Urinary System Flashcards

Flashcards covering the anatomy, physiology, and function of the urinary system.

Kidneys

The organs that form the urine.

Excretion

The removal of metabolic waste products from the human body.

Functions of the kidneys

Regulate blood volume and electrolytes, remove urea, conserve nutrients, regulate acid-base balance and blood pressure, calcium homeostasis, and produce erythropoietin and renin.

Kidney damage/disorders

Acute Kidney Injury, Chronic kidney disease, Polycystic Kidneys, Kidney infection, Kidney stones

Tubular reabsorption

Passive and active process returning material to the blood from the filtrate.

Tubular secretion

Removing material from the blood into the filtrate.

Nephron

Functional unit of the kidney.

Renal cortex

Outer region of the kidney.

Renal medulla

Inner region of the kidney made up of triangles.

Nephron vascular component

Interlobular artery -> Afferent arteriole -> Glomerulus -> Efferent arteriole -> Peritubular capillaries

Nephron tubular component

Bowman’s capsule, Proximal Convoluted Tubule (PCT), Loop of Henle (LH), Distal Convoluted Tubule (DCT), Collecting Tubules/Ducts (CD)

Bowman’s capsule (BC)

Encloses the glomerulus and is where filtration occurs.

Proximal Convoluted Tubule (PCT)

Responsible for most reabsorption/secretion.

Loop of Henle (LH)

Responsible for osmotic gradient in medulla.

Distal Convoluted Tubule (DCT)

‘Fine-tuning’ of solute/water reabsorption.

Collecting Tubules/Ducts (CD)

‘Fine-tuning’ of urine concentration.

Juxtaglomerular apparatus (JGA)

Regulates blood pressure and the filtration rate of the glomerulus.

Macula densa (MD)

Densely staining cells of DCT that detect low Na+ in DCT and can alter flow through glomerulus and water volume

JG cells (afferent arteriole)

Releases hormones (Renin) that control how much water is reabsorbed and filtration rate

Filtration

Mass movement of water and solutes from plasma to the renal tubule

Reabsorption

Movement of water and solutes from the tubule back into the plasma

Secretion

Secretion of additional substances into the tubular fluid

Renal corpuscle

Combination of glomerulus and Bowman’s capsule.

Podocytes

Epithelium around glomerular capillaries modified into.

Filtration

Movement of solutes and water a balance between osmotic/hydrostatic forces.

Hematuria

Red blood cells in urine.

Proteinuria

Protein in urine.

Tubular Re-absorption

Water regulation through solute regulation

Secretion

Transfer of molecules from extracellular fluid into the nephron.

RAAS, ADH, ANP

Hormonal mechanisms to fine-tune urine osmolarity