URINARY SYSTEM - Human Anatomy and Physiology€¦ · DEVELOPMENT OF THE URINARY SYSTEM In the...
Transcript of URINARY SYSTEM - Human Anatomy and Physiology€¦ · DEVELOPMENT OF THE URINARY SYSTEM In the...
URINARY SYSTEM
FUNCTIONS:
Excretion
Regulation of blood volume and pressure
Regulation of the concentrated of solutes in the blood
Regulation of extracellular fluid pH
Regulation of red blood cell synthesis
Vitamin D synthesis
Ureters transport urine urine from the kidneys to the Urinary bladder
Urinary bladder stores urine and expels into the Urethra
It discharges urine from the body
o KIDNEYS: They lie on the posterior abdominal wall, behind the peritoneum, with one kidney
on either side of the vertebral column
Small dark red organ, bean shaped 12 cm long, 6 cm wide, 3m thick
FUNCTION:
Cleanse the blood and adjust pH composition.
3 REGIONS OF KIDNEY
1. RENAL CORTEX
-Comes from Latin word meaning “bark”
-outer light red Region
2. RENAL MEDULLA
Dark red brown region
-medulla has many triangular regions with a striped appearance called
MEDULLARY PYRAMIDS.
APEX-tip of the boarder base of each pyramid faces toward the cortex.
RENAL COLUMN- extension of renal cortex
3. RENAL PELVIS
-Funnel shape cavity
MAJOR AND MINOR CALYCES- cup like structure and extension of
pelvis that collect urine.
BLOOD SUPPLY IN THE KIDNEY
RENAL ARTERY- arterial supply of each kidney. Renal artery approaches the
hilus, it divides into SEGMENTAL ARTERIES. Inside the pelvis, segmental
arteries break up into LOBAR ARTERIES. Each of which has a branches called
INTERLOBAR ARTERIES give off the ARCUATE ARTERIES. Venous
blood INTERLOBULAR VEIN to ARCUATE VEINS to INTERLOBAR
VEINS to RENAL VEIN.
http://www.austincc.edu/apreview/PhysText/Renal.html
ROLES OF KIDNEY:
1. Excretion of nitrogen containing waste
2. Maintaining waste
3. Electrolyte balance of the blood
4. Ensuring proper blood pH
NEPHRONS Structural units of kidney
Responsible for forming the urine
TWO PARTS OF NEPHRON:
1. RENAL CORPUSCLE – blood plasma is filtered
2. RENAL TUBULE
-extra length
-more surface area, more filtration
- reabsorb water, sodium, potassium
- secrete waste
TWO COMPONENTS OF A RENAL TUBULE
1. GLOMERULUS- knot of capillaries
Fed and drained by ARTERIOLES (EFFERENT & EFFERENT
ARTERIOLE)
AFFERENT ARTERIOLE- arises from interlobular artery
- Feeder vessel
EFFERENT ARTERIOLE – receives blood that passed through the
glomerulus.
2. GLOMERULAR/ BOWMAN’S CAPSULE- portion of renal tubule that is
enlarged and cup-shaped surrounds the glomerular capillaries.
PODOCYTES-visceral layers consists of modified simple squamous
epithelial cells.
REGIONS OF RENAL TUBULE
1. PROXIMAL CONVOLUTED TUBULE- lumen surface covered with
dense microvilli that increases surface area.
-Simple cuboidal epithelial cells
-denotes part of the tubule attached to the glomerular capsule
2. LOOP OF HENLE- links ascending limb and descending limbs
- Connects distal and proximal convoluted tubule.
- Simple squamous epithelial cell
TWO PARTS OF LOOP OF HENLE
1. DESCENDING LIMB OF THE LOOP OF HENLE- first part
2. ASCENDING LIMB OF THE LOOP OF HENLE- makes the
hairpin turn.
3. DISTAL CONVOLUTED TUBULE- denotes part of the tubule that is
further away.
-Simple cuboidal epithelial cells
COLLECTING DUCT- delivers the urine
NEPHRONS ARE CALLED:
CORTICAL NEPHRONS- nephrons located within the cortex
JUXTAMEDULLARY NEPHRONS- nephrons closely to the cortex- medulla junction.
RENAL PHYSIOLOGY
http://moodle.rockyview.ab.ca/mod/book/view.php?id=56711&chapterid=20684
1. GLOMERULAR FILTRATION
First step urine production, water and most solutes in blood plasma move across
the wall of glomerular capillaries into the glomerular capsule and then into the renal
tubule. Glomerulus acts as filter.
