Myth or Fact? 1. Urinating on a jellyfish sting will help alleviate the pain. 2. It is safe to drink your own urine. 3. If someone is sleeping and you.

Myth or Fact?

1. Urinating on a jellyfish sting will help alleviate the pain. 2. It is safe to drink your own urine.

3. If someone is sleeping and you put their hand in warm water, they will pee their pants.

4. Holding your urine can cause a bladder infection.

5. There is a fish that will follow a urine stream and enter the urethra.

Myth or Fact?1. Myth-treating a jellyfish sting by urinating on it may actually cause

someone even more pain. The jellyfish’s cnidocytes (stinging cells) are set off by changes to the balance of salts and electrolytes (http://www.scientificamerican.com/article/fact-or-fiction-urinating/)

2. Myth-Urine is at least 95 percent water, but the remaining 5 percent carries excess electrolytes, such as chloride, sodium and potassium. Urine also carries small traces of excess toxins in the form of acids from your kidney, but you'd need to drink a lot for that to do damage. Drinking urine for survival is even more harmful, since dehydration makes it less dilute and all those electrolytes and acids appear in greater concentration. http://

www.popsci.com/science/article/2011-03/fyi-it-ever-ok-drink-your-own-urine

3. Myth-Although many people claim to have pulled it off successfully, Mythbusters found it to not be scientifically reliable http://www.discovery.com/tv-shows/mythbusters/mythbusters-database/hand-water-asleep-urinate.htm

http://www.scientificamerican.com/article/fact-or-fiction-urinating/

http://www.scientificamerican.com/article/fact-or-fiction-urinating/

http://www.popsci.com/science/article/2011-03/fyi-it-ever-ok-drink-your-own-urine

http://www.popsci.com/science/article/2011-03/fyi-it-ever-ok-drink-your-own-urine

http://www.discovery.com/tv-shows/mythbusters/mythbusters-database/hand-water-asleep-urinate.htm



Myth or Fact?

4. Fact - When urine stays in the bladder for a long time, more germs are made, and the worse a urinary tract infections can become. Women tend to be more susceptible to UTIs due to their shorter urethra. http://womenshealth.gov/publications/our-publications/fact-sheet/urinary-tract-infection.html#b

5. Fact - The candiru is a parasitic member of the catfish family and can be found in lakes and streams of the Amazon region. It's only gets up to an inch long and has been known to enter the urethras of bathers and swimming animals. "Once in the passage, it erects the short spines on its gill covers and may thereby cause inflammation, hemorrhage, and even death to the victim.“ http://urbanlegends.about.com/od/fish/a/candiru.htm

http://womenshealth.gov/publications/our-publications/fact-sheet/urinary-tract-infection.html#b

http://womenshealth.gov/publications/our-publications/fact-sheet/urinary-tract-infection.html#b

http://urbanlegends.about.com/od/fish/a/candiru.htm



The Urinary System

Chapter 25

Parts of the Urinary System

http://www.youtube.com/watch?v=hiNEShg6JTI

http://youtube.com/v/aQZaNXNroVY

• consists of a pair of kidneys which remove substances from the blood

• ureters which transport urine from the kidneys to the bladder

• urinary bladder temporary storage reservoir for urine• urethra conveys urine to the outside of the body

Urinary System Organs

kidneys

ureters

bladder

urethrasphincter

Copyright © 2010 Pearson Education, Inc.

Blood and Nerve Supply

• Renal arteries deliver ~ 1/4 (1200 ml) of cardiac output to the kidneys each minute!!!

Interlobar arteries pass between the renal pyramids

Afferent arterioles lead to the nephrons

• Nerve supply is via sympathetic fibers from the renal plexus


Kidney Functions

• Removal of toxins, metabolic wastes, and excess ions from the blood

• Regulation of blood volume, chemical composition, and pH

• Gluconeogenesis during prolonged fasting

• Endocrine functions

• Renin: regulation of blood pressure and kidney function

• Erythropoietin: regulation of RBC production

• Activation of vitamin D

Kidneys•lie on either side of the

vertebral column deep in the abdominal cavity

•positioned behind the parietal peritoneum (retroperitoneally)

•lateral side is convex, medial is concave, kidneys sit in a depression called the renal sinus

•Entrance is called the HILUM


Internal Anatomy

• Renal cortex

• A granular superficial region (appears granulated due to presence of nephrons)

• Renal medulla – center of the kidney

• The cone-shaped medullary (renal) pyramids separated by renal columns

• Lobe

• A medullary pyramid and its surrounding cortical tissue


Internal Anatomy

• Papilla

• Tip of pyramid; releases urine into minor calyx

• Renal pelvis

• The funnel-shaped tube within the renal sinus

• Continuous with the ureter, used for drainage


Internal Anatomy

• Major calyces

• The branching channels of the renal pelvis that

• Collect urine from minor calyces

• Empty urine into the pelvis

• Urine flows from the renal pelvis to ureter

• Common site for bacteria build up (kidney infections)

Copyright © 2010 Pearson Education, Inc. Figure 25.3

Renal cortex

Renal medulla

Major calyx

Papilla ofpyramidRenal pelvis

Ureter

Minor calyx

Renal column

Renal pyramid in renal medulla

Fibrous capsule

Renalhilum

(a) Photograph of right kidney, frontal section (b) Diagrammatic view


Nephrons

• Structural and functional units that form urine

• ~1 million per kidney

• Two main parts

1. Glomerulus: a tuft of capillaries

2. Renal tubule: begins as cup-shaped glomerular (Bowman’s) capsule surrounding the glomerulus

glomerulus proximal tubule nephron loop (also called Loop of Henle distal tubule collecting duct ureter bladder

Urine Formation 1. glomerular filtration - urine formation begins, plasma is

filtered2. tubular reabsorption - Returns all glucose and amino

acids, 99% of water, salt, and other components to the blood

3. tubular secretion - Reverse of reabsorption: selective addition to urine

http://www.youtube.com/watch?v=U1m7egrEdk0

What blood vessel enters the glomerulus?


Corticalradiateartery

Afferent arteriole

Glomerular capillaries

Efferent arteriole

Glomerular capsule

Rest of renal tubulecontaining filtrate

Peritubularcapillary

To cortical radiate vein

Urine

Glomerular filtration

Tubular reabsorption

Tubular secretion

Three majorrenal processes:


Reabsorption of Nutrients, Water, and Ions

•Water is reabsorbed by osmosis (obligatory water reabsorption), aided by water-filled pores called aquaporins

• Cations and fat-soluble substances follow by diffusion

• Reabsorption is hormonally regulated

• Ca2+ (PTH)

• Water (ADH)

• Na+ (aldosterone and ANP)


Chemical Composition of Urine

• 95% water and 5% solutes

• Nitrogenous wastes: urea, uric acid, and creatinine

• Other normal solutes

• Na+, K+, PO43–, and SO4

2–,

• Ca2+, Mg2+ and HCO3–

• Can contain trace amino acids

• Abnormally high concentrations of any constituent may indicate pathology

Urine may also contain other chemicals that can be detected.

Hormones present in a pregnant woman are detectable in urine

Color and transparency

• Some European alchemists in the middle ages thought there was gold in urine.

• German alchemist Hennig Brand discovered phosphorus while trying to make gold from urine.


Color and transparency

• Clear, pale to deep yellow due to urochrome (a breakdown product of bile)

• These same yellow chemicals also cause the yellow color of jaundice and of bruises, which result when more hemoglobin than usual is being broken down and/or the processing of its breakdown products by the liver is not able to keep up.

• Drugs, vitamin supplements, and diet can alter the color

• Cloudy urine may indicate a urinary tract infection


Ureters

• Convey urine from kidneys to bladder

• Retroperitoneal

• Enter the base of the bladder through the posterior wall

• As bladder pressure increases, distal ends of the ureters close, preventing backflow of urine


Ureters

• Three layers of wall of ureter

1. Lining of transitional epithelium

2. Smooth muscle muscularis

• Contracts in response to stretch

3. Outer adventitia of fibrous connective tissue


Lumen

AdventitiaCircular

layerLongitudinal

layer

Transitionalepithelium

Laminapropria


Urinary Bladder

• Collapses when empty; rugae appear

• Layers of the bladder wall

1. Transitional epithelial mucosa

2. Thick detrusor muscle (three layers of smooth muscle)

3. Fibrous adventitia (peritoneum on superior surface only)

Urine Elimination

•After urine forms in the nephrons, the ureters (starting with the renal pelvis) carry the urine away to the bladder

•Bladder is an expandable structure that stores urine before it is eliminated from the body.

