Kidneys, Ureters, Urinary bladder, urethra
Member Organs of Urinary System
Filter blood and make urine; Involved in the homeostatic control of fluid volume and composition and acid/base balance by its small number of renal cells (endocrine) which make renin/ erythropoietin hormones
Function of Kidneys
Carries urine from kidney (renal) pelvis to the urinary bladder where they enter (on the back of bladder at the base)
Function of Ureters (2)
paired, oval-shaped, retroperitoneal location (behind peritoneum against muscle), left one higher than the right
Structure of Kidneys
renal arter enters
renal vein exits
ureters exits
renal vein exits
ureters exits
Hilus of the Kidney structure
filter blood, form urine (H2O, nitric wastes and excess blood substances), critical in homeostatic regulation of fluid water balance, hormone levels, electrolyte levels, and Ph (acid/base balance)
Function of the Urinary System
Paired, smooth muscle in wall which contracts to move urine down the tubes, muscle walls work by peristalsis action, contains some transitional epithelium tissue lining which allows it to change shape.
Ureter Structure
temporarily stores and releases urine; emptying controlled by reflexive actions of urethral sphincters and gravity
function of urinary bladder
trigone shaped arrangement with 3 openings, 2 ureters and the urethra; lining contains transitional epithelium which changes shape and allows the bladder to distend.
structure of bladder
single tube which carries urine from the bladder to the urinary orifice
function of the urethra
at the bladder/urethra junction is the internal sphincter, external sphincter, length is 3-4 cm in fmales; orifice above vaginal opening 20cm in males; goes through penis which also carries semen.
structure of the urethra
contracts…closed to prevent leaking, relaxes to void
involuntary smooth muscle; controlled by ans reflex; external and internal sphincters must relax for bladder to empty into urethra.
involuntary smooth muscle; controlled by ans reflex; external and internal sphincters must relax for bladder to empty into urethra.
Internal sphincter
voluntary skeletal muscle; controlled by somatic motor reflex; external and internal sphincters must relax for bladder to empty into urethra.
external urethral sphincter
indentation for entrance of the renal artery and exit of the renal vein and ureter.
Renal Hilus
connective tissue sac covering kidney
Renal capsule
outer area of kidney that contains glomerulii, bowman’s capsules, and proximal and distal convoluted portions of nephrons
cortex
(Capillary beds) filters blood and begins process of filtrate formation
glomerulii
mostly in cortex, beginning of nephron tubule which collects filtrate; surrounds each glomerulus, collects filtrate, beginning of nephron tubule, modifications of its epithelial cells form the podocytes
bowman’s capsules
arranged in alternating columns and pyramids
medulla
contains cortex extentions
columns
contain loop of henle’s and collecting ducts, papillae terminate into the minor calyx
pyramids
contains both the major/minor calyces and the renal sinus which gives rise to the ureter.
renal pelvis
receive urine draining through renal papillae at bottom of pyramid.
minor calyces
urine flows from minor calyces into major calyces and then into the renal sinus -> Ureters -> (Exits kidney at hills) -> bladder
Urine flow in renal pelvis of kidney
the functional unit of the kidney; millions in each kidney
nephron
mostly in cortex, capillary ‘tuft’ or bed, forms from afferent arteriole, filters blood, epithelial wall is covered with specialized filtration slits of podocytes
glomerulus (renal corpuscle)
initial winding portion of tubule, transports filtrate and modifies it via tubular reabsorption and secretion, surrounded by peritubular capillaries, mostly in cortex
proximal convolutions
mostly in medullary pyramids for juxtamedullary nephrons, half of the loop is in cortex for cortical nephrons
loops of henle
descending limb, ascending limb, surrounded by peritubular capillary networking cortical nephrons, surrounded by vasarecta in juxtamedullary nephrons
structure of loops of henle
transports and modifies filtrate via tubular reabsorption and secretion esp. CCMM
function of loop of henle
mostly in cortex, final winding portion of tubule, transports and modifies filtrate via tubular reabsorption and secretion, surrounded by peritubular capillary network
distal convolutions
mostly in medullary pyramid, several tubules empty into one duct, terminates into minor calyx in renal pervis via renal papillae, concentrates (by tubular reabsorption) and collects urine (first time the waste product is called urine)
collecting ducts