OLIGURIA- abnormally low urinary output
2. TUBULAR REABSOPRTION
As filtered fluid flows along the renal tubule and through the collecting duct,
tubule cells reabsorb about 99% of the filtered water and many useful solutes. The water
and solutes return to the blood as it flows through the peritubular capillaries and vasa
recta. Reabsorption refers to the return of substances in the bloodstream. Absorption
means entry of new substances into the body, as occurs in the gastrointestinal tract.
Tubule cells are transporters.
3. TUBULAR SECRETION
As fluid flows along the renal tubule and through the collecting duct, the tubule
and duct cells secrete other materials, such as wastes, drugs, and excess ions, into the
fluid. Notice that tubular secretion removes a substance from the blood.
SITE OF REABSORPTION AND SECRETION IN A NEPHRON
http://manashsubhaditya.blogspot.com/2012/07/urinary-system-filter-system-of-human_04.html
*urine contains most of the wastes and unneeded substances.
CONTROL OF BLOOD COMPOSITION BY THE KIDNEY
*Blood composition depends on THREE MAJOR FACTORS: diet, cellular metabolism and
urine output
* kidney filters 150 to 180 litters of blood plasma through their glomeruli.
EXCRETION OF NITROGENOUS WASTES
MOST IMPORTANT NITROGENOUS WASTES
1. Urea- formed by the liver when amino acids are used to produce energy. End
product of protein breakdown
2. Uric acid- released when nucleic acids are metabolized.
3. Creatinine- associated with creatine metabolism in muscle tissue
MAINTAINING WATER AND ELECTROYLTE BALANCE OF BLOOD
FLUID COMPARTMENTS- 3 location which water occupies
INTRACELULLAR FLUIDS- body fluids contained within the living cells
EXTRACELLULAR FLUIDS- body fluids located outside the cells.
ANTIDURETIC HORMONE (ADH)- Increase osmolarity of extracellular fluid
or decreased blood volume promotes release of ADH from the posterior pituitary
gland
ALDOSTERONE- major factor regulating sodium ion content of the ECF and in
the process helps regulate the concentration of other ions such as chlorine,
Potassium, Magnesium.
SODIUM ION- electrolyte responsible for osmotic water flow
JUXTAGULOMERULAR APPARATUS- helps regulate blood pressure within
the kidneys
RENIN- catalyze the series of reactions that produce , angiotensin II, cause
vasoconstriction and promotes aldosterone release
POLYURIA- excrete large volumes of urine
MAINTAINING ACID-BASE BALANCE OF BLOOD
ALKALOSIS- arterial blood rise above 7. 45
ACIDOSIA- arterial pH to below 7. 35
PHYSIOLOGICAL ACIDOSIS- arterial pH between 7.35-7.0
BLOOD BUFFER
RESPIRATORY SYSTEM CONTROL
RENAL MECHANISMS
CHARACTERISTICS OF URINE -clear and pale to deep yellow
UROCHROME- pigment that results from the body’s destruction of haemoglobin.
Cause a normal yellow color
-more solutes the deeper the yellow color
- sterile and slightly aromatic odor.
-allow to stand, ammonia odor caused by the action of bacteria on the urine.
-pH is slightly acid (around 6)
ACID-ASH FOODS- diet contains large amounts of proteins and whole-wheat products
causes urine to become quite acid.
ALKALINE-ASH FOODS- vegetarian diets
- water plus solute equals urine
- more dense than distilled water
- specific gravity is 1. 001 to 1.035
PHELONEPHITIS- kidney inflammation
SOLUTES IN THE URINE
-Sodium and potassium ions
-urea
-uric acid
-creatinine
-ammonia
-bicarbonate ions
URINALYSIS
-tells much about the state of the body
-analysis of the volume and physical, chemical and microscopic properties of urine
-volume of urine 1-2 L per day
-water 95% volume of urine
o URETERS
-transport urine from the renal pelvis in the kidney to the urinary bladder
-slender tube 25-30 cm long, 6 mm in diameter
THREE LAYERS OF TISSUE FORM THE WALL OF THE URETER
1. MUCOSA- deepest coat
2. TRANSITIONAL EPITHELIUM
3. LAMINA PROPRIA
MUSCULARIS- intermediate coat, inner longitudinal and outer circular layers of
smooth muscle
ADVENTITIA- superficial coat layer of areolae connective tissue containing
blood vessel
RENAL CALCULI- crystals/ kidney stones
-uric acid salts
o URINARY BLADDER -smooth collapsible muscular sac that stores urine temporarily
-located retroperitoneally in the pelvis just posterior to the pubic symphysis
TRIGONE- small triangular area
INTERNAL URETHRAL ORIFICE- the opening into the urethra. lies anterior corner
THREE COATS MAKE UP THE WALL OF URINARY BLADDER
1. MUCOSA- deepest coat
2. TRANSITIONAL EPITHELIUM
3. LAMINA PROPRIA
RUGAE- fold in the mucosa is present
INTERMEDIATE MUSCULARIS/ DETRUSOR MUSCLE- surrounding of mucosa
INTERNAL URETHRAL SPHINCTER- around the opening to the urethra by the
circular fibers
EXTERNAL URETHRAL SPHINCTER -inferior to internal urethral sphincter.
