Urin
40 flashcards
- Urinary System,
- Major excretory system of the body
- Components of Urinary System
- 2 Kidneys, 2 Ureters, Urinary Bladder, Urethra
- Functions of Urinary System
- Excretion (waste / urine), Regulates blood, Hormone production
- Blood Regulation of
- ionic comp., pH, volume, pressure(renin), osmolarity(Concentration), glucose
- Hormones produced
- Erythropoietin, renin
- Kidney Location
- just above the waist, Bilateral, retroperitoneal organs
- Kidney Shape
- Bean-shaped
- Kidney Size
- ~5 ounces; size of a clenched fist
- Kidney specific Location
- Between 12th thoracic and 3rd lumbar vertebrae
- Renal Capsule
- Connective tissue around each kidney
- Hilum
- Indentation; contains renal artery, renal vein, nerves, and ureters
- Renal Sinus
- Contains the renal pelvis, blood vessels, fat
- Renal Cortex
- Outer portion
- Renal Medulla
- Inner portion
- Renal Pyramids
- Cone-shaped structures in the medulla whose bases project into the cortex
- Renal Papillae
- Tips of pyramids which drain into the calyces
- Renal Pelvis
- Where calyces join together to form the ureter
- The Nephron
- Functional unit of the kidney, Each kidney has over 1 million nephrons
- Structures of Nephron
- 1. Renal Corpuscle, 2. Proximal Convoluted Tubule (PCT), 3. Loop of Henle, 4. Distal Convoluted Tubule (DCT), 5. Collecting Ducts
- 2 Kinds of Nephrons
- Cortical Nephrons (~85%), Juxtamedullary Nephrons (~15%)
- Cortical Nephrons (~85%)
- Renal corpuscles distributed throughout the cortex, Loops of Henle are shorter and closer to the outer edge of cortex
- Juxtamedullary Nephrons (~15%)
- Renal corpuscles are deep in the cortex near the medulla, Loops of Henle extend deep into the medulla, Well adapted for water conservation
- Nephron parts
- Renal corpuscle, proximal convoluted tubule (PCT), loop of henle, distal Concoluted Tubule(DCT), Collecting ducts
- Renal Corpuscle
- Filtration portion of nephron
- (RC)Glomerulus
- Network of capillaries twisted around each other like a ball of yarn
- (RC)Bowman's Capsule
- Enlarged end of nephron surrounding glomerulus; opens into PCT; contains podocytes (specialized cells around glomerulus capillaries)
- Proximal Convoluted Tubule (PCT)
- Where filtrate passes first; drains filtrate from Bowman's capsule
- Loop of Henle
- Contains descending and ascending loops; water and solutes pass through thin walls by diffusion
- Distal Convoluted Tubule (DCT)
- Structure between Loop of Henle and collecting ducts
- Collecting Ducts
- Empties into calyces; carries fluid from cortex through medulla
- Urine formation processes
- Filtration, Tubular reabsoption, Secretion
- 1. Filtration,
- Blood Plasma ’ Bowman's Space, Occurs in Renal Corpuscle. Fluid and solutes leave glomerulus and enter Bowman's capsule.
- 2. Tubular Reabsorption, Tubule Blood
- Involves removing substances from filtrate and placing them back into the blood. ’
- 3. Secretion
- substances Blood ’ nephron Tubule
- Lower Urinary Tract
- Ureters, Urinary Bladder, Urethra, Micturition reflex
- Ureters
- Small tubes that carry urine from renal pelvis to bladder
- Urinary Bladder
- Located in pelvic cavity, Function: Store urine, Can hold urine up to maximum 1 L
- Urethra
- The tube that exits the bladder, Function: Carries urine from urinary bladder to outside of body
- 1. Internal Urethral Sphincter
- Smooth muscle (involuntary), Located at the junction of the urinary bladder and urethra
- 2. External Urethral Sphincter
- Skeletal muscle (voluntary), Located in the pelvic floor