Week 10 Flashcards
what is ingestion?
ingestion is the entry of food into the alimentary canal/gastrointestinal tract through the mouth.
what is movement?
the muscular contractions that push food and liquid through the gi tract from the mouth to the anus.
what is secretion?
secretion is the process by which cells release substances that aid in digestion into the lumen of the gastrointestinal tract.
what is digestion?
digestion is the process by which food is broken down into smaller molecules that can be absorbed and used by the body
what is absorption?
the process by which nutrients, water, and other substances that have been broken down during digestion are taken up from the gi tract into the bloodstream or lymphatic system
what is defecation?
the final step in digestion, indigested materials are removed from the body as feces
what are the 4 layers of the gastrointestinal tract?
mucosa, submucosa, muscularis, and serosa/adventitia
describe the mucosa…
structure:
- epithelium
- lamina propria
- muscularis mucosae
function:
absorption of nutrients and secretion of mucus, enzymes, and hormones
describe the submucosa…
structure:
connective tissue that contains large blood vessels, lymphatic vessels, and nerves: the submucosal plexus
function: supples the mucosa with nutrients through blood vessels
describe the muscularis…
structure:
inner circular layer and outer longitudinal layer
also has the myenteric plexus located between the layers.
function: responsible for peristalsis/moving food through the gi tract
describe the serosa/adventitia…
structure:
the serosa consists of a thin layer of connective tissue covered by simple squamous epithelium.
function: reduces friction between gi tract and surrounding organs by secreting serous fluid and anchors the gi tract to surrounding structures.
distinguish between serosa and adventitia layers of the gastrointestinal wall…
serosa is found in parts of the gi tract that are within the peritoneal cavity: stomach, small and parts of large intestine.
adventitia is found in parts of the gi tract that are outside of the peritoneal cavity such as esophagus and some parts of the large intestine.
what is the greater omentum?
the greater omentum is at the bottom part of the stomach it is a large fatty fold of peritoneum that covers the abdominal organs
what is the lesser omentum?
the lesser omentum is a smaller fold of peritoneum compared to the greater omentum. it is on the top part of the stomach.
what is the falciform ligament?
divides the liver into left and right lobes
what is the mesentery?
attaches the intestine to the posterior wall of the abdomen
what is the mesocolon?
attaches the colon to the posterior abdominal wall
what are the structures that form the roof, floor, and sides of the buccal cavity?
roof: hard palate and soft palate.
floor: mandible, tongue, muscles that move it
sides of cavity: cheeks which are formed by muscles
what is the location of the uvula in the buccal cavity?
the small fleshy projection hanging down from the soft palate at the back of the mouth.
what is the division of pharynx into which the buccal cavity opens?
the oropharynx
what are divisions of the two body cavities that the esophagus lies in?
thoracic cavity and the abdominal cavity
what is the esophagus location in relation to the trachea and the heart?
esophagus is located posterior to the trachea and lies posterior to the heart.
what is the function of the pharynx in the digestive process?
provides pathway for food and liquids from the mouth to the esophagus.
what is the function of the epiglottis in the digestive process?
prevents food and liquid from entering the airway during swallowing