6 - The Digestive System, The Excretory System Flashcards
Order of entry from mouth:
Mouth–>esophagus–>stomach–>
small intestine (duo, ile, jej)–>
large intestine(ascending, transverse, descending, signmoid)–>
rectum–>anus
Alpha-amylase=
- breaks down long chains of starch into ______
- chewing also _______ the food and increases the _____ which enables more enzymes to act on the food at any one point in time.
- From the mouth the ball of chewed food is put into the esophagus which moves down by peristaltic action which is wave-like motion of smooth muscle that moves food through the_______.
- Saliva acts to______ the food and make it easier to travel down the ______.
Alpha-amylase= digesting begins in the mouth with this which is found in the saliva.
- breaks down long chains of starch into polysaccharides.
- chewing also “physically” digests the food and increases the surface area which enables more enzymes to act on the food at any one point in time.
- From the mouth the ball of chewed food is put into the esophagus which moves down by peristaltic action which is wave-like motion of smooth muscle that moves food through the digestive tract.
- Saliva acts to lubricate the food and make it easier to travel down the esophagus.
Chyme=
- the stomach contains _______
- the stomach also begins_______ with the enzyme ______. _______ also helps with the denaturation of proteins. And helps kills ingested bacteria.
Chyme= semifluid mass.
- the stomach contains exocrine glands.
- the stomach also begins protein digestion with the enzyme pepsin. Low pH also helps with the denaturation of proteins. And helps kills ingested bacteria.
*______ major cell types in the stomach*
1) mucous cells–> secrete ______. Composed of mainly _______ and ______ which mainly lubricate the stomach wall so it can slide without causing damage. *mucous also protects the _______ from acidic environment of the stomach. May also secrete a small amount of _______ as well.
2) chief (peptic) cells–> found deep in _____ glands, they secrete _______ which is the precursor to ______, which is activated by low pH and begins ______ proteins.
3) parietal (oxyntic) cells–> are found in the _____ glands as well. Creates ______ which diffuses to the lumen.
4) G cells–> secrete _____ into the _____ Gastrin, a large peptide hormone, is absorbed into the blood and stimulates parietal cells to secrete _______
*Acetylcholine–> increases secretion of ________
*Gastrin and histamine–> increases mainly ______
*Four major cell types in the stomach*
1) mucous cells–> secrete mucous. Composed of mainly glycoproteins and electrolytes which mainly lubricate the stomach wall so it can slide without causing damage. *mucous also protects the epithelial lining from acidic environment of the stomach. May also secrete a small amount of pepsinogen as well.
2) chief (peptic) cells–> found deep in exocrine glands, they secrete pepsinogen which is the precursor to pepsin, which is activated by low pH and begins digesting proteins.
3) parietal (oxyntic) cells–> are found in the exocrine glands as well. Creates HCl which diffuses to the lumen.
4) G cells–> secrete gastrin into the interstitium. Gastrin, a large peptide hormone, is absorbed into the blood and stimulates parietal cells to secrete HCl.
*Acetylcholine–> increases secretion of all cell types.
*Gastrin and histamine–> increases mainly HCl.
*_____% of digestion and absorption occurs in the small intestine.
Villi=
Lacteal=
Microvilli=
Brush border=
Goblet cells=
*90% of digestion and absorption occurs in the small intestine.
Villi= on the wall of the small intestine there is finger-like projections which increase the surface area of the intestinal wall allowing for greater digestion and absorption.
Lacteal= within each villus are a capillary network and a lymph vessel called a lacteal. Nutrients absorbed through the wall of the small intestine pass into the capillary network and the lacteal.
Microvilli= smaller finger-like projections which increase the surface area further.
Brush border= fuzzy covering of the microvilli, which contain bound digestive enzymes (carb, protein and nucleotide)
Goblet cells= some of the epithelial cells which secrete mucus to lubricate the intestine and help protect the brush border from mechanical and chemical damage.
- pH in the duodenum is about ____, mainly because of _____ ion which is secreted by the ______.
- pancreas enzymes: ? (6)
–>trypsin is the enzyme which activates ______.
–>trypsin and chymotrypsin degrade proteins into ______
–>_______ hydrolyzes polysaccharides to disaccharides and trisaccharides; but pancreatic is ________
- pH in the duodenum is about 6, mainly because of bicarbonate ion which is secreted by the pancreas.
- pancreas enzymes: trypsin, chymotrypsin, pancreatic amylase, lipase, ribonuclease, and deoxyribonuclease.
–>trypsin is the enzyme which activates all the others.
