Quiz 6: Lab Study Guide

Urinary system functions

Removes wastes, regulates blood volume and pressure, maintains electrolyte balance, regulates pH, produces hormones

Pathway of urine drainage

Kidney → Renal pelvis → Ureter → Urinary bladder → Urethra

Nephron basic function

Functional unit of the kidney that forms urine

Parts of the nephron

Glomerulus, Bowman’s capsule, proximal tubule (PT), loop of Henle (descending & ascending), distal tubule (DT), collecting duct

Renal blood flow pathway

Renal artery → arterioles → afferent arteriole → glomerulus → efferent arteriole → peritubular capillaries

Glomerulus function

Filters blood to form filtrate

Bowman’s capsule function

Collects filtrate from the glomerulus

Proximal tubule (PT) function

Major site of reabsorption (nutrients, water, ions)

Descending loop of Henle

Reabsorbs water only (not NaCl)

Ascending loop of Henle

Reabsorbs NaCl only (not water)

Distal tubule (DT) function

Site of secretion and fine-tuning of filtrate

Collecting duct function

Final concentration of urine; drains into renal pelvis

Three stages of urine formation

Filtration, Reabsorption, Secretion

Filtration definition

Movement of fluid and small solutes from blood into nephron

Reabsorption definition

Movement of substances from filtrate back into blood

Secretion definition

Movement of substances from blood into filtrate

Aldosterone effect

Increases potassium secretion and sodium reabsorption → increases blood volume and pressure

Antidiuretic hormone (ADH) function

Increases water reabsorption → concentrated urine and increased blood volume

Other name for ADH

Vasopressin

Composition of urine

Water, urea, salts, pigments, and waste products

Urochrome

Pigment responsible for yellow color of urine

Effect of high solute concentration on urine color

Darker urine color

Vegetarian diet effect on urine pH

Increases pH (more alkaline)

High protein diet effect on urine pH

Decreases pH (more acidic)

Purpose of urine pH regulation

Maintains blood pH (homeostasis)

Glucose reabsorption

Normally reabsorbed in PCT

Glucose in urine (diabetes)

Occurs when glucose levels exceed transport capacity

RBF meaning

Renal blood flow

Ureter histology

Transitional epithelium with smooth muscle for peristalsis

Bladder function

Stores urine until excretion