Urinary System

Flashcards summarizing key concepts from the urinary system lecture.

Urinary System

The organ system that produces, stores, and eliminates urine.

Urinalysis

A test that analyzes urine for appearance, concentration, and content.

Urochrome

A yellow pigment that gives urine its color.

Hydrated

Having adequate water content; normal urine production.

Dehydrated

Absence of adequate water content; decreased urine production.

Polyuria

Excessive urine production, defined as greater than 2.5 L/day.

Oliguria

Low urine output, defined as 300-500 mL/day.

Anuria

Absence of urine production, defined as less than 50 mL/day.

Homeostasis

The maintenance of stable internal conditions in the body.

Urine Composition

Urine is composed of approximately 95% water.

Clarity (of urine)

Refers to how clear or cloudy the urine appears.

pH Level

The measure of acidity or alkalinity of urine, typically ranging from 4.5 to 8.0.

Leukocytes

White blood cells; their presence in urine may indicate infection.

Protein (in urine)

Normally not present; if found, may suggest glomerular damage.

Ketones

Byproducts of fat metabolism often seen in urine during fat utilization for energy.

Nitrites

Indicate a urinary tract infection; formed by bacteria from nitrates.

Glomerulus

A tuft of capillaries involved in filtration in the kidney.

Renal Corpuscle

The structure comprised of the glomerulus and Bowman’s capsule.

Bowman's Capsule

The cup-shaped structure surrounding the glomerulus, capturing filtrate.

Glomerular Filtration Rate (GFR)

The volume of filtrate produced by the kidneys per minute, usually about 125 mL/min.

Filtration Membrane

The barrier between blood and glomerular capsule, composed of fenestrated endothelium, podocytes, and a basement membrane.

Tubular Reabsorption

Process of reclaiming water and solutes from the filtrate back into the blood.

Tubular Secretion

Process of moving substances from blood into the filtrate to be eliminated as urine.

Antidiuretic Hormone (ADH)

Hormone that promotes water reabsorption in the kidneys.

Diuretics

Substances that promote the excretion of water and salt through urine.

Micturition

The act of voiding or urinating.

Cystitis

Inflammation of the bladder, often due to infection.

Bladder Cancer

Malignant growth in the bladder, often linked to smoking.

Prostate Enlargement

The increase in size of the prostate, commonly affecting urine flow in men.

Kidney Stones

Hard deposits made of minerals and salts that form in the kidneys.

Hemodialysis

A procedure to clean the blood of waste products when kidneys fail.

Renal Clearance Rate

The volume of plasma from which a particular substance is completely removed by the kidneys per time.

Filtrate

The fluid that passes through the filtering process in the kidney.

Vasa Recta

Specialized capillaries associated with the nephron that play a role in maintaining osmotic gradient.

Osmolarity

A measure of the concentration of solute particles in a solution.

Urinary Tract Infection (UTI)

Infection in the urinary system, often leading to symptoms like frequent urination and pain.

Renin-Angiotensin Mechanism

Hormonal system that regulates blood pressure and fluid balance.

Macula Densa

Cells in the distal convoluted tubule that sense sodium concentration and help regulate GFR.

Afferent Arteriole

The blood vessel that supplies blood to the glomerulus.

Efferent Arteriole

The blood vessel that carries blood away from the glomerulus.

Peritubular Capillaries

Small blood vessels surrounding the nephron that aid in reabsorption.

Detrusor Muscle

The smooth muscle of the bladder that contracts to facilitate urination.

External Urethral Sphincter

A voluntary sphincter that controls the release of urine from the bladder.

Renal Pelvis

The funnel-shaped structure that collects urine from the calyces and directs it into the ureter.

Ureter

The tube that carries urine from the kidneys to the bladder.

Urethra

The tube that carries urine from the bladder to the outside of the body.

Nephron

The functional unit of the kidney responsible for filtering blood and forming urine.

Collecting Duct

The duct that carries urine from the renal tubules to the ureter.

Distal Convoluted Tubule (DCT)

Part of the nephron where further processing of filtrate occurs, mainly tubular secretion.

Loop of Henle

Part of the nephron that concentrates urine by creating osmotic gradients.

Proximal Convoluted Tubule (PCT)

Part of the nephron where most reabsorption of water and solutes occurs.

Renal Cortex

The outer region of the kidney where the nephron components are located.

Renal Medulla

The inner region of the kidney, consisting of renal pyramids.

Glomerular Filtration

The process by which the kidneys filter blood to form urine.

