Download urinary system - Practicum-Health-Science-I-2011-2012

URINARY SYSTEM
HST I
SPRING 2010
Anatomy and Physiology
Urinary elimination depends on the
function of the:
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Kidneys
Ureters
Bladder
Urethra
Kidneys
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Paired
Reddish-brown color
Bean-shaped
Lie on either side of the vertebral
column
• Extend to the 12th thoracic and
third lumbar vertebrae
• Left kidney is normally higher than
the right due to the anatomical
position of the liver
Kidneys
• Waste products of metabolism that collect in
the blood are filtered in the kidneys
• Blood reaches the kidneys by a renal artery
that branches from the abdominal aorta
• Approximately 20-25% of the cardiac output
circulates daily through the kidneys
• Each kidney contains 1 million nephrons
Kidneys
• Responsible for maintaining normal Red Blood
Cell (RBC) volume
• Produce erythropoietin, a hormone released
primarily from specialized glomerular cells that
sense decreased RBC oxygenation
• After being released from the kidney
erythropoietin functions within the bone
marrow to stimulate erythropoiesis (production
of mature RBCs)
Renin
• Another hormone produced by the
kidneys
• Major role is the regulation of blood flow
in times of renal ischemia (decreased
blood supply)
Anatomy of Kidney
• Cortex –hard outer layer
• Medulla – fleshy portion
• Pyramids – triangular
shaped open areas
• Nephrons – microscopic
units that make urine.
• Renal sinus or pelvis –
collection basin for urine
at base of kidney
Nephron
• The functional unit of
the kidney, forms urine
• Composed of the
glomerulus, Bowman’s
capsule, proximal
convoluted tubule, loop
of Henle, distal tubule,
and collecting duct
Glomerulus
• Initial site of filtration of the blood and the
beginning of urine formation
• The capillaries here are porous and allow
filtration of water and substances such as
glucose, amino acids, urea, creatinine, and
major electrolytes into the Bowman’s capsule
• Large proteins and blood cells are not normally
filter through
Glomerulus
• The presence of large
proteins in the urine
(proteinuria) is a sign
of glomerular injury
• Filters approximately
125ml of filtrate per
minute
Bowman’s Capsule
• A C-Shaped structure
• Surrounds the
glomerulus
• Is the start of the
convoluted tubule
• Passes the filtered
materials into the
convoluted tubule
Tubules
• Filtered substances needed
by the body are reabsorbed
and returned to the blood
through capillaries
• Most of the sugar, water,
and salts are reabsorbed
• Urea, uric acid, and
creatinine remain in the
tubules
Ureters
• Tubular structures measuring 25-30cm in
length and 1.25cm in diameter
• Extend from renal pelvis to bladder
• Peristalsis of the muscular layer of the
ureter transport urine through this
structure
Bladder
• Hollow, distendable muscular
sac
• Located behind symphysis
pubis
• Midline in pelvic cavity
• Lined with mucous
membrane
• Reservoir for urine,
minimum held usually 300ml
Urethra
• Tube that carries urine from the bladder
outside of the body
• External opening is called the urinary
meatus
• Different in male and females
• Normally the turbulent flow of urine
washes it free of bacteria
Male Urethra
•About 8 inches
long
•Passes through
the prostate
gland and
through the
penis
•Carries both
urine and semen
Female Urethra
•About 1.5 inches
long
•Opens in above
the vagina
•Carries only
urine outside the
body
Urine
• About 1500 to 2000ml (1 1/2 - 2 QTS)
produced daily
• 150 Quarts of liquid filtered through
kidneys daily
• Made up of concentrated liquid or urea,
uric acid, creatinine, mineral salts,
pigments, and 95% water
• Liquid waste product produced by
urinary system
Urine Consistency
• Normal – clear, straw colored
• Cloudy – white blood cells, pus –
infection
• Lighter the color – more water
• Darker the color – more waste
• Pink or red color – blood
Act of Urination
• Several brain structures influence
bladder function, including the cerebral
cortex, thalamus, hypothalamus, and
brainstem
• Together they suppress contraction of the
bladder’s muscles until a person wishes
to void (urinate)
Act of Urination
• The desire to urinate can be sensed when the
bladder contains approximately 150ml of urine
• As the volume increases, the bladder walls
stretch, sending sensory impulses to the brain
• Impulses from the brain then cause rhythmic
contraction of the bladder muscles
• The urethral sphincter relaxes so that urine can
enter the urethra (although voiding does not
occur yet)
Act of Urination
• As the bladder continues to contract, nerve
impulses travel to the brain making a person
conscious of the need to urinate
• If the person chooses not to void, then the
external urinary sphincter remains contracted,
and the urinary reflex is stopped.
