EXAM 5 URINARY & FLUID/ELECTROLYTES/ACID AND BASES

What are the 4 main urinary system structures?

Kidneys, ureters, bladder, sphincters

Function of kidneys

Filter blood and produce urine

Function of ureters

Transport urine to bladder (peristalsis)

Function of bladder

Stores urine

Function of urethra

Conducts urine out of body

What does the afferent arteriole do?

Brings blood to glomerulus

What does the efferent arteriole do?

Carries blood away from glomerulus

Function of peritubular capillaries

Reabsorption and secretion

Function of vasa recta

Maintains concentration gradient

What is the renal corpuscle?

Glomerulus + capsule

What drives filtration?

Blood pressure

NFP formula

GHP – (BCOP + CsHP)

Normal GFR

~125 mL/min

Anabolism

Building molecules

Catabolism

Breaking molecules

Reabsorption

Tubule → blood

Secretion

Blood → tubule

Function of glomerulus

Filtration

Function of PCT

Reabsorbs most nutrients + water

Descending limb

Reabsorbs water

Ascending limb

Reabsorbs Na⁺ and Cl⁻

DCT

Secretion + regulation

Collecting duct

Water reabsorption (ADH)

Renin function

Increases BP (RAAS)

Aldosterone function

Reabsorbs Na⁺, secretes K⁺

ADH function

Reabsorbs water

EPO function

Stimulates RBC production

Obligatory water reabsorption

PCT + descending limb (not controlled)

Facultative water reabsorption

DCT + collecting duct (ADH controlled)

Brain center for urination

Pontine micturition center

Acute renal failure

Rapid, reversible

Chronic renal failure

Gradual, irreversible

Polyuria

Excess urine

Oliguria

Low urine

Anuria

No urine

Dysuria

Painful urination

Incontinence

Loss of control

Male urethra

Longer, carries urine + semen

Female urethra

Shorter, higher UTI risk

ICF

Fluid inside cells

ECF

Fluid outside cells (plasma + interstitial)

Osmosis

Water moves low → high solute

Diffusion

High → low concentration

How is water gained?

Drinking + food

How is water lost?

Urine, feces, sweat, lungs

ADH effect

↑ water reabsorption, ↓ urine

ANH effect

↓ Na⁺ reabsorption, ↑ water loss, ↓ BP

Hyponatremia

Low Na⁺ (overhydration)

Hypernatremia

High Na⁺ (dehydration)

Hypokalemia

Low K⁺ → weakness, arrhythmias

Hyperkalemia

High K⁺ → cardiac issues

Normal blood pH

7.35–7.45

Normal PCO₂

35–45 mmHg

Normal HCO₃⁻

22–26 mEq/L

Na⁺ role

Fluid balance, BP

K⁺ role

Heart and muscle function

H⁺ role

pH balance

Metabolic acidosis compensation

↑ breathing, ↑ H⁺ excretion

Respiratory alkalosis compensation

↓ breathing, ↑ HCO₃⁻ excretion

Relationship between pH and PCO₂

Inverse

Signs of dehydration

Thirst, dry skin, low BP, shock