| organs part of alimentary canal | mouth esophagus,small & large intestine |
| organs part of accessory organs | tongue, liver, partotid gland,gallbladder, stomach, pancreas |
| 8 activities of the digestive system | swallowing, chewing, moving, churning, discharge, breakdown, taking in, defection |
| what is absorbed by lymph | fatty acids |
| what is the main substance absorbed from the large intestines into blood vessels | nutrients and water |
| what is segmentation | part of physical digestion: alimentary tract organs alternately contract and relax, churning or mixing contents |
| anohter term for chewing | mastication |
| distinguish between segmentation and peristalsis | peristalsis-adjacent segments of alimentary tract, moves contents along tract
segmentation- non adjacent segments of alimentary tract, mixes contents |
| name the three histological layers of the alimentary canal | mucosa submucosa muscularis externa |
| function of mucosa | lines lumen, secretes,absorbs small intestine, protects |
| function of muscularis mucosa | produces local movement |
| what is found in submucosa | dense connective tissue, lymphatic vessels, capillaries and blood vessels |
| which layer is responsible for peristalsis and segmentation | muscularis externa |
| Which GI tract actions are controlled by the myenteric plexus? | peristalsis and segmentation |
| What are the effects of the sympathetic and parasympathetic ANS on the submucosal plexus and the myenteric plexus? | parasympathetic- relaxes sphincters stimulates contraction and secretion
sympathetic- inhibits contractions/secretions and constricts blood |
| Type of mucosal epithelium found in each section of the alimentary canal | mucosa - simple columnar epithelium w/ goblet cells |
| which layer would have glands and crypts | muscosa |
| where lymphoid follicles would be found | submucosa |
| what part of the alimentary canal has a submucosal plexus | submucosa |
| What parts of the alimentary canal have modifications in the muscularis externa | proximal esophagus is skeletal muscle. stomach has 3 layers of smooth muscle instead of 2 |
| where is the myenteric plexus found | muscularis externa |
| .- List the components of the local reflexes of the GI tract | interoreceptors- chemoreceptors and stretch receptors
enteric motor neurons- smooth muscle contractions, glandular secretions |
| .- List the type of stimuli that stimulate mechanoreceptors in the GI tract | distention(stretch) |
| Explain the effects of ENS motor neurons on effector muscles and glands | stimulate secretion |
| What types of activities of the GI tract are controlled by local reflexes? | control of blood flow in GI, smooth muscle contractions, glandular secretions |
| List the types of receptors that initiate the long reflexes (CNS). | extroreceptors- sight, smell, taste of food |
| Enteric sensory neurons: | chemoreceptors and stretch receptors |
| Which parasympathetic nerve carries motor commands to the GI tract during long reflexes? | C.N X- vagus nerve |
| which plexus is responsible for muscle contractions | myenetric |
| which plexus is responsible for glandular secretions | submucosal |
| hirschsprung's disease | results of missing nerve cells in large intestines that make passing stool difficult |
| multiple endocrine neoplasia type 2 | rare, increases risk of having thyroid cancer, affects other endocrine glands |
| symptoms of multiple endocrine neoplasia type 2 | increase levels of gastrin, ulcers, inflammation of espophagus |
| what is the effect of stimulation of the myenteric plexus | smooth muscle contractions |
| what is the effect of stimulation of the submucosal plexus | glanduluar secretions |
| acetylcholine | parasympathetic |
| norepinephrine | sympathetic |
| seotonin | ens neurons |
| secretin | inhibit stomach activity |
| histamin | stimulate HCI secretions in stomach |
| function of mesenteries | to attach to walls of abdominal cavity(hold organs) |
| functions of oral cavity | formation of bolus, ingestion mastication, mechanical/chemical digestion, deglutition |
| bolus | formation of food in mouth to go down esophagus |
| chyme | bolus with mix of stomach secretions |
| function of tongue | to push bolus of food against hard palate, taste food |
| primary teeth | thin enamel, baby teeth |
| permanent teeth | 32, thich enamel, larger dimensions, adult teeth |
| dental formula for permanent teeth | 2 incisors, 1 canine, 2 premolars, 3 molars |
| incisors | chisel shaped teeth for cutting |
| canines | for tearing and piercing |
| premolars | grinding/crushing |
| gingivities | inflammation of gums |
| halitosis | build-up of bacteria in mouth from gum disease ( bad breath) |
| pyorrea | ligaments and bones that support teeth become inflamed and infected |