• If the person chooses to void, the external
sphincter relaxes, nerve impulses stimulate the
bladder to contract, and emptying of the
bladder occurs
Diseases and Abnormal Conditions
Cystitis
• Inflammation of the bladder usually caused
by pathogens entering the urinary system
Glomerulonephritis
• Inflammation of the glomerulus of the
kidney (two types)
• Acute – follows a streptococcal infection
• Chronic – a progressive disease causing
scarring and sclerosing of the glomeruli
Pyelonephritis
• Inflammation of the kidney tissue and renal
pelvis caused by pyogenic ( pus forming)
bacteria
Renal Calculus
• A kidney stone
• Formed when salts in the urine precipitate
• Small calculi may be eliminated in the
urine, but larger stones often become lodged
in the renal pelvis or ureter
Renal Failure
• When the kidneys stop functioning (two
types)
• Acute – caused by hemorrhage, shock,
injury, poisoning, nephritis, or dehydration
• Chronic – results from progressive loss of
kidney function
Uremia
• A toxic condition that occurs when the
kidneys fail and urinary waste products are
present in the bloodstream.
Urethritis
• An inflammation of the urethra, usually
caused by bacteria
Careers
Dialysis Technician
• Operates machines that remove waste and
excess fluids from the blood of patients
whose kidneys can no longer carry out those
functions.
Medical Laboratory Technician
• Works under supervision of a medical
technologist or physician to perform test on
tissue, blood and body fluids to help
physicians diagnose and treat diseases.
Medical Laboratory Technologist
• A health care professional who performs
test procedures in laboratories using
sophisticated instruments to aid in the
diagnosis, prognosis and treatment of
diseases.
Nephrologist
• A doctor who is a kidney specialist.
Urologist
• A doctor who specially deals with the
urinary system which includes the bladder,
the urethra and possibly the ureters.
Key Words
• Bladder – vesicle that acts as the reservoir
for the urine
• Bowman’s capsule – part of the renal
corpuscle in the kidney; picks up substances
filtered from the blood by the glomerulus
• Cortex – the outer section of the kidney
• Excretory system – also known as the
urinary system, responsible for removing
certain wastes and excess water from the
body and for maintaining the body’s acidbase balance
• Glomerulus – microscopic cluster of
capillaries in Bowman’s capsule of the
nephron in the kidney
• Hilum – a notched or indented area through
which the ureter, nerves, blood vessels, and
lymph vessels
• Homeostasis – a constant state of natural
balance within the body
• Kidneys – bean-shaped organ that excretes
urine; located high and in back of the
abdominal cavity
• Medulla – the inner section of the kidney;
contains most of the collecting tubules
which carry the urine from the nephrons
• Nephrons – microscopic filtering units
located in the kidneys; consists of a
glomerulus, a Bowman’s capsule; a
proximal convoluted tubule, a distal
convoluted tubule and a collecting duct.
• Renal pelvis – a funnel shaped structure
that is the first section of the ureter
• Ureters – tubes that carry urine from the
kidneys to the urinary bladder
• Urethra – tube that carries urine from the
urinary bladder to outside the body
• Urinary meatus – external opening of the
urethra
• Urine – the fluid excreted by the kidney
• Void – to empty the bladder; urinate
Medical Terminology
Nephro (o) denotes kidney
• Nephritis – inflammation of the kidney
• Nephrohydrosis – disease condition of
water in the kidney
• Nephrolithiasis – disease condition of
rock/stone in the kidney
• Nephropathy – disease of the kidney
• Nephroptosis – falling out/prolapse of the
kidney
• Nephrolithotomy – surgical incision to
remove rock/stone in the kidney
• Nephrosclerosis – disease condition of
hardening of the kidney
• Hydornephrosis – disease condition of
water in the kidney
• Nephrostomy – opening/mouth of the
kidney
Pyel (o) denotes pelvis of the
kidney
• Pyelitis – inflammation of the pelvis of the
kidney
• Pyeloscopy – visual examination of the
pelvis of the kidney
• Pyelophlebitis – inflammation of the vein
and pelvis of the kidney
• Pyelectasis – dilatation of the pelvis of the
kidney
• Pyelotomy – surgical incision of the pelvis
of the kidney
• Pyelolithotomy – surgical incision to
remove rock/stone in pelvis of the kidney
Ur (o)
• Uremia – urea in the blood (toxic condition
in the blood)
• Enuresis – in urine (condition of being in
urine – bedwetting)
• Diuresis – diluted urine (caused by caffeine
and alcohol
• Urinary Incontinence – loss of control of the
bladder
• Urinary Retention – can not release urine
(blockage)
Uria denotes urine/urea
• Anuria – without urine
• Melanuria – dark/black urine
• Albuminuria – protein in urine
• Hematuria – blood in the urine
• Nocturia – night urine
• Pyuria – pus in the urine
• Oliguria – scanty urine
• Dysuria – bad, difficult, painful urination
Medical Abbreviations
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Mat – maternity
Med – medicine
Mg – milligram
MI – myocardial infarction
Min – minute
MN – midnight
MT – medical technologist
MOM – Milk of Magnesia
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N – nitrogen
Na – sodium
NaCl – salt
NB – new born
Neg – negative
Neur – neurology
NIH – National Institute of Health
Nil – none
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No – number
Noct – night
NP – nurse practitioner
NPO – nothing by mouth
NSY – nursery
N/V – nausea and vomiting
NVS – neurological vital signs
Questions