URINARY SYSTEM

A&P

URINARY SYSTEM

•AKA EXCRETORY SYSTEM

•REMOVES WASTES & EXCESS WATER

•MAINTAIN ACID-BASE BALANCE

•HELPS MAINTAIN BODY’S HOMEOSTASIS

URINARY SYSTEM

PARTS OF THE URINARY SYSTEM:

2 KIDNEYS

2 URETERS

1 BLADDER

1 URETHRA

KIDNEYS

•BEAN-SHAPED ORGANS

•FOUND ON EITHER SIDE OF VERTEBRAL COLUMN

•LOCATED IN RETROPERITONEAL SPACE

•RETROPERITONEAL SPACE=AREA BEHIND UPPER PART OF ABD CAVITY; SEPARATED FROM ABD CAVITY BY PERITONEAL MEMBRANE

KIDNEYS

•PROTECTED BY RIBS & FAT CUSHION

•HELD IN PLACE BY CONNECTIVE TISSUE

•EACH KIDNEY IS ENCLOSED IN MASS OF FATTY TISSUE=ADIPOSE CAPSULE

•EACH KIDNEY IS COVERED BY A TOUGH, FIBROUS TISSUE=RENAL FASCIA OR FIBROUS CAPSULE

KIDNEYS

DIVIDED INTO 2 MAIN SECTIONS: CORTEX & MEDULLA

CORTEX=

oOUTER SECTION

oCONTAINS MOST OF THE NEPHRONS (NEPHRONS AID IN PRODUCTION OF URINE)

KIDNEYS

MEDULLA=

oINNER SECTION

oCONTAINS MOST OF THE COLLECTING TUBULES (COLLECTING TUBULES CARRY URINE FROM NEPHRONS THROUGH THE KIDNEY)

KIDNEYS

•EACH KIDNEY HAS A HILUM

•HILUM=NOTCHED OR INDENTED AREA

•THE URETER, NERVES, BLOOD VESSELS, & LYMPH VESSELS ENTER & LEAVE THE KIDNEY THROUGH THE HILUM

KIDNEYS

•NEPHRONS=MICROSCOPIC FILTERING UNITS OF THE KIDNEY

•THERE ARE MORE THAN 1 MILLION NEPHRONS PER KIDNEY

KIDNEYS

EACH NEPHRON CONSISTS OF A:

GLOMERULUS

BOWMAN’S CAPSULE

PROXIMAL CONVOLUTED TUBULE

DISTAL CONVOLUTED TUBULE

COLLECTING DUCT (TUBULE)

KIDNEYS

•THE RENAL ARTERY CARRIES BLOOD TO THE KIDNEY

•BRANCHES OF THE RENAL ARTERY PASS THROUGH THE MEDULLA TO THE CORTEX

•THIS IS WHERE BLOOD ENTERS THE 1ST PART OF THE NEPHRON, THE GLOMERULUS

•GLOMERULUS=CLUSTER OF CAPILLARIES

KIDNEYS

•WATER, MINERAL SALTS, GLUCOSE, METABOLIC PRODUCTS, & OTHER SUBSTANCES ARE FILTERED OUT OF THE BLOOD AS IT PASSES THROUGH THE GLOMERULUS

•RBCS & PROTEINS ARE NOT FILTERED OUT

KIDNEYS

•FILTERED BLOOD LEAVES THE GLOMERULUS & MOVES TO THE RENAL VEIN WHICH CARRIES IT AWAY FROM THE KIDNEY

•THE SUBSTANCES FILTERED OUT BY THE GLOMERULUS ENTER THE NEXT SECTION OF THE NEPHRON, BOWMAN’S CAPSULE

KIDNEYS

•BOWMAN’S CAPSULE=C-SHAPED STRUCTURE THAT SURROUNDS THE GLOMERULUS

• IT IS THE START OF THE CONVOLUTED TUBULE

•BOWMAN’S CAPSULE PICKS UP THE FILTERED MATERIALS & PASSES THEM INTO THE CONVOLUTED TUBULE

KIDNEYS

•AS THE FILTERED MATERIAL PASSES THROUGH THE TUBULE, SUBSTANCES NEEDED BY THE BODY ARE REABSORBED AND RETURNED TO THE BLOOD CAPILLARIES

