GI Phys Flashcards
Mouth: CN ass. with taste (3)
Taste buds (CN VII, CN IX) Salty, sour, bitter, sweet, and umami (savory)
Olfactory nerves (CN I)
Salivary Glands (3)
Submandibular
Sublingual
Parotid
Saliva
what it is made up of (6)
what it is used for
Water with mucus, sodium, bicarbonate (so acid doesn’t kill amylase), chloride, potassium, and amylase (carbohydrate digestion)
needed to form a bolus
smooth muscle wave
Peristalsis
Upper esophageal sphincter (UES):
aka
function
disfunction
must relax to allow food to pass
Upper esophageal Stenosis leading to aspiration
Lower esophageal sphincter (LES)
aka
function
disfunction
cardiac sphincter
allows food into stomach
Sphincter insufficiency leading to GERD
Lower esophageal Stenosis leading to emesis
Stomach: 3 Muscle layers allow for churning
Longitudinal
Circular
Oblique
secretes digestive juices
pepsinogen
partially digested food
chyme
Stomach: Cardiac sphincter Pyloric sphincter Pylorus duodenum Fundus
Cardiac sphincter (upper)
Pyloric sphincter (lower)
Pylorus: the opening from the stomach into the duodenum (small intestine).
Fundus: the upper part of the stomach, which forms a bulge higher than the opening of the esophagus
Body
HCl Acid:
Enzymes:
Hormones
Intrinsic factor
HCl Acid: activates pepsinogen, kills pathogens,
Enzymes: pepsinogen converted into pepsin (by CHl Acid)
Hormones: Intrinsic factor- B12 absorption, pernicious anemia
Parietal cells
Chief cells
G cells
Ghrelin
Parietal cells: Hydrochloric acid and intrinsic factor
Stimulates chief cells
Chief cells: secrete Pepsinogen
G cells:secrete Gastrin: increase HCl secretion
Ghrelin: works on brain to stimulate hunger
Sm intestine
Three segments:
Duodenum
Jejunum
Ileum
Ileocecal valve
Peritoneum
Sm intestine
Villi:
Microvilli
Lacteal
Villi: Finger like extensions on the inner wall increasing surface area
Microvilli
Brush border: increase surface even MORE (for absorption)
Lacteal: lymph duct, absorb digestive fat
Intestinal Absorption (8)
Carbohydrates Proteins Fats Water Electrolytes Vitamins Minerals
Large Intestine: entrance
Cecum
Intestinal Bacteria
function
location
increased bacterial location
Bile acid secretion, motility, and antibody production keeps bacteria low in duodenum
Low concentration of aerobes in the jejunum
Bacterial numbers increase distal to the ileocecal valve
95% anaerobic strains
Liver
function
Liver lobules
Kupffer cells
Mainly filters deoxygenated blood
Drains into hepatic portal system
Helps to clean and detoxify, metabolize, stores stuff from GI.
Common bile duct:
Liver lobules
Hepatocytes
Sinusoids (Specialized Capillaries)
Kupffer cells: involved in the breakdown of red blood cells.
Liver: Bile
what it is
Bilirubin
Formation
Bile is an alkaline, bitter-tasting yellowish green fluid that contains bile salts (come from cholesterol), bilirubin, electrolytes, and water
Bilirubin is a by-product of the destruction of aged red blood cells and gives bile a greenish black color and produces the yellow tinge of jaundice
Functions of Liver (7)
1) Blood storage
2) Bacterial and foreign particle removal
3) Synthesizes plasma proteins (albumin, drive oncotic pressure)/clotting factors (fibrinogen etc.)
4) Produces bile
5) Metabolizes fats, proteins, and carbohydrates (stored as glycogen)
6) Detoxification of metabolic products/wastes (ethanol alcohol, ammonia- waste product from the break down of proteins, liver converts into urea which is sent to kidneys)
7) Storage of minerals and vitamins
The gallbladder
what it is
function
volume of bile
a saclike organ that lies on the inferior surface of the liver
The function of the gallbladder is to store and concentrate bile between meals
The gallbladder holds about 90 mL of bile
The exocrine pancreas
what it is composed of
composed of acini and networks of ducts that secrete enzymes and alkaline fluids (bicarb to combat gastric acid) to assist in digestion
Diff. from endocrine pancreas
Pancreas Secretions (6)
Bicarbonate
Zymogens: activated from inflammatory response
Trypsinogen, chymotrypsinogen, procarboxypeptidase
Pancreatic amylase
Pancreatic lipase
Nucleases
Abdominal pain
assessment
Abdominal pain is a symptom of a number of gastrointestinal disorders
assessed by which quadrant
do not have large A nociceptors, referred pain is common
Osmotic diarrhea:
(pull and attraction of water into GI) major imbalance in osmotic balance causing water to not be pulled into the blood stream and instead is pulled in the intestines (eg: high Na+ or protein intake)
Secretory diarrhea:
Mucous is being brought into the intestines to fight an immune response and eliminate unwanted things
Motility diarrhea:
over activation of peristalsis, over activation (IBS), use of caffeine, stress