Structure of nephron - class-XI
Description: structure of nephron | |
Number of Questions: 50 | |
Created by: Varsha Mane | |
Tags: biology animal physiology excretory system of human excretion zoology excretory products and their elimination excretion and osmoregulation excretory products and elimination |
Malpighian body is found
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In kidney of vertebrates and is involved in the formation of urine
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In vertebrates and involved with filtration of blood
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In insects and involved in excretion
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In invertebrates and involved with filtration of blood
Malpighian body is also called kidney corpuscle. Malpighian body is the structure at the beginning of a vertebrate nephron, consisting of a glomerulus and its surrounding Bowman's capsule. It mainly involved in filteration of blood. Thus, option B is correct.
Nitrogenous waste in the Malpighian tubule flows into
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Haemocoel
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Vacuole
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Intestine
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Duodenum
Malpighian tubules are excretory organs of insects like cockroach, grasshopper etc. These are blind ending excretory tubes which open into the alimentary canal near the junction of the midgut and hind gut. These tubules remove nitrogenous wastes from the haemolymph and also function in osmoregulation.
The number of uriniferous tubules in each kidney of man is
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About 10,000
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About 5,000
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Cannot be calculated
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About 1.0 x 10$^6$
Malpighian body is present in
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Skin
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Kidney
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Testes
-
Ovaries
Nephrons are the cells of kidney which are composed of a renal corpuscle and a renal tubule. The renal corpuscle is also known Malpighian body. It consists of cup like double walled structure known as Bowman’s capsule and the bunch of capillaries present in the Bowman’s capsule is known as glomerulus. It helps in filtration of blood at high pressure. So, the correct answer is 'Kidney'.
Marcello Malpighi after whom Malpighian tubules are named was born in
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Germany
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Australia
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Austria
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Italy
Malpighian tubules are excretory organs present in the cockroach. They lie freely in haemolymph. They remove excretory products from the haemolymph and open in the alimentary canal at the junction of the midgut and hindgut. In each cockroach, they are about 150 in number. The Malpighian tubule system is named after 17th-century anatomist Marcello Malpighi. He was born in Italy,
Macula densa is found in
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Internal ear
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Kidney
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Liver
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Spleen
JGA (Juxta Glomerular Apparatus ), a sensitive region, which regulates the glomerular filtration rate is present near the
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DCT and PCT
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DCT and efferent arteriole
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DCT and afferent arteriole
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Loop of Henle's and DTC
A) Henle's loop is present between DCT and PCT.
Which part of Juxta medullary nephron is found in cortical region
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Malpigian body
-
Proximal convulated tubule
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Distal convulated tubule
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Loop of henle
The Juxta medullary nephron is one in which the renal corpuscle (Malphigian corpuscle having the Malphigian body) is located in the cortex but near to the medulla and the other regions, such as the proximal convulated tubule, the loop of Henle, and the distal convulated tubule are located deeper in the medulla. The only region present in the cortex is malphigian body. So, the correct answer is A.
Juxtaglomerular apparatus is formed by ____ and ___
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Bowman's capsule, Glomerulus
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PCT, Glomerulus
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DCT, Bowman's capsule
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DCT, Glomerulus
Which of the following is not a part of the structure pf uriniferous tubule?
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Collecting duct
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Loop of Henle
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Convoluted tubule
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Bowman's capsule
Which is true about the difference between cortical and juxtamedullary nephrons?
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Majority of nephrons ae juxtamedullary
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Glomeruli and loops of Henle and cortical nephrons lie completely in cortex
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The afferent arterioles of the juxtamedullary nephrons give rise to most of vasa recta
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Cortical nephrons lack vasa recta
The maintenance of concentration gradient in the medullary interstitium is mainly done by?
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Glucose and $Na^+$
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NaCl and Urea
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Amino acids and creatinine
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$Na^+$ and $Ca^{2+}$
Podocytes are the cells, present in?
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Cortex of nephron
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Inner wall of Bowman's capsule
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Outer wall of Bowman's capsule
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Wall of glomerular capillaries
Podocytes are a type of cells in the Bowman's capsule of the nephrons in the kidneys that wrap around the capillaries of the glomerulus. The long processes or foot projections of the podocytes wrap around the capillaries and leave slits between them. Blood is filtered through these slits, each known as a slit diaphragm or filtration slit.
Large amount of fluid is reduced to relatively concentrated small volume of urine in
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Ureter
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Urinary bladder
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Renal tubule
-
Bowman's capsule
As blood enters your kidneys, it is filtered by glomerulus. The ultrafiltrate produced by the glomerulus initially contains small molecules like water, glucose, amino acids, bicarbonate, urea, and creatinine as well as ions such as potassium, sodium, chloride, calcium, and phosphate. All of this filtrate is channeled from the Bowman's space inside of the Bowman's capsule into the long series of ducts in the nephron, which are collectively called the renal tubule. During this journey, many things will be added and subtracted to and from the ultrafiltrate by the cells lining these ducts in order to finally form the urine. After this the tubular fluid leaves the renal tubules and passes to the collecting duct system, which connects the nephron to the ureter. Urine then enters the urinary bladder ( which collects waste excreted by the kidneys prior to disposal by urination) via the ureters and exits via the urethra.
Which one of the four parts mentioned below does not constitute a part of a single uriniferous tubule?
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Bowman's capsule
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Distal convoluted tubule
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Loop of Henle
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Collecting duct
"Uriniferous tubule" or "nephron" are the structural and functional unit of kidney. It is present in the outer firm region of kidney, the renal cortex. It consist of renal corpuscle and a long renal tubule.
Whereas collecting duct is present in the inner region of the kidney, the renal medulla. It carries the urine from the nephron in the cortex to the pelvis in the kidney. It is not part of one nephron but it is formed with the distal of many nephrons.
Uriniferous tubules of a kidney are concerned with formation of
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Glucose
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Amino acids
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Hormones
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Urine
The functional unit of the kidney is the uriniferous tubule, a highly convoluted structure that modifies the fluid passing through it to form to form urine as its final output. This tubule consists of two parts, the nephron and the collecting tubule.
A Malpighian tubule empties urine into the
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Gut
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Coelom
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Lymph
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Ureters
Malpighian tubule, in insects, any of the excretory organs that lie in the abdominal body cavity and empty into the junction between midgut and hindgut. The tubule cells actively transport initial urine constituents (potassium ions, water, urate ions, sugar, amino acids) into the tubule. In some species urine is acidified in the distal end of the tubule and an aqueous suspension of uric acid crystals is conducted into the rectum, where water and nutrients are reabsorbed. In other species the urine is acidified in the rectum. Certain tubule cells may have special functions, as in the secretion of the sticky substance that surrounds eggs of certain leaf beetles or in the secretion of silk by certain immature beetles. Thus, option A is correct.
A malpighian tubule empties its content into the
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Gut
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Coelom
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Lymph
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Ureters
A malpighian tubule empties its content into the gut. Malpighian tubule, in insects, any of the excretory organs that lie in the abdominal body cavity and empty into the junction between midgut and hindgut. In species having few malpighian tubules, they are long and coiled; in species with numerous (up to 150) tubules, they are short. The tubule cells actively transport initial urine constituents (potassium ions, water, urate ions, sugar, amino acids) into the tubule. In some species urine is acidified in the distal end of the tubule and an aqueous suspension of uric acid crystals is conducted into the rectum, where water and nutrients are reabsorbed. In other species the urine is acidified in the rectum. Certain tubule cells may have special functions, as in the secretion of the sticky substance that surrounds eggs of certain leaf beetles or in the secretion of silk by certain immature beetles.