•THOSE SUBSTANCES ARE MOST OF THE WATER, GLUCOSE, VITAMINS, AND MINERAL SALTS

KIDNEYS

•EXCESS GLUCOSE AND MINERAL SALTS, SOME WATER, AND WASTES (UREA, URIC ACID, AND CREATININE) REMAIN IN THE TUBULE

•THESE EXCESS SUBSTANCES ARE A CONCENTRATED LIQUID=URINE

KIDNEYS

•URINE ENTERS COLLECTING DUCTS (TUBULES) LOCATED IN THE MEDULLA

•THE COLLECTING DUCTS EMPTY INTO THE RENAL PELVIS (RENAL BASIN),

•RENAL PELVIS=FUNNEL-SHAPED STRUCTURE THAT IS THE 1ST SECTION OF THE URETER

URETERS

•2 MUSCULAR TUBES

•10-12 INCHES LONG

•RENAL PELVIS=FUNNEL-SHAPED 1ST SECTION OF URETER

•ONE URETER EXTENDS FROM THE RENAL PELVIS OF EACH KIDNEY TO THE BLADDER

URETERS

•PERISTALSIS MOVES URINE THROUGH URETER FROM KIDNEY TO BLADDER

BLADDER

•HOLLOW, MUSCULAR SAC

•FOUND BEHIND SYMPHYSIS PUBIS

•LOCATED AT MIDLINE OF PELVIC CAVITY

•RECEIVES URINE FROM URETERS

•STORES URINE UNTIL IT IS VOIDED

•VOID=URINATE=MICTURATE

BLADDER

•LINED WITH MUCOUS MEMBRANE

•MUCOUS MEMBRANE HAS RUGAE (FOLDS)

•RUGAE DISAPPEAR AS BLADDER EXPANDS TO FILL WITH URINE

•BLADDER WALLS ARE MADE OF TRIPLE LAYER OF VISCERAL (SMOOTH) MUSCLE

BLADDER

•CIRCULAR SPHINCTER MUSCLE CONTROLS THE BLADDER OPENING TO PREVENT EMPTYING

•RECEPTORS IN BLADDER SEND OUT A REFLEX ACTION WHICH OPENS THE MUSCLE

•URGE TO VOID OCCURS WHEN BLADDER HAS 250ML BUT IT CAN HOLD MUCH MORE

BLADDER

• INFANTS CANNOT CONTROL THE REFLEX ACTION

•AS CHILDREN GROW, THEY LEARN TO CONTROL THE REFLEX

URETHRA

•TUBE THAT CARRIES URINE FROM BLADDER TO OUTSIDE OF BODY

•URINARY MEATUS=EXTERNAL OPENING OF URETHRA

URETHRA

FEMALE URETHRA:

1.5 INCHES LONG

OPENS IN FRONT OF VAGINA

CARRIES ONLY URINE

URETHRA

MALE URETHRA:

8 INCHES LONG

PASSES THROUGH THE PROSTATE GLAND

EXISTS THE PENIS

CARRIES BOTH URINE & SEMEN (NOT AT THE SAME TIME)

URINE

•LIQUID WASTE PRODUCT OF URINARY SYSTEM

•APROX 95% WATER

•CONTAINS DISSOLVED WASTE PRODUCTS:

UREA, URIC ACID, CREATININE, MINERAL SALTS, PIGMENTS

URINE

•EXCESS USEFUL PRODUCTS (LIKE SUGAR) CAN ALSO BE FOUND IN URINE

•WHEN USEFUL PRODUCTS ARE IN URINE, IT USUALLY INDICATES DISEASE

URINE

•KIDNEYS FILTER ABOUT 150 QUARTS OF LIQUID DAILY

•ABOUT 1,500-2,000 ML (1.5-2 QUARTS) OF URINE ARE PRODUCED DAILY

URINATION TERMS

TERMS USED TO DESCRIBE CONDITIONS THAT AFFECT URINATION:

POLYURIA=EXCESSIVE URINATION

OLIGURIA=BELOW NORMAL AMOUNT OF URINE

ANURIA=ABSENCE OF URINATION

HEMATURA=BLOOD IN URINE

URINATION TERMS

PYURIA=PUS IN URINE

NOCTURIA=URINATION AT NIGHT

DYSURIA=PAINFUL URINATION

RETENTION=INABILITY TO EMPTY BLADDER

INCONTINENCE=INVOLUNTARY URINATION

URINATION TERMS

PROTEINURA=PROTEIN IN URINE

ALBUMINURA=ALBUMIN (A BLOOD PROTEIN) IN URINE