[PF2] EXCRETORY pt 2

Where is the proximal convoluted tubule located?

Cortex

What type of epithelium lines the proximal convoluted tubule?

Simple cuboidal epithelium

What gives the cells of the proