anatomy of the urinary system
DESCRIPTION
Anatomy of the Urinary System. Kidneys Ureters Bladder Urethra. The Kidneys. Functions of the Kidneys: - removal of waste products from blood - control of blood volume - control of salt balance in blood - control of pH of the blood (acid-base balance). - PowerPoint PPT PresentationTRANSCRIPT
Anatomy of the Urinary System
Kidneys
Ureters
Bladder
Urethra
The Kidneys
Functions of the Kidneys:
- removal of waste products from blood
- control of blood volume
- control of salt balance in blood
- control of pH of the blood (acid-base balance)
Gross Anatomy of the Kidneys
The kidneys are bean-shaped organs located on the posterior abdominal wall
Gross Anatomy of the Kidneys
Kidneys are retroperitoneal
Kidneys are covered by a renal capsule, and enclosed in a renal fat pad
The kidney and associated fat pad are enclosed by renal fascia
Gross Anatomy of the Kidneys
Renal hilus: site where renal artery enters and renal vein and ureter leave the kidney
Internal structures:- cortex- medulla (pyramids)- renal columns- renal papillae- minor calyx- major calyx- renal pelvis-ureter
renal pelvis
hilus
ureter
renalpapilla
renal capsule
renalcolumns
majorcalyx
renal pyramids
minorcalyx
cortex
medulla
Renal Blood Supply
Blood goes to the kidney in the renal artery, which branches into segmental arteries as it enters the hilus
Segmental arteries branch into interlobar arteries, which become arcuate arteries as they curve over the base of the renal pyramids
Arcuate arteries give off interlobular arteries in the cortex, from which branch the afferent arterioles (to the nephron)
Efferent arterioles carry blood away from the nephron, into the peritubular capillary network
The capillaries drain into interlobular veins, which drain into arcuate, interlobar, and renal veins
Renal Blood Supply
renal artery
renal vein
segmentalartery interlobar
arteries
interlobulararteries
interlobar veins
arcuate veins
arcuate arteries
interlobularartery
arcuateartery
interlobar vein
interlobar artery
Histology of the Kidney
The basic functional unit of the kidney is the nephron
The nephron is composed of:
- renal corpuscle
- Bowman’s capsule
- glomerulus (capillary tuft)
- proximal convuluted tubule
- Loop of Henle
- distal convuluted tubule Each nephron is connected to a collecting
duct
renalcorpuscle
proximalconvuluted
tubule
distalconvuluted
tubule
descendinglimb
ascendinglimb
collectingduct
Location of Functional Units
Nephrons are located primarily in the cortex; Loops of Henle extend into medullary pyramids
Juxtamedullary nephrons are located near medulla, have longer Loops of Henle
Collecting ducts are found in the medullary pyramids, and empty urine into the renal papillae
Renal Corpuscle
The renal corpuscle (site of filtration) is composed of Bowman’s capsule and the glomerulus
Bowman’s capsule is double-walled structure
Podocyte cells glomerulus: capillary tufts gaps in epithelium: fenestrae juxtaglomerular cells: renin macula densa
parietal epithelium
podocyte
glomerularcapillary
afferentarteriole
efferentarteriole
DCT
macula densa
juxtaglomerularcells
The Ureters
Function: carry urine from the kidneys to the bladder
Histology: three layers to ureter wall
- mucosa: transitional epithelium, lamina propria
- muscularis: inner longitudinal, outer circular, outermost longitudinal in lowest 1/3rd
- adventitia Enter bladder as narrow slit-like
opening
The Bladder
Function: storage of urine Located in pelvic cavity, posterior to
the pubic symphysis Histology: mucosa, muscularis, and
adventitia, as in ureters (thicker muscularis in bladder)
Specialization of internal bladder wall: trigone
Internal urinary sphincter: smooth muscle at junction of bladder and urethra
External urinary sphincter: skeletal muscle
Urethra
In the male, three named parts:
- prostatic
- membranous
- spongy
Urethra
In the female, the urethra is much shorter:
Next Lecture.....
Physiology of the Urinary System