59 Cards in this Set
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Waste
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any substance that is useless to the body or present in excess of the body's needs
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Urea Formation
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proteins broken down to amino acids, nitrogen removed forming ammonia liver then converts to final product
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Uric Acid
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Waste product of nucleic acid catabolism
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Creatine
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Waste product of creatine phosphate catabolism
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Excretion
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Separation of wastes from body fluids eliminating metabolic wastes, toxins, drugs, hormones, salts, hydrogen, and water
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Renal Corpuscle
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Consists of the glomerulus and two-layered glomerular capsule that encloses glomerulus
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Renal Tubule
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A duct that leads away from the glomerular capsule and ends at the tip of the medullary pyramid
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Nephron Flow of Fluid
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Glomerular Capsule > Proximal Convoluted tubule > Nephron Loop > Distal Convoluted Tubule > Collecting Duct > Papillary Duct > Minor Calyx > Major Calyx > Renal Pelvis > Ureter > Urinary Bladder > Urethra
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Cortical Nephrons
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Make up 85% of all nephrons; short loops with efferent arterioles branching into peritubular capilaries around PCT and DCT
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Juxtamedullary Nephrons
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Make up 15% of all nephrons; very long loops, that maintain salinity gradient in the medulla and helps conserve water; efferent arterioles branch into vasa recta around long nephron loops
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Glomerular filtrate
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Fluid in the capsular space of kidney that is formed from blood plasma but has no protein.
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Tubular Fluid
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fluid from the proximal convoluted tubule through the distal convoluted tubule that has been reabsorbed from glomerular filtrate
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Urine
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Secreted fluid that enters the collecting duct that has undergone littler alteration from tubular fluid except changes in the water content. `
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Glomerular Filtration Rate
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(GFR) the amount of filtrate formed per minute by the 2 kidneys combined; total amount of filtrate produced equals 50 to 60 times the amount of blood in body. 99% reabsorbed 1-2 liters urine excreted a day.
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Renal Autoregulation
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The ability of the nephrons to adjust their own blood flow and GFR without external control; enables them to maintain a relatively stable GFR in spite of changes in systemic arterial blood pressure.
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Macula Densa
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Patch of slender, closely spaced epithelial cells at end of the nephron loop; senses variations in flow or fluid composition and secretes a paracrine that stimulates JG cells
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Juxtaglomerular Cells
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(JG) Enlarged smooth muscle cells in the afferent arteriole; when stimulated by macula dilation or constriction occurs, they contain granules of renin which is secreted in response to drop in blood pressure.
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Mesangial Cells
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In the cleft between the afferent and efferent arterioles and among the capillaries of the glomerulus; They communicate by means of paracrines and build supportive matrix for glomerulus, constrict or relax capillaries to regulate blood flow.
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Negative Feedback of GFR
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High GFR means rapid flow of filtrate in renal tubules which is sensed by the macula densa, paracrine is secreted to cause constriction of afferent arteriole to reduce the GFR.
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Sympathetic Control of GFR
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Sympathetic nervous system and adrenal epinephrine contstrict the afferent arterioles in strenuous exercise or acute conditions like circulatory shock; reduces GFR/Urine output, redirects blood from kidneys, GFR may be as low as few milliliters per min.
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Renin
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Secreted by juxtaglomerular cells if BP drops dramatically; converts angiotensinogen into in angiotensin I
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Angiotensin II
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Stimulates adrenal cortex to secrete aldosterone promoting Na and H2O reabsorption in DCT and collecting duct; stimulates thirst & H2O intake also constricts efferent arterioles raising GFR.
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Proximal Convoluted Tubule
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(PCT) reabsorbs about 65% of glomerular filtrate, removes some substances from the blood, and secretes them into tubular fluid for disposal in urine; account for 6% of resting ATP.
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Sodium Chloride
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Creates an osmotic and electrical gradient that drives the reabsorption of water and other solutes, moste abundant cation in filtrate, and creates steep concentration gradient that favors its diffusion into epithelial cells.
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Tubular Secretion
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Process in which the renal tubule extracts chemicals from the capillary blood and secretes them into tubular fluid; two purposes: waste removal and acid-base balance.
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Function of Nephron Loop
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Primarily functions to generate salinity gradient that enables collect duct to concentrate the urine and conserve water; electrolyte reabsorption from filtrate (25% absorbs Na, K, and Cl)
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Aldosterone
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Hormone acting on DCT and collecting duct that is secreted when blood Na concentration falls, when K concentration rises, or drop in BP. "Salt-retaining" hormone.
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Artial Natriuretic Peptide
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(ANP) Results in the excretion of more salt and water in urine because it dilates afferent arterioles , increasing GFR, inhibits renin/aldosterone secretion, inhibits ADH, and inhibits NaCl reabsorption; THUS REDUCING BLOOD VOLUME AND PRESSURE.
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Antidiuretic Hormone
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(ADH) Secreted in response to dehydration and rising blood osmolarity to make the collecting duct mroe permeable to water; water in the tubular fluid reenters the tissue fluid and bloodstream rather than being lost in urine.
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Countercurrent Multiplier
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Nephron loop continually recaptures salt and returns it to extracellular fluid of medulla which multiplies the salinity in adrenal medual; because of gluild flowing in opposite directions in adjacent tubules of nephron loop.
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Urinalysis
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The examination of the physical and chemical properties of urine.
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Diabetes Insipidus
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ADH hyposecretion causing not enough water to be absorbed in the collecting duct so more water passes in urine.
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Glycosuria
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Glucose in the urine.
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Diuretics
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Any chemical that increases urine volume; commonly used to treat hypertension and congetive heart failure by reducing the body's fluid volume and blood pressure.
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Renal Calculus
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(kidney stone) hard granuale of calcium phosphate, calcium oxalate, uric acid, or a magnesium salt called struvite
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Body Water Content
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Infants: 73% or more water
Adult Males: 60% water
Adult Females: 50% water (higher fat content, less muscle mass)
Old Age: down to 45%.
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Nonelectrolytes
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Most are organic however, glucose, lipids, creatinine, and urea do not dissociate in water.
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Electrolytes
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Determine the chemcial and physical reactions of fluids and have greater osmotic power than nonelectrolytes; PROTIENS, ACID AND BASES, INORGANIC SALTS DISASSOCIATE.
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Extracellular Fluid
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(ECF) Similar to plasma; except higher protein content; major cation is Na and anion is Cl.
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Intracellular Fluid
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(ICF) Low Na and Cl content. Major cation is K and anion is HPO4
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Electrolyte Balance
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Salts enter the body by ingestion and are lost via perspiration, feces, and urine; they control fluid movments, excitability of cells, secretory activity, and membrane permeability.
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Central Role of Sodium
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In the ECF it contributes to 280 osmotic pressure of the total 300 ECF solute concentration. Leaks into cells and is pumped out against electrochemical gradient.
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Potassium Balance
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Affects RMP in neurons and muscle cells; Increase in ECF leads to decreased RMP, depolarization, and reduced excitiability. Decrease in ECF leads to hyperpolarization and nonresponsiveness
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Regulation of Calcium
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In ECF IS IMPORTANT for neuromuscular excitability, blood clotting, cell membrane permeability, and secretory activities; controlled by parathyroid hormone and calcitonin
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Regulation of Anions
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Cl major anion in ECF to help maintain the osmotic pressure of the blood 99% of cl is reabsorbed under normal pH conditions.
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Acid-Base Balance
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pH affects all functional proteins and biochemical reactions; concentration of hydrogen ions is regulate by chemical buffer systems, brain stem respiratory centers, and renal mechanisms.
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Bicarbonate Buffer System
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Buffers ICF and ECF to resist pH changes when strong acid or base is added. Mixture of Weak Acid - H2CO3 and Weak Base - HCO3.
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Phosphate Buffer System
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Action is identical to bicarbonate buffer system. Effects the buffer in urine and ICF when phosphate concentrations are high. Weak acid - H2PO4 Weak Base - HPO4
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Protein Buffer System
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Intracellur proteins are the most plentiful and power buffers; plasma proteins are also important; these molecules are AMPHOTERIC pH rises = COOH pH falls = NH2
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Respiratory Acidosis
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Pco2 above 45 mmHg; most common cause of acid-base imbalances due to decrease in ventilation or gas exchange.
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Respiratory Alkalosis
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Pco2 below 35 mmHg; common result of hyperventilation due to stress or pain.
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Metabolic Acidosis
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Indicated by HCO3 levels; caused by ingestion of to much alcohol, excessive loss of HCO3, and accumulation of lactic acid
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Metabolic Alkalosis
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Indicated by rising blood pH and HCO3 caused by vomiting of acid contents of the stomach or by intake of excess base
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Scrotum
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Superficial Fascia hanging outside the abdominopelvic cavity containing testes; 3 degree lower than core body temperature is necessary for sperm production.
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Epididymis
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Nonmotile sperm enter this organ and pass slowly through, and become motile; during ejaculation the epididymis contracts, expelling sperm into the ductus deferens
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Seminal Vesicles
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Produces viscous alkaline seminal fluid; 70% of the volume of semen
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Prostate
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Encircles part of the urethra inferior to the bladder; secretes milky, slightly acid fluid playing a role in the activation of sperm
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Spermatogenesis
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Sequence of events that produces sperm in the seminiferous tubules of the testes. Spermatids lose excess cytoplasm and form tail, becoming spermatozoa.
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Meiosis
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Gamete formation; nucleardivision in the gonads in which the number of chromosomes is halved 2n > n. Introduces genetic variation
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BIOL 244: Exam 1