Chapter 16 - Urinary System

Components of the urinary system

Kidneys

Ureters

Urinary bladder

Urethra

Functions of the kidney

Filters blood to remove wastes

Regulates water, electrolytes, and pH

Helps control blood pressure

Produces hormones like erythropoietin (RBC production)

Excretion

The process of removing waste products from the body

Metabolic waste

Waste produced by normal chemical reactions in cells

nitrogenous waste

Waste containing nitrogen, mainly from protein metabolism

Examples: urea, uric acid, creatinine

Renal (fibrous) capsule (function and characteristics)

Function:

Protects the kidney and maintains its shape

Characteristics:

Tough, dense connective tissue

Thin but strong outer covering

renal cortex (function and characteristics)

Function:

Site of blood filtration

Characteristics:

Outer region of the kidney

Contains glomeruli and renal corpuscles

Darker appearance

renal medulla (function and characteristics)

Function:

Concentrates urine

Characteristics:

Inner region of the kidney

Contains renal pyramids

Lighter, striated appearance

renal sinus (function and characteristics)

Function:

Space that collects urine before it enters the ureter

Characteristics:

Hollow cavity inside the kidney

Contains renal pelvis, calyces, blood vessels, nerves

renal pyramid (function and characteristics)

Function:

Transports urine to the calyces

Characteristics:

Cone-shaped structures in the medulla

Composed of collecting ducts and loops of Henle

renal calyx minor and major (function and characteristics)

Function:

Collect urine and move it toward the renal pelvis

Characteristics:

Minor calyx receives urine from one pyramid

Major calyx receives urine from several minor calyces

renal pelvis (function and characteristics)

Function:

Funnels urine into the ureter

Characteristics:

Funnel-shaped

Located in the renal sinus

ureter (function and characteristics)

Function:

Transports urine from kidney to bladder

Characteristics:

Muscular tube

Uses peristalsis

About 25–30 cm long

labeled kidney

Renal capsule

Renal cortex

Renal medulla

Renal pyramids

Minor calyx

Major calyx

Renal pelvis

Ureter

labeled nephron

Afferent arteriole

Glomerulus

Bowman's capsule

Proximal convoluted tubule

Loop of Henle

Distal convoluted tubule

Collecting duct

function of a nephron

Filters blood

Reabsorbs needed substances

Secretes additional wastes

Produces urine

Follow the flow of fluids (filtrate) through the nephron

afferent arteriole

glomerulus

glomerular capsule

proximal convoluted tubule

nephron loop (loop of henle)

distal convoluted tubule

collecting duct

2 components of the renal corpuscle

Glomerulus

Bowman's (glomerular) capsule

how much filtrate is produced and reabsorbed in a day (male/female)

About 180 liters of filtrate produced daily

About 178-179 liters reabsorbed

Around 1-2 liters excreted as urine

Similar amounts for males and females

Ureters (function and location)

Carry urine from kidneys to bladder

Located retroperitoneally, behind the abdominal cavity

Urinary bladder (function and location)

Stores urine temporarily

Located in the pelvic cavity

urethra (function and location)

Carries urine from bladder to outside the body

Shorter in females, longer in males

Located inferior to the bladder

scientific name for urination

micturition

What is normally found in healthy urine

Water

Urea

Uric acid

Creatinine

Electrolytes (Na⁺, K⁺, Cl⁻)

what should NOT be found in healthy urine

Glucose

Proteins

Blood cells

Bacteria

Ketones

color, pH, and odor of normal urine

Color: Pale yellow to amber

pH: Around 6 (slightly acidic)

Odor: Mild, slightly ammonia-like