HESI Digestive Flashcards
___ is the movement of food through the digestive tract
propulsion
Besides the stomach, additional churning occurs in the ___ ___
small intestine
Food is churned in the small intestine. This process called ___ is similar to peristalsis, except that the rhythmic timing of the muscle constrictions forces food back and forth instead of forward only
segmentation
When digested food enters the body it’s now called ___
nutrients
How many layers aka tunics are associated with the D tract
4
The 4 layers are
mucosa
submucosa
muscularis
serosa
The mucosa has 3 layers itself. the 1st is the ___, the innermost layer. it’s composed of simple columnar epithelium or stratified squamous epithelium.
epithelium
In the epithelium of the mucosa, there are ___ cells and ___ cells
goblet cells
endocrine cells
The 2nd layer of the mucosa is the ___ ___
lamina propria
The lamina propria is composed of ___ connective tissue
areolar connective tissue
___ vessels and ___ vessels are in the lamina propria
blood vessels and lymphatic vessels
The lamina propria also has the ___ ___ ___ ___ (MALT) which is lymphatic tissue bearing lymphocytes and macrophages that protect the GI tract
mucosa associated lymphatic tissue
The 3rd and outer layer of the mucosa is the ___ ___
muscularis mucosae
The muscularis mucosae is a thin layer of ___ ___ which is responsible for the folds that increase surface area
smooth muscle
After the mucosa is the submucosa. It contains ___ vessels, ___ vessels, and ___ fibers
blood lymph nerve
The submucosa is made of ___ connective tissue
areolar connective tissue
After the submucosa is the muscularis, then the ___
serosa
The ___ is an extension of the visceral peritoneum that attaches the small intestine to the rear abdominal wall
the mesentary
The enzyme that breaks down starch aka carbohydrates aka polysaccharides are called
amylase
Enzyme for breaking down proteins
protease
Enzyme for nucleic acids
nuclease
Narrow region between cheeks and teeth
vestibule
The tongue is covered with ___, which help grip food and bear taste buds
papillae
muscular projection suspended from the soft palate
uvula
The 3 pairs of salivary glands are
parotid
submandibular
sublingual
tooth structure, ___ is a calcified tissue that makes up the bulk of the tooth
dentin
tooth structure, the ___ is the top section
the crown
tooth structure, ___ is the region at the gumline where the crown and root meet
neck
tooth structure, ___ is the hard, nonliving material that covers the crown. Calcium compounds make it the hardest substance in the body
enamel
tooth structure, the ___ cavity is the central cavity
pulp
Another word for swallowing
delgutition
The innermost mucosa of the stomach contains simple ___ epithelium which has goblet cells
columnar
___ ___ on the surface of the stomach mucosa penetrate deep, forming ducts
Gastric pits
___ surface cells are goblet cells that secrete mucus
mucous cells
___ cells secrete HCL
parietal
parietal cells also secrete ___ ___
intrinsic factor
___ cells secrete pepsinogen
chief cells
Pepsinogen becomes pepsin. Pepsin breaks down ___
proteins
___ cells secrete various hormones that diffuse into nearby blood vessels
Enteroendocrine cells
One important hormone secreted by enteroendocrine cells is ___, which stimulates other glands in the stomach to increase their output
gastrin
The folds of the stomach are called
rugae
The stomach mixes the food with water and gastric juice to produce _____
chyme
Pepsinogen is converted to pepsin by
HCL
Movement of chyme into the small intestine is done through the
pyloric sphincter
3 sections of the small intestine
duodenum
jejunum
ileum
Ducts the emtpy into the duodenum deliver substances from the ___ and the ___
pancreas
liver
the liver delivers ___ into the duodenum
bile
what does bile do with fat?
separates it into smaller droplets
Vitamin ___ combines with intrinsic factor and is absorbed by receptor-mediated endocytosis
vitamin B12
___-soluble vitamins and ___s are packaged in clusters of bile salts called micelles
fat-soluble vitamins and lipids
lipids are absorbed by simple diffusion and once inside the cells mix with cholesterol and protein to form
chylomicrons
Chylomicrons are passed on to ___ capillaries
lymphatic capillaries
in the mucosa of the small intestines, the ___ ___ are permanent ridges in the mucosa that encircle the lumen.
