Lab Exam 2 Study Guide Flashcards
Know the location of the kidneys with respect to the vertebrae and ribs.
Located between T10 and L3. Partially protected by 11th and 12th ribs.
What does the term retroperitoneal mean?
situated behind the peritoneum
Which kidney is lower than the other and why?
Right kidney slightly lower than left kidney because of size of right liver lobe.
What type of cells lines the parietal and visceral layers of the glomerular capsule?
The visceral layer forms part of the filtration membrane and is adjacent to the glomerulus, and the parietal layer forms a funnel-like structure that collects the filtrate within the capsular space (glomerular cavity) – Both layers are simple squamous epithelium; however, the simple squamous epithelial cells of the visceral layer have foot-like projections that wrap around glomerular capillary walls (called podocytes)
What are the components of the filtration membrane?
Capillary walls and the visceral wall of the glomerular capsule.
Components of the juxtaglomerular apparatus: macula densa, juxtaglomerular cells. What do they look like? Where are they? What do they do? How?
In thick ascending loop of Henle (in juxtamedullary
nephrons) epithelia gradually becomes cuboidal
and then columnar.
Epithelial cells in thick ascending limb make
contact with afferent arterioles of renal corpuscle -
become crowded - often called macula densa.
Macula densa in contact with modified smooth
muscle fibers of the arteriole wall - called
juxtaglomerular apparatus.
What are the 3 processes involved in urine formation by the nephron and collecting ducts?
- Glomerular filtration – The first step in urine production. Water and most solutes in blood pass through the filtration membrane (glomerular capillary walls and visceral wall of glomerular capsule) into the glomerular cavity. 2. Tubular reabsorption – Water and solutes cross the wall of the renal tubule, diffuse through the interstitial fluid, and return to blood by entering the peritubular capillaries or vasa recta. 3. Tubular secretion – Solutes leave the peritubular capillaries or vasa recta, diffuse through the interstitial fluid, cross the wall of the renal tubule, and are eliminated in urine.
What is the major site of tubular reabsorption of water and solutes?
The proximal convoluted tubule
Which part of the loop of Henle is more permeable to water but not solutes?
The descending limb of the loop of Henle
Which part of the loop of Henle is impermeable to water but permeable to solutes?
The ascending limb of the loop of Henle
What ions are reabsorbed in the late distal convoluted tubules?
further Na+ and Cl- are reabsorbed into t.e blood/
What ions are secreted in the late distal convoluted tubule?
K+
What hormone increases the reabsorption of sodium and chloride ions and the secretion of potassium ions?
Aldosterone
What hormone is most important in determining the water content of urine?
ADH (antidiuretic horomone)
What cells are important in pH regulation? What enzyme must be present in these cells to enable secretion of protons?
intercalated cells: reabs K+ and HCO3-, sec H+
enzyme: carbonic anhydrase–catalyzes CO2 and HOH to H2CO3 to H+ and HCO3
Define urinalysis.
An analysis of the physical, chemical, and microscopic characteristics of urine and a measure of urine volume.
Define specific gravity.
Specific gravity (density) is the ratio of the weight of a substance to the weight of an equal volume of water.
Recognize a urinometer. What do you measure with this instrument? Know how to use a urinometer.
The device used to measure specific gravity. Take measurement at the meniscus.
What is the range of specific gravity of human urine?
More dilute urine has a lower specific gr.avity. Normal range is 1.001-1.035
Know the meaning of the following terms: glucosuria
glucose in urine
Know the meaning of the following terms: hematuria
erythrocytes in urine
Know the meaning of the following terms: pyuria
white blood cells in urine
Know the meaning of the following terms: ketonuria
ketone bodies in urine
Know the meaning of the following terms: albuminuria
Excess albumin in urine
Know what it may indicate if the pH of urine is very low or very high.
Normal range is 4.6-8.0, with an average of 6.0; high protein diets produce an acidic urine, vegetarian diets produce an alkaline urine. Very acidic could be a urinary tract infection.
Know the significance of glucose in the urine. Refer to your textbook and lab manual.
Glucosuria - usually caused by diabetes mellitus, but sometimes may be caused by stress (epinephrine stimulates glycogen breakdown); diabetes mellitus and stress result in high blood glucose levels and therefore high levels of glucose in the filtrate; glucose transporters cannot work fast enough to reabsorb all glucose from filtrate.