritoneum.
What does the visceral peritoneum adhere to?
Directly to the internal organs.
What does the parietal peritoneum adhere to?
The abdominal wall.
What is between the layers?
Peritoneal cavity.
Are the layers continuous?
YES’M.
What are mesentaries?
Sheets of peritoneum connected to organs.
What are the functions of mesentaries?
Access route for vessels and nerves and stabilize position.
What are the mesentaries of the peritoneum?
Lesser omentum and greater omentum.
What does the lesser omentum connect?
Stomach to liver.
Greater omentum characteristics?
Starts at stomach, descends inferior, the ascends to form a pouch and attaches to colon.
What is the pouch filled with?
Adipose.
What is mesentery proper?
Attaches to the majority of the small intestine.
What is the mesocolon?
Attaches to large intestine.
What do the mesentery proper and mesocolon allow?
Allow for nerves, BVS, and lymphatics to connect to intestines.
What is peristalsis?
Propels bolus down the tract.
What is a bolus?
Swallowed food.
What muscles contract first in peristalsis?
Circular muscles prevent bolus from moving back.
What do longitudinal muscle do?
Advances it down the tract.
What is segmentation?
No net movement in any particular direction, goal is to fragment bolus, and mostly circular muscle contractions.
What are the functions of the mouth?
Mastication/mixing, lubrication, speech, taste/evaluation, and limited digestion.
Components of the mouth?
Hard and soft palate.
What is the hard palate?
Palatine bone on roof of mouth.
What is the soft palate?
CT extension of the palate and uvula.
Uvula position?
Dangles at the end of the soft palate.
Functions of the uvula?
Prevents food from going down prematurely.
What are the salivary glands?
Parotid, submandibular, and sublingual.
What are the functions of salivary glands?
Produce saliva, form food bolus, make salivary amylase, and dissolve chemicals for taste.
What is saliva made of?
Mucous and serous fluid.