Transcript urinary system

URINARY SYSTEM
OBJECTIVES
Describe major functions of the urinary
system
Name and describe structures of the
urinary system
Recognize, define, spell, pronounce
terms related to the urinary system
OBJECTIVES
Explain the importance of filtration,
tubular re-absorption, tubular secretion
in formation of urine
Discuss urine control mechanisms
Explain how the kidneys act as vital
organs in maintaining homeostasis
FUNCTIONS OF THE URINARY
SYSTEM
Maintains proper balance of:
Water
Salts
Acids
……in body fluids,
…by removing excess fluids from the
body, or reabsorbing water as needed
FUNCTIONS OF THE URINARY
SYSTEM
Constantly filters the blood to
remove urea and other waste
materials from the bloodstream.
Urea: the major waste product
of protein metabolism
FUNCTIONS OF THE URINARY
SYSTEM
Converts waste products and excess
fluid into urine in the kidneys and
excretes them from the body via the
urinary bladder
STRUCTURES OF THE
URINARY SYSTEM
KIDNEYS
•Two kidneys located retroperitoneally
with one on each side of the vertebral
column below the diaphragm
STRUCTURES OF THE
URINARY SYSTEM
KIDNEYS
• The kidneys play and important role in
homeostasis by filtering waste from the
blood, and eliminating them by forming
urine.
•Output is adjusted to equal the intake
of the body.
STRUCTURES OF THE
URINARY SYSTEM
KIDNEYS
•Regulate chloride, sodium, potassium,
and bicarbonate levels.
•Salt and water balance
•Assists in regulating blood pressure.
•Consist of two layers that surround the
renal pelvis
STRUCTURES OF THE
URINARY SYSTEM
KIDNEYS
• Renal Cortex:
•Outer layer of the kidney
-- Contains over one million
microscopic units called nephrons
STRUCTURES OF THE
URINARY SYSTEM
KIDNEYS
• Medulla:
•Inner layer of the kidney.
•Contains most of the urine-collecting
tubules.
-- Tubules are small tubes
Renal Cortex
Medulla
STRUCTURES OF THE
URINARY SYSTEM
RENAL PYRAMIDS
•Triangular divisions of the medulla of
the kidney.
•Extensions of cortical tissue that dip
down into the medulla between the
renal pyramids are called the renal
columns
Renal Pyramids
Renal Columns
STRUCTURES OF THE
URINARY SYSTEM
RENAL PAPILLA
• Narrow, innermost end of a pyramid
STRUCTURES OF THE
URINARY SYSTEM
CALYX
•Division of the renal pelvis (the
papilla of a pyramid opens into
each calyx)
STRUCTURES OF THE
URINARY SYSTEM
RENAL PELVIS
•Funnel-like expansion of the
upper end of the ureters that
drains to the bladder.
STRUCTURES OF THE
URINARY SYSTEM
NEPHRONS
•Functional units of the kidneys.
•Form urine by filtration, reabsorption,
and secretion.
-- Contains glomerulus which is a cluster
of capillaries surrounded by a membrane
called Bowman’s capsule
STRUCTURES OF THE
URINARY SYSTEM
NEPHRONS
•Blood flows into the kidney through the
renal artery, filtered by the capillaries of
the glomerulus and leaves the kidney
through the renal vein.
NEPHRONS
STRUCTURES OF THE
URINARY SYSTEM
NEPHRONS
•Waste products pass through a series
of urine-collecting tubules and are
transported to the renal pelvis before
entering the ureters.
STRUCTURES OF THE
URINARY SYSTEM
NEPHRONS
•Urochrome is the pigment that gives
urine its normal yellow-amber color.
- Color can be influenced by normal
factors such as the amount of liquid
consumed or by disease or medications
STRUCTURES OF THE
URINARY SYSTEM
NEPHRONS
• The Nephron is composed of two
principle components.
•Renal Corpuscle
•Renal Tubule
STRUCTURES OF THE
URINARY SYSTEM
NEPHRONS
•Renal Corpuscle is subdivided into two
further segments.
•Bowman’s Capsule
•Glomerulus
STRUCTURES OF THE
URINARY SYSTEM
Renal Corpuscle
•Bowman’s Capsule
-- Cup shaped sac surrounding the
Glomerulus at the top of the nephron.
STRUCTURES OF THE
URINARY SYSTEM
Renal Corpuscle
•Glomerulus
-- Network of capillaries inside the
Bowman’s Capsule where the blood is
filtered.
-- High pressures are present in the
capillaries to filter wastes.
Renal
Corpuscle
STRUCTURES OF THE
URINARY SYSTEM
NEPHRONS
•Renal Tubule is subdivided into four
segments.
•Proximal Convoluted Tubule
•Loop of Henle
•Distal Convoluted Tubule
•Collecting Tubule
STRUCTURES OF THE
URINARY SYSTEM
Renal Tubule
•Proximal Convoluted Tubule
-- First segment of winding renal
tubule near the Bowman's Capsule.
STRUCTURES OF THE
URINARY SYSTEM
Renal Tubule
•Loop of Henle
-- Thin, hairpin loop of the proximal
tubule.
-- Located in the Medulla
STRUCTURES OF THE
URINARY SYSTEM
Renal Tubule
•Distal Convoluted Tubule
-- Winding segment of renal tubule
after the Loop of Henle.
STRUCTURES OF THE
URINARY SYSTEM
Renal Tubule
•Collecting Tubule
-- Straight final segment of renal
tubule.
-- Several nephrons will join to empty
into a single collecting tube.
STRUCTURES OF THE
URINARY SYSTEM
URETERS
•Narrow tubes about 10 – 12 inches
long.
