The Urinary System

Functions of the Urinary system Maintain homeostasis of: Blood Fluid volume Blood pressure pH Removes waste

Fluid intake and output Food, water by mouth Cellular respiration

Fluid intake and output Voiding (urination) Micturition (urination) Sweat Exhaled vapor Feces

Kidneys Size of your fist Paired organs Renal Fascia = thin membrane on outside of kidney anchors the kidney to abdominal wall

Kidneys Adipose Capsule = adipose tissue around each kidney -protects the kidney from trauma -holds the kidney firmly in place Renal Capsule = skin-like covering of tissue surrounding each kidney

Kidney (cont) Hilus = where the ureter leaves the kidney Renal Sinus = a cavity within the kidney by the hilus (contains renal pelvis) Calyx = channels urine into the renal pelvis

Three Major Regions of Kidney 1. Cortex = outer region of the kidney 2. Medulla = middle brownish area of the kidney contain Renal (Medullary) Pyramids = 8 to 18 triangular structures within the medulla 3. Renal Pelvis = region that collects urine

The Ureters Tubes that carry urine from kidneys to urinary bladder Extension of renal pelvis 10 to 12 inches Primary function is to transport urine gravity -hydrostatic pressure peristaltic action by muscularis layer

The Urinary Bladder Hollow muscular organ Stores urine until excretion Shape depends on how much urine is present When filled with urine somewhat pear shaped

The Urethra Tube leading from bladder to exterior of body Female-- 1 1/2 in Male-- 8 in Internal Sphincter aids in expansion of bladder External Urethral Sphincter controls urination

Urine is made in the kidneys

Nephrons Functional units of kidney Filters blood by removing waste products Forms urine Regulates blood fluid and electrolyte balance

Components of a Nephron Renal Corpuscle contains the Glomerulus and Bowman's Capsule Renal Tubules thin twisting ducts of tubes

Renal Corpuscle contains: Glomerulus MAIN FUNCTION IS FILTRATION Tuft (ball) of capillaries

Renal Corpuscle contains: Glomeruler-Bowman’s capsule Collects fluid Leads into PCT (proximal convoluted tubule)

The Renal Tubules Three main sections: Proximal Convoluted Tubule --PCT Loop of Henle Distal Convoluted Tubule DCT Surrounded by Peri-Tubular Capillaries Reabsorption of fluid back into the blood Secretion of excess ions into urine

Urine Production Three process involved in Urine Production All occur in Nephrons Glomerular Filtration (blood filtered) – in RENAL CORPUSCLE Tubular Reabsorption (fluid & electrolytes to blood)—PCT & LOOP OF HENLE Tubular Secretion (from ( blood tubular fluid) - DCT

Physical Characteristics of Urine Color = yellow or amber can vary considerably with diet Turbidity = clear then turns cloudy Odor = usually odorless, but can smell if left standing

Urine Volume Normally one to three quarts per day Influenced by: Blood Pressure Blood Concentration Temperature Diuretics Emotions Hormones

Chemical Composition of Urine Water = 95% 5% solutes from cellular metabolism Organic Components of Urine Urea Uric Acid Creatine Hippuric Acid Ketone Bodies Others

Chemical Composition of Urine Inorganic Components of Urine NaCl Ca++ NH4+ Mg++ PO4(3-) SO4 (2-)

Abnormal Substances in Urine Glucose Ketone Bodies in large numbers Erythrocytes Leukocytes Billirubin Large number of microbes

Fun Facts The entire volume of blood in the body is filtered by the kidneys about 60 times each day Filters about 180 Liters (45 gallons) of fluid a day Returns over 99% of the fluid back to the body

URINARY SYSTEM DISORDERS

Cystitis (bladder infection) An inflammation of the urinary bladder More common in women than men Can be caused by injury, infection, or chemicals Symptoms include burning sensation upon urination, painful urination, frequent urination, urgency, low back pain and possibly bed wetting Dysuria Treated with antibiotics

Diabetes Insipidus (DI) Characterized by excretion of large volumes of urine polyuria 5 to 15 L/day of extremely dilute urine Caused by an ADH production disorder hyposecretion of ADH Patients exhibit extreme thirst (polydipsia)

Glomerulonephritis (Bright’s Disease) Inflammation of the glomeruli of the kidneys Caused by bacterial infection Can result in kidney failure

Incontinence Inability to control urination Caused by pregnancy, age, childbirth Medications, muscle retraining and surgery

Kidney Stones Also called renal calculi or nephrolithiasis Calculus or crystalline masses present in the pelvis of the kidney composed primarily of hardened minerals May be treated with lithotripsy

Renal Failure A decrease or cessation of glomerular filtration (less than 10% of function) Acute Renal Failure (ARF) sudden worsening of renal function may follow a case of hypovolemic shock

Renal Failure Chronic Renal Failure (CRF) progressive, irreversible decline in function can be caused by chronic glomerulonephritis, pyelonephritis, congenital polycystic disease

Urinary Tract Infections (UTI’s) Infection of a part of the urinary system or a abnormally large number of microbes present in the urine Much more common in females

Urinary Tract Infections (UTI’s) Individuals at risk include: pregnant women renal disease hypertension diabetes Symptoms include burning or painful urination, pubic and back pain, chills, fever, nausea, vomiting, etc.

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