–>trypsin and chymotrypsin degrade proteins into smaller polypeptides.
–>pancreatic amylase hydrolyzes polysaccharides to disaccharides and trisaccharides; but pancreatic is much more powerful.
Bile=
*Major function of the large intestine=
Bile= is produced in the liver and stored in the gall bladder. Bile emulsifies the fat which breaks it into small particles without changing it chemically. Increases the surface area and allows lipases to degrade it into mainly fatty acids. Bile is reabsorbed in the small intestine and brought back to the liver.
*Major function of the large intestine= is water absorption and electrolyte absorption. The large intestine contain E. Coli which produces B and K vitamins.
Glycogenesis=
Glycogenolysis=
Urea=
*Fat is insoluble in water so it typically requires a _____
Vena Cava=
Glycogenesis= formation of glucose.
Glycogenolysis= takes place in the liver, and glucose is returned to the blood.
Urea= nearly all ammonia (from protein digestion) is converted to urea by the liver and then excreted in the urine by the kidney.
*Fat is insoluble in water so it typically requires a carrier (lipoprotein or albumin)
Vena Cava= all the blood received by the liver moves through large flattened spaces and leads to the vena cava.
Liver functions:
(8)?
Liver functions:
- blood storage= the liver can expand to act as a blood reservoir for the body
- blood filtration= kupfer cells hagocytize bacteria picked up from the intestines
- carb metabolism= the liver maintains normal blood glucose levels through gluconeogenesis, glycogenesis, and storage of glycogen.
- fat metabolism= the liver synthesizes bile from cholesterol and converts carbs and proteins into fat. It oxidizes fatty acids for energy, and forms most lipoproteins.
- protein metabolism= the liver deaminates amino acids, forms urea from ammonia in the blood, synthesizes plasma proteins such as fibrinogen (clotting factor), prothrombin (clotting factor), albumin (major osmoregulatory protein in blood), and most globulins (include ABs), synthesizes nonessential amino acids.
- detoxification= detoxified chemicals are excreted by the liver as part of bile or polarized so they may be excreted by the kidney.
- Erythrocyte destruction= kupfer cells also destroy irregular erythrocytes, but most irregular erythrocytes are destroyed by the spleen.
- vitamin storage= the liver stores vitamins such as vit. A, D, and B12; as well as iron combining with proteins.
Kidney:
1)
2)
3)
Kidney:
1) excrete waste products such as urea, uric acid ammonia, and phosphate
2) maintain homeostasis of the body fluid volume and solute composition
3) help control plasma pH.
-Two kidneys, made of up of an outer ____, and inner ____
Urine is created by the ____ and emptied into the ____
The renal pelvis is emptied by the ______, which carries urine to the _____, which is drained by the _______.
-Two kidneys, made of up of an outer cortex, and inner medulla.
Urine is created by the kidney and emptied into the renal pelvis.
The renal pelvis is emptied by the ureter, which carries urine to the bladder, which is drained by the urethra.
Nephron=
- blood flows into the first capillary bed of the nephron called the _____. Glomerulus + bowman’s capsule make up the ______
- hydrostatic pressure forces some plasma through fenestrations of the _______
- filtrate moves from bowman’s capsule to the ______. (_______ takes place)
- drugs toxins and other solutes are secreted into the filtrate by the cells of the ______.
- Hydrogen ions are secreted through an ______ with sodium, which is driven by the ______ gradient.
- from the proximal tubule the filtrate flows into the ________
Nephron= functional unit of the kidney.
- blood flows into the first capillary bed of the nephron called the glomerulus. Glomerulus + bowman’s capsule make up the renal corpuscle.
- hydrostatic pressure forces some plasma through fenestrations of the glomerular endothelium.
- filtrate moves from bowman’s capsule to the proximal tubule. (reabsorption takes place)
- drugs toxins and other solutes are secreted into the filtrate by the cells of the proximal tubule.
- Hydrogen ions are secreted through an antiport system with sodium, which is driven by the sodium concentration gradient.
- from the proximal tubule the filtrate flows into the loop of henle.
Distal tube= reabsorbs _______ while secreting ________
—>this empties into the _____
Juxtaglomerular apparatus=
ADH (antidiuretic hormone)=
Distal tube= reabsorbs Na+ and Ca2+ while secreting K+, H+, and HCO3-
—>this empties into the collecting duct.
Juxtaglomerular apparatus= monitors filtrate pressure in the distal tubule.
ADH (antidiuretic hormone)= always digging holes, in the collecting duct.
