Unit 2 Urinary Flashcards
Cells that make up the Proximal Convoluted Tubule
Simple Cuboidal w/ microvilli
Cells that make up the Loop of Henle: descending and thin ascending
Simple Squamous
Cells that make up the Loop of Henle: thick ascending
Simple Cuboidal to low columnar
Most of the cells that make up the distal convoluted tubule
Simple cuboidal
cells that make up the last part of DCT and all of the collecting duct
Simple cuboidal consisting of principal cells and intercalated cells
What are the three layers of tissue that surround each kidney? List Deep to superficial
Renal capsule, Adipose capsule, Renal fasica
Kidneys are _________ & __________ (two things)
Paired, Retroperitoneal
The size of the kidney in an adult
4 1/2” long, 2 1/2” wide, and 1” thick
What is Nephroptosis?
Floating kidney; May cause kink in ureter, block urine flow and damage kidney
Kidneys are on ____% of body mass, but get ____% of blood flow. (_______ mls per minute)
1, 25, 1200
How many times a day does our 5 liter blood supply get filtered by the kidneys?
60 times (300 liters a day)
Whats the length of a female urethra?
4 cm (1 1/2 inches)
Whats the length of a male urethra?
15-20 cm (6-8 inches)
The urinary bladder has rugae, except which area?
Trigone
What is the the name of the bladder muscle and what are its three layers (deep to superficial)?
Detrusor Muscle, inner longitudinal, circular, outer longitudinal
What kind of epithelium cells make up the bladder?
Transitional
What are the primary functions of the urinary system?
Control volume, composition and pressure of the blood to maintain homeostasis
What is the functional unit of the kidney?
Nephron
What are the two types of nephrons?
Cortical and Juxamedullary
What are the three functions in a nephron?
Glomerular Filtration, Tubular Secretion, Tubular Reabsorption
What is the normal Glomerular Filtration Rate (GFR)?
125 mls per minute (180 liters per day)
What percent of the filtrate is reabsorbed?
99% (178 1/2 liters per day)
What percent of filtrate is excreted as urine?
1% (1 1/2 liters per day)
What are the two parts of a nephron?
Renal Corpuscle (filters) and Renal Tubule (passage of filtered fluid)
What are the two parts of the Renal Corpuscle?
Glomerulus and Glomerular (Bowman’s) Capsule
What are the tree parts of the Renal Tubule?
Proximal Convoluted Tubule (PCT), Loop of Henle, Distal Convoluted Tubule (DCT)
What does the PCT reabsorb?
60-70% of filtered water
100% filtered glucose and amino acids
60-70% Na+ and Cl-
What does the Loop of Henle reabsorb?
15% of filtered water, 30% filtered K+ (potassium), 20% Na+ (Sodium), and 35% Cl- (Chloride)
What are the two hormones that regulate reabsorption in the DCT and collecting duct?
Aldosterone and Antidiurectic
What does the hormone Aldosterone do?
It is an adrenal hormone that increases Na+ and water reabsorption
What does the hormone Antidiuretic hormone (ADH) do?
its produced in the hypothalamus and affects the DCT cell permeability to water. (increased ADH more water is absorbed, less is secreted in urine)
Normally, what percent of glomerular filtrate is reabsorbed?
99%
What is being reabsorbed out of the filtrate?
Water, Glucose, amino acids, and ions (Ca++, Na+, K+, Cl-)
What percent of water reabsorption occurs by osmosis? What is it called?
90%, it is called Obligatory Water Reabsorption
What percent of water reabsorption is regulated by ADH? and what is it called?
10%, it is called Facultative Water Reabsorption
What are the two functions of tubular secretion?
Rids body of certain substances such as drugs or wastes (urea, creatine, H+, NH4+) and Controls blood pH by secreting H+ and increasing or decreasing HCO3- (bicarbonate)
What is normal blood pH?
7.35 to 7.45
What is the path of blood flow in the kidney?
Renal Artery Segmental Artery Interlobar Artery Arcuate Artery Interlobular Artery Afferent Arteriole NEPHRON (Glomerular Capillaries) Efferent Arteriole Peritubular Caps./ vasa recta Venules Interlobular Vein Arcuate Vein Interlobar Vein Renal Vein
What percent of nephrons are cortical?
80-85%
What percent of nephrons are juxamedullary?
15-20%
What does diluted or concentrated urine depend on?
ADH, which controls water permeability of the las portion on the DCT
What happens if the ADH is decreased?
Dilute urine, Excess water is secreted; Solute concentration is low
What happens if the ADH is increased?
Concentrated urine, Most water is reabsorbed; Solute concentration is high
What are diuretics?
drugs that INCREASE urine output and produce dilute urine
What and where is the Juxtaglomerular Apparatus (JGA)?
Juxtaglomerular (JG) cells of the afferent arteriole AND the macula densa at the juncture of the final portion of the ascending Loop of Henle and beginning of the DCT
What do the cells of the macula densa monitor?
Solute content in filtrate
What do JG cells secrete when blood pressure falls?
RENIN
What is the 5 steps that happen to raise your blood pressure?
