Urinary System




Chapter 20: Urinary System Note from Dr. Davis: This chapter is probably the most difficult to comprehend in the entire histology text mainly because so much inconsequential detail is presented so as to virtually obscure the impressive physiology of the kidneys and the “big picture” concepts such as filtration, secretion, and reabsorption that are the quintessential aspects of kidney function. Students will probably need to rely on their knowledge of kidney function gained in the Physiology course to grasp the histology of the kidneys since this chapter does not clearly or simply explain how cells and tissues of the renal system achieve their functions.

What layers and cell types are found in the capsule of the kidney? What are renal corpuscles and what is found within them? 3.


What constitutes a medullary ray? What term is given to the cortex that surrounds medullary rays? 5.


Which portions of the nephron are found in the medulla? What are renal columns? 7.

What is a renal papilla and what is the name for the openings at the tip of the renal papilla that empty into minor calyces? 8.


How does one distinguish the glomerulus from Bowman’s capsule? What is the vascular pole and urinary pole of the renal corpuscle? 10.

Name the tubular portions of the nephron beginning with the pars convoluta of the proximal thick segment and ending with the pars convoluta of the distal thick segment. 11.

By what structure is the distal convoluted tubule sometimes attached to the collecting duct? 12.

What are the four subdivisions (and their synonyms) of the loop of Henle? 13.

Which portion of the nephron makes up the macula densa and what is the nearest blood vessel? 14.

How are subcapsular nephrons distinguished from juxtamedullary nephrons? 15.

What are ducts of Bellini? 16.

Are glomerular capillaries continuous, discontinuous, or fenestrated? 17.

Name the cells that constitute the visceral layer of Bowman’s capsule and contribute to the glomerular basement membrane. 18.

What are pedicels and what are the gaps between them called? 19.

What is the function of the glomerular basement membrane? 20.

What is the role of the polyanionic glycosaminoglycans of the GBM? 21.

Explain why the urine normally contains very little protein.


Classify the parietal layer of Bowman's capsule. 23.

Classify the epithelium of the proximal convoluted tubule. 24.

What is the main function of mesangial cells? 25.

What are the components of the juxtaglomerular apparatus? 26.

How can the macula densa be recognized in light microscope sections? 27.

How do juxtaglomerular cells differ from typical smooth muscle cells? 28.

Why are juxtaglomerular cells considered secretory? 29.

What stimulates secretion by juxtaglomerular cells? 30.

What do macula densa cell monitor? 31.

What suppresses secretion by juxtaglomerular cells? . 32.

How can proximal tubule cells be distinguished from other portions of the tubule? 33.

Fluid that is reabsorbed in the proximal tubules enters which blood vessel? 34.

Compare the water and salt permeabilities of the thin descending and ascending limbs. 35.

Which portion of the loop of Henle is the site of most reabsorption of Na+, Cl- and other ions? 36.

What are the major functions of the distal convoluted tubule? 37.

Which hormone acts on the distal convoluted tubule to promote Na+ reabsorption and K+ secretion? P. 719 aldosterone. 38.

How are collecting tubules distinguished from proximal and distal tubules? 39.

What part of the renal vascular system provides blood to the medulla but does not disturb the osmotic gradients established in the medulla? 40.

What type of innervation is provided to the kidney? How do we know this innervation is not essential for normal kidney function? 41.

What layers make up the wall of the excretory passages (except the urethra?) 42.

What type of epithelium lines all excretory passages except for the urethra? 43.

How is the arrangement of muscle in the muscularis layer of the ureter different from that of the digestive tract? 44.

What is the detrussor muscle?