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40 Cards in this Set
- Front
- Back
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The Basic Anatomy of the Digestive Tract
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1) Mouth
2) Esophagus 3) Stomach 4) Small Intestine(duodenum, ileum, jejunum) 5)Large Intestine(ascending colon, transverse colon, descending colon, sigmoid colon) 6) Rectum 7) Anus |
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Alpha-Amylase
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Contained in the saliva, breaks down starch into polysaccarides.
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Purpose of Saliva
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Acts to lubricate the food to help it move down the esophagus
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T or F: Digestion occurs in the esophagus
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FALSE!
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The Stomach
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-Very flexible pouch that both mixes and stores food, reducing it to a semifluid mass called chyme.
-Contains exocrine glands -Begins protein digestion w/ enzyme pepsin (low ph of stomach assists this process, as well as killing bacteria) |
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Four Major Cell Types in Stomach
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1) Mucous Cells
2) Chief (peptic) cells 3) Parietal Cells 4) G cells |
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Mucous Cells
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-Secrete Mucus
-Cells line the stomach wall and necks of the exocrine glands. -Mucus is composed of sticky glycoprotein and electrolytes, and lubricates the stomach wall |
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Chief Cells
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-Found deep in exocrine glands
-Secrete Pepsinogen (zymogen precursor to pepsin) |
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Parietal Cells
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-Found in exocrine glands of stomach
-Secrete HCl, which diffuses to lumen (net result = lowers pH of stomach and raises pH of blood) |
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G cells
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-Secrete gastrin(hormone) into the interstitium, which is absorbed into the blood and stimulates parietal cells to secrete HCl
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Major hormones that affect the secretion of the stomach juices are:
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1) acetylcholine
2) gastrin 3) histamine |
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T or F: About 50% of the digestion and absorption occurs in the small intestine
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False: 90%
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Villi
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-Form the outermost layer of the small intestine
-Increase the surface area of the intestinal wall allowing for greater digestion and absorption -Within each villus = capillary network and a lacteal (lymph vessel) |
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Microvilli
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-Finger-like projections on the lumen side of each villus
-Increase the surface area of the intestinal wall still further -"Brush Border" contains enzymes that digest everything |
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Goblet Cells
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-Epithelial cells covering the microvilli; secrete mucus to protect the brush border from mechanical and chemical damage.
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Crypts of Lieberkuhn
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-Located deep w/in the villi in the small intestine
-Secrete an intestinal juice w/ a pH of 7.6 and lysozyme |
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Why does the fluid inside the duodenum have a pH of 6?
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Because of the bicarbonate ion secreted by the pancreas.
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The Pancreas in relation to the small intestine:
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-Pancreas acts as an exocrine gland, releasing enzymes into the duodenum:
1) trypsin 2) chymotrypsin 3) pancreatic amylase 4) lipase 5) ribonuclease 6) deoxyribonuclease |
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Trypsin and Chymotrypsin
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-Released by the pancreas
-Degrade proteins into small polypeptides |
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Pancreatic Amylase
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-Released by the pancreas
-Hydrolyzes polysaccharides to disaccharides and trisaccharides |
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Lipase
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-Released by the pancreas
-Degrades fat (triglycerides) |
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Bile
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-Produced in the liver and stored in gall bladder
-Emulsifies fat (breaks into smaller particles w/out changing it chemically) - allows lipase to more efficiently degrade it |
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The Major Functions of The Large Intestine:
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-Water absorption, electrolyte absorption
-Also contains e-coli, which live off our leftover, and we get vitamins from them |
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Gastrointestinal Hormones
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-Regulate the digestive system so we can eat a large amount of food at a single time, and take a long time to digest it.
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Sucrose
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Disaccharide made from glucose and fructose
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Lactose
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Disaccharide made from glucose and galactose
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Role of the liver in producing carbohydrates
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When the glycogen stores are full, the glucose is converted to fat, a long-term form of energy storage. The conversion of glucose to fat takes place in the liver and is stored in the fat cells.
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Virtually ALL dietary protein is completely broken down to its amino acids ________ being absorbed into the ________.
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before, blood
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Fat is _________ in water, so it typically requires a ________, such as __________.
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insoluble, carrier, lipoprotein/albumin
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ALL functions of the LIVER
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1) blood storage
2) blood filtration 3) carbohydrate metabolism 4) fat metabolism 5) protein metabolism 6) detoxification 7) erythrocyte destruction 8) vitamin storage (pg 132) |
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Ketosis
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-When the liver mobilizes fat for energy, it produces acids called ketone bodies, this often results in a condition called ketosis
-When the liver mobilizes fat/protein for energy, the blood acidity INCREASES |
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Function of the Kidney
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1) Excrete waste products, such as urea, uric acid, ammonia, and phosphate
2) to maintain homeostasis of the body fluid volume and solute composition 3) to help control plasma pH |
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Cortex
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-Forms the outer layer of the kidney
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Medulla
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-Forms the inner part of the kidney
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Renal Pelvis
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-Urine created by the kidney is emptied into the renal pelvis.
-The renal pelvis is emptied by the ureter. |
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Ureter
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-Carries urine to the bladder
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Bladder
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-Drained by the urethra
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Glomerulus
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-First capillary bed of the nephron
-Together, with the bowman's capsule, it makes up the renal corpuscle -Screens out blood cells and large proteins from entering bowman's capsule(enters as filtrate) |
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Proximal Tubule
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-Filtrate from bowman's capsule comes into the proximal tubule
-Proximal tubule is where most of the reabsorption takes place (secondary active transport responsible for reab. of glucose/proteins/solutes) -Water is absorbed into the renal interstitium of the proximal tubules across permeable tight junctions due to osmotic gradient -Net result = to reduce the amount of filtrate in nephron while changing solute composition w/out changing osmolarity |
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THE KIDNEY
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read pages 134-137
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