The Urinary System Chapter 17

Bladder Schistosomes Normally, urine is sterile. Presence of blood may indicate an infection.

-Cells produce waste that can become toxic if they accumulate 17.1 Introduction -Cells produce waste that can become toxic if they accumulate Functions the urinary system removes salts and nitrogenous wastes maintains normal concentration of water and electrolytes maintains pH, controls red blood cell production and blood pressure

Composition consists of a pair of kidneys which remove substances from the blood ureters which transport urine from the kidneys to the bladder urinary bladder stores urine urethra conveys urine to the outside of the body

17.2 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 a concave area called the renal sinus Entrance is called the HILUM

The nephron is the functional unit of the kidney -superior end of the kidney forms a funnel shaped sac - renal pelvis -renal medulla = center of the kidney -renal cortex = outer shell around the medulla; the cortex appears granulated due to the presence of nephrons -renal arteries and veins supply blood to  the kidneys The nephron is the functional unit of the kidney

kidneys ureters bladder sphincter urethra

Kidney Label

Myth or Fact? 1. Urinating on a jellyfish sting will help alleviate the pain. ~Answer 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. ~Answer 4. Holding your urine can cause a bladder infection. 5. There is a fish that will follow a urine stream and enter the urethra. ~Answer

Renal Arteries & Veins Arteries attach to the abdominal aorta Veins attach to the inferior vena cava Pathway: Renal Artery → Interlobar arteries → Afferent arterioles → Efferent arterioles (wraps around tubules) → Renal Vein → inferior vena cava

Parts of the Urinary System - The NEPHRON

NEPHRONS - functional unit of the urinary system Quick Analogy:  A nephron is to the urinary system as the _________________ is to the nervous system -each kidney contains about 1 million nephrons -renal corpuscle: composed of a tangled cluster called a glomerulus which filters fluid Pathway = glomerulus -> proximal tubulue --> nephron loop (also called loop of henle) --> distal tubule --> collecting duct --> ureter --> bladder

Also see Kidney and Nephron Coloring

What blood vessel enters the glomerulus? → afferent arteriole What blood vessel leaves the glomerulus? → efferent arteriole

17.3 Urine Formation (section is abbreviated) glomerular filtration - urine formation begins, plasma is filtered → FILTRATE moves into proximal tubule afferent arteriole efferent arteriole

-tubular reabsorption - returns most of the fluid to the body - Proximal Tubule -tubular secretion - removes what is not needed; produces urine - Distal Tubule *Filtrate contains waste products removed from the blood by DIFFUSION.

Diuretic = chemicals that increase urination Urine Composition 95 % Water Contains urea and uric acid (characteristic smell) Can contain trace amino acids Diuretic = chemicals that increase urination

Urine may also contain other chemicals that can be detected. Hormones present in a pregnant woman are detectable in urine

17.4 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

Micturation = urination; as the bladder fills this reflex occurs though it is also under voluntary control Urethra = tube carries urine to the outside of the body Detrusor Muscle - attach to bladder and sphincter, control urination

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.

Kidney Stones Extracorporeal shock wave lithotripsy (ultrasonic waves) used to shatter simple stones in the kidney or upper urinary tract, stones are made smaller so they can pass. Most of the time, patients are managed for pain and the stone passses without treatment.

Commonly known as a "bladder infection" Cystitis = bacteria enters the bladder or kidneys (kidney infection); more common in women because the urethra is shorter Commonly known as a "bladder infection"   UTI = urinary tract infection Frequent  need to urinate Pain in the abdomen Burning sensation during urination Cloudy, bad-smelling urine Blood in the urine Leaking urine Low back pain Fever and chills Nausea and poor appetite

The American Cancer Society’s estimates for bladder cancer in the United States for 2015 are: About 74,000 new cases of bladder cancer diagnosed (about 56,320 in men and 17,680 in women). About 16,000 deaths from bladder cancer (about 11,510 in men and 4,490 in women). Bladder cancer is the fourth most common cancer in men.

Bladder Cancer Treatment Bacillus Calmette-Guerin therapy (BCG): intravesical immunotherapy for treating early-stage bladder cancer. BCG is a germ that is related to the one that causes tuberculosis (TB), BCG is put directly into the bladder through a catheter. The body’s immune system cells are attracted to the bladder and activated by BCG, which in turn affects the bladder cancer cells. Chemotherapy drugs can also be used to destroy cancer cells - either injected directly into the bladder or into the bloodstream.

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

Overactive Bladder = sudden contractions of the bladder produce sensation of urgency, also more common in women Incontinence - inability to control urination (or defecation)   Overactive Bladder Commercial

Prostate Enlargement BPH = benign prostate hypertrophy While the prostate* is considered part of the reproductive system, as this organ grows in size, it can affect urine output in men. * a gland that produces a fluid that carries sperm during ejaculation. It surrounds the urethra, which is the tube through which urine passes from the body. BPH = benign prostate hypertrophy

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