4.01 Remember the structures of the urinary system

4.02 Understand the functions and disorders of the urinary system ESSENTIAL QUESTIONS Essential Questions What are the structures of the urinary system? What are the functions of the urinary system? What are some disorders of the urinary system? How are disorders of the urinary system treated? How do you relate the body’s hormone control to the urinary system? 4.02 Understand the functions and disorders of the urinary system

Function Excretion – removing nitrogenous wastes, certain salts and excess water from blood Maintain acid-base balance Secrete waste products in the form of urine Eliminate urine from bladder

Structures of the urinary system Kidneys Ureters Bladder Urethra Urinary meatus 4.01 Remember the structures of the urinary system

4.01 Remember the structures of the urinary system Kidneys Most important excretory organ Bean-shaped Located between peritoneum and the back muscles (retroperitoneal) Held in position by connective tissue Enclosed in an adipose capsule Protected by the ribs 4.01 Remember the structures of the urinary system

Structures of the urinary system Kidneys External structures Renal capsule Renal hilum Internal structures Renal cortex Renal medulla Renal pelvis 4.01 Remember the structures of the urinary system

Structures of the urinary system External kidney Renal fascia Fibrous layer of connective tissue Renal hilum Indentation that gives the kidney its bean-shaped appearance 4.01 Remember the structures of the urinary system

Structures of the urinary system Internal kidney Renal cortex Outer layer Renal medulla Middle layer Renal pelvis Innermost layer 4.01 Remember the structures of the urinary system

Structures of the urinary system Renal cortex Composed of millions of microscopic functional units called nephrons 4.01 Remember the structures of the urinary system

Structures of the urinary system Nephron Functional unit of kidney Renal corpuscle Bowman’s capsule Glomerulus Renal tubule Proximal convoluted tubule Loop of Henle Distal convoluted tubule Collecting tubules Each kidney contains about 1.3 MILLION nephrons! 4.01 Remember the structures of the urinary system

Structures of the Urinary system Renal medulla Inner, striated layer RENAL PYRAMIDS are the striated cones. Base of each pyramid faces cortex, while apex empties into cuplike cavities called CALYCES Renal columns Located between the pyramids Cortical tissue 4.01 Remember the structures of the urinary system

Structures of the urinary system Renal pelvis Funnel shaped structure at the beginning of the ureter 4.01 Remember the structures of the urinary system

Urine Formation in the Nephron

Understand the functions of the urinary system Excretion What is excretion? Why does the body have excretory functions? What is the composition of wastes excreted by the urinary system? How is it relevant to health? 4.02 Understand the functions and disorders of the urinary system

Understand the functions of the urinary system Filtration Reabsorption Secretion 4.02 Understand the functions and disorders of the urinary system

1st Filtration First step in urine formation Blood from renal artery enters glomerulus High BP in glomerulus forces fluid (filtrate) to filter into Bowman’s capsule Filtrate does not contain plasma proteins or RBC’s (they are too big) Bowman’s capsule filters out 125cc of fluid/min – 7500cc/hour As filtrate continues through nephron, 9-% of water is reabsorbed

2nd Reabsorbption Water and useful substances are reabsorbed If blood levels of certain substances are high (glucose, amino acids, vitamins, sodium) then those substances will not be reabsorbed.

3rd Secretion Opposite of reabsorbtion Secretion transports substances from blood into collecting tubules Substances include creatinine, H & K ions, and some drugs Electrolytes are selectively secreted to maintain body’s acid-base balance

Urinary Output Ave= 1500 ml/day Urinalysis – examination of urine to determine presence of blood cells, bacteria, acidity level, specific gravity and physical characteristics (color, clarity, and odor)

Ureters One from each kidney Carry urine from kidney to bladder Smooth muscle tube with mucous membrane lining Peristalsis pushes urine down ureters

Urinary Bladder Hollow, muscular organ Made of elastic fibers and involuntary muscle Stores urine – usually about 500 cc Emptying urine (voiding) is involuntary but controlled through nervous system (voluntary) Urine leaves through urethra to outside opening (urinary meatus)

Structures of the urinary system Female Urethra Connects the bladder to the outside of the body Female 1-2” long Male 4-6” long Urinary meatus Opening to the outside of the body Male 4.01 Remember the structures of the urinary system

Fluid and electrolyte balance Electrolytes are selectively secreted to maintain body’s acid-base balance. What are electrolytes? What do they do? What is the relevance to health? 4.02 Understand the functions and disorders of the urinary system

Control of Urinary Secretion Chemical Control Reabsorption of H2O in distal convoluted tubule controlled by ADH (antidiuretic hormone) Secretion and regulation of ADH controlled by hypothalamus Diuretics inhibit reabsorption of H2O Aldosterone: secreted by the adrenal cortex promotes excretion of K and H atoms and reabsorption of Na, Cl, and water Nervous Control Direct control through nerve impulses on kidney blood vessels Indirect control through stimulation of endocrine glands

4.02 Understand the functions and disorders of the urinary system Urinalysis An examination of urine What does normal urine look like? What constitutes an abnormal urinalysis? 4.02 Understand the functions and disorders of the urinary system

4.02 Understand the functions and disorders of the urinary system Urinalysis What could the presence of blood in urine indicate? What is the medical term for this condition? 4.02 Understand the functions and disorders of the urinary system

Where would excess glucose show up? Urinalysis Where would excess glucose show up? What does this mean? 4.02 Understand the functions and disorders of the urinary system

4.02 Understand the functions and disorders of the urinary system Urinalysis 4.02 Understand the functions and disorders of the urinary system

Disorders of the Urinary System

Glomerulonephritis There are 2 types: Acute and Chronic

Acute Renal Failure Caused by nephritis, shock, injury, bleeding, sudden heart failure or poisoning S/sx: Olguria – scant urine Anuria – no urine produced Treatment: Hemodialysis or Peritoneal dialysis

Chronic Renal Failure gradual loss of function of nephrons Chronic kidney disease leads to a buildup of fluid and waste products in the body. Protein present in urine

Renal Calculi (kidney stones) Made of crystals of Ca phosphate and uric acid Gradually they get larger until they block ureters First symptom is severe pain Other symptoms – nausea, vomiting, frequency, chills, fever, hematuria Diagnosis – by s/sx, ultrasound, or x-ray Tx – increase fluids to flush out stone, medications, and if needed - lithotripsy

Lithotripsy Surgical procedure to remove kidney stones Shock waves hit dense stones and break them up Done on outpatient basis

nephritis Inflammation of the kidney (kidney infection)

Cystitis Inflammation of the mucous membrane lining of the urinary bladder Most common cause - E.Coli s/sx – dysuria (painful urination) and frequency Urually in females (shorter urethra) Rx - antibiotics

dialysis Hemodialysis Used for kidney failure Involves the passage of blood through device with semipermeable membrane Dialysis serves as substitute kidney Blood from patient flows though machine and is filtered Can be done at home or in clinic Takes 2-4 hours, 2-3 times a week

Peritoneal Dialysis Uses patients own peritoneal lining instead of dialyzer to filter blood Cleaning solution called dialysate travels through catheter in the abdomen Solution sits in peritoneal cavity for 4-6 hours absorbing wastes, fluids, electrolytes, and chemicals

Kidney Transplant As a last resort Involves donor organ from someone with a similar immune system Main complication is rejection

Other terms Enuresis – bedwetting Glycosuria – sugar in urine Nocturia – frequent urination at night Pyuria – pus in urine Anuria – no urine produced Hematuria – blood in urine Diuretic – drug or substance to increase urine production Incontinence – involuntary urination