Urinary System Flashcards
1
Q
What are the organs of the urinary system?
A
2 kidneys, 2 ureters, 1 urinary bladder, and 1 urethra
2
Q
Where are the kidneys located in relation to the peritoneum?
A
Retroperitoneal (behind the peritoneum).
3
Q
Which kidney is higher?
A
The left kidney is higher than the right.
4
Q
How much of the cardiac output do the kidneys receive?
A
About 20% of the total cardiac output.
5
Q
About how many nephrons are in each kidney?
A
Approximately 1 million.
6
Q
What are the main functions of the kidneys?
A
Filter blood & produce urine
Regulate water volume
Control electrolyte levels
Remove metabolic waste
Regulate blood pH
Produce renin (regulates BP)
Produce erythropoietin (stimulates RBC production)
7
Q
what is renin
A
in kidney that regulates BP, produced by the juxtaglomerular (JG) cells in the afferent arteriole of the kidney. (add myself)
8
Q
What is the function of the ureters?
A
Transport urine from the kidneys to the bladder.
9
Q
What is the function of the urinary bladder?
A
Stores urine until excretion.
10
Q
What is the function of the urethra?
A
Carries urine from the bladder to outside the body.
11
Q
What are renal columns?
A
Extensions of cortex between renal pyramids.
12
Q
What are renal pyramids composed of?
A
Nephron loops and collecting ducts.
13
Q
What is the outer portion of the kidney called?
A
Cortex.
14
Q
What is the inner region of the kidney called?
A
Medulla.
15
Q
What is the renal capsule?
A
A fibrous covering that surrounds the kidney.
16
Q
What structure lies beneath the renal capsule?
A
The cortex.
17
Q
What is the hilum of the kidney?
A
The indentation where the renal artery, vein, and ureter enter/exit.
18
Q
What is the renal pelvis?
A
A large open area (not in medulla) that collects urine from major calyces and delivers it to the ureter.
19
Q
What is the function of a major calyx?
A
It delivers urine from minor calyces to the renal pelvis.
20
Q
What is the function of a minor calyx?
A
Collects urine from the renal papilla (point of pyramid) and delivers it to a major calyx.
21
Q
What is the pathway of urine out of the kidney?
A
Renal papilla → Minor calyx → Major calyx → Renal pelvis → Ureter → Bladder
22
Q
What is the order of arterial blood flow into the kidney?
A
Renal artery
Segmental artery
Interlobar artery (runs between pyramids)
Arcuate artery (arches over pyramids)
Cortical radiate artery (aka interlobular artery)
Afferent arteriole (brings blood to nephron)
Glomerulus (capillary ball for filtration)
Efferent arteriole (leaves glomerulus)
23
Q
Where does filtration of blood occur in the kidney?
A
In the glomerulus, located in the cortex.
24
Q
What is the renal papilla?
A
The apex of each renal pyramid where filtrate (soon to be urine) is collected.
25
What is the venous return pathway of blood in the kidney?
Vasa recta → Cortical radiate veins → Arcuate veins → Interlobar veins → Renal vein → Inferior vena cava
26
What happens at the glomerulus in the kidney cortex?
Filtration of blood occurs; waste and excess substances are removed, forming filtrate.
27
Where does filtrate go after it's formed in the glomerulus?
To the renal papilla, then into the minor calyx, major calyx, renal pelvis, and finally the ureter
28
What are the main functions of the nephron?
Filters blood
Produces urine
29
What are the two main parts of the nephron?
Renal Corpuscle
Renal Tubules
30
What is the renal corpuscle composed of?
Glomerulus (Capillary network where filtration starts)
Glomerular (Bowman’s) Capsule (Surrounds the glomerulus and collects filtrate)
31
What is the function of the glomerulus?
It is the capillary network where filtration of blood starts.
32
What is the function of the afferent arteriole?
Brings blood into the glomerulus; it’s larger and has higher pressure, which aids in filtration.
33
What is the function of the efferent arteriole?
Carries blood away from the glomerulus; it’s narrower, which helps maintain pressure for filtration.
34
How would you describe the relationship between the afferent arteriole, glomerulus, and efferent arteriole?
The afferent arteriole brings in the full pot of coffee (blood).
The glomerulus filters it (removes waste, water, and solutes).
The efferent arteriole carries away the remaining liquid (filtered blood).
35
What is the glomerular (Bowman’s) capsule and its role?
The glomerular capsule surrounds the glomerulus and collects the filtrate from blood filtration.
36
What is the role of the renal tubules?
The renal tubules are the site for urine formation and modification. They consist of the following sections:
Proximal Convoluted Tubule (PCT)
Nephron Loop (Loop of Henle)
Distal Convoluted Tubule (DCT)
Collecting Duct
37
What happens in the Proximal Convoluted Tubule (PCT)?
Major portions of the glomerular filtrate are reabsorbed here. (abt 80%?)
38
What is the Nephron Loop (Loop of Henle), and what are its components?
It consists of a descending limb and an ascending limb. These parts help in the reabsorption of water and ions.
39
What is the role of the Distal Convoluted Tubule (DCT)?
The DCT is highly folded and twisted. It plays a role in the reabsorption of ions and the secretion of certain substances. It is not part of the renal corpuscle.
40
What happens after the filtrate passes through the Distal Convoluted Tubule (DCT)?
The filtrate enters the Collecting Duct, which becomes part of the renal pyramid and delivers filtrate/urine to the renal papilla.
41
Describe the flow of urine after it leaves the renal papilla.
Renal Papilla →
Minor Calyx →
Major Calyx →
Renal Pelvis →
Ureter →
Bladder →
Urethra → Out of the body.
42
What is the primary role of renal corpuscles and renal tubules?
Renal Corpuscle (glomerulus and Bowman's capsule): Filters blood.
Renal Tubules (PCT, nephron loop, DCT, collecting duct): Play roles in reabsorption and secretion.
43
What is reabsorption in the nephron?
Reabsorption is when substances are taken out of the filtrate in the renal tubules and put back into the blood.
44
What is secretion in the nephron?
Secretion is when substances from the peritubular capillaries are secreted into the filtrate to be excreted in urine.
45
How does the collecting duct connect to the renal papilla?
The collecting duct delivers urine to the renal papilla, which is then directed into the minor calyx.
46
How does aldosterone affect the Distal Convoluted Tubule (DCT) and collecting duct?
Aldosterone increases sodium and potassium reabsorbtion/secretion, helping regulate blood pressure and fluid balance.
47
How does ADH (antidiuretic hormone) affect the DCT and collecting duct?
ADH increases the permeability to water in the DCT and collecting duct, promoting water reabsorption and reducing urine output.
48
Where does the nephron receive oxygenated blood from?
The nephron receives oxygenated blood from the renal artery, which branches off to arterials that deliver blood to the nephron (part of which is in the cortex, and part is in the medulla).
49
How does urine flow out of the renal pyramid?
Urine flows out of the renal pyramid through the renal papilla, through the minor calyx, then the major calyx, and into the renal pelvis before it enters the ureter.
50
What does the first section of the nephron (renal corpuscle) do?
The renal corpuscle (glomerulus and Bowman's capsule) works together to filter blood.
51
What is the function of the second section of the nephron (renal tubules)?
The renal tubules play a role in reabsorption (taking substances out of the filtrate and putting them back into the blood) and secretion (where peritubular capillaries secrete substances into the filtrate to be excreted in urine).
52
What are ureters and what do they do?
Tubes that extend from each kidney to the urinary bladder; transport urine.
53
What lines the ureters and what type of muscle do their walls have?
Lined with transitional epithelium
Walls made of smooth muscle
54
What is the function of the urinary bladder?
Receives urine from the ureters (urine from kidney to bladder)
Stores urine until it’s released
55
What type of muscle is in the urinary bladder wall?
Detrusor muscle — smooth muscle with 2 longitudinal and 1 circular layer.
56
What type of epithelium and special feature lines the bladder?
Transitional epithelium
Rugae (folds that allow stretching)
57
What is the internal urethral orifice?
Entrance into the urethra from the bladder.
58
What is the internal urethral sphincter?
Smooth muscle
Involuntary
Prevents involuntary urination (contracted at rest, relaxes when bladder is full)
59
What is the external urethral sphincter?
Skeletal muscle
Voluntary — relaxed to allow urination
60
What is the urethra and what is it lined with?
A tube that transports urine to the exterior
Lined with stratified squamous epithelium
61
What is the urethral meatus?
The external opening of the urethra (also called the external urethral orifice).
62
What are urinary calculi?
-
Crystals formed from concentrated minerals in urine (e.g., calcium oxalate, uric acid, struvite) that grow into stones.
63
Symptoms of urinary stones?
- means was on tophat but not slides
Renal colic (severe pain)
Obstructed urine flow
Hematuria (blood in urine)
Urinary tract infection (UTI)
64
Why do urinary stones hurt?
-
They are sharp/jagged and scrape the urinary tract → pain and bleeding
A stuck stone can cause hydronephrosis (urine backs up into kidney)
65
Treatments for urinary stones?
-
ESWL (Extracorporeal Shock Wave Lithotripsy): Non-invasive sound waves break stones
Laser + Endoscopy: For lower urinary tract stones
66
What do these terms mean? Nephrolithiasis
Ureterolithiasis
Cystolithiasis
-
Nephrolithiasis = Stone in kidney (renal pelvis)
Ureterolithiasis = Stone in ureter
Cystolithiasis = Stone in bladder
67
What does urinalysis reveal about the body?
Urine is a filtrate of blood, so its composition reflects what is in the blood and how well the kidneys are working.
68
What is urinalysis?
A diagnostic test used by doctors to evaluate urine composition and detect abnormalities.
69
What is the normal color of urine, and what might abnormal colors indicate?
Normal: Pale yellow to amber (depends on concentration)
Abnormal:
Yellow-brown or green = bile pigments
Red/dark brown = blood
70
What does urine transparency tell us?
Normal: Clear to slightly cloudy
Cloudy: May indicate sediment or pus → infection
71
What are normal and abnormal urine odors?
Normal: Aromatic
Abnormal:
Ammonia = bacteria
Fruity = ketones (seen in diabetes)
72
What is the normal pH range of urine, and what can alter it?
Normal: 4.5–8.0 (avg. 6.0, slightly acidic)
↑ pH = bacteria
pH can also vary based on diet
73
What is normal specific gravity of urine and what do extremes suggest
Normal: 1.001–1.030
<1.001 = diabetes insipidus
1.030 = fever or kidney infection
74
What does glycosuria (glucose in urine) suggest?
Diabetes mellitus – normally glucose is almost completely reabsorbed.
75
What does ketonuria (ketones in urine) suggest?
Seen in high-protein diet, starvation, or diabetes mellitus – normally absent or trace depending on diet.
76
What does albuminuria (albumin in urine) indicate?
Hypertension, glomerulonephritis, trauma, or kidney disease – normally only trace amounts.
77
What does hemoglobinuria (hemoglobin in urine) suggest?
RBC destruction or hemolytic anemia – hemoglobin should NOT be present normally.
78
What does bilirubinuria (bilirubin in urine) suggest?
Liver disease, hepatitis, or cirrhosis – bilirubin should NOT be present.
79
What does the presence of mucus or epithelial cells in urine mean?
Strands normally present – normal finding.
80
What does the presence of crystals in excess indicate?
UTI or urinary retention – small amounts are normal.
81
What does pyuria (many WBCs in urine) or hematuria indicate?
Bacterial infection; Presence of RBCs in urine
82
What are podocytes and where are they found?
Large cells that form the inner wall of the glomerular capsule.
83
What are pedicels?
Extensions of podocytes that have filtration slits—spaces between them that allow filtrate to leave the capillaries and enter the glomerular capsule.
84
What are filtration slits?
Gaps between pedicels that allow substances in blood to pass into the glomerular capsule as filtrate.
85
What are mesangial cells and where are they found?
Support cells found between glomerular capillaries; help maintain structure and function of the capillary bed.
86
What is the glomerulus?
A ball of capillaries inside the glomerular capsule, involved in filtering blood.
87
What are the afferent and efferent arterioles?
Afferent arteriole: Brings blood into the glomerulus
Efferent arteriole: Carries blood away from the glomerulus
88
What is the juxtaglomerular complex (JGC)?
Specialized structure between the afferent/efferent arterioles and the distal convoluted tubule that helps regulate blood pressure.
89
What does the juxtaglomerular complex secrete, and when?
Secretes renin when glomerular blood pressure is too low.
90
What is the macula densa?
Support cells of the capillaries in the distal convoluted tubule that detect sodium levels and help regulate filtration rate
91
What are the three main steps of urine production and where do they occur?
Filtration, Reabsorption, and Secretion—all occur in the nephrons, the functional units of the kidney.
92
Where does filtration occur?
In the renal corpuscle (glomerulus → glomerular capsule).
93
What happens during filtration?
Water and small solutes are filtered from blood into the glomerular capsule.
94
What substances are included in the filtrate?
Water, electrolytes, glucose, amino acids, and small molecules.
95
How much filtrate is produced daily?
Approximately 180 liters per day.
96
Where does reabsorption mainly occur?
In the PCT, nephron loop, and DCT.
97
What is reabsorption?
Movement of substances from renal tubules back into the blood via peritubular capillaries or the vasa recta.
98
What is the vasa recta?
A capillary network around the nephron loop that performs reabsorption and secretion in the loop of Henle.
99
What substances are reabsorbed in each nephron segment?
PCT: Water, ions, glucose, amino acids
Descending limb: Water
Ascending limb: Sodium, chloride, potassium, electrolytes
DCT: Water, calcium, sodium, chloride
100
Where does secretion occur?
Mainly in the PCT and DCT.
101
What happens during secretion?
Waste and excess substances move from the blood into the tubules.
102
What substances are secreted by each segment?
PCT: Hydrogen ions, ammonium, creatinine, drugs, toxins
DCT: Hydrogen ions, potassium
103
What happens in the collecting duct?
Final adjustments to water and ion balance are made; fluid becomes urine and drains toward the renal pelvis.
104
