Question

Under normal conditions which is completely reabsorbed in the renal tubule?
A) Urea
B) Uric acid
C) Salt
D) Glucose

Answer 1

The part of the nephron containing the tubular fluid filtered through the glomerulus is the renal tubule. The filtrate proceeds into the collecting duct system after passing through the renal tubule.

Complete answer:
The renal tubule components are:

Proximal convoluted tubule (located in the cortex and lined with clear cuboidal epithelium and brush borders that significantly increase the absorption area.)
Henle's loop (hair-pin like, i.e., U-shaped, lying in a medulla)
Descending limb of Henle 's loop
Ascending limb of Henle 's loop:
The ascending limb of the Henle loop is divided into 2 segments: it is very thin at the lower end of the ascending limb and lined by a plain squamous epithelium. The distal part of the ascending limb is dense and lined with a simple cuboidal epithelium.
Thin ascending limb of Henle 's loop
Henle 's thick ascending loop limb (enters the cortex and becomes-distal convoluted tubule.)
Convoluted distal tubule
Connecting Tubule

Filtration, reabsorption, secretion and excretion are the four processes used to produce and process the filtrate (the result of which is to convert blood to urine). In the glomerulus, filtration occurs and is essentially passive: it relies on intracapillary blood pressure. When the blood passes through the glomerular capillaries, about one-fifth of the plasma is filtered; four-fifths continue to reach the peritubular capillaries.Blood proteins, red blood cells , white blood cells and platelets are normally the only blood components that are not filtered into Bowman's capsule. Every day, more than 150 litres of fluid enter the adult glomeruli: 99 percent of the water in the filtrate is reabsorbed. In the renal tubules, reabsorption occurs and is either inactive due to diffusion or active due to pumping against a gradient of concentration.Secretion also occurs and is active in the tubules. Water, sodium chloride, glucose, amino acids, lactate, magnesium, calcium phosphate, and bicarbonate are among the substances reabsorbed. Secreted compounds include urea, hydrogen, potassium, hydrogen, and uric acid.Some hormones that signal the tubules to adjust the rate of reabsorption or secretion and thus maintain homeostasis include antidiuretic hormone (water), aldosterone (sodium , potassium), parathyroid hormone (calcium, phosphate), atrial natriuretic peptide (sodium), and brain natriuretic peptide (sodium) along with the affected material.

Thus the correct answer is option (D) Glucose.

Note: Small blood vessels that form the circle of Henle and the proximal and distal tubules, where the tubular fluid flows, containing everything that has not been discharged from the glomerulus, blood from the efferent arteriole passes into the peritubular capillaries. The toxins are then reabsorbed back into the latter's bloodstream.The peritubular capillaries then recombine to form an efferent vein which blends with the efferent veins of other nephrons into the renal vein and enters the primary vein.