Urinary System Flashcards
Urinary system function:
- EXCRETION – Elimination of toxins, metabolic wastes, and excess ion
- REGULATON OF BLOOD VOLUME AND BLOOD PRESSURE
- ION CONCENTRATION REGULATION
- PH REGULATION
- VITAMIN D AND RBC SYNTHESIS – erythropoietin
The urinary system consists of the following:
- Kidneys
- Ureters
- Urethra
- Urinary bladder
- bean shaped organs, each about the size of a tightly clenched fist.
- Size: 11cm (compare to a bar of soap)
- Location: Extending from T12-L3, Retroperitoneal (between the dorsal wall and parietal peritoneum).
kidneys
lower side of the kidney because it is crowded by the liver
right kidndey
connective tissue that surrounds each kidney
RENAL CAPSULE
the 3 layers of the renal capsule
- Renal Fascia
- Perirenal fat capsule
- Fibrous capsule
Anchors the kidney to the surrounding structures
Renal Fascia
- Cushions the kidney
- prevents trauma
- stabilize the kidney
Perirenal fat capsule
Prevents the spread of infection
Fibrous capsule
where renal artery and nerves enter and renal vein, ureter and lymph vessels exit the kidney.
RENAL HILUM
cavity which contains blood vessels
RENAL SINUS
outer superficial region which is light-colored and granular in appearance
RENAL CORTEX
inner deep layer which is dark-colored and striped in appearance
RENAL MEDULLA
coned shape tissue masses located between the cortex and medulla
RENAL PYRAMIDS
separates the renal pyramids
RENAL COLUMNS
funnel-shaped structure which surround the tip of renal pyramid
RENAL CALYCES
The calyces from all the renal pyramids join to form a larger funnel called
renal pelvis
- Structural and functional unit of the kidney
- About 1million nephrons each kidney
- Site of urine formation/production
NEPHRON
- located at the renal cortex
- function to FILTER
RENAL CORPUSCLE
resembles as ball of yarn, fenestrated (pored)
Glomerulus
encapsulates the glomerulus
Glomerular capsule
- located partially at the renal cortex and mostly at the medulla
o Proximal Convoluted Tubule
o Nephron Loop
§ Descending Loop
§ Ascending Loop
o Distal Convoluted Tubule
RENAL TUBULES
Those in the renal cortex (85% of the nephrons)
CORTICAL
Those in the renal medulla (15% of the nephrons)
JUXTAMEDULLARY
transports the blood to the glomerulus
AFFERENT ARTERIOLE
exchange of nutrients, will deliver the blood to the kidney.
GLOMERULUS (CAPILLARIES)
will transport the reabsorbed substances to the peritubular capillary/vasa recta back to the heart.
EFFERENT ARTERIOLE
Urine is produced by three processes
- Filtration
- Tubular Reabsorption
- Tubular Secretion
FILTRATION
a. Location: Glomerulus and Bowman’s Capsule
b. Function: The movement of water, ions and small molecules through the filtration membrane into Bowman’s capsule. Substances that cannot pass through the glomerulus (blood cells and big proteins) will be transported to
vasa recta for reabsorption.
- Filtered substances is called as filtrate.
TUBULAR REABSORPTION (PROXIMAL CONVOLUTED TUBULE)
a. Location: Renal Cortex
b. Permeability: Water and Solutes
c. How reabsorption takes place? As solutes molecules are transported out of the proximal convoluted tubule (via active transport and co-transport) into the interstitial fluid, water moves by osmosis in the same direction. All of the reabsorbed substances go to the vasa recta.
d. Reabsorption Rate: 65%
TUBULAR REABSORPTION (NEPHRON LOOP: DESCENDING LOOP)
a. Location: Renal Medulla
b. Permeability: High to water and Slightly/Semi to solutes
c. How reabsorption takes place? As the filtrate passes through the descending limb into the medulla, water moves out of the nephron by osmosis
and some solutes moves into the nephron by diffusion. (Very concentrated/salty)
TUBULAR REABSORPTION (NEPHRON LOOP: ASCENDING LOOP)
a. Location: Renal Medulla
b. Permeability: High to solutes and Not permeable to water
c. How reabsorption takes place? Solutes diffuses out of the nephron (Diluted!!!)
d. Reabsorption Rate in the entire nephron loop: 15%
TUBULAR REABSORPTION (DISTAL CONVOLUTED TUBULE AND COLLECTING DUCT)
b. Permeability: Water and Solutes
c. How reabsorption takes place? As the filtrate enters the distal convoluted tubule, it is more dilute than the interstitial fluid of the renal cortex. It furthers remove the water and solutes remaining.
d. Reabsorption Rate: 19%
e. Urine formed that will be collected by the renal calyces: 1%
TUBULAR REABSORPTION (DISTAL CONVOLUTED TUBULE AND COLLECTING DUCT)
a. Location: Renal Medulla and Renal Calyces
b. Permeability: Water and Solutes
c. How reabsorption takes place? As the filtrate enters the distal convoluted tubule, it is more dilute than the interstitial fluid of the renal cortex. It furthers remove the water and solutes remaining.
d. Reabsorption Rate: 19%
e. Urine formed that will be collected by the renal calyces: 1%
TUBULAR SECRETION
- The active transport of solutes across the nephron walls into the filtrate.
- Useful for:
o Disposing of substances, such as certain drugs and metabolites, that are tightly bound to plasma proteins.
o Eliminating undesirable substances or end products that have been reabsorbed by passive processes.
o Ridding the body of excess potassium ions.
o Controlling blood pH.
URINE
- Color:
- Odor:
- pH:
- Specific Gravity:
Color: clear pale – deep yellow (amber)
Odor: Aromatic
pH: 6.0
Specific Gravity: 1.001-1.035
CHEMICAL COMPOSITIONS OF URINE
- Urea
- Uric Acid
- Creatinine
- Sodium, Phosphate, ammonia
Water Reabsorption is ______ proportional to Blood Solute Concentration
DIRECTLY
Water Reabsorption is _________ proportional to Urine Output
INVERSELY
Blood Pressure is ________ proportional to Blood Volume
DIRECTLY
Water Reabsorption is ________ proportional to Blood Volume and Blood Pressure
INVERSELY
Water Reabsorption is ________ proportional to Urine Output
INVERSELY
Water Reabsorption is ________ proportional to Urine Output
INVERSELY
- Divided into right and left.
- Small tubes that carry urine from renal pelvis of the kidney to the posterior portion of the urinary bladder.
- Movement: Peristalsis
URETERS
- A hollow muscular (detrusor muscle) container that lies in the pelvic cavity just posterior to the pubic symphysis.
- Sphincters:
- Storage of urine
- Trigone: three openings
URINARY BLADDER
- A hollow muscular (detrusor muscle) container that lies in the pelvic cavity just posterior to the pubic symphysis.
- Sphincters:
- Storage of urine
- Trigone: three openings
URINARY BLADDER
- Tube that exits the urinary bladder inferiorly and anteriorly
- Female- 1 1⁄2 inches (shorter, exposed, prone to infection)
- Male – 6 to 8 inches
URETHRA
- Located at the inferior part of the urinary bladder.
- closes (via autonomic nervous system) when semen is passing through the urethra.
Internal Urinary Sphincter (Involuntary)
- Located at the inferior part of the urethral orifice.
- It is controlled by skeletal muscles
External Urinary Sphincter (Voluntary)
act of voiding or urinating
Micturition
3 events must occur for micturition reflex
a. Detrusor muscle must contract
b. Internal urinary sphincter must open
c. External urinary sphincter must open
A person can override micturition reflex at the age of what
- 2-3 years old and above
- when a person gains conscious thinking
contain high concentration of potassium ions, magnesium ions, phosphate and sulfate than the extracellular compartment)
Intracellular Fluid Compartment (INSIDE CELL)
contain high concentration of sodium ions, calcium ions and bicarbonate ions than the intracellular compartment.
Extracellular Fluid Compartment (OUTSIDE CELL)
Two mechanisms help regulate the levels of ions in the extracellular fluid:
- Thirst Regulation (Hypothalamus – center for thirst)
- Ion Concentration Regulation
- Sodium Ions
- Potassium Ions
- Calcium Ions
- Phosphate and Sulfate Ions
kidney stone
Nephrolith
Excessive accumulation of urine in the renal pelvis due to obstruction of a ureter
Hydronephrosis
inability to expel urine
Urinary Retention
disorder characterized by hardening of kidney tissue
Nephrosclerosis
Inflammation of the renal pelvis of the kidney
Pyelonephritis
- A person gets hypotensive/low blood pressure
- Stimulates the secretion of RENIN from the kidney
- Stimulates the release of ANGIOTENSINOGEN
- Converts into ANGIONTENSIN I
- Converts into ANGIOTENSIN II
- Stimulates the release of ALDOSTERONE from the ADRENAL CORTEX.
Renin-Angiotensin-Aldosterone Mechanism (RAA System)
Increases the permeability of the distal convoluted tubule and collecting duct, as a result, water reabsorption increases.
Antidiuretic Hormone Mechanism (ADH)