•Transitional epithelial cells change shape to allow for expansion and contraction.

artificial bladder grown in a lab


Urethra

• Muscular tube

• Lining epithelium

• Mostly pseudostratified columnar epithelium, except

• Transitional epithelium near bladder

• Stratified squamous epithelium near external urethral orifice


Urethra

• Sphincters

• Internal urethral sphincter

• Involuntary (smooth muscle) at bladder-urethra junction

• Contracts to open

• External urethral sphincter

• Voluntary (skeletal) muscle surrounding the urethra as it passes through the pelvic floor


Urethra

• Female urethra (3–4 cm):

• Tightly bound to the anterior vaginal wall

• External urethral orifice is anterior to the vaginal opening, posterior to the clitoris

Copyright © 2010 Pearson Education, Inc. Figure 25.21b

Ureter

Trigone

Peritoneum

Rugae

Detrusor muscle

Bladder neck

Internal urethralsphincter

External urethralsphincter

Urogenital diaphragm

Urethra

External urethralorifice

Ureteric orifices

(b) Female.


Urethra

• Male urethra

• Carries semen and urine

• Three named regions

1. Prostatic urethra (2.5 cm)—within prostate gland

2. Membranous urethra (2 cm)—passes through the urogenital diaphragm

3. Spongy urethra (15 cm)—passes through the penis and opens via the external urethral orifice

Copyright © 2010 Pearson Education, Inc. Figure 25.21a

Ureter

Trigone of bladder

Prostate

Membranous urethra

Prostatic urethra

Peritoneum

RugaeDetrusor muscle

Bladder neckInternal urethral sphincter

External urethral sphincterUrogenital diaphragm

Spongy urethraErectile tissue of penis

Ureteric orificesAdventitia

(a) Male. The long male urethra has three regions: prostatic, membranous and spongy.

External urethral orifice


Micturation = urination; as the bladder fills this reflex occurs though it is also under voluntary control

Detrusor Muscle - attach to bladder and sphincter, control urination


Events of Micturition

1. Contraction of detrusor muscle by ANS

2. Opening of internal urethral sphincter by ANS

3. Opening of external urethral sphincter by somatic nervous system



Diuretics

• Chemicals that enhance the urinary output

• Osmotic diuretics: substances not reabsorbed, (e.g., high glucose in a diabetic patient)

• ADH inhibitors such as alcohol

• Substances that inhibit Na+ reabsorption and obligatory H2O reabsorption such as caffeine and many drugs


Somatic motornerve activity

External urethralsphincter opens

Sympatheticactivity

Parasympatheticactivity

Urinary bladderfilling stretches

bladder wall

Spinalcord

Promotes micturitionby acting on all three

spinal efferents

Inhibits micturitionby acting on all three

spinal efferents

Allow or inhibit micturitionas appropriate

Brain

Simplespinalreflex

Spinalcord

Inhibits

Parasympathetic activitySympathetic activity

Somatic motor nerve activity

Pontine micturitioncenter

Pontine storagecenter

Higher braincenters

Detrusor musclecontracts; internalurethral sphincter

opens

Afferent impulsesfrom stretch

receptors

Micturition

Disorders of the Urinary System

Many urinary problems can be solved by drinking enough water. So how much fluid does the average, healthy adult living in a temperate climate need? The Institute of Medicine determined that an adequate intake (AI) for men is roughly 3 liters (about 13 cups) of total beverages a day. The AI for women is 2.2 liters (about 9 cups) of total beverages a day.

Catheters In medicine, a catheter is a tube that can be inserted into a body cavity, duct, or vessel. The process of inserting a catheter is catheterization.

Catheterization of the bladder is a common medical procedure, often performed by nurses

When Kidneys Fail....

Dialysis may be used to clean the blood(hemodialysis)

4 hours, 3 times a week

Patients will eventually need a new kidney

Kidney Transplants

Modern Family Actress talks about kidney disease

Domino Kidney Transplants or Kidney Exchanges - when you aren't a match for a family member, you can participate in a kidney exchange.

http://abcnews.go.com/WNT/video/modern-family-actress-kidney-transplant-16346967

Myth or Fact? 1. Urinating on a jellyfish sting will help alleviate the pain. 2. It is safe to drink your own urine. 3. If someone is sleeping and you.

Documents

urine urethra

electrolytes http

urinary system slide

urine stream

sheeturina http

reliable http

renal plexus slide

urinary system chapter