Ch 24 Digestive Part 1 Flashcards
What consists of the GI tract (alimentary canal) and accessory organs
digestive system
What is the pathway for food, breakdown into nutrients and packaging of waste products
GI tract
what includes accessory organs that aid in mastication and glandular secretions that aid in enzymatic digestion
accessory organs
What is the stuff we ingest
food
What is the substance that provides nourishment essential for growth and maintaining life
nutrients
What is the process of breakdown of food via mechanical and chemical means
digestion
Digestion occurs in what part of the GI tract (starts and ends where)
mouth to the duodenum
What is the process by which nutrients are absorbed into the bloodstream
absorption
Where does absorption start and end
jejunum to the colon
What the 6 essential digestive functions/activites
ingestion
propulsion
mechanical digestion
chemical digestion
absorption
defecation
What digestive function is the intake of solid food and drink via the oral cavity
ingestion
What is the chewing of food called, involving teeth and tongue, involving mechanical breakdown
mastication
What digestive function is the downward movement of food through the GI tract (24-36 hrs), use of peristaltic waves — PERISTALSIS
propulsion
Swallowing is also called…
deglutination
What digestive function is the mixing of food with digestive secretions via muscular contraction, which alters forward and back movement of GI content in the small and large intestines
mechanical digestion (segmentation)
What digestive function is the break down of food into smaller molecules for easier digestion via enzymes
chemical digestion
What digestive function is the movement of molecules from digestive tract into the blood or lymph
absorption
What digestive function is when the waste products of digestion are eliminated from the body, occuring in the large intestine
defecation
What are the 4 layers (tunics) of the digestive tract
mucosa
submucosa
muscularis externa
serosa (adventitia)
Where do the 4 tunics of the digestive track span from (start and end)
esophagus to anus
What is the innermost tunic of the digestive tract
mucosa
what are the two types of epithelium in the mucosa
lamina propria and muscularis mucosae
What kind of epithelium lines the mouth, oropharynx, esophagus, and anus
nonkeratinized stratified squamous epithelium
What kind of epithelium is classic and lines the rest of the GI tract
simple columnar epithelium
What digestive tract layer is a thick layer of CT, with nerves, BVs, lymph vessels, and small glands
submucosa
What digestive tract layer is the inner circular smooth muscle and outer longitudinal smooth muscle
muscularis
The muscularis of the stomach has an extra 3rd layer called the
oblique
the muscularis of the upper esophagus contains what kind of muscle
skeletal
What digestive tract layer is the outermost tunic, making up the visceral peritoneum
serosa (adventitia)
The adventitia is connective tissue in what two places
esophagus and retroperitoneal organs
What is used to increase surface area in the digestive tract
fold
what are examples of folds in the esophagus
none
what are examples of folds in the stomach (3)
microvilli
rugae
pits
what are examples of folds in the small intestines (3)
microvilli
villi
circular folds
what are examples of folds in the large intestines (3)
microvilli
pits
haustra
What involves local control of the enteric nervous system, made up of a network of neural tissue
nervous regulation
What are the two nervous regulatory areas in the GI tract
submucosal plexus
myenteric plexus
What nervous regulatory areas in the GI tract innervates smooth muscle of the gut, controls local secretion, absorption, and muscle movements
submucosal (Miessner) plexus
what nervous regulatory areas in the GI tract is found between circular and longitudinal smooth muscle layers along the entire GI tract, that is involved with increasing tone of gut and velocity and intensity of contractions
myenteric plexus
What disease causes a megacolon from a painful developmental disorder due to lacking a subset of enteric neurons in distal large instestines
Hirschsprung disease
In Hirschsprung disease, a mutation in the _______ gene encodes a receptor normally activated by growth factors required for survival and differentiation of enteric neuron subset
RET
In Hirschsprung disease, the loss of enteric neurons cause what 2 problems
poor intestinal motility and severe constipation
Hirschsprung disease is more common in _______ (what sex) and is also associated with what two inherited conditions
males
downs
CHD
In Hirschsprung disease, there is difficulty passing stool at birth, as the bowel doesn’t relax and stool builds up causing a ____
bowel obstruction
What symptoms do newborns experience with Hirschsprung disease
abdominal distension
no BM after birth
vomiting
What is used to Dx Hirschsprung disease (3)
-rectal biopsy (to see absence of ganglion cells)
-abdominal xray
-anal manometry (balloon)
What is the Tx Hirschsprung disease (6)
surgical bypass
removal of colon
high fiber content
increased fluids
physical activity
laxative
What is a complication of Hirschsprung disease because of susceptibility to serious intestinal infection
enterocolitis (life threatening)
What are 3 neurotransmitters (of the 30 associated with the ENS) that are involved in chemical digestion
acetylcholine
norepinephrine
serotonin
in chemical digestion, what neurotransmitter stimulates digestive tract motility and secretions
acetylcholine
in chemical digestion, what neurotransmitter inhibits digestive tract motility and secretions
NE
in chemical digestion, what neurotransmitter stimulates digestive tract motility (95%)
serotonin
chemotherapy affects digestive activity causing _______ by activating vomiting center in the enteric center of the brain
nausea
What blocks serotonin receptors that can alleviate digestive nausea
ondansetron
In chemical regulation of digestion, digestive hormones and histamine (paracrine) effect nearby cells by causing effects on what thing
pH
What is the serous membrane sheet covering walls and abdominal cavity organs
peritoneum
What is secreted and lubricates between the membranes of the peritoneum
serous fluid
Membrane and fluid reduces ________ as the organs move in the abdomen
friction
What is the outer layer surrounding the abdominal cavity called
parietal peritoneum
What is the inner layer surrounding the organ in the abdominal cavity called
visceral peritoneum
What is life threatening inflammation of the peritoneum due to chemical irritation
peritonitis
What are the 2 S/S of peritonitis
acute abdominal pain
tenderness
What is an accumulation of excess serous fluid in the peritoneal cavity, seen with starvation, alcoholism, and cancer
ascites
What do you perform to remove fluid from an abdomen with ascites
paracentesis
What is the continuous, double layer of epithelial tissue that is attached to the posterior abdominal wall
mesentery
What holds all digestive organs in the abdominal cavity in place, and extends from the junction between esophagus/stomach to rectum,
mesentery
What part of the mesentery is mobile attaching the jejunum and the ileum to the posterior abdominal wall
small intestine mesentery
What part of the mesentery is anchored to mobile to anchored
right, transverse, and left mesocolon
What part of the mesentery is anchored and mobile
mesosigmoid and mesorectum
What is the lesser curve of the stomach to the proximal duodenum and to the liver and diaphragm
Lesser omentum
What is the greater curve of the stomach to the transverse colon, and a double fold of mesentery from stomach over the small intestines
greater omentum
What tissue is the greater omentum composed of and what cells are present in
adipose tissue
B/T cells
What part of the mesentery is the liver to the diaphragm
coronary ligament
what part of the mesentery is the liver to anterior abdominal wall
falciform
