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enzymes that aid in carbohydrate digestion & their source
- salivary amylase-saliva
- pancreatic amylase - small intestine
- dextrinase & glucoamylase
- maltase sucrase & lactase
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enzymes that aid in protein digestion & source
- pepsin - stomach
- renin-kidneys
- trypin & chymotrypsin-pancrease
- carboxypeptidase
- aminopeptidase
- dipeptidase
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enzymes that aid in lipid digestion & source
lipoprotein lipase - bloodstream
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deep, permanent folds of the mucosa & submucosa; force chyme to spiral through the lumen, slowing its movement & allowing time for full nutrient absorption:
plicae circulares
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fingerlike projections of the mucosa; digested foodstuffs are absorbed through the epitheal cells into both the capillary blood & the lacteal:
villi
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major means of propulsion, involves alternate waves of contraction & relaxation of muscles in the organ walls; squeezes food along the tract, but some mixing occurs as well:
peristalsis
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physically prepares food for chemical digestion by enzymes; includes chewing, mixing food with saliva by the tongue, churning food in stomach & segmentation of the small intestine:
mechanical digestion
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series of catabolic steps in which complex food molecules are broken down to their chemical building blocks by enzymes secreted into the lumen of the alimentary canal; begins in the mouth & is complete in the small intestine:
chemical digestion
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digestion in the mouth:
mechanical
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digestion in the stomach:
chemical
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digestion in the small intestines:
chemical
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digestion in the large intestines:
chemical
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organs of the urinary system:
- kidneys
- urinary bladder
- uretars
- urethra
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allows filtrate to pass into the glomerular capsule:
glomerulus
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extensions terminate food processes that cling to basement membrane & filtration slits allow filtrate to pass into the capsular space:
Bowman's capsule
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allows large amounts of solute-rich, virtually protein-free fluid to pass from blood into glomerular capsule:
renal corpuscle
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functions in reabsorption & secretion:
proximal convolued tubule
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functions more in secretion that reabsorption:
loop of Henle
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filtrate from the renal corpuscle passes through the proximal convoluted tubule first & then the distal:
distal convolued tubule
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plays an important role in regulating the rate of filtrate formation and systemic blood pressure:
juxtaglomerular apparatus
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low-pressure porous capillaries adapted for absorption:
peritubual capillaries
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characteristics of urine:
- color & transparency (clear, pale to deep yellow)
- odor (slightly aromatic when fresh, ammonia after sitting out)
- pH (slightly acidic)
- 95% water; 5% solutes
- nitrogenous wastes- urea, uric acid & creatinine
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hormone that acts enzymatically on angiotensinogen (plasma globulin made by liver) converting it to angiotensin I:
renin
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stabilizes blood pressure & extracellular fluid volume:
angiotensin II
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triggers for micturition:
- contraction of detrusor muscles by ANS
- opening of internal urethral sphincter by ANS
- opening of external urethral sphincter by somatic nervous system
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percent of the filtrate that is finally released as urine:
5%
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3 steps of diluted urine formation:
- 1. filtrate is diluted in ascending loop of Henle
- 2. in the absence of ADH, dilute filtrate continues into renal pelvis as dilute urine
- 3. Na+ & other ions maybe selectively removed in the DCT & collecting duct, decreasing osmolaity to as low as 50 mOsm
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3 steps of concentrate urine formation:
- 1. depends on the medullary osmatic gradient & ADH
- 2. ADH triggers reabsorption of water in collecting ducts
- 3. facultative water reabsorption occurs in the presence of ADH fo that 99% of water filtrate is reabsorbed
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