OIA1004 (TERMS) URINARY SYSTEM I

Filtration / Tubular secretion

Process of removing waste/substance from blood.

Kidney Functions

Maintain blood osmolarity and electrolyte balance.

Excretion

Removal of metabolic waste and foreign substances.

Hormone Production

Kidneys produce hormones like erythropoietin.

Blood Pressure Regulation

Kidneys help maintain stable blood pressure.

Acid-Base Balance

Regulation of blood pH levels.

Urinary System Components

Includes kidneys, ureters, bladder, and urethra.

Retroperitoneal Cavity

Space behind the peritoneum housing kidneys.

Kidney Size

Approximately 3 cm thick, 6 cm wide, 12 cm long.

Renal Cortex

Outer reddish region of the kidney.

Renal Medulla

Darker region containing renal pyramids.

Renal Pyramids

8-15 cone-shaped structures in the medulla.

Renal Columns

Extensions of cortex between renal pyramids.

Renal Pelvis

Central region collecting urine from calyces.

Calyx

Cupped structure collecting urine from pyramids.

Nephrons

Functional filtration units within the kidneys.

Cortical Nephrons

Short nephron loops located in the cortex.

Juxtamedullary Nephrons

Long nephron loops near the medulla.

Renal Corpuscle

Structure composed of glomerulus and Bowman's capsule.

Endothelial-Capsular Membrane

Filters blood in the renal corpuscle.

Collecting Duct

Final segment of nephron for urine concentration.

Juxtaglomerular Apparatus

Structure regulating blood pressure in kidneys.

Juxtaglomerular Cells

Granular cells secreting renin in arterioles.

Mesangial Cells

Phagocytic cells influencing capillary filtration.

Afferent Arteriole

Brings blood to the glomerulus.

Efferent Arteriole

Carries blood away from the glomerulus.

Glomerulus

Network of capillaries for blood filtration.

Bowman's Capsule

Double-walled structure surrounding the glomerulus.

Endothelial-Capsular Membrane

Barrier filtering blood components in nephron.

Proximal Convoluted Tubule

First segment of renal tubule for reabsorption.

Loop of Henle

U-shaped segment for urine concentration.

Ascending Limb

Part of Loop of Henle moving upwards.

Descending Limb

Part of Loop of Henle moving downwards.

Glomerular Filtration Rate (GFR)

Rate of fluid filtered into Bowman's capsule// Rate of blood filtration in kidneys.

Normal GFR Value

120 ml/min or 180 L/day.

Tubular Reabsorption

Process of reclaiming water and solutes.

Renal Corpuscle

Combination of glomerulus and Bowman's capsule.

Filtrate

Fluid collected in Bowman's space, not urine.

Podocytes

Specialized cells forming filtration slits in Bowman capsule.

Glomerular Filtration Rate (GFR)

Volume of fluid filtered per minute, ~125 ml/min.

Hydrostatic Pressure (HPc)

Blood pressure in glomerular capillaries, 60 mmHg.

Colloid Osmotic Pressure (CPo)

Pressure due to plasma proteins, 25 mmHg.

Glomerular Filtration Pressure

Net pressure driving filtration, 17 mmHg.

Net Filtration Pressure

Difference between hydrostatic and osmotic pressures.

Renal Autoregulation

Kidney's ability to maintain constant GFR.

Intrinsic Control of GFR

Regulation initiated by the kidneys themselves.

Extrinsic Control of GFR

Regulation influenced by neural and hormonal factors.

Tubuloglomerular Feedback

Mechanism adjusting GFR based on fluid flow.

Macula Densa Cells

Chemoreceptors monitoring sodium chloride concentration in distal tubules.

Myogenic Response

Vascular response to changes in blood pressure.

Juxtaglomerular Apparatus

Structure regulating blood flow and GFR.

Systemic Blood Pressure

Overall pressure in the circulatory system.

Colloid Osmotic Pressure Effect

Opposes filtration, retains fluid in capillaries.

Filtration Rate Increase

More fluid filtered due to elevated blood pressure.

Filtration Rate Decrease

Less fluid filtered due to decreased blood pressure.

Endothelin

Vasoconstrictor released by macula densa cells.

Bradykinin

Vasodilator potentially released by macula densa.

Normal GFR Maintenance

Constant GFR despite fluctuations in systemic BP.

GFR

Glomerular filtration rate, measures kidney filtration efficiency.

Extrinsic control of GFR

Neural and hormonal regulation affecting GFR.

Intrinsic control of GFR

Local mechanisms regulating GFR independently.

Norepinephrine & Epinephrine /Angiotensin II (Hormone)

Neurotransmitter/Hormone causing vasoconstriction, decreases GFR.

ANP

Hormone increasing GFR by dilating afferent arterioles.

Nitric oxide

Vasodilator, increases GFR by relaxing arterioles.

Endothelin

Vasoconstrictor, reduces GFR by constricting arterioles.

Prostaglandin

Hormones that modulate GFR through vasodilation.

Renin

Enzyme triggering angiotensin II production.

Glomerular filtrate

Fluid filtered from blood in glomerulus.

Renal clearance

Measurement of substance excretion in urine.

Creatinine clearance

Estimates GFR using creatinine levels.

Inulin

Ideal substance for measuring GFR, not reabsorbed.

Sympathetic activity

Nervous system response, overrides intrinsic GFR control.

Fluid imbalance

Occurs with excessive or insufficient filtrate formation.

Tubular reabsorption

Process of reclaiming substances from filtrate.

Filtrate flow rate

Speed of fluid movement through renal tubules.