Tubular Absorption vs. Secretion

Absorption moves substances from filtrate to blood; secretion moves substances from blood to filtrate.

External Sphincter

Muscle that regulates the flow of urine out from the urethra.

Renal Pyramid

Triangular structures in the renal medulla that contain nephrons.

Interstitial Fluid

Fluid surrounding cells in tissues, involved in reabsorption and secretion.

Atrial Natriuretic Peptide (ANP)

Hormone that lowers blood sodium levels and reduces blood volume.

Hormonal Control of Urine Volume

Regulation of water and electrolyte balance via hormones like ADH and aldosterone.

Path of Blood Flow in Kidneys

Blood flow from renal arteries to afferent arterioles, glomeruli, efferent arterioles, and renal veins.

Kidney Failure

A condition where kidneys lose their ability to filter waste from the blood.

Bladder Capacity

The volume the bladder can hold, typically up to 500-600 mL in adults.

Congenital Renal Abnormalities

Conditions present at birth that affect kidney structure or function.

Volume of Urine Excretion

Normal urine production is approximately 1-2 L/day.

Urge Incontinence

Inability to control urination due to an involuntary contraction of the detrusor muscle.

Stress Incontinence

Loss of urine due to increased abdominal pressure, often during physical activity.

Urethral Stricture

Narrowing of the urethra that impedes urine flow.

Urinary Retention

Inability to empty the bladder completely.

Dilation (of ureters)

The widening of ureters that may occur due to obstruction or reflux.

Transitional Epithelium

The type of tissue that lines the bladder, allowing for stretching.

Homeostatic Function of Kidneys

Kidneys regulate blood volume, pressure, electrolyte balance, and pH.

Glomerular Hydrostatic Pressure

The blood pressure in the glomerular capillaries that drives filtration.

KIDNEY VASCULARIZATION

Blood vessels that supply and drain blood from the kidneys.

Countercurrent Multiplier

Mechanism that maintains a concentration gradient in the kidney.

ADH Action

Increases the permeability of collecting ducts to water during periods of dehydration.

Filtration Slits

Gaps between podocyte cells in Bowman’s capsule that allow filtration of fluid.

Vasa Recta Function

Capillary system supporting nephron function by aiding in delivery of nutrients and waste removal.

Filtration Dynamics

Principles governing the movement of substances in and out of capillary spaces.

Juxtamedullary Nephrons

Nephrons that have long loops of Henle and are involved in concentrated urine production.

Collecting Duct Function

Final segment of nephron responsible for collecting urine from several nephrons.

Renal Failure Treatment

May involve dialysis or kidney transplantation depending on severity.

Kidney Exchanges

Process allowing people to receive a kidney from a donor who is not a direct match.

Uterine Reflexes

Neuronal responses to bladder distension that control micturition.

Detrusor Tone Regulation

Involves both voluntary and involuntary muscle control during bladder filling and emptying.

Urethral Health and Maintenance

Preventing infections and maintaining unobstructed urine flow is essential for kidney health.

Kidney Function Tests

Tests such as creatinine clearance and blood urea nitrogen to assess kidney performance.

Diuretic Drugs Mechanism

Most diuretics inhibit sodium transporters, leading to increased urine output.

Potassium Sparing Diuretics

Medications that promote sodium and water excretion without potassium loss.

Reabsorption in Nephron

Processes involve both passive and active mechanisms across various nephron segments.

Epidemiology of UTIs

Urinary tract infections are more common in women due to short urethra.

Bladder Reconstruction Techniques

Procedures that aim to restore bladder function after cancer or trauma.

Electrolyte Composition in Urine

Urine contains sodium, potassium, and chloride ions, reflecting body electrolyte balance.

Ureters and Peristalsis

Ureters use muscular contractions to move urine from the kidneys to the bladder.

Detrusor Muscle Nerve Supply

Innervated by both sympathetic and parasympathetic fibers to control contractions.

Visceral Sensations of Bladder

Sensations from stretched bladder walls trigger the urge to urinate.

Blood-Urea Nitrogen (BUN) Test

A test measuring the amount of urea nitrogen in blood to assess kidney function.

Fluid and Electrolyte Balance

Maintained by kidneys to ensure optimal physiological processes.

Urinary Retention Causes

Conditions like enlarged prostate or nerve damage can lead to urinary retention.

Anatomical Orientation of Kidneys

Kidneys are located retroperitoneally, lying against the posterior abdominal wall.