Excretory Products and their Elimination Test -1

Explanation:

The excretory system in human consistsof a pair of kidneys, one pair of ureters, aurinary bladder and a urethra. Kidneys are reddish brown, bean shaped structures situated between the levels of last thoracic and third lumbarvertebra close to the dorsal inner wall of the abdominal cavity.

 

Explanation:

On the medial margin of the kidney is concave region called the renal hilum. The renal hilum is the entrance to the renal sinus. Structures such as the renal veins, artery, nerves and lymphatic vessels are located in the renal hilum.

 

Explanation:

The efferent arteriole emerging from the glomerulus forms a fine capillary network around the renal tubule called the peritubular capillaries.

A minute vessel of this network runs parallel to the Henle’s loop forming a ‘U’ shaped vasa recta. Vasa recta is absent or highly reduced in cortical nephrons.

 

Explanation:

Inside the kidney, there are two zones, an outer cortex and an inner medulla. The cortex extends in between the medullary pyramids as renal columns called columns of Bertini.

 

Explanation:

Each nephron consists Bowman’s cup, tubules and loops of Henle’s. filtration of blood occurs in glomerulus cells present in Bowman’s cup. Some materials are added to initial filtrate in distal convoluted tubule.

 

Explanation:

Nephrons are the physical unit or functional unit of kidney. Millions of nephrons are present in each kidney but physiological unit of kidney is urinigerous tubule.

 

Explanation:

Urinary bladder is absent in snake and bird because the urine of these is semi-solid consisting mainly of uric acid. The primary function of urinary bladder is to store urine in mammals. The urinary bladder cannot store semi-solid urine.

 

Explanation:

Homeostasis is the maintenance of constant body temperature. It is mainly maintained by excretion and osmoregulation, which is the function of kidney.

 

Explanation:

Renal corpuscle, also called malpighian body, filtration unit of vertebrate nephrons, functional units of the kidney. It consists of a knot of capillaries (glomerulus) surrounded by a double-walled capsule (Bowman's capsule) that opens into a tubule.

 

Explanation:

The blood plasma is filtered through the capillaries of the glomerulus into the capsule. The Bowman's capsule empties the filtrate into the proximal tubule that is also part of the duct system of the nephron. A glomerulus receives its blood supply from an afferent arteriole of the renal circulation

 

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'.

The nephron is the structural and functional unit of the kidney. The body of the nephron is composed of Bowman's capsule, proximal convoluted tubule (PCT), Loop of Henle and distal convoluted tubule (PCT). The glomerular blood is filtered through the minute pores called filtration slits present in the wall of Bowman's capsule. The filtrate is collected by Bowman's capsule and passed to the proximal convoluted tubule. Hence in Kidney, glomerulus is involved in urine formation by filtration.

The mammals are ureotelic organisms. The ammonia which is produced by the deamination reactions during the metabolism of amino acids and proteins is converted to urea in the liver by the urea cycle. The urea is excreted along with the urine and feces.

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,

Nephrons are the cells of kidney which are considered as smallest functional unit because it is microscopic structure which actively participates in functions of kidney like blood filtration and osmoregulation. A healthy adult has 0.8 to 1.5 million nephrons in each kidney. It is composed of a renal corpuscle and a renal tubule. The renal corpuscle filters the blood components. The filtrate is transferred to renal tubule for process of tubular secretion and tubular reabsorption which further forms the urine by maintaining its concentration. So the correct answer is “nephron”.

Ureotelism occurs in mammals because it excretes urea as a waste product. Urea is less toxic than ammonia so it can be stored in the body for longer duration. The extra proteins in the body are degraded by the process of deamination where the NH$$_2 $$ group is removed and it is converted into ammonium ions in the liver. The ammonium ions enter urea cycle and get converted into urea. The urea formed in liver is transported to kidney through circulation and finally gets excreted.

GFR is the amount of filtrate formed per minute by the glomerulus of the nephrons in the kidneys. In a healthy person the GFR is about 125 ml/min which makes it 7.5 liters per hour and 180 liters per day. Of the 180 liters of filtrate formed per day only 1.5 liters is passed through the urethra as urine, rest of it is reabsorbed by the the tubules of nephron. Thus, the correct option is A.

The excretory product of spider is guanine. It is formed as a result of nucleotide metabolism. It does not require water for elimination because it is less soluble the uric acid.