•Carry urine from the renal pelvis in
the kidney to the urinary bladder
STRUCTURES OF THE
URINARY SYSTEM
URETERS
•Lined with mucous membranes and
sensory nerves, urine is moved to the
bladder by peristaltic movements of
the thick muscular walls.
STRUCTURES OF THE
URINARY SYSTEM
URINARY BLADDER
•Hollow, muscular organ that acts
as a reservoir for urine.
•Located in the anterior portion of
the pelvic cavity behind the pubic
symphysis.
STRUCTURES OF THE
URINARY SYSTEM
URINARY BLADDER
•Elastic fibers, muscles, and rugue
lining allow the bladder to expand
with urine and contract when
emptying.
STRUCTURES OF THE
URINARY SYSTEM
URINARY BLADDER
•The bladder will expand with little
pressure until approx 300 to 400ml
of urine is collected, indicating a
need to void.
•Emptying reflex is initiated and the
bladder will contract, sending urine
to the urethra.
STRUCTURES OF THE
URINARY SYSTEM
URETHRA
•The tube extending from the
bladder to the outside of the body.
NOTE: The spelling of ureter and
urethra are very similar.
STRUCTURES OF THE
URINARY SYSTEM
URETHRA
•Two urinary sphincters
-One controls the flow of urine from the
bladder into the urethra
(internal/Involuntary)
-One controls the flow of urine from the
urethra through the urethral meatus
(external/voluntary)
STRUCTURES OF THE
URINARY SYSTEM
URETHRA
•When the emptying reflex is
initiated, the bladder contracts, and
the internal urethral sphincter will
relax.
•The external sphincter must be
voluntarily opened in order to expel
urine.
STRUCTURES OF THE
URINARY SYSTEM
URETHRA
•The urethral meatus is the external
opening of the urethra.
•Female urethra is approx 1.5 inches
long.
•Male urethra is approx 8 inches long.
•Also a passageway for semen.
FORMATION OF URINE
• The 2 million or more nephrons form
urine by a series of three processes
Filtration
Reabsorption
Secretion
FORMATION OF URINE
FILTRATION
•Continual process in the renal
corpuscles
• Blood flowing through the glomeruli
exerts pressure and this glomerular
pressure is high enough to push water
and dissolved substances out of the
glomeruli into the Bowman’s capsule
FORMATION OF URINE
FILTRATION
•Normal filtration results in approx 180 L
of fluid a day.
•It is obvious that no one ever excretes
that much fluid daily…..this is where the
second stage take place….reabsorption
FORMATION OF URINE
REABSORPTION
•Begins in the proximal convoluted
tubules and continues in the loop on
Henle, distal convoluted tubules and
collecting tubules
•Large amounts of water—approx 178 L
per day are absorbed by osmosis and
returned to the blood.
FORMATION OF URINE
SECRETION
•Secretion is reabsorption in reverse.
•Process by which substances move
into urine in the distal and collecting
tubules from blood in the capillaries
around these tubules.
•Hydrogen, Potassium, Ammonia
FILTRATION
REABSORBSION
SECRETION
CONTROL OF URINE VOLUME
HORMONES
•ADH – Allows for control of
reabsorption of water.
•Aldosterone – Controls salt and water
retention
•ANH – Controls salt and water loss.
EXCRETION OF URINE
URINATION
•Also known as micturation or voiding
•Requires the coordinated contraction
of the bladder muscles and sphincter
relaxation. This forces urine through the
urethra and out through the urinary
meatus
TERMINOLOGY OF THE
URINARY SYSTEM
Incontinence
•Condition where the patient voids
urine involuntarily.
•Common in patients with stroke or
spinal injury.
•Stress Incontinence
TERMINOLOGY OF THE
URINARY SYSTEM
Oliguria
•Scant amounts of urine is produced.
Polyuria
•Unusual large amount of urine is
produced.
TERMINOLOGY OF THE
URINARY SYSTEM
Dysuria
•Painful or difficult urination.
Nocturia
•Excessive urination at night.
TERMINOLOGY OF THE
URINARY SYSTEM
Nephrologist
•Specializes in diagnosing and
treating diseases and disorders of
the kidney.
TERMINOLOGY OF THE
URINARY SYSTEM
Urologist
•Specializes in diagnosing and
treating diseases and disorders of
the female urinary system and the
male genitourinary system.
TERMINOLOGY OF THE
URINARY SYSTEM
Renal Failure
•Inability of one or both kidneys to
perform their functions
Dialysis
•Procedure to remove waste
products from the blood in patients
with renal failure.
TERMINOLOGY OF THE
URINARY SYSTEM
Nephritis
•Inflammation of the kidney.
Nephrolithiasis
•Disorder characterized by the
presence of stones or calculus in the
kidney.
TERMINOLOGY OF THE
URINARY SYSTEM
Cystitis
•Inflammation of the bladder.
Cystocele
•Herniation of the bladder through
the vaginal wall.
TERMINOLOGY OF THE
URINARY SYSTEM
Urinary Tract Infection - UTI
•Usually begin in the bladder.
•More frequent in women due to
shorter urethra.
Hypospadias
•Congenital deformity, where in
males the urethral opening is on the
underside of the penis.
TERMINOLOGY OF THE
URINARY SYSTEM
Cystoscopy
•Visual exam of the bladder by
endoscope.
TERMINOLOGY OF THE
URINARY SYSTEM
Lithotripsy
•Destruction of
urinary stones
with the use of
high energy
ultrasonic waves
to break up the
stones
TERMINOLOGY OF THE
URINARY SYSTEM
Urethropexy
•Surgical fixation of the Urethra to
correct stress incontinence.
•Burch procedure
•MMK
URINARY SYSTEM
• Questions?