Ch 6-7 Flashcards
(113 cards)
3 things the urinary system consists of
Kidneys
Ureters
Bladder
Functional unit of the kidney; each kidney contains more than a million
Nephrons
3 functions of the nephrons
Filter waste products from the blood
Reabsorb water and nutrients (e.g., glucose and amino acids) from the tubular fluid
Secrete excess substances in the form of urine
In the average person, the nephron filters approximately how much water out of glomerular blood each day and how much of that is excreted in the urine? Therefore, more than what percentage of water is reabsorbed into tubular blood?
Nephron filters approximately 190 L of water out of glomerular blood each day (this enormous amount is many times the total volume of blood in the body); however, only a small proportion of this water (1-2 L) is excreted in the urine. Therefore, more than 99% of water is reabsorbed into tubular blood
Tuft of capillaries with very thin walls and a large surface area where the formation of urine begins
Glomerulus
Reservoir for urine before it leaves the body
Bladder
Triangular area of the posterior bladder, between the openings for the ureters and urethra
Trigone
Where do the ureters enter the bladder and where is the urethral opening?
Through an oblique tunnel that functions as a valve to prevent vesicoureteral reflux during bladder contraction
The openings of the two ureters lie at the posterior corners of the trigone and the urethral opening is situated at the anterior lower corner
Approximately how many mL’s fills the average person’s bladder?
250 mL
Filling of the bladder stimulates autonomic nerve endings in the wall that are perceived as a distended sensation and the desire to void
Micturate
Nervous system injury results in involuntary emptying of the bladder at intervals
Incontinence
A rare congenital anomaly (born with it) in which only one kidney forms, associated with a variety of other malformations
Imaging appearance: IVU = hypertrophic single functioning kidney
Unilateral renal agenesis (solitary kidney)
A rare anomaly in which a small, rudimentary third kidney forms
Functions normally, but is prone to infections that eventually may require its removal
Imaging appearance: IVU = hypoplastic 3rd kidney, may or may not be fused
Supernumerary kidney
Appears as a miniature replica of a normal kidney, with good function
Hypoplastic kidney
An acquired condition that develops when one kidney is forced to perform the function normally carried out by two kidneys
Lone kidney usually a little bigger to make up for the other one
Compensatory hypertrophy
Abnormally positioned kidney that may be found in various locations
Ectopic kidney
Kidney in the true pelvis
Pelvic kidney
Kidney above the diaphragm
Intrathoracic kidney
Both kidneys are malrotated, and fused at the lower poles (joined by a band of normal renal parenchyma [isthmus] or connective tissue)
The most common fusion anomaly
Horseshoe fusion
Rotation of the kidney on the longitudinal or horizontal axis; asymptomatic
Imaging appearance: bizarre appearance of renal parenchyma, calyces, and pelvis
Malrotation
An ectopic kidney lies on the same side as the normal kidney and is very commonly fused
Crossed ectopia
A rare kidney anomaly that produces a single irregular mass that has no resemblance to a renal structure
Complete fusion
Disk, cake, lump, and doughnut kidney
A common anomaly that varies from a simple bifid pelvis to a completely double pelvis, ureter, and ureterovesical orifice.
Complete can be complicated by obstruction or by vesicoureteral reflux with infection
Duplication (duplex kidney)
Cystic dilatation of the distal ureter near its insertion into the bladder
Uretrocele