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A&P Chapter 18 & 19
Urinary System & Acid-Base Fluid Balance
Question | Answer |
---|---|
Do the kidneys lay posterior or anterior to the parietal peritoneum? | Posterior |
What protects the kidney's? | Adipose tissue |
Renal Medulla | Inner region of the kidney |
Renal Columns | Divide the interior of the kidney into cone-shaped sections |
Hilum | Slit on concave side of kidney through which blood, vessels, the ureter, and nerves enter & leave |
Renal Cortex | Outer region of the kidney |
Renal Pyramids | Cone-shaped sections in the kidney's interior |
Major Calyx | Structures that converge to form the renal pelvis |
Renal Pelvis | Structure that becomes the ureter |
The functional filtration unit of the kidney is? | Nephron |
The nephron's are located on the inner or outer region of the kidney? | Outer |
What do peritubular capillaries pick up? | Water & solutes |
Water & solutes are reabsorbed by the? | Renal tubules |
Where does blood enter the kidney? | Renal artery |
Bowman's capsule | Two layers of epithelial cells that envelop the glomerulus in an open-ended covering; also called a glomerular capsule |
What is the function of bowman's capsule? | Fluid that filters out of the glomerulus collects in between the two layers of Bowman's capsule & then flows into the renal tubule on the other side of the capsule |
What lines the inside of the proximal convoluted tubule? | Millions of microvilli |
What is urine formed from? | Blood Plasma |
What pushes the normally high glomerular pressure even higher? | Systemic Hypertension |
Systemic hypertension allows what to filter out into the urine? | Protein |
What is the average amount of urine excreted daily? | 1-2 liters |
Glomerular Filtration Rate | GFR - The amount of fluid filtered by both kidneys |
What should GFR be despite changes in the blood? | Constant |
What follows Na? | Water |
What causes the distal convoluted tubule to retain sodium, which leads to increased retention of water? | Aldosterone (ADH) |
What happens when blood volume increases? | Blood pressure rises |
Where does water diffuse out of in the nephron? | Loop of Henle |
What plays a role in acid-base balance? | Distal convoluted tubule |
What is a diuretic? | Drug frequently used to increase urine volume (makes you pee a lot) |
What is the composition of urine? | 95% water; 5% dissolved substances |
What should NOT be in your urine? | Glucose, blood, free hemoglobin, albumin, ketones & bile pigments |
What is oliguria? | Urine output less than 400 ml/day |
What allows the bladder to expand? | Rugae |
How much urine can the average bladder hold? | 800 ml |
Do males or females have a higher risk of UTI? | Females bc they have a shorter urethra |
What can override impulses in the stretch receptor of the bladder? | Pons |
Where is the pons located & what is its function? | In the brain; evaluates whether the time is appropriate or not to pee |
What is intracellular fluid? | Fluid that resides inside the cell (65%) |
What is extracellular fluid? | Fluid that resides outside cells |
What is interstitial fluid? | Fluid inside tissue; between cells |
What determines the amount and direction of flow within each compartment? | Concentration of solutes; particularly electrolytes |
What happens when the osmolarity of tissue fluid declines? | Water moves out of the tissues and into the cells |
How does most fluid intake occur? | Eating and drinking |
What produces a fair amount of water as a by-product of metabolic reactions? | The cells |
How is fluid lost? | Through the kidney's (as urine), the intestines (as feces), the skin (by sweat as well as diffusion), and the lungs (through expired air) |
How much water does an adult normally gain & loose by the body each day? | 2500 mL |
Where is the thirst center located? | Hypothalamus |
What happens when total body water declines? | Blood pressure drops, sodium concentration rises, and osmaolarity increases. Osmaolarity triggers mechanisms to increase intake, as well as mechanisms to decrease output |
When your hypothalamus is stimulated to decrease output, what does the posterior pituitary secrete? | ADH - antidiuretic hormone |
What happens with volume depletion? | Results from blood loss or loss of both water & sodium |
What is dehydration? | Results when the body eliminates more water than sodium |
What are the three reasons infants are more prone to dehydration? | Immature kidney's don't concentrate urine effectively, they have a high metabolism rate that requires more water to flush out toxins, and they have a large surface area in relationship to their volume (lose more water to evaporation) |
What does fluid accumulation involve? | The accumulation of fluid between compartments |
What does fluid accumulation typically affect? | Lungs, brain and dependent areas (such as legs) |
What is edema? | Fluid accumulation in interstitial spaces, causing tissue swelling |
What are some triggers of edema? | Electrolyte imbalances, increased capillary pressure, and decreased concentration of plasma proteins |
What does Na do for electrolyte balance? | Maintains electrolyte in extra cellular fluid, determines volume of total body water, influences how body water is distributed between fluid compartments, plays key role in depolarization, making it. Crucial for proper nerve & muscle control |
What is hypernatremia? | Plasma concentration greater that 146 mEq/L, indicates fluid deficit, usually self corrects |
What is hyponatremia? | Plasma concentration less that 139 mEq/L, results from excess body water, usually corrected by excretion |
What is hyperkalemia? | Plasma concentration above 5.0mEq/L, may occurs suddenly following a crush injury or severe burn, or gradually, K diuretics or renal insufficiency, makes nerve & muscle cells irritable |
What is hypokalemia? | Plasma concentration below 3.5 mEq/L, may result from diuretics, vomiting, or chronic diarrhea, makes cells less excitable |
What is hypercalcemia? | Plasma concentration greater than 5.8 mEq/L, may result from hyperparathyroidism, hypothyroidism, alkalosis, inhibits depolarization |
What is hypocalcemia? | Plasma concentration less than 4.5 mEq/L. May result in hypothyroidism, hyperthyroidism, acidosis, diarrhea. Increases excitation of nerves & muscles |
Where does the Ca cation exist? | Mostly outside the cell |
What is acid-base balance? | Influences homeostasis, pH of blood ranges from 7.35 to 7.45. The pH of a solution is determined by its concentration of H ions. The body uses chemical & physiological buffers to keep acids & bases in balance |
What is the main chemical buffer? | Bicarbonate - use weak base to bind H ions and weak acid to release them |
What are the two physiological buffers? | Respiratory & urinary |
Explain respiratory control of pH | When you have metabolic acidosis (too much acid), the brain signals the respiratory centers to increase the rate & depth of breathing which causes the lungs to blow off CO2, which in turn increases pH, quicker to respond |
Explain renal control of pH | It is the most powerful buffer system, but is slower to respond |
What is the body's normal pH range? | 7.35-7.45 |
What does the body's normal pH range depend on? | Precise ratio of bicarbonate ions to carbonate acid |
What is alkalosis? | Loss of CO2 (via hyperventilation) |
How does the respiratory respond to metabolic disturbances? | By adjusting ventilation - if pH is low, respirations increase (more acidodic) If pH is high, respirations decrease (less acidodic) |
How does the renal system respood to respiratory disturbances? | By adjusting the rate of H ion excretion. When pH is low, kidney's eliminate H & reabsorb more more bicarbonate When pH is high, kidney's conserve H and excrete more bicarbonate |