Excretory products and their elimination Flashcards
Which six things are accumulated by animals? Either by metabolic activities or by other means like excess ingestion.
Ammonia, urea, uric acid, carbon dioxide, water and ions
The three major forms of nitrogenous wastes excreted by the animals are called
Ammonia, urea and uric acid
The most toxic nitrogenous form which requires large amounts of water for its elimination is
Ammonia
The least toxic nitrogenous form which can be removed with a minimum loss of water
Uric acid
The process of excreting ammonia is
Ammonotelism
Many bony fishes, aquatic amphibians and aquatic insects are _______ in nature.
Ammonotelic
Ammonia is generally excreted by diffusion across body surfaces or through gill surfaces (in fish) as
Ammonium ions
_______ necessitated the production of lesser toxic nitrogenous wastes like urea and uric acid for conservation of water.
Terrestrial adaptation
Mammals, many terrestrial amphibians and marine fishes mainly excrete urea and are called
Ureotelic animals
Reptiles, birds, land snails and insects excrete nitrogenous wastes as?
Uric acid
Nitrogenous waste like uric acid is excreted in the form of____
Pellet or paste
Reptiles, birds, land snails and insects excrete nitrogenous wastes as uric acid is called
Uricotelic animals
What are the excretory structure in Planaria?
Protonephridia or flame cells
Protonephridia or flame cells are the excretory structures in ___,___,___ &___
Platyhelminthes, rotifers, some annelids and the cephalochordate – Amphioxus
Protonephridia are primarily concerned with ____ and _____ regulation i.e osmoregulation.
ionic, fluid volume
Ionic and fluid volume regulation known as?
osmoregulation-
The tubular excretory structure of earthworms & some annelids is called
Nephridia
The excretory structures of most of the insects including cockroaches is called
Malpighian tubules
Name the organ which performs the excretory structures in crustaceans like prawns.
Antennal glands or green glands
In humans, kidneys are situated between the levels of ________ thoracic and _________ lumbar vertebra.
last thoracic and third lumbar vertebra
Kidneys are situated close to the
Dorsal inner wall of the abdominal cavity
The length of each kidney of an adult human is
10-12 cm
The width of each kidney of an adult human is
5-7 cm
The thickness of each kidney of an adult human is
2-3 cm
The average weight of each kidney of an adult human
120-170 g
Towards the centre of the inner concave surface of the kidney is a notch called
hilum
Inner to the hilum is a broad funnel shaped space called
renal pelvis
Renal pelvis has projections called
calyces
There are two zones inside the kidney
an outer cortex and an inner medulla
The medulla is divided into a few conical masses are called
medullary pyramids
The cortex extends in between the medullary pyramids as renal columns is called
Columns of Bertini
How many complex tubular structures are present in each kidney?
One million
Complex tubular structures in kidneys called
nephrons
The functional units of kidney are
nephrons
Each nephron has two parts known as
the glomerulus and the renal tubule
A tuft of capillaries formed by the afferent arteriole
Glomerulus
Glomerulus is formed by
afferent arteriole
Afferent arterioleis a fine branch of _______ artery.
renal
Blood from the glomerulus is carried away by
efferent arteriole
The renal tubule begins with a double walled cuplike structure called
Bowman’s capsule
The glomerulus is enclosed by
Bowman’s capsule
Glomerulus along with Bowman’s capsule, is called the
malpighian body or renal corpuscle
The renal tubule continues further to form a highly coiled network known as
proximal convoluted tubule
The hairpin shaped part of the tubule is known as
Henle’s loop
Henle’s loop has a ____ & ____ limb.
descending and an ascending limb
The ascending limb continues as highly coiled tubular region called
distal convoluted tubule (DCT)
The DCTs of many nephrons open into a straight tube called
collecting duct
The Malpighian corpuscle, PCT and DCT of the nephron are situated in the ___ of the kidney.
cortical region
The loop of Henle of the nephron is situated in the ___ of the kidney.
medullary region
Nephrons in which the loop of Henle is too short and extends only very little into the medulla are called
cortical nephrons
Nephrons in which the loop of Henle is very long and runs deep into the medulla are called
juxta medullary nephrons
The efferent arteriole forms a fine capillary network around the renal tubule called
peritubular capillaries
A minute vessel of this network runs parallel to the Henle’s loop forming a
‘U’ shaped vasa recta
In which nephrons, vasa recta is absent or highly reduced?
cortical nephrons
What are the three main processes involved in Urine formation?
glomerular filtration, reabsorption and secretion
The first step in urine formation is?
filtration of blood
The first step in urine formation is carried out by
glomerulus
The filtration of blood is carried out by the glomerulus and is called
glomerular filtration
Amount of blood filtered by the kidneys per minute
1100-1200 ml
Blood filtered by the kidneys per minute constitute roughly ____ of the blood pumped out by each ventricle of the heart in a minute.
1/5th
The glomerular capillary blood pressure causes filtration of blood through 3 layers
the endothelium of glomerular blood vessels, the epithelium of Bowman’s capsule and basement membrane between these two layers