involuntary
ADVENTITIA- most superficial coat of the urinary bladder.
THE MICTURATION REFLEX
MICTURATION/ urination/ voiding -discharge of urine from the urinary bladder
Impuses propagate to the Micturation center in sacral spinal cord segments S2 and S3
and trigger a spinal reflex called Micturation reflex.
o URETHRA
-Thin walled tube that carries urine by peristalsis from the bladder to the exterior of
the body
-female urethra lies directly posterior to the pubic symphysis, us directed obliquely,
inferiorly and anteriorly and has length of 4 cm. EXTERNAL URETHRAL ORIFICE,
located between the clitoris and the vaginal opening. The wall of female urethra consists
of deep mucosa composed of epithelium and lamina propria (areolar connective
tissue) and superficial muscularis .
male urethra extends to internal urethral orifice to the exterior. Consists of deep mucosa
and a superficial muscularis has three anatomical regions:
1. Prostatic urethra- passage through the prostate
2. Membranous (intermediate)urethra-shortest portion passes through the deep
muscle of peritoneum.
3. Spongy urethra- longest portion passes through penis
DEVELOPMENT OF THE URINARY SYSTEM
In the third week of fetal development the intermediate mesoderm, differentiates into the
kidneys. The intermediate mesoderm is located in paired elevations called urogenital ridges.
Three pairs of kidneys form within the intermediate mesoderm in succession: the pronephrons,
the mesonephrons, and the metanephros. Last pair remains as the functional kidneys of newborn.
PRONEPHROS first kidney form the most superior of the three and has an associated pronephric
duct. Ducts empties into the cloaca, the expanded terminal part of the hindguts, which function s
as a common outlet for the urinary, digestive, and reproductive ducts. The pronephrons begins to
degenerate during the fourth week and is completely gone by the sixth week.
MESONEPHROS the second kidney, replaces pronephros of the pronephric duct, which
connects to the meseonephros, develops into the mesonephric duct. The mesonephros beginds to
degenerate by the sixth week and gone by eight week.
URETERIC BUD fifth week, a mesodermal outgrowth. By the third month, the fetal kidneys
begin excreting urine into the surrounding amniotic fluid: indeed, fetal urine makes up most of
the amniotic fluid. During development, the cloaca divides into a urogenital sinus, into which
urinary and genital ducts empty, and a rectum that discharges into the anal canal. The urinary
bladder develops from the urogenital sinus. ultimate destination in the abdomen. As they do so,
they receive renal blood vessels. Although the inferior blood vessels usually degenerate.
Consequently, some individuals (about 30%) develop multiple renal vessels
http://mednotesforyou.blogspot.com/2010/06/indiana-university-school-of-medicine.html
Diseases of the Urinary System
NEPHROLOGY - branch of medicine concerned with the diagnosis and treatment of conditions
related to the kidneys, and physicians who specialize in kidney disease are called nephrologists.
Other health professionals who treat kidney problems include primary care physicians,
pediatricians, transplant specialists, and urologists
Benign Prostatic Hyperplasia
Benign prostatic hyperplasia (BPH) is a condition in which the prostate gland is enlarged,
making urination difficult for men with this disease
Bladder Cancer
Bladder cancer is the result of uncontrolled, abnormal cell growth within the bladder. According
to the American Cancer Society, there are three major types of bladder cancer: transitional cell
carcinoma, squamous cell carcinoma and adenocarcinoma. Of these, the most common is
transitional cell carcinoma, which is also called urothelial carcinoma.
Cystocele (Fallen Bladder)
Cystocele is a disease affecting females in which the wall between the bladder and vagina
becomes weak, allowing the bladder to fall into the vagina.
Hematuria (Blood in the Urine)
The Mayo Clinic describes hematuria as the presence of red blood cells in urine. Though the
blood might not be visible to patients with this disease, a doctor will be able to see the red blood
cells under a microscope.