Malpighian body is found
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In kidney of vertebrates and is involved in the formation of urine
-
In vertebrates and involved with filtration of blood
-
In insects and involved in excretion
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In vertebrates and involved with filtration of lymph
Malpighian body is found in the kidneys of the vertebrates. It is also called kidney corpuscle and is composed of a glomerulus and the Bowman's capsule. It is concerned with the filtration of the blood and forms the glomerular filtrate. In insects, the malpighian tubules are present for the excretion.
The opening of the urinary bladder is
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Nephron
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Ureter
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Urethra
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Nephridia
Urine is formed in the kidney. The tubes which connect the kidney and urinary bladder are known as the ureter. From the kidney, urine is propelled into the urinary bladder through ureters which are made of smooth muscle fibres. The bladder stores urine, allowing urination to be infrequent and can be controlled. The urethra is a long tube which connects urinary bladder to the urinary meatus for removal of urine from the body. In males, urethra travels through the penis and meet the urethral meatus located at the tip of the penis. In females, urethra connects to the urethral meatus above the vagina. The urethra is also known as the urinary opening. Hence the opening of urinary bladder is urethra.
Medullary rays are made up of ________________.
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Parenchymatous cells
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Sclerenchymatous cells
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Tracheids
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Fibres
Number of uriniferous tubules in the two mammalian kidney are.
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Nearly $2$ millions
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More than $3$ millions
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Less than $1$ million
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More than $1$ million
Filteration takes place in
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Malpighian corpuscles
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Bowman's capsule
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Glomerulus
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Collecting tubule
Filtration takes place through semipermeable walls of glomerulus and Bowman's capsule. Glomerulus and Bowman's capsule are collectively called malpighian corpuscle.
Uriniferous tubules are mainly concerned with
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Concentration of urine
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Passage of urine
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Reabsorption of useful substances from glomerular filtrate
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Removal of urea from blood
In humans, the Kidney is the excretory organ. Nephron or uriniferous tubule is the structural and functional unit of the kidney. On an average, 25-30 gm of urea is excreted out per day through urine. Hence uriniferous tubules are mainly concerned with removal of urea from the blood.
Uriniferous/nephrons tubules occur in
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Stomach
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Testes
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Ovary
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Kidney
Part not belonging to uriniferous tubule is
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Glomerulus
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Henle's loop
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Distal convoluted tubule
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Connecting tubule
The nephrons along with collecting ducts are called as uriniferous tubule. The nephron is the structural and functional unit of the kidney. The body of the nephron is divided into Bowman's capsule, PCT, Henle's loop and DCT. Hence glomerulus does not belong to the uriniferous tubule. Glomerulus are the tuft of capillaries present in the Bowman's capsule.
Vital morphological and physiological units of mammalian kidney are
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Ureters
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Seminiferous tubules
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Uriniferous tubules
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Nephridia
Malphigian tubules remove excretory products from
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Kidney
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Haemolymph
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Alimentary canal
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None of the above
Juxtaglomerular cells of renal cortex synthesises an enzyme called
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ADH
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Oxytocin
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Renin
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Urochrome
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Glucocorticoids
Renin is produced in the kidney by the juxtaglomerular cells of renal cortex. It participates in the renin–angiotensin–aldosterone system which maintains the blood pressure and fluid balance in the body. It breaks the angiotensinogen secreted from the liver into a peptide angiotensin I. Angiotensin I is further cleaved into angiotensin II. Angiotensin II acts on the adrenal glands and releases aldosterone which acts on the collecting tubules to absorb more sodium ions which in turn increases the absorption of water and increases the blood volume. It also acts on the CNS to increase water intake by stimulating thirst. So the correct answer is 'Renin'.
Which of the following processes creates high osmotic pressure in uriniferous tubule?
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Active secretion of $Na^+$ into efferent arteriole followed by Cl secretion
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Active $Na^+$ absorption followed by Cl absorption
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Active secretion of $Cl^-$ and absorption of $Na^+$ into efferent arteriole
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Active Cl absorption followed by absorption of $Na^+$
The nephron is the structural and functional unit of the kidney. It is also called as uriniferous tubule. The active absorption of Na+ ion followed by the absorption of Cl created high osmotic pressure in the uriniferous tubule.
Number of mitochondria is maximum in part of uriniferous tubule
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PCT
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Loop of Henle
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DCT
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Bowmans capsule
Under low glomerular blood flow, juxta glomerular cells release
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Angiotensin I
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Angiotensin II
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Aldosterone
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Renin
Juxta-glomerular cells are specialized smooth muscle cells of the afferent arteriole, which supplies blood to the glomerulus. When the kidney receives the low volume of blood (low glomerular blood flow)the juxtaglomerular cells are stimulated to release renin.
Juxtaglomerular apparatus is made of
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Juxtaglomerular cell, macula densa and lacis cell
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Juxtaglomerular cell, lacis cell and myoepithelial cell
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Juxtaglomerular cell, lacis cell and Purkinje cell
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Juxtaglomerular cell, macula densa and argentaffin cell
A fall in glomerular filtration rate activates
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Juxtaglomerular cells to release renin
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Adrenal cortex to release aldosterone
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Posterior pituitary to release vasopressin
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Adrenal medulla to release adrenaline
The juxtaglomerular apparatus is a specialized structure formed by the distal convoluted tubule and the glomerular afferent arteriole. It consists of three cell types: The macula densa, juxtaglomerular cells, and extraglomerular mesangial cells. A fall in glomerular filtration rate activates juxtaglomerular cells to release renin. Renin increases blood pressure via the renin-angiotensin-aldosterone system.
Juxtaglomerular cells secrete _________(a) when there is fall in blood pressure (b) ______ ion concentration. Choose the correct option.
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a-Renin, b-Chloride
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a-Carbonic anhydrase, b-Sodium
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a- ATPase, b-Potassium
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a-Renin, b-Sodium
Juxta-glomerular cells are specialized smooth muscle cells of the afferent arteriole, which supplies blood to the glomerulus. When the kidney receives the low volume of blood the juxtaglomerular cells are stimulated to release Renin.renin converts angiotensinogen in blood to angiotensin I and further to angiotensin II. Angiotensin II, being a powerful vasoconstrictor, increases the glomerular blood pressure and thereby GFR. Angiotensin II also activates the adrenal cortex to release Aldosterone. Aldosterone causes reabsorption of Na+ and water from the distal parts of the tubule. This also leads to an increase in blood pressure and GFR.
In which part uriniferous tubule, $Na^+$ passes out
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Descending loop of Henle
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Collecting tubule
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Ascending loop of Henle
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None of the above
The nephron is the structural and functional unit of the kidney. It is also called as uriniferous tubule. During the process of urine formation in nephron certain substances are secreted (passes out) and some are reabsorbed along the length of the nephron. The ascending loop of Henle is impermeable to water but allows transport of electrolytes like Na(+). ions actively or passively.
Cells of macula densa produce
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Erythropoietin
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Renin
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Angiotensinogen
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Angiotensin
Macula densa are specialized cells present in the distal convoluted tubule of nephron where distal convoluted tubule come in contact with the afferent renal arteriole of the glomerulus. When blood volume has decreased the cells of macula densa give signals to juxtaglomerular cells to secrete renin enzyme. Hence cells of macula densa produce renin in response to low blood volume by stimulating juxtaglomerular cells.
Juxta-glomerular cells form
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Angiotensinogen and angiotensin
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Renin and erythropoietin
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Counter-current
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Selective secretory and absorptive apparatus
Which one is the diluting segments of uriniferous tubule?
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Ascending loop of Henle
-
Descending loop of Henle
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PCT
-
DCT
What conditions are responsible for stimulation of juxtaglomerular apparatus?
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An increase in blood pressure or blood volume in heart.
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An increase in the solute concentration the blood plasma.
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A decrease in the solute concentration oil the blood plasma.
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Decrease in blood pressure or blood volume in afferent arteriole.
The nephrons discharge their urine at the:
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Urinary bladder
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Urethra
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Renal pelvis
-
Renal pyramid (calyses)
The renal pelvis or pelvis of the kidney is the funnel-like dilated part of the ureter in the kidney. In humans, the renal pelvis is the point where the two or three major calyces join together. Renal pelvis, enlarged upper end of the ureter, the tube through which urine flows from the kidney to the urinary bladder.
A Malpighian body is constituted by
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Glomerulus only
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Glomerulus and Bowman's capsule
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Glomerulus and Efferent vessel
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Glomerulus, Bowman's capsule and Efferent vessel
A malphagian body is constituted of two parts - Glomerulus and Bowman's capsule. The glomerulus is the tuft of capillaries and has the filtering apparatus. The Bowman's capsule has a cup-like sack present at the beginning of the tubular component of a nephron.
Of the total nephrons, juxtamedullary nephrons constitute
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15%
-
45%
-
65%
-
85%
Juxtamedullary nephrons form about $15%$ of total nephrons. Their glomeruli are found in the inner margin of the cortex. They control plasma volume when water supply is short.
Which is true about the difference between cortical and juxtamedullary nephrons?
-
Most nephrons are juxtamedullary.
-
The efferent arteriole's of cortical nephrons give rise to most of the vasa recta.
-
The aaferent arterioles of the juxtamedullary nephrons give rise to most of the vasa recta.
-
Juxtamedullary nephrons generate a hyperosmotic medullary interstitium.
Cortical nephrons either have short or absent loops of Henle. Only juxtamedullary nephrons have long loops of Henle, which plunge into the renal medulla and create a hypersomotic interstitium via counter current multiplication.
Of the total nephrons,the juxtamedullary nephrons constitute ........... %.
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15
-
45
-
65
-
85
Nephron is the structural and functional unit of the kidney. Juxtamedullary nephrons are found only in birds and mammals. These are juxtamedullary on the basis of their Loop of Henle which is deep in the renal medulla and the renal corpuscle is in the medulla and only around 15-20% of the nephrons are juxtamedullary.
Malpighian tubules empty the excretory wastes into the
-
Ureter
-
Gut
-
Coelom
-
Urinary bladder
The excretory organs of insects are malpighian tubules. They collect water and uric acid from surrounding haemolymph (blood) and empty it into the gut.
Difference between glomerular filtrate and plasma is of
-
Proteins
-
Potassium
-
First is white whereas latter is yellow.
-
First is yellow whereas latter is white.
Blood plasma contains red and white blood cells, blood proteins, glucose, water, nitrogenous wastes, salt. Glomerular filtrate contains glucose, salt, water, nitrogenous wastes. Blood cells and plasma proteins are not filtered through the glomerular capillaries because they are relatively larger in size.
The renal threshold value of glucose is normally
-
80 mg/100 ml
-
160-180 mg/100 ml
-
100-120 mg/100 ml
-
80-110 mg/100 ml
The proximal tubule can only reabsorb a limited amount of glucose. When the blood glucose level exceeds about 160-180 mg/dl or 160-180 mg/100ml, the proximal tubule becomes overwhelmed and begins to excrete glucose in the urine. this point is called the renal threshold of glucose (RTG).
So, the correct answer is option B.
Function of glomerulus in mammalian kidney is
-
Reabsorption of salts
-
Urine formation through blood filtration
-
Urine collection
-
All of the above
A glomerulus is a network of capillaries responsible for the filtration of blood in the nephron the functional unit of the kidney. The glomerulus is surrounded by a single layer of epithelium called the Bowman's capsule constitute a renal corpuscle, the basic filtration unit of the kidney.
The size of the filtration slits present in the glomerulus is
-
10 cm.
-
15 nm.
-
25 nm.
-
10 nm.
The filtration slits present in the endothelium of the glomerulus are of the size 25 nm that can allow the plasma and solutes to diffuse in but not the blood cells. So the filtrate in the Bowman's Capsule that has diffused in from the glomerulus is colourless due to an absence of RBCs.