lecture 11 Flashcards
what does the digestive tract consist of
mouth, esophagus, stomach, small intestine, large intestine, rectum, anus
what do the accessory organs consist of
salivary glands, liver, pancreas, gallbladder
what are the general processes of the digestive tract
motility, secretion, absorption, digestion
what are the three types of salivary gland and where are they
parotid glands - either side of cheek
sublingual glands - under tongue
submandibular gland - under lower jaw
what are the major components of saliva
bicarbonate - neutralize environment for anylase
amylase - breaks down carbs, needs alkaline environment
mucous - make food slide
lysozome - destroy bacteria in mouth
what are mumps
infection of parotid glands, swelling of cheeks
what are the swelling of the brain, spinal cord, and testicles called
encephalitis, meningitis, orchitis
what are the characteristics of the esophagus
thin walled, pliant, collapses when there is no food
what are the sphincters associated with the esophagus
upper esophageal sphincter - b/t mouth and esophagus
lower esophageal sphincter - b/t esophagus and stomach, prevent acid refluz
what is acid reflux
backflow of acidic stomach contents into esophagus
what is acid reflux also known as
heartburn
gastroesophageal disease (GERD)
what causes acid reflux
pressure in abdomen, hiatal hernia, nicotine (relaxing lower sphincter)
what is esophagitis
irritation of esophagus - infection
how do you treat mild acid reflux
take medicine to reduce stomach pH
what is barrett’s esophagus
when cells in lower esophagus becomes acid resistant - precursor to esophageal cancer
what is a hiatal (diaphragmatic) hernia
the stomach pushed into thoracic cavity through hiatus of diaphragm
further heart burn, unconfortable
what are the processes of the stomach
mechanical (mixing) and chemical (digestive enzymes)
what are the components of the stomach
fundus, body, antrum
gastric pits
pyloric sphincter
rugae, lumen, chyme
what are the three main cell types of gastric pits and what do they secrete
parietal cells - HCl, break down tissue, kill pathogens, activate pepsin
chief cells - release pepsinogen - cleaved by HCl - pepsin - protein breakdown
mucous cells - mucous, lubricate food and protective layer
what happens if there is no more mucous secreted for the protective layer of the stomach
stomach will self-digest
what do FW fish do with the HCl that are secreted into the stomach
move Cl into gill when losing it to water
exchanged back for proton and bicarbonate
hydration of CO2 in the body, proton goes to the stomach and bicarbonate is dissolved into the blood
what are gastric ulcers and what are they caused by
caused by hylicobacter pylori - secretes enzymes to destroy stomach lining - acid and pepsin will cause holes in the stomach - bleeding and infections
what are the parts of the small intestines
duodenum, jejunum, ileum
what is the valve between the small and large intestines
ileocecal valve
what is the main purpose of the small intestines
absorb nutrients
what are the materials in large intestines called
feces
what are the parts of the large intestine
cecum (appendix), ascending colon, transverse colon, descending colon, sigmoid colon, rectum, anus
what is the main job of the large intestines
reabsorb water and ions
what is the defecation reflex
muscle contractions push feces from sigmoid colon into rectum - anus - internal sphincter (opens with stretch) - external sphincter
what is the purpose of the appendix
no function, evolutionary
neonatal, made immune cells
adults, lymphatic system makes immune system instead
what age do immune cells stop producing
60
what is appendicitis and what are the conditions/treatments associated with it
the opening of appendix blocked by feces - inflammation and infection
mild case = antibiotics
paritonitis - eruption of the appendix
appendectomy - remove appendix
pain on the lower right side
what is diverticulosis
diverticuli - walls of intestines weaken, lining bulges out
diverticulitis - infected or inflamed bulge
pain on left side, usually in sigmoidal colon
caused by fecalith/painkillers
antibiotics or colon resection
what is a megacolon
hard feces make colon wall swollen, pinch on urethra, can’t urinate
what is colonoscopy
camera through the anus to see the large intestines and check for abnormalities
what does the pancreas do for digestion
makes inactive digestive enzymes - pancreatic duct with secretory cells - duodenum
what is pancreatitis and what is it caused by
pancreas inflamed . can be due to active digestive enzymes in pancreas/pancreatic duct - caused by alcohol consumption - pancreatic cancer
what does the liver do for digestion
makes bile
stores in gallbladder when not eating
goes through bile duct to duodenum if eating
how does bile work
gut is aqueous solution, bile binds to large fat globules, pulls it apart to smaller fat globules so lipase can break it down easier
what do foul feces that floats mean
high fat content, abnormal production of bile
what are gallstones
precipitate of cholesterol and bile from the gallbladder
blocks the ducts
what is endoscopy
camera going through mouth to the duodenum to grab the gallstone and remove it
what does a liver do
filter blood, susceptible to poison
what is jaundice
yellowing of the skin caused by bilirubin
bilirubin is supposed to remove waste from haemoglobin and gives body waste their colour
liver not working = bilirubin not filtered
what is liver cirrhosis
due to alcohol consumption, interfere with metabolism of mitochondria in liver cells
makes fat globules - liver is shiny
scar tissue - takes over liver tissue - lost liver function - need liver transplant
describe the hormone regulation for appetite
ghrelin - produced in stomach - goes to hypo - ghrelin receptors - stimulate appetite
leptin - made in fat cells - stimulate fullness
more adipose tissue - more leptin - more resistance to feeling full - eat more - make more adipose tissue
