AP110 Chp 22 Urinary system Flashcards
Excretion
Body systems work interdependently to maintain homeostasis by excretion
Urinary
Organs of the urinary system
Two kidneys
Two ureters
Single urinary bladder
Single urethra
Kidney activities
Excretion Urea Water balance maintenance Body fluid acid-base regulation Blood pressure regulation -Angiotensin -Adosterone RBC production regulation
Located in the retroperitoneal space
Blood supply to the kidney
Renal artery supplies blood
Nephrons are functional units
Renal vein drains blood
Kidney Structure
Hilum (renal artery, renal vein and ureter connect with kidney)
Renal cortex (kidneys outer portion)
Renal medulla (kidneys inner portion)
Renal pyramids (cone shaped structures in medulla)
Renal pelvis (funnel basin that forms upper end of ureter)
Calyces (collect urine for transport to bladder thru the ureters)
Nephron
Functional kidney unit Glomerular capsule -Glomerulus -Afferent arteriole Peritubular capillaries Proximal convoluted tubule (PCT) Nephron loop (loop of Henle) -Descending limb -Ascending limb Distal convoluted tube (DCT) Collecting duct
Formation of urine
Glomerular filtration (movement of materials under pressure from the blood)
-Glomerular filtrate (fluid that enters the glomerular capsule)
Tubular reabsorption (water and substances leave the tubule and enter surrounding tissue)
-Dissusion
-Osmosis
-Active transport
Tubular secretion (removal of H+)
Countercurrent mechanism (fluid traveling in opposite directions within the ascending and descending limbs of the nephron)
-Concentration of urine
-Antidiuretic hormone (ADH)
Control of blood pressure
Juxtaglomerular apparatus: Specialized cells that regulate kidney function
Triggered by low blood pressure
-Secretes renin enzyme into afferent arteriole activates angiotensinogen connects with angiotensin 1, then travels to the lungs to connect with angiotensin 2 causing vasoconstriction stimulating heart activity to increase blood pressure.
The ureters
Long, slender, muscular tubes
Extend from kidney to urinary bladder
Move urine by gravity and peristalsis
Urinary bladder
Temporary reservoir for urine Multiple layers Mucous membrane -Transitional epithelium -Rugae Trigone (Triangular shaped region in the floor of the bladder)
The urethra
Tube that extends from the bladder to the outside
-Male
Part of both reproductive and urinary systems
-Female
Entirely separate from reproductive system
Urination
Process of expelling urine from bladder (micturition)
Involuntary control
-Internal urethral sphincter
Voluntary control
-External urethral sphincter
Urine
95% water, 5% dissolved solids and gases
pH averages 6.0
Specific gravity measures amount of dissolved substances
-Normal range 1.002 - 1.040
(The more concentrated the higher its gravity, the less concentrated the lower its gravity)
Normal urine constituents
Dissolved solids normally found in urine -Nitrogenous waste products Urea (main) Uric acid Creatinine (metabolism of skeletal muscle)
-Electrolytes
Soduim chloride
Sulfates
Phosphates
-Pigment
Abnormal constituents
Glucose (Diabetic) Albumin (Kidney damage) Blood (internal bleeding) Ketones WBC's (UTI) Casts
