| A | B |
|---|
| digestive system | the process of altering food for the purpose of digestion |
| the digestive system is composed of what two parts | the digestive tract and accessory organs |
| mechanical digestion | physical breakdown of food into smaller particles |
| chemical digestion | series of hydrolysis reactions that break down macromolecules into their molecules |
| what are the 5 steps of the digestive system? | ingestion, digestion, absorption, compaction, and defaction |
| taking in food | ingestion |
| breakdown of molecules | digestion |
| uptake of nutrients into blood and lymph | absorption |
| absorbing H2O and consolidating residue | compaction |
| elimination of undigested material | defaction |
| muscular contractions that break up food, mix it with enzymes and move it along | motility |
| secretion is? | digestive enzymes and hormones |
| membrane transport | absorption of nutrients |
| what are the two types of salivary glands? | extrinsic and intrinsic |
| intrinsic salivary glands? | secrete saliva at a slow but constant rate |
| extrinsic salivary glands include what three types? | sublingual, parotid, and submaxillary |
| sublingual | secretes only mucous |
| parotid | secretes only enzymes |
| submaxillary | secretes both mucous and enzymes |
| what moistens, begin startch and fat digestion, cleaneses teeth, inhibits bacteria, and binds food together into bolus | saliva |
| in a hypotonic solution amylase does what? | begins startch digestion |
| in a hypotonic solution lingual lipase does what? | digests fat after it reaches the stomach |
| in a hypotonic solution mucous does what? | aids in swallowing |
| in a hypotonic solution lysozyme does what? | enzyme that kills bacteria |
| in a hypotonic solution immunoglobinA does what? | inhibits bacterial growth |
| in a hypotonic solution electrolytes does what? | Na+, K+, Cl-, phosphate and bicarbonate |
| serous cells secrete fluid rich in what? | amylase |
| the tissue layers of the GI tract include | mucosa, muscularis mucosae, submucosa, and serosa |
| enteric nervous communication | controls motility and mixing (autonominc nervous system) |
| enteroendocrine system | controls motility and enzyme secretion |
| swallowing | series of muscular contractions coordinated by two phases the buccal phase and pharyngoeophageal |
| buccal phase | tounge collects food and pushes it back where the larynx is lifted and epiglottis is folded |
| what pushes bolus down the esophogas? | pharngeal constrictors |
| pharyngoesophageal phase is voluntary or involuntary? | involuntary |
| the buccal phase is? | voluntary |
| What phase blocks food from re-entering the mouth | pharyngoesophogeal |
| peristalis | a wave of muscular contraction that pushes the bolus ahead |
| stomach | a muscular sac that is a food storage organ, it breaks down the food mechanically into chyme |
| there are 4 regions of the stomach what are they? | cardiac, fundic, body, and pyloric |
| which region of the stomach is divided into the antrum and pyloric canal? | pyloric |
| alimentary canal | mouth, pharynx,esophogas, stomach, intestines, rectum, anal canal |
| acessory organs | salivary glands, pancreas, liver, gallbladder |
| parietal cells secrete what? | HCL acid and intrinsic factor |
| chief cells secrete what in infancy | renin and lipase |
| chief cells secrete what throughout life | pepsinogen |
| enteroendocrine cells secrete what | hormones and paracrine messangers |
| hydrochloric acid activates enzymes..... | pepsin and lingual lipase |
| hydrochloric acid breaks things down into | chyme |
| ferric ions are xonverted to ferrous ions by hydrochloric acid, they can be used for what | hemoglobin synthesis |
| intrinsic factor does what 3 thinfs | secreted by parietal cells. essential for B12, necessary for RBC function |
| what is the chief cell function in protein digestion | pepsin |
| what is the inactive form of pepsin | HCl |
| what center signals the stomach to relax | the swallowing center |
| receptive-relaxation response | resists stretching og the stomach briefly and then relaxes to hold more food |
| the rhythm of peristalsis is controoled by what kind of cells | pacemaker cells in longitudinal muscle layer |
| the duodenum... | neutralizes acids and digests nutrients little at a time |
| cephalic phase | vagus nerve stimulates gastric secretion, and motility justwith sight smell taste or though |
| gastric phase | activated by presence of food or semidigested protein |
| stretch of stomach activates what | the myenteric and cagovagal reflexes |
| gastric secretion is stiulated by what? | ACH, histamine and gastrin |
| intestinal phase | duodenum regulates gastric activity through hormones and nervous reflexeS |
| gastric activity does what if the duodenum is stretched | incresases |
| where is gastrin released from? | the duodenum |
| enterogastric reflex | duodenum inhibits stomach,blocks parasympatheitc input to stomch and stimulates inhibitory sympathetic nerves |
| what stimulates duodenal cells to release secretin CCK and GIP | chyme |
| CCk and secretion do wha | surpress gastric secretion and motility |
| GIP stimulates what? | insulin release from pancreas |
| the central vein of the liver is surrounded by sheets of what? | hepatocyte cells |
| the gallbladder does what | stores and concentrates bile |
| bile acid does what to fats | in emulsify's them and aids in digestion |
| enterohepatic circulaition | form the liver to the gallbladder to ileum and back to the liver |
| what serves as an endocrine and exocrine gland | pancreas |
| pancreas secretes what? | insulin and glucagon into the blood |
| zymogens include | trypsinogen, chymotrypsinogen, and procarboxypeptidase |
| amalyase | digests startch |
| lipase | digests fat |
| ribonuclease and deoxyribonuclease | digest RNA and DNA |
| trypsinogen is converted to trypsin by what? | intestinal epithelium |
| CCK is released from the duodenum by the arrival of what | fat and acid |
| secretin released from the dupdenum in response to acidic chyme | stimulates all ducts to secrete sodium bicarbonate |
| fingerlike projections that contain blood vessels and lymphatics | villi |
| segmentation and peristaltic wave move food toward the large intestine | segmentation is when ringlike constrictions mix and churn contents, while peristaltic waves being in the duodenum but each one moves further down |
| food in sotmach causes the gastroileal relflex and release of gastrin which does what> | relaxes illeocecal valve to fill with cecum |
| peristalsis | gradual movement of contents towards the colon |
| migrating motor complex | controls waves of contraction |
| salivary amylase stops working in what | acidic stomach |
| pepsin is inactivated when it passes into the | duodenum |
| infants absorb proteins by | pinocytosis |
| nucleases hydrolyze dna and rna into | nucleotides |
| osmotic diuresis | is diarehha caused when you dont have enough water in the body |
| sodium is cotransported with | sugars and amino acids |
| chloride is actively exchanged for bicarbonate in the | ileum |
| potassiu is absored by | simple diffusion after water is absorbed |
| in the duodenum, what is needed for active uptake | parathyroid hormone and vitamin D |
| intestinal crypts produce | mucus |
| bacterial flora poulatewhat | large intestine |
| bacterial flora synthesize | vitamin B and K |
| hemorrhoids are | permentatly distended veins |
| intrinsic defaction | via the myenteric plexus, cause rectum to contract and internal sphincter to relax |
| parasympathetic defaction | involves spinal cord, stretching of rectum send sensry signals to spine and theu tell you you need to poop |