plicae circulares
The plicae circulares creates a ___ motion to help move the food forward
spiral
___ are finger like projections that cover the surface of the mucosa
villi
The spaces between villi lead to deep cavities called ___ ___
intestinal crypts
___ are microscopic extensions of the outer surface of the cells lining each villus
microvilli
___ cells, the primary cell type of the epithelial layer, synthesize digestive enzymes called brush border enzymes that become embedded in the plasma membranes around the microvilli
Absorptive cells
Various nutrients in the chyme that move over the microvilli are broken down by the ___ ___ enzymes and subsequently absorbed
brush border
___ cells secrete hormones into blood vessels that penetrate each villus
enteroendocrine cells
___ cells, located in the epithelial layer facing the intestinal crypts, secrete lysozymes
Paneth cells
The submucosa of the small intestines has ___ glands, which secrete mucus that neutralizes the acid in the incoming chyme
Brunner’s Glands
The submucosa of the small intestine also has ___ ___, which are clusters of lymphatic nodules
peyer’s patches
The large intestine- the ___ is a dead-end pouch at the beginning
cecum
Large intestine- the ___ is a finger-like attachment containing lymphoid tissue
appendix
At regular distances along the colon, the smooth muscle of the muscularis layer causes the intestinal wall to gather, producing pouches called
haustra
___ ___ is produced in the pancreas to make the pancreatic juice more alkaline
sodium bicarbonate
pancreatic juice is produced in clusters of exocrine cells called
acini
The remaining cells in the pancreas form ___ ___, which are endocrine cells that produce the hormones insulin, glucagon, etc
pancreatic islets
The main pancreatic duct exits the pancreas and merges with the ___ ___ ___
common bile duct
A smaller, second duct that exits the pancreas, the ___ pancreatic duct, joins the duodenum
accessory pancreatic duct
The digestive function of the liver is to produce ___
bile
The primary bile pigment is
bilirubin
bilirubin is the end product of the breakdown of ___
hemoglobin
When blood glucose is high, the liver converts glucose to
glyocen
when blood glucose is low, ___ is broken down and glucose is released into the blood
glycogen
In the liver, ammonia is converted to ___
urea
The liver is composed of numerous functional units called
lobules
within each lobule, epithelial cells called ___a are arranged in layers
hepatocytes
___ ___ are spaces that lie between groups of layers, while smaller channels called bile canaliculi separate other layers
Hepatic sinusoids
each corner of a lobule has 1 ___ duct and 2 ___ vessels
bile duct
blood vessels
These blood vessels are branched from the ___ artery
hepatic artery
Within the sinusoids, phagocytes called ___ cells kill bacteria and break down RBCs and WBCs
Kupffer cells
___ cells that border the sinusoids screen incoming blood
hepatocytes
Bile ducts from the lobules merge and exit the liver as a single ___ ___ ___
common hepatic duct
The common hepatic duct merges with the ___ ___ from the gallbladder
cystic duct
the common hepatic duct and cystic duct merge to form the ___ ___ ___
common bile duct
The common bile duct then merges with the ___ duct
pancreatic duct
the common bile duct merges with the pancreatic duct to form the ___ ___
hepatopancreatic ampulla
the ___ stores excess bile
gallbladder
hormone, causes stimulation of gastric juice (especially HCL)
gastrin
hormone, stimulation of bile production in liver
secretin
hormone, inhibition of gastric juice secretions
secretin
hormone, stimulates bile release by the gallbladder
CCK
hormone, in general responsible for the stomach doing everything it does
gastrin
hormone, stimulation of pancreatic juice secretion
CCK
hormone, stimulates the pancreas to begin releasing insulin
GIP
To sum up, the 4 important hormones are
Gastrin
Secretin
CCK
GIP
Neural response: Stimuli that arouse digestion are relayed to the ___ which in turn initiates nerve impulses in the ___ nerve
hypothalamus
vagus
