Module 7 - Digestive Tract Flashcards

Question

Peritoneum - Lesser Omentum

Answer 1

Lesser Omentum – Suspends the stomach from inferior border of liver Pathway for structure to connect to liver

Answer 2

Mesentery – Vertical band of tissue anterior to lumber verte – Anchors all small intestine except duodenum

Answer 3

Mesocolon – Attaches two portions of large intestine to ab wall

Answer 4

Salivary Glands Saliva – 99.5% water and 0.5% solutes – salts, dissolved gases, organic substances, and enzymes 1.5L daily pH 7-8 (alkaline) Major glands located outside of mouth – pour product into ducts – empty into oral cavity Parotid Submandibular (submaxillary) Sublingual glands – below tongue – sublingual ducts Rest – buccal glands

Answer 5

Moisten and lube lining of mouth and pharynx Moisten, soften, and dissolve food – especially carbs Clean mouth and teeth Salivary Amylase breaks down food

Answer 6

Parotid – b/w skin & masseter muscle (near ears) – parotid duct – second upper molar

Answer 7

Submandibular (submaxillary) – floor of mouth – submandibular ducts

Answer 8

Sublingual glands – below tongue – sublingual ducts

Answer 9

buccal glands (cheeks) in mucous membrane

Answer 10

Pharynx runs from nostrils to esophagus & larynx Swallowing Short tube of skeletal muscle Lined with mucous membrane Subdivisions Nasopharynx – breathing and speech Oropharynx – respiratory & digestion Laryngopharynx – resp & digs

Answer 11

Swallowing Elevator skeletal muscle contracts – expands pharynx for bolus – push bolus Elevator relaxes Constrictor muscles contract – force bolus to esophagus Soft palate & uvula close off nasopharynx Larynx pulled superiorly Epiglottis – folds coving glottis – blocks trachea – “wrong way”

Answer 12

Esophagus Muscular tube – behind trachea Lined stratified squamous epithelium Connects pharynx to stomach – thru mediastinum Collapsed when not swallowing Penetrates diaphragm – esophageal hiatus Upper 2/3s of esophagus – smooth and skeletal muscle Lower 1/3 – smooth muscle

Answer 13

Peristalsis – rhythmic waves of muscle contraction in Muscularis to move bolus

Answer 14

Upper esophageal sphincter – b/w trachea and eso – controls food movement from laryngopharynx to esophagus

Answer 15

Lower esophageal sphincter – entrance to stomach – relaxed food enters – contracts to keep stomach acids (chime) from coming up

Answer 16

Deglutition – phases Voluntary – chewing complete – tongue goes upward – bolus to oropharynx Pharyngeal – uvual and soft palate move upward to close nasopharynx Esophageal – peristalsis

Answer 17

Stomach Links esophagus to duodenum Highly active – contracting and changing position and size Stretch to hold 4L Absence of food – deflates inward Temp holding chamber – slowly releases to duodenum Continues carb digestion Initiates digestion of proteins and triglycerides

Answer 18

regions Cardia – connects to esophagus – food passageway Fundus – roof – top Body – main part Pylorus – funnel-shaped – connects to duodenum Pyloric antrum – connects to body Pyloric sphincter – at duodenum – controls emptying

Answer 19

Lining Mucosa Surface Mucous cells – simple columnar cells Lamina propria – gastric pits and glands – secrete gastric juices Inner oblique smooth muscle added to Muscularis – helps churn and mix

Answer 20

Exocrine Glands Mucous neck cells Chief cells Parietal cells Enteroendocrine cells

Answer 21

Mucous neck cells – secrete thin acidic mucus

Answer 22

Chief cells – pepsinogen (inactive pepsin) & gastric lipase – breaks down molecules

Answer 23

Parietal – secrets HCI and intrinsic factor Hydrochloric acid – activates pepsin (digestive enzyme) – breaks down proteins Intrinsic – B12 absorption – allows DNA synthesis – RBC production

Answer 24

Mechanical digestion – peristaltic movements – mixing waves Chemical digestion – conversion of proteins into peptide by Pepsin – pH2 – acidic Gastric emptying – periodic release of chyme into duodenum

Answer 25

Pancreas In retroperitoneum – behind stomach Head into c-shaped curve of duodenum End at hilum of spleen Exocrine and endocrine gland

Answer 26

Exocrine – cell clusters – Acinus – produce pancreatic juice into tiny ducts – merge into two dominant ducts Pancreatic (Wirsung) duct fuses w/ common bile duct Smooth muscle sphincter controls release of juice & bile into small intest. Accessory (Santorini) duct – runs into duodenum

Answer 27

Endocrine – islets of Langerhans – produce hormones Hormone pancreatic polypeptide Insulin & glucagon – b & a cells Somatostatin

Answer 28

Pancreatic Juice – 1L/day – clear – water w/ salt, sodium bicarbonate, & digestive enzymes Ductal cells Pancreatic enzymes Active enzymes

Answer 29

Ductal cells around pancreatic duct ends – Sodium bicarbonate – alkaline – neutralized gastric juices in chyme

Answer 30

Pancreatic enzymes to be activated digest sugars, proteins, and fats Inactive enzymes – would eat pancreas – need to be activated by enzymes in duodenum – activated by enteroendocrine in duodenum Proteins – trypsin, chymotrypsin, & carboxypeptidase

Answer 31

Active enzymes Starch – pancreatic amylase Fat – lipase Nucleic acids – ribonuclease and deoxyribonuclease

Answer 32

Regulated by parasympathetic NS and hormones Acidic chyme enters duodenum – stims secretin by enteroendocrine cells – tells pancreas to release sodium bicarb juice – balances HCI produced in stomach Proteins and fats in duodenum – stims CCK – stims acini – secrete pancreatic juice and enhances secretin secretion

Answer 33

Liver Accessory digestive organ Metabolism and regulation Two primary lobes – larger right & smaller left – separated by Falciform Ligament Lobes made up of lobules – each arranged by central vein Hepatocytes Sinusoids Kupffer’s cells – macrophages Connected to abdominal wall and diaphragm

Answer 34

Porta hepatis – gate – hepatic artery and hepatic portal vein enter liver

Answer 35

Hepatic artery – delivers oxygenated blood from heart to liver

Answer 36

Hepatic portal vein – delivers partially deoxygenated blood w/ nutrients, toxins, and waste – absorbed by small intest. – most O2 for liver is here

Answer 37

Blood w/ nutrients, toxins, and waste pass thru – everything is filtered Nutrients – back into blood – for cells Drains into central vein Then hepatic vein To inferior vena cava

Answer 38

Gallbladder – sac located in depression posterior to liver Stores bile No submucosa Muscularis – ejects bile into cystic duct (merges into common duct) Outer layer – visceral peritoneum

Answer 39

Bile – produced by hepatocytes Yellow-brown alkaline solution Water, bile salts, bile pigments, phospholipids, electrolytes, proteins, cholesterol Breaks down fats – emulsification Secretion regulated by nervous and hormones Absorption of fat-soluble vitamins – A, D, E, & K

Answer 40

Emulsification of triglycerides – bile salts and phospholipids Reabsorbed by enterohepatic circulation – reused

Answer 41

Small Intestine Primary digestive organ All absorption Large surface area for absorption Coil tube of smooth muscle

Answer 42

Duodenum – after stomach Chyme is slowly release by Pyloric sphincter Hepatopancreatic ampulla – opening for bile and pancreatic juices enter – controlled by hepatopancreatic sphincter

Answer 43

Jejunum – more villi

Answer 44

Ileum – largest section Thicker, more vascular, more developed mucosal folds Joins the Cecum (larger intest.) at ileocecal sphincter Peyer’s patches – lymph tissue – keeps bacteria from blood

Answer 45

Mucosa Absorptive cells Goblet cells – secrete mucus Endocrine cells – hormones producing

Answer 46

Absorptive cells Circular folds Villi Microvilli

Answer 47

Circular folds – plicae circulares – deep ridges in mucosa and sub – being at end of duodenum and end middle ileum – facilitate absorption – chyme will spiral slowly = more absorption

Answer 48

Villi – hair-like vascular projections – increase surface area – each contains capillary bed – contain Lacteal – proteins and carbs nutrients drain straight into blood – fats drain into lacteal

Answer 49

Microvilli – cylindrical surface extensions of plasma membrane – brush border – finish digesting carbs and proteins – enhance absorption – contain enzymes

Answer 50

Submucosa – contains duodenal glands – secrete alkaline mucus – neutralize gastric acid in chime

Answer 51

Intestinal juice – vehicle of absorption of substances from chyme

Answer 52

Superior mesenteric artery – blood supply Superior mesenteric vein – drains Nutrient rich blood – carried to liver – hepatic portal vein

Answer 53

Phase of digestion Cephalic phase Gastric phase Intestinal phase

Answer 54

Cephalic phase – saliva & gastric juice – sight, smell, thought of food Hypothalamus stims medulla Medulla tells parasym. To stim gastic secretion

Answer 55

Gastric phase – food enter stomach – gastric juices breakdown – chyme leaves pH increases – stims gastric breakdown of food

Answer 56

Intestinal phase – chyme enters small intest. – digestion occurs – acidity is buffered

Answer 57

Mechanical Digestion – movement of chyme Segmentation Migrating motility complex Chemical Digestion – breakdown of molecules

Answer 58

Segmentation – smooth muscle contract and relax – pinching chyme – pushes it back and forth – mixing with digestive juices – pushes particle against mucosa for absorption

Answer 59

Migrating motility complex – peristalsis – transport movement – duodenum secrets motilin to stim – circular pattern of contraction – push everything towards large intest.

