URINARY SYSTEM

FUNCTIONS OF THE URINARY SYSTEM

• FILTERING BLOOD & EXCRETION OF WASTES• REGULATION OF BLOOD VOLUME & BLOOD

PRESSURE• REGULATION OF SOLUTE CONCENTRATIONS &

OSMOLARIY OF THE BLOOD• REGULATION OF p H• REGULATION OF RBC SYNTHESIS• ERYTHROPOEITIN &VITAMIN D SYNTHESIS• GLUCONEOGENESIS

URINARY SYSTEM

• KIDNEYS

• URETER

• BLADDER

• URETHRA

KIDNEYS

• RETROPERITONEAL

• POSTERIOR WALL OF ABDOMINAL CAVITY

• CAPPED BY ADRENAL GLAND

• RIGHT KIDNEY LOWER THAN LEFT

TISSUES COVERING THE KIDNEYS

• RENAL CAPSULE

• PERIRENAL FAT

• RENAL FASCIA

RENAL HILUS

• INDENTATION

• VESSELS ENTER AND LEAVE KIDNEY HERE

• URETERS LEAVE HERE

RENAL SINUS

• HILUS OPENS TO FORM THIS SPACE

REGIONS OF THE KIDNEYS

• CORTEX

• MEDULLA

• PELVIS

CORTEX

• OUTERMOST LAYER

• JUST DEEP TO RENAL CAPSULE

RENAL COLUMNS

• EXTENSIONS OF CORTEX THAT EXTEND INTO MEDULLA

• CONTAIN BLOOD SUPPLY FOR CORTEX AND MEDULLA

MEDULLA

• DEEP TO CORTEX

• UP TO 18 RENAL PYRAMIDS

RENAL PYRAMIDS

• PAPILLAE EXTEND TOWARD RENAL PELVIS

• PROJECT INTO MINOR CALYX (13) WHICH EMPTIES INTO MAJOR CALYX(2 OR 3)