Interstitial Cystitis
Interstitial cystitis is described by the Interstitial Cystitis Association as chronic and often painful
inflammation of the bladder. This disease is also referred to as Painful Bladder Syndrome or
Frequency-Urgency-Dysuria Syndrome.
Kidney Stone
Kidney stone is a term used to describe a solid piece of material---most commonly made up of
calcium from the urine--that forms in one or both of the kidneys. These can cause harmful and
painful blockages that require the stone(s) to be broken into pieces by lasers for easier passage.
Neurogenic Bladder
Neurogenic bladder is caused by the malfunction of nerve signaling in the muscles that control
the bladder. When these nerves fail to transmit messages properly to the brain, an individual may
lose the ability to urinate normally.
Prostate cancer
Prostate cancer is the result of uncontrolled, abnormal cell growth within the prostate gland. It is
highly curable in the early stages, so men should be checked routinely.
Prostatitis
Prostatitis is a condition that results in inflammation of the prostate gland. Men with prostatitis
may find it difficult or painful to urinate, and can also experience pain in the back or genital area.
Proteinuria
Proteinuria is a term used to describe the presence of protein in the urine at levels that are
deemed abnormal. Urine with a high concentration of protein may be indicative of more
complicated kidney problems.
Renal (Kidney) Failure
Renal failure occurs when the kidneys malfunction, preventing the normal removal of waste
from the body. There are three major diseases that can lead to renal failure: Acute renal failure,
chronic kidney disease and end-stage renal disease.
Urinary Incontinence
Urinary incontinence is a condition that results in the involuntary loss of bladder control. This
condition can be remedied through surgical procedures, and sometimes by exercising the
muscles of the pelvic floor.
URINE TRIVIA
A study in Finland demonstrated that human urine mixed with wood ash makes a good fertilizer
for tomatoes.
In May 2009 a system for recycling astronauts urine and sweat into drinking water finally
became operational after months of repeated mechanical failures. Out one end and in the other
(sorry, I couldn't resist that). The system recycles 93% of the astronauts' sweat and urine.
The Cow Protection Department of India's oldest Hindu nationalist group (Rashtriya
Swayamsevak Sangh) announced in 2009 that is was developing a new soft drink made from
cow urine. The soft drink, flavored with herbs, is expected to be ready for sale in a few months.
The healthy beverage is being developed in part to counteract what many in India consider the
corrupting influence of Western food imports. Many in India believe that cow urine has strong
healing properties, and is capable of even curing cancer.
There is a lot of frozen urine floating around in space. For years, most of the urine produced by
astronauts has just been dumped overboard. When it hits the cold vacuum of space, it instantly
freezes into tiny pee crystals. With a new urine recycling system installed on the International
Space Station that turns urine into drinking water, there should be a decrease in the quantity of
pee ice debris in orbit.
Some individuals have odorous urine after eating asparagus, and it was long thought to be a
genetic trait since some people seemed to be immune to this effect. The odor is caused by a
asparagusic acid which the body converts into methanethiol (closely related to skunk spray!). It
now appears that there are exceptions on both sides of the phenomenon. Due to genetic
differences, most but not all people produce methanethiol after eating asparagus, and most but
not all people can detect the odor.
According to my friend and his wife in Thailand, slices of the kafir lime are used as a deodorant
in urinals.
Research at the University of Kuopio in Finland has shown that human urine used as fertilizer
increases the yield of cabbage over conventional fertilizers. The cabbages were also bigger and
had fewer germs. The urine had been stored for 6 months before use as fertilizer. It also works
with cucumbers.
Science News 10/6/07
Both the ancient Egyptians and the Aztecs rubbed urine on their skin to treat cuts and burns.
Urea, a key chemical in urine, is known to kill fungi and bacteria.
REFERRENCES:
Essentials of Anatomy and Physiology 6th Edition,. Rod R. Seeley, Trent D. Stephens, Philip
Tate
Introduction to the Human Body the Essentials of Anatomy and Physiology 7th
Edition and 12th
Edition ., Gerard J. Tortora, Bryan Derrickson,
Essentials of Anatomy and Physiology 6th Edition., Elaine N. Marieb, R.N., Ph.D.
http://www.livestrong.com/article/46314-diseases-urinary-system/#ixzz27ZfyoCNy
http://pinnaclehealthresources.staywellsolutionsonline.com/Library/DiseasesConditions/Adult/Kidney/
85,P08231
http://www.foodreference.com/html/f-urine-trivia.html