- Renin (enzyme released by kidney)
- Angiotensinogen (a plasma protein produced by the liver) is converted by renin into —v
- Angiotensin I, which is then conveyed by Angiotensin Converting Enzyme (ACE) into —v
- Angiotensin II (an active hormone) which causes the adrenal cortex to secrete —v
- Aldosterone (adrenal hormone that increases reabsorption of Na+ and water.
This causes blood volume to RISE to blood pressure returns to NORMAL
What assists a substance to cross the membrane during facilitated transport?
An integral membrane protein
What are the three types of transporters?
- Uniport; moves single substance across membrane
- Symporter; moves TWO substances across membrane in the same DIRECTION
- Antiporter; moves TWO substances across the membrane in DIFFERENT directions
Why can urine be 1000 times more acidic than blood?
It is due to H+ primary active transport pumps
What is Glomerular (blood) Hydrostatic Pressure (GHP/GBHP)?
Pressure inside glomerular Capillaries; pressure is 55 mm Hg (Mercury)
What does GBHP do?
it promotes filtration by forcing fluid into the capsular space. The fluid resembles blood except it lacks blood cells and plasma proteins since these are to large to be filtered
What are the pressures that Oppose Glomerular Filtration?
- Capsular Hydrostatic Pressure (CHP)
2. Blood Colloid Osmotic Pressure (BCOP)
How do we get Net Filtration Pressure (NFP)?
GBHP (55 mm Hg) - [CHP (15 mm Hg) + BCOP (30 mm Hg)] = NFP (10 mm Hg)
GBHP (55 mm Hg) - [CHP (15 mm Hg) + BCOP (30 mm Hg)] = NFP (10 mm Hg) produces a glomerular filtration rate of _____ mls per minute or _____ liters per day.
125 mls, 180 liters
List the three layers of the Filtration Membrane of the Glomerulus? (Deep to Superficial)
- Glomerular Cap. epithelium (Glomerular endothelium; has fenstrations)
- Basal Lamina (basement membrane)
- Filtrations Slits (space between pedicels of podocytes)
What is Renal Auto-Regulation?
Regulation of Myogenic (Muscle tissue)
What are the two major stimulus of Myogenic?
- Stretching of afferent arteriole walls due to increased systematic blood pressure. (higher BP)
- Decline in glomerular BP. (lower BP)
What are the two mechanism changes of the Myogenic?
- Contraction of smooth muscles in in afferent arteriole wall. (slowing down flow)
- Dilation of afferent arteriole and glomerular capillaries; constriction of efferent arteriole
What are the two effects on the GFR?
- Decrease GFR by constricting lumen
2. Increase GFR
What are the two Neural Regulations?
- Tubuloglomerular Feedback
2. Sympathetic Nerves (Autonomic)
What is the major stimulus for Tubuloglomerular feedback?
Rapid increase in Na+ (sodium) and Cl- (chloride) in lumen at macula densa due to increased BP (blood pressure)
What is the mechanism of Tubuloglomerular feedback?
Decreased release of Nitric Oxide by JGA (juxtaglamerular apparatus) causing AA (afferent arteriole) constriction
What is the effect on GFR due to Tubuloglomerular feedback?
Decrease in GFR (Glomerular Filtration Rate) and filtrate volume
What is the major stimulus of Sympathetic Nerves?
Acute fall (decrease) in systematic blood pressure. Release of norepinephrine
What is the mechanism of Sympathetic Nerves?
Constriction of Afferent arterioles
What is the effect on GFR due do Sympathetic Nerves?
Decrease GFR and filtrate volume to maintain blod volume
What are the 4 hormones in Hormonal Regulation?
- Angiotensin II
- Atrial Natriuretic Peptide
- Antidiuretic Hormone (ADH)
- Aldosterone
What is the major stimulus, mechanism, and GFR effect of Angiotensin II?
-MAJOR STIMULUS Decreased blood volume or blood pressure -MECHANISM Constriction of both afferent and efferent arterioles -EFFECT ON GFR Decrease GFR
What is the major stimulus, mechanism, and GFR effect of Atrial Natriuretic Peptide?
-MAJOR STIMULUS
Stretching of the arterial walls due to increased blood volume
-MECHANISM
Relaxation of mesangial cells (endo. cells) increasing filtration surface (can inhibit water and electrolyte reabsorption)
-EFFECT ON GFR
Increase GFR
What is the major stimulus, mechanism, and GFR effect of Antidiuretic Hormone (ADH)?
-MAJOR STIMULUS
Increased Angiotensin II or decreased volume of extracellular fluid
-MECHANISM
Stimulate insertion of aquaporin-2 (water channels) in apical membrane or principal cells (regulates permeability of prickle cells)
-EFFECT ON GFR
Increases blood volume to return GFR to normal
What is the major stimulus, mechanism, and GFR effect of Aldosterone?
-MAJOR STIMULUS
Secreted from Adrenal Cortex because of increased Angiotensin II levels
-MECHANISM
Increases reabsorption of Na+ and water by principal cells of the DCT/Collecting duct
-EFFECT ON GFR
Increases blood volume to return GFR to normal