| dental caries | tooth decay |
| periodontal disease | affects bone and supporting tissue; forms pockets between teeth |
| mastication reflex | type of stretch reflex brought by activation of muscle spindles associated w/ the mandibular jaw |
| intrinsic | scattered throughtout tongue, palate, cheek and lips |
| extrinsic | parotid submandibular sublingual |
| acinar glands | region of mouth that secretes saliva |
| parotid | secretes serous saliva into mouth, duct is above tongue and under hard palate |
| submandibular | secretes saliva (mixed serous and mucous), duct is underneath the sublingual gland ( under tongue ) |
| sublingual | secretes mucous saliva,duct under tongue and lines the side of mouth |
| acinar gland | region of mouth that secretes saliva |
| function of saliva | cleanses mouth, mositen/dissolves food chemicals, aids in bolus formation |
| composition of saliva | 97-99% water( slightly acidic), amylase, mucin, electrocytes, lysozyme, IgA defensis |
| swallowing reflexes controlled | medulla |
| voluntary phase | tongue pushes bolus of food into hard palate |
| pharyngeal phase | soft palate elevated, uvula closes nasopharynx, pharynx and larynx elevates, pharyngeal constrictor muscles moves bolus toward esophagus, epiglottis pushes downward closing glottis |
| esophageal phase | bolus of food is moved by peristalsis toward stomach |
| Describe the histological characteristics of the esophagus. | mucosa- stratified squamous epithelium, submucosa- areolar connection tissue, lumen- opening center, muscularis externa- longitudinal layer (distal lumen) circular layer(next to longitudinal) |
| gross anatomy of esophagus | posterior to trachea, crosses diaphragm, 2 sphincters; upper and lower(cardiac or gastroesophageal sphincter) |
| what part of the brain controls peristalsis of the esophagus | medulla |
| what is the epithelial muscosa of the stomach | layer contains glads and gastric pits, simple columnar epithelium w/ numerous goblet cells |
| rugae | folding of mucosa and submucosa layers. non-permanent folds |
| function of stomach | storage and mixing of foods. digestion of proteins |
| what parts of the stomach contain enteroendocrine cells | gastric glands |
| what are the sphincters of the stomach | pyloric and gastroesophageal |
| function of HCI | kill bacteria, denature proteins, activates pepsin, deactivates salivary amylase |
| cephalic phase | duration; short, purpose; prepares for arrival of food, stimuli; exteroreceptors- sight taste smell, control; CNS control in medulla, secretions; ACH-gastrin-pepsinogen-HCI-histamin |
| what secretions has the greates effect of HCI secretion | histamin |
| why are drugs that block histamine secretion used to control HCI secretion | because histamin has the greatest effect on HCI secretion |
| gastric phase | stimulus; presence of food and undigested proteins, duration;long,purpose; secretions used to break down food(proteins), mix, acidify, control; CNS and ENS; secretions; gastrins stimulates parietal and cheif cells, parietal cells secrete HCI and intrinsic factor, chief cells secrete pepsionogen, hisamin stimulates parietal cells secretion of HCI |
| what are the effects of alcohol and caffeine on gastric secretions | stimulates gastric secretions |
| what happens to acid secretions when the stomach ph reaches 2 | they stop to prevent excessive HCI secretions |
| intestinal phase | duration; long, purpose; chemical digestion of foods in the duodenum,moves food to duodenum, where food will be digested.secretin and CKK will trigger pancreatic enzymes an bile secretion, while inhibiting the gastric phase by stopping gastrin secretion in stomach, stimuli; entrance of small volume of acidic chyme into duodenum, secretions; secretin and cholesystokinn hormones, control; enterogastric reflex-from CNS, ENS |
| what is the enterogastric reflex | relex of duodenal contents into stomach, ph of 3-4 or 1.5 |
| peptic ulcers | opens sores that develop on the inside lining of stomach. occurs when stomach acids damages the lining due to pylori bacteria |
| hypertrophic pyloric stenosis | blockage of the passage out of the stomach due to thickening of the muscle at the junction between the stomach and intestines |
| gastroesophageal reflux disease | when stomach acid or bile irritates the food pipe lining. occurs when the sphincter at the lower end of esophagus relaxes at the wrong time |
| pyloric pump | empties contents of the stomach into duodenum |
| mixing waves | are weak peristaltic waves that start at the upper stomach and into antrum |
| peristalic waves | are stronger to push food through the pylorus into duodenum |
| in small intestine most absorption takes place in | the duofenum and jejunum |
| the parts of small intestine | duodenum jejunum, ilium |
| lymphatic tissue numerous in | jejunum and ilium |
| chemical digestion of chyme takes place in | duodenum |
| duodenum jejunum ileum lined with what epithelium | simple columnar epithelium |
| What features of the small intestine are adaptations that increase surface area? | folds of the mucosa and submucosa come together w/ villi and microvilli |
| What features of the small intestine are adaptations that increase surface area? | large surface area allows for more food and nutrient absorption |
| what are lacteals | lymphatic vessels that absorb lipids |
| function of absorptive cell in intestinal gland | secrete digestive enzymes (brush border enzymes) and absorb nutrients to be delivered to capillaries |
| function of goblet cell in intestinal gland | secrete protective mucous |
| function of granular cells in intestinal gland | provide host defense against microbes in small intestine |
| function of enteroendocrine cells in intestinal gland | secrete hormones; secretin and CCK |
| histology of duodenum | cells are crypts or intestinal glands; have absorptive cells, goblet cells, paneth cells, enteroendocrine cells microvilli |
| histology of jejunum | less plicae and villi |
| histology of lleum | less plicae, villi; peyers patches, ileocecal junction, ileocecal sphincter and valve |
| .- What are brush border enzymes? | are the site for terminal carbohydrate digestions |
| Where are bile salts secreted | secreted by liver into duodenum |
| where are pancreatic enzymes secreted | by pancreas into duodenum |
| What type of movements are present in the small intestine? Are this localized or long movement? | peristalsis; long movement to move chyme along. localized contractions |
| gross anatomy of liver 1 | has 2 major lobes that are separated as right and left by the falciform |
| gross anatomy of liver 2 | there are 2 minor lobes that are inferior (caudate and quadrate) |
| gross anatomy of liver 3 | porta is the entrance of the hepatic vein |
| gross anatomy of liver 4 | common hepatic duct made of left and right ducts |
| gross anatomy of liver 5 | cystic duct and common duct= common bile duct |
| gross anatomy of liver 6 | common bile duct joins pancreatic duct at the hepatopancreatic duct |
| hepatic traids | consist of portal arteriole, venule and bile ducts |
| functions of liver | bile production and excretion, filter blood from GI, detoxify chemicals and metabolizes drugs,makes albumin complement and clotting factors |
| functions of bile | dilute HCI, raise pH of chyme that allow pancreatic enzymes to work, emulsifies lipids (bile salt), absorption of cholesterol(fats) |
| How is bile secretion controlled? | under neural(parasympathetic) and hormonal control(secretin and CCK) |
| functions of hepatocytes | bile production and storage, phagocytosis, interconversion of nutrients detoxification, phagocytosis synthesis of blood components |
| hepatitis A | virus that causes inflammation of the liver cells through consumption of contaminated food or water |
| hepatitis B | disease that can cause cirrhosis and scarring of liver; can be chronic and fatal. transmitted through bodily fluids |
| hepatitis C | triggers immune response of inflammation and decreases blood flow to liver |
| cirrhosis of the liver | chronic liver damage that leads to liver failure. can be from hepatits or alcoholism |
| gallstones | hardened deposits of digestive fluid in gallblader |
| pancreas location | below and behind stomach |
| gross anatomy of pancrea | has a head (duofenum), body and tail portions(extends toward spleen) |
| exocrine of pancreas | acini cells secrete enzymes into pancreatic duct |
| endocrine of pancreas | regulate blood levels of glucose and amino acids |
| pancreatic islets secrete | insulin and glucagon |
| appendicitis | inflammation of appendix |
| appendectomy | removal of appendix |
| peritontis | inflammation of peritoneum(lining of addominal walls) caused by leakage of an intestine |
| most water is absorbed | in small intestine (92%) |
| hepatic portal system | system that returns blood from GI tract delivers nutrients to liver but not lipids |
| what is absorbed in stomach | lipids alcohols aspirin |
| what is absorbed in colon | water and salt |
| where each of the three classes of nutrients are digested, and name the enzymes involved | carbohydrated; mouth(salivary amylase)-duodenum
lipids; mouth(lingual lipase) & stomach(gastric lipase)-duodenum
proteins; stomach(pepsin)-duodenum |
| Describe the changes in the digestive system as we age | muscles in GI tract stiffen and weaken becoming less efficient, damage to tissues increases |
| causes of diarrhea | from a virus, bacterial infection or food intolerance |
