Kidneys and Excretion Flashcards

Flashcards covering the topic of Kidneys and Excretion, including kidney function, nephron anatomy, urine formation, pH and water balance, kidney disorders, and dialysis.

Main role of the kidneys

Balance blood pH, maintain water balance, and remove wastes.

Deamination

Removal of an amino group (NH2) from an organic compound using water.

Ammonia (NH3)

Extremely toxic byproduct of deamination.

Urea

Less toxic substance formed in the liver when two molecules of ammonia combine with carbon dioxide.

Uric acid

Waste product formed by the breakdown of nucleic acids.

Ureters

Tubes that transport urine from the kidneys to the bladder.

Urethra

Tube that carries urine from the bladder to the exterior of the body.

Cortex

Outer layer of the kidney.

Medulla

Area inside the cortex of the kidney.

Renal pelvis

Hollow area where the kidney joins the ureter.

Nephron

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

Afferent arterioles

Carry blood from the renal artery to the nephrons.

Glomerulus

High-pressure capillary bed in the nephron where waste filtration occurs.

Efferent arterioles

Carry blood away from the glomerulus to the peritubular capillaries.

Peritubular capillaries

Network of small blood vessels surrounding the tubules of the nephron where gas exchange occurs.

Bowman’s capsule

Cup-like structure that surrounds the glomerulus and receives filtrate.

Filtration

Movement of dissolved solutes from the blood into the Bowman’s capsule.

Reabsorption

Transfer of essential solutes and water from the nephron back into the blood.

Secretion

Movement of further waste material from the blood into the nephron.

Threshold level

Maximum amount of a substance that can be moved across the nephron during reabsorption.

Aldosterone

Increases sodium and water retention by the kidneys to increase blood pressure.

Antidiuretic hormone (ADH)

Regulates the osmotic pressure of body fluids by increasing water reabsorption in the kidneys.

Osmoreceptors

Detect changes in osmotic pressure in the hypothalamus.

Diabetes mellitus

Caused by inadequate secretion of insulin, resulting in large volumes of sweet urine.

Diabetes insipidus

Caused by the destruction of ADH producing cells in the hypothalamus, leading to losses of large amounts of water in the urine.

Nephritis / Bright’s Disease

Inflammation of the nephron.

Kidney Stones

Formed by precipitation of mineral solutes from the blood, causing damage to the excretory system.

Dialysis machine

Restores proper solute balance for people whose kidneys cannot effectively process bodily wastes.

Hemodialysis

Dialysis where blood is pumped through dialysis tubes in a bath of solutes.

Peritoneal dialysis

Dialysis where dialysate is pumped into the abdominal cavity to filter wastes.