Excretory System Flashcards

Flashcards on Excretory Products and Their Elimination

Ammonotelism

The process of excreting ammonia.

Uricotelic Animals

Animals that excrete nitrogenous wastes as uric acid in the form of pellet or paste with a minimum loss of water.

Protonephridia or flame cells

Excretory structures in Platyhelminthes that are primarily concerned with ionic and fluid volume regulation, i.e., osmoregulation.

Nephridia

The tubular excretory structures of earthworms and other annelids that help to remove nitrogenous wastes and maintain a fluid and ionic balance.

Malpighian tubules

The excretory structures of most insects including cockroaches that help in the removal of nitrogenous wastes and osmoregulation.

Antennal glands or green glands

The excretory function in crustaceans like prawns.

Hilum

The notch towards the center of the inner concave surface of the kidney through which the ureter, blood vessels, and nerves enter.

Renal pelvis

A broad funnel-shaped space inside the hilum of the kidney.

Medullary pyramids

Conical masses that divide the medulla.

Cortex

The outer layer of the kidney.

Medulla

The inner layer of the kidney.

Columns of Bertini

Extensions of the cortex in between the medullary pyramids.

Nephrons

Complex tubular structures in the kidney which are the functional units.

Glomerulus

A tuft of capillaries formed by the afferent arteriole.

Bowman’s capsule

A double-walled cup-like structure that encloses the glomerulus.

Malpighian body or renal corpuscle

The glomerulus along with Bowman’s capsule.

Proximal Convoluted Tubule (PCT)

A highly coiled network after the Bowman's capsule.

Henle’s loop

A hairpin-shaped part of the tubule with a descending and ascending limb.

Distal Convoluted Tubule (DCT)

Another highly coiled tubular region after the ascending limb of Henle’s loop.

Collecting duct

A straight tube into which the DCTs of many nephrons open.

Cortical nephrons

Nephrons with a short loop of Henle that extends only very little into the medulla.

Juxta medullary nephrons

Nephrons with a very long loop of Henle that runs deep into the medulla.

Peritubular capillaries

A fine capillary network around the renal tubule formed by the efferent arteriole.

Vasa recta

A minute vessel running parallel to the Henle’s loop.

Glomerular filtration

The first step in urine formation, where blood is filtered by the glomerulus.

Glomerular filtration rate (GFR)

The amount of filtrate formed by the kidneys per minute.

Juxta glomerular apparatus (JGA)

A special sensitive region formed by cellular modifications in the distal convoluted tubule and the afferent arteriole.

Reabsorption

The process where nearly 99 percent of the filtrate is reabsorbed by the renal tubules.

Tubular secretion

The term that defines tubular cells secreting substances like H+, K+, and ammonia into the filtrate.

Counter current

The flow of filtrate in the two limbs of Henle’s loop is in opposite directions.

Antidiuretic hormone (ADH) or vasopressin

Hormone released from the neurohypophysis that facilitates water reabsorption from latter parts of the tubule, thereby preventing diuresis.

Renin

A fall in glomerular blood flow/glomerular blood pressure/GFR can activate the JG cells to release this, which converts angiotensinogen in blood to angiotensin I and further to angiotensin II.

Aldosterone

A hormone that causes reabsorption of Na+ and water from the distal parts of the tubule, leading to an increase in blood pressure and GFR.

Atrial Natriuretic Factor (ANF)

An increase in blood flow to the atria of the heart can cause the release of this, which can cause vasodilation and decrease the blood pressure.

Micturition

The process of release of urine.

Glycosuria

Presence of glucose in urine.

Ketonuria

Presence of ketone bodies in urine.

Uremia

Accumulation of urea in blood.

Hemodialysis

A process used to remove urea from the blood using an artificial kidney.

Renal calculi

Stone or insoluble mass of crystallised salts formed within the kidney.

Glomerulonephritis

Inflammation of glomeruli of kidney.