Question

need to know a,b,c

A. illustrate the macroscopic and microscopic structures of the kidney and the flow of blood through the kidney. describe the renal cortex, medulla, pyramids, calyx, and other features such as Bowmans capsule and the glomerulus.

B. identify and give the significance of the following: podocytesc pedicels, filtration slits, afferent arteriole, efferent arteriole, renal corpuscle, peritubular capillaries, vasa recta, proximal convoluted tubules, distal convoluted tubules, and loop of Henle.

C. why should everyone have periodic urine analyses? what might be problematic if large amounts of protein or sugar are found? or leukocytes? or the presence of blood?

Answer 1

Blood flow through kidney

Renal cortex or the outer cortex is dark and granular in appearance. It contains renal corpuscles and convoluted tubules. At intervals, cortical tissue penetrates medulla in the form of columns, which are called renal columns or columns of Bertini.

Medulla contains tubular and vascular structures arranged in parallel radial lines. Medullary mass is divided into 8 to 18 medullary or Malpighian pyramids. Broad base of each pyramid is in contact with cortex and the apex projects into minor calyx.

After the medullary layer lies the renal sinuses.

Renal sinus consists of the following structures:

i. Upper expanded part of ureter called renal pelvis ii. Subdivisions of pelvis: 2 or 3 major calyces and about 8 minor calyces . iii. Branches of nerves, arteries and tributaries of veins. iv. Loose connective tissues and fat.

​​​​​Glomerulus is a tuft of capillaries enclosed by Bowman  capsule. It consists of glomerular capillaries interposed  between afferent arteriole on one end and efferent  arteriole on the other end. Thus, the vascular system in  the glomerulus is purely arterial.

Bowman capsule is a capsular structure, which encloses the glomerulus.
It is formed by two layers:
i. Inner visceral layer
ii. Outer parietal layer.
Visceral layer covers the glomerular capillaries. It  is continued as the parietal layer at the visceral pole.
Parietal layer is continued with the wall of the tubular  portion of nephron. The cleft­like space between the  visceral and parietal layers is continued as the lumen of  the tubular portion.

B

Filtration slits -

Glomerular capillaries are made up of single layer of  endothelial cells, which are attached to a basement  membrane. Endothelium has many pores called  fenestrae or filtration pores. Diameter of each pore is  0.1 µ. Presence of the fenestra assists in filtration function of the glomerulus.

Podocyte cell -

Epithelial cells of the visceral layer fuse with the
basement membrane but the fusion is not complete.
Each cell is connected with basement membrane by  cytoplasmic extensions of epithelial cells called pedicles  or feet. These pedicles are arranged in an interdigitating  manner leaving small cleft­like spaces in between. The  cleft­like space is called slit pore. Epithelial cells with  pedicles are called podocytes

C.

Routine urine examination needs to be to done to assess kidney function. , As kidney is not only an organ of excretion but also helps in maintaining water , electrolyte balance and acid base balance.

Blood in urine suggests haematuria , hemoglobinuria . It can be due to glomerulonephritis or any stone in kidney ureter or urinary bladder .

Protein in urine is proteinuria which can be due to glomerulonephritis , amyloidosis , multiple myeloma , UTI , heart failure , focal segmental glomerulosclerosis , membranous glomerulonephritis , etc

Leucocytes are found in urine during UTI , tuberculosis , prostatitis , urethritis , pyelonephritis , interstitial nephritis etc.

Sugar is seen in case of diabetes mellitus patients.