Answer 60

Proteins and carbs digestion completed Proteins – amino acids – begins in stomach Carbs – monosaccharides

Answer 61

Lipid – emulsification with bile salts and pancreatic juices Bile breaks into triglycerides droplets Pancreatic juices hydrolyze triglycerides – fatty acids & monoglycerides Not water soluble – needs fluid medium for absorption – osmosis

Answer 62

Carbs –polysaccharides – starch, glycogen, and cellulose absorbed into blood capillaries broken into Monosaccharides – Glucose, galactose, and fructose gastric juices trigger enteroendocrine cells – chemical into bloodstream – CCK CCK – stims pancreas to release juice – a-amylase – breaks down poly bonds Disaccharides– maltose, malt triose, sucrose, lactose – pulls water towards it Brush border cells – produce enzymes – breakdown disaccharides into monosaccharides Monosaccharides – Glucose, fructose, galactose Cell – Na+ comes in – glucose & galactose uses this to get into cell – sodium glucose transporter – fructose moves thru its own channel – glucose transporter 5 channel Glucose transporters bring monosaccharides into blood stream

Answer 63

CCK – stims pancreas to release juice – a-amylase – breaks down poly bonds CCK - triggers gallbladder contraction to release bile into small intestine - breaks down fats

Answer 64

Absorption - Proteins active transport into blood capillaries of villi Single amino acids, dipeptides, and tripeptides Gastric pits in stomach Chief cells – release pepsinogen – inactive when stored Parietal cells – release hydrochloric acid – activates pepsinogen to pepsin Denature – H+ breakdown the protein – unravels proteins – 3D to line Pepsin – cuts up unraveled protein Small intestine – polypeptides go Enteroendocrine cells – releases CCK – stims pancreas to release juice w/ inactive proteases – stim enterokinase cells in duodenum activate proteases Cut up amino binds in polypeptides– with Brush border in villi Enterocyte Cell – Na+ brings amino acids, di and tripeptides Bloodstream – channels bring amino – facilitated diffusion to liver

Answer 65

Nucleic acids – active transport into blood Pentose sugars, phosphates, and nitrogenous bases

Answer 66

Electrolytes – active transport Dissociate into ions

Answer 67

Water – osmosis – lumen of intestine – epithelial cells in capillaries

Answer 68

Vitamins – Fat soluble (A, D, E, & K) – ingested dietary lipids in micelles – simple diffusion – Water (B & C) – simple diffusion

Answer 69

Dietary Lipids – simple diffusion

Answer 70

Triglycerides, Monoglycerides & long fatty chains – Micelles Micelles After fats broken down into small bits following bile and pancreatic juices – push Bile salts facilitate the diffusion on the intestinal wall – across membrane’s bilayer Bile salts left behind – reused – back to liver Golgi packages separated fats – into triglycerides – resynthesize w/ ApoB (hat) – CHYLOMICRON Chylomicron – goes into lymph – distributes into organs of the body

Answer 71

Micelles – tiny lipid-transport compound made of bile salts and phospholipids w/ fatty acid and monoglyceride cord

Answer 72

Large Intestine Finish absorption of nutrients, electrolytes & water Synthesize some vitamins Forms and eliminates feces – defecation Appendix to anus

Answer 73

4 regions Cecum Colon Rectum Anal Canal

Answer 74

Cecum – opens from small intest. via ileocecal valve – controls flow of chyme – continued absorption of water and salts Appendix

Answer 75

Appendix – winding tube attached to cecum – lymph tissue – repopulates the gut with flora

Answer 76

Colon – ascending, transverse, descending, & sigmoid

Answer 77

Rectum – separates feces from gases – bacteria flora creates gas during fermentation

Answer 78

Anal Canal – opens to exterior – sphincters control defecation Internal – smooth muscle – involuntary External – skeletal muscle – voluntary

Answer 79

Mucosa – no circular folds or villi – contains lots of enterocytes and goblet cells Enterocytes – absorb water and salts – vitamins produced by flora Goblet cells – secrete mucus to ease feces

Answer 80

Muscularis – specialized muscles – taeniae coli – contract – gather colon into pouches Movements – churching, peristalsis, and mass peristalsis

Answer 81

Hepatitis Inflammation of liver – caused by viruses, autoimmune disorders, alcohol, drugs, and toxic chemicals Symptoms – yellowish skin, poor appetite, abdominal pain Treatment – meds and transplant A, B, C, D, & E – most common A, B, & C

Answer 82

A – Fecal-oral infection highly contagious – spread by fecal contamination of food and fomites mild and acute (short term)

Answer 83

B – sexual contact, syringes, razors, tears and saliva Chronic inflammation Liver failure and cancer

Answer 84

C – sexual contact, syringes, razors, tears and saliva Can be passed at birth 25% can defeat – 75% infected for life

Module 7 - Digestive Tract Flashcards

(108 cards)