• MAJOR CALYCES JOIN TO MAKE RENAL PELVIS

FUNCTIONAL UNITS OF KIDNEY

• NEPHRONS

• OVER 1 MILLION PER KIDNEY

• JUXTAGLOMERULARY NEPHRONS

• CORTICAL NEPHRONS

ANATOMY OF A NEPHRON

• RENAL CORPUSCLE

• RENAL TUBULE

RENAL CORPUSCLE

• BOWMAN’S CAPSULE

• GLOMERULAUS

ANATOMY OF THE BOWMAN’S CAPSULE

• PARIETAL LAYER– SIMPLE SQUAMOUS EPITHELIUM– BECOMES CUBE SHAPED NEAR

PROXIMAL TUBULE

• VISCERAL LAYER– SPECIALIZED PODOCYTES – COVERS GLOMERULAR CAPILLARIES

ANATOMY OF THE GLOMERULUS

• FENSTRATED CAPILLARY

• FILTRATION SLITS

• FILTRATION MEMBRANE– ENDOTHELIUM– BASEMENT MEMBRANE– PODOCYTES OF BOWMAN’S CAPSULE

GLOMERULAR BLOOD SUPPLY

• AFFERENT ARTERIOLE– SUPPLIES BLOOD TO GLOMERULUS

• EFFERENT ARTERIOLE– CARRIES BLOOD AWAY FROM

GLOMERULUS

JUXTAGLOMERULAR CELLS

• SMOOTH MUSCLE LINING BOTH ARTERIOLES

MACULA DENSA

• SPECIALIZED TUBULE CELLS

JUXTAGLOMERULAR APPARATUS

• COUPLING OF SMOOTH MUSCLE CELLS AND MACULA DENSA CELLS

RENAL TUBULES

• PROXIMAL CONVOLUTED TUBULE

• LOOP OF HENLE

• DISTAL CONVOLUTED TUBULES

• COLLECTING DUCTS

PROXIMAL CONVOLUTED TUBULE

• 14 MM LONG

• 60 MICRONS IN DIAMETER

• SIMPLE CUBOIDAL

• MICROVILLI

• BASEMENT MEMBRANE FORMS OUTER PORTION OF TUBULE

LOOPS OF HENLE

• NEPHRONIC LOOPS

• DESCENDING LIMB

• ASCENDING LIMB

DESCENDING LOOP OF HENLE

• FIRST PART SIMILAR IN STRUCTURE TO PROXIMAL CONVOLUTED TUBULE

• LOOPS THAT EXTEND INTO MEDULLA BECOME VERY THIN AT END OF LOOP

• LUMEN OF NARROWED LOOP BECOMES SIMPLE SQUAMOUS

ASCENDING LOOP

• FIRST PORTION THIN– SIMPLE SQUAMOUS

• LATER PORTIONS BECOMES THICKER – SIMPLE CUBOIDAL

DISTAL CONVOLUTED TUBULE

• SHORTER THAN PROXIMAL

• ARISES NEAR MACULA DENSA

• SIMPLE CUBOIDAL– SMALLER– LITTLE MICROVILLI

• CONNECT WITH COLLECTING DUCTS

COLLECTING DUCTS

• SIMPLE CUBOIDAL

• LARGER DIAMETER

• MAKE UP MUCH OF MEDULLARY RAYS

• EXEND THROUGH MEDULLA TO TIPS OF PYRAMIDS

BLOOD SUPPLY TO THE KIDNEYS

ARTERIES

• ABDOMINAL AORTA

• RENAL ARTERY• SEGMENTAL• INTERLOBAR

ARTERY• ARCUATE ARTERY• INTERLOBULAR

ARTERY

ARTERIOLES AND CAPILLARIES

• AFFERENT ARTERIOLE

• GLOMERULUS• EFFERENT

ARTERIOLE• PERITUBULAR

CAPILLARIES– VASA RECTA

VEINS

• INTERLOBULAR VEINS

• ARCUATE VEINS

• INTERLOBAR VEINS

• RENAL VEIN

• INFERIOR VENA CAVA

ANATOMY OF THE URETERS

ANATOMY OF THE URETERS

• MUCOSAL LAYER– TRANSITIONAL EPITHELIUM

• MUSCULAR LAYER– PERISTALTIC CONTRACTIONS

• FIBROUS LAYER

ANATOMY OF THE URINARY BLADDER

• RETROPERITONEAL

• ENTERS BLADDER ON POSTERIOR LATERAL SURFACE

• TRAVELS OBLIQUELY THROUGH WALL

• VALVE LIKE FOLDS AT ORIFICE PREVENTS BACKFLOW

URINARY BLADDER

• HOLLOW MUSCULAR ORGAN

• STORES URINE

• RESTS ON PELVIC FLOOR

• RETROPERITONEAL

• ANTERIOR SURFACE BEHIND SYMPHYSIS

MALE ANATOMY

• IN FRONT OF RECTUM

FEMALE ANATOMY

• IN FRONT OF VAGINA AND UTERUS

BLADDER ANATOMY

• SPHERICAL WHEN FULL

• INVERTED PYRAMID WHEN EMPTY

• MUCOUS MEMBRANE– TRANSITIONAL EPITHELIUM

• THREE LAYERS OF SMOOTH MUSCLE

TRIGONE

• TRIANGULAR AREA WHERE MUCOUS MEMBRANE FIRMLY ATTACHED

• URETERS ENTER HERE

• URETHRA LEAVES HERE

VOLUMES AND PRESSURES

• AS FILLS INTITIAL RISE IN PRESSURE

• REMAINS RELATIVELY CONSTANT UP TO 300-400 MLs

• RISES RAPIDLY AFTER THIS

• MAXIMUM 600-800 MLs

URETHRA

• MUSCULAR TUBE

• MUCOUS MEMBRANE

• INTERNAL URETHRAL SPHINCTER– SMOOTH MUSCLE

• UROGENITAL DIAPHRAGM

• EXTERNAL URETHRAL SPHINCTER– SKELETAL MUSCLE

FEMALE URETHRA

• 4 CM LONG

• RUNS ALONG ANTERIOR SURFACE OF VAGINA

• EXTERNAL URETHRAL ORIFICE

• BETWEEN CLITORIS AND VAGINAL ORIFICE

MALE URETHRA

• 20 CM

• EXTERNAL URETHRAL ORIFICE

• PROSTATIC URETHRA

• MEMBRANOUS URETHRA

• SPONGY URETHRA

PROSTATIC URETHRA

• PASSES THROUGH PROSTATE

• RECEIVES EJACULATORY DUCTS

• USED FOR BOTH REPRODUCTION AND URINE TRANSPORT

MEMBRANOUS URETHRA

• SHORT PORTION

• PASSES THROUGH UROGENITAL DIAPHRAGM

SPONGY URETHRA

• LONGEST PORTION• FROM UROGENITAL DIAPHRAGM TO

EXTERNAL URETHRAL ORIFICE• DILATES IN GLANS PENIS TO FORM FOSSA

NAVICULARIS• RECEIVES BULBOURETHRAL GLAND

DUCTS• PASSES THROUGH CORPUS SPONGIOUSUM