Urinary System

Slide 1 X400 The Kidney - Medulla In this transverse section through the medulla of the kidney note: The collecting ducts with prominent cell borders (what type of epithelium?) Ascending thick limbs of the loops of Henle, with low cuboidal epithelium and cell borders not prominent; Capillaries and small blood vessels, with erythrocytes in the lumen (what type of epithelium?) Thin limbs of loops of Henle, lined by a simple squamous epithelium with several dark stained nuclei bulging into the lumen. Draw a diagram to illustrate an entire uriniferous tubule (nephron plus collecting duct) as seen in longitudinal section. Technique: Haematoxylin and eosin A882

Slide 2 X100 The Kidney – area cribrosa of a papilla With this special staining technique note: The collecting ducts opening into a minor calyx; The simple columnar epithelium of the collecting ducts; and The transitional epithelium lining the minor calyx. What is meant by the “area cribrosa”? Along what route does the urine travel from a minor calyx to the urinary bladder? Technique: Brazilian – Wasserblau A493

THE URINARY SYSTEM

Kidney Area Cribrosa of a Papilla slide A493 x400 Technique: Brazilin-Wasserblau

Slide 3 X100 The urinary bladder Note: The transitional epithelium; The cellular and vascular lamina propria; The smooth muscle bundles. What changes occur in the transitional epithelium when the bladder fills? See EMG16 Technique: Haematoxylin and eosin A339

THE URINARY SYSTEM Slide A339 Urinary Bladder x400 Technique: H&E.

Slide 4 X100 The Kidney – area cribrosa of a papilla In this section through the kidney note: Several renal corpuscles; A branching inter-lobular artery with an afferent arteriole (centre – right of field); Numerous sections through eosinophilic proximal convoluted tubules; and A few distal convoluted tubules with darker staining nuclei. The macula densa in a distal convoluted tubule and The urinary pole associated with one of the renal corpuscles. How did you identify the macula densa? What are the structural and functional differences between proximal and distal convoluted tubules? Which of these do you see at the urinary pole? Technique: Haematoxylin and eosin A876

Slide 5 X400 Renal corpuscles – afferent arterioles With this special staining technique note: Two renal corpuscles, each with an afferent arteriole; The clear – staining cell borders demarcating epithelioid smooth muscle cells in the tunica media of each arteriole; and The flattened nuclei of the endothelial cells. Describe the pathway of blood from the renal artery to a renal corpuscle. In this field, how are the arterioles identified as “afferent” not “efferent”? Technique: Ponceau and acid fuchsin; haematoxylin and light green A496

Slide 6 X400 Renal corpuscles – afferent arterioles Note: The parietal layer of Bowman’s capsule (what type of epithelium?) The glomerular capillaries, with darkly stained endothelial nuclei; The more palely stained nuclei of the podocytes (the visceral epithelial layer of Bowman’s capsule); The urinary space; An arteriole at the vascular pole (afferent or efferent?) The macula densa in the distal tubule; and The nuclei of juxta – glomerular (J.G.) cells. Describe how the ultrafiltrate from the blood in the glomerulus reaches the urinary space. Technique: Haematoxylin and eosin A507

Slide 7 X400 The renal corpuscle Note: The parietal layer of Bowman’s capsule (what type of epithelium?) The glomerular capillaries, with darkly stained endothelial nuclei; The more palely stained nuclei of the podocytes (the visceral epithelial layer of Bowman’s capsule); The urinary space; An arteriole at the vascular pole (afferent or efferent?) The macula densa in the distal tubule; and The nuclei of juxta – glomerular (J.G.) cells. Describe how the ultrafiltrate from the blood in the glomerulus reaches the urinary space. Technique: Haematoxylin and eosin A507