Exam 3: Digestive System Flashcards
What are the two parts of the digestive system
alimentary canal and accessory organs
What is the purpose of ingestion
carry in or intake
Where does ingestion happen
mouth
what does mechanical breakdown do
increases surface area
Where does mechanical breakdown happen
mouth, stomach and small intestine
What does propulsion do
peristalsis and segmentation
What is peristalsis
movement
What is segmentation
seperating
Where does propulsion take place
everywhere
What is digestion
chemical breakdown
WHere does digestion happen
mouth, stomach and small intestine
What is absorption
nutrients (building blocks) enter the body
WHere does absorption take place
primarily small intestine
What is defecation
removing of feces
What are globular proteins that act as biological catalysts
enzymes
What two things do enzymes do
regulate reactions and lower activation energy, increased speed
Are enzymes used up after starting a reaction
no
Whats the difference between peristalsis and segmentation
peristalsis is motion only while segmentation is mixing and motion
What is the peritoneum
serous membrane covering the abdominal viscera
What is the parietal
outer wall
What is the visceral
inner covering of organs
What is the mesentery
Where peritoneal membranes are back to back
What is serous fluid
fills space between membranes
What is the master regulator of metabolism
liver
What are the four layers of tissues
- mucosa 2. submucosa 3.muscularis externa 4. serosa
What are the three layers of the mucosa
epithelium, lamina propria and muscularis mucosae
What are the two layers of the muscularis
longitudinal muscle and circular muscle
What are the three roles of mucosa
secrete enzymes, absorb nutrients and protect
What three things make up saliva
mostly water, ions/electrolytes and proteins
What proteins are in saliva
mucin, antimicrobials and digestive enyzmes
Whaat is mucin
protein that mixes with water to make mucus
What three antimicrobials are in saliva
lysozyme, defensins and IgA
what is a myxovirus infection of the parotid gland
mumps
how many total teeth do humans have
32
Whats the common term for dental caries
cavities
What are dental caries caused by
plaque
What makes up plaque
sugar and bacteria
how does plaque work
bacteria produces acids that erode the tooth
WHat is the common term for periodontal disease
gum disease
What is periodontal disease caused by
begins as gingivitis and caused by calculus
what is calculus
calcified plaque
What happens in periodontal disease
gums recede and teeth eventually fall out
What is the buccal phase
when the food is still in the mouth
WHat is the pharyngeal- esophageal phase
when the food is in the throat
What is gastric bypass surgery do
by passes the stomach and duodenum
WHat does the enteroendocrine cell do
sectrete hormones like gastrin
What does a chief cell secreate
pepsinogen
What does pepsinogen secrete
pepsin
what does pepsinogen use to create pepsin
HCl
WHat does the parietal cell create
HCl
What binds Vitamin B12
Interinsic factor
WHat causes pernicious anemia
B12 deficiency
What is pernicious anemia
RBCs cannot mature
What does IF stand for
Intrinsic Factor
90% of what is caused by helicobacter pylori
stomach ulcers
What is the cephalic phase
central nervous system
The taste sight and smell of food triggers what
vagus nerve
Rest and digest
parasympathetic
Is gastrin release by G cells triggered by a full stomach or an empty one?
full
What does pepsin do
breaks down proteins
What does filling the stomach with food do to pH?
increases it
What does the G cell gastrin do
stimulates parental cells
What are the three steps of gastric peristalsis
population, grinding and retropulsion
What does propulsion do
peristalsis from fundus to pylorus
What happens in the grinding phase of gastric peristalsis
increasing strength as wave approaches pylorus
What happens in the retropulsion phase
small pieces and liquid may pass through the pylorus the rest returns to the stomach
What is the rate of waves per minute in gastric peristalsis
3 waves per minute
What three main structures are used to increase surface area
circular folds, villi and micro villi
List the order of three main structures that increase surface area by size
biggest- Circular folds
middle- villi
Smallest- microvilli
What are the two main functions of the liver
master regulator of metabolisum and assist in digestion by secreating bile
What secreates bile
hepatocytes
What two things does bile contain
bile salts and phospholipids
What are biliary calculi
gall stones
WHat are the two catagories of pancreas function
endocrine and exocrine
What happens in the endocrine of the pancreas
creates glucagon and insulin
what happens in the exocrine of the pancreas
digestive enzymes
What cells secreate glucagon
alpha cells
What cells secreate digestive enzymes
acinar cells
What cells secreate insulin
beta cells
What specifically do acinar cells secreate
inactive proenzymes
When are proenzymes activated
when they are in the intestines
What does trypsin do
it activates all other enzymes
what causes the enteroendocrine cells to secrete hormones
chime in the duodenum
What hormones does the enteroendocrine secrete
CCK and secretin
What hormone causes the gallbladder to contract
CCK
what happens when the gallbladder contracts
bile release
What causes secreation of pancreatic juice
both CCK and secretin
What does gastrin do
increases motility which promotes the switch from segmentation to peristalsis
Whats the main job of the Small intestine
help with absorption
What relaxes the ileocecal sphincter
gastrin
What happens when the ileocecal sphincter is relaxed
permits flow of cecum of large intestine
What is the purpose of the large intestine
to compact waste and move it along
Does the large intestine have structures to increase surface area
no
What does the large intestine have more of then the small intestine
goblet cells and mucus
What is celiac disease
allergy to gluten
What is inflammatory bowel disease
immunogenic response to gut flora
what is flora
micros that live in the large intestine
What are the two main types of inflammatory bowel disease
crohns disease and ulcerative colitis
What is crohns disease
very severe includes multiple ulcers throughout the intestine
What is ulcerative colitis
mostly inflammation and a few ulcers
WHat three things does bacterial flora do
- makes certain B and K vitamins
- breaks down molecules humans cant
- competes against harmful bacteria for resources
Bacterial flora can be harmful if found where
outside the colon like in the mouth
What should you do to promote good flora
eat fermented foods and fruits and veggies
What is clostridium dificile infection caused by
lack of good bacteria
WHat causes hemorrhoids: four things
pressure from excessive sitting, straining bowel movements, obesity and age
WHat does mechanical breakdown change
appearance and increases surface area
What does digestion change
molecular structures
What does absorpution do
moves nutrients from alimentary canal into body
what is gastric lipase
stomach enzyme breaks down proteins
What is ribonuclease
breaks down RNA
What is deoxyribonuclease
enzyme breaks down dna
Where is salivary amylase found
mouth
where is pancreatic amylase found
small intestine
where is brush bordaer enzyme found
small intestine
where is pepsin found
stomach
where is carboxypeptidase, chymotrypsin and trpsin found
small inestine
where is lingual lipase found
mouth
lipase is a type of
fat
gastric lipase is found in
stomach
emulsifaction by bile salts happens where
small intestine
pancreatic lipase is found where
small intestine
ribonuclease is found where
small intestine
salivary amylase, pancreatic amylase and brush border enzymes are all what
carbs
ribonuclease and deoxyribonuclease are what
nucleic acids
pepsin, trypsin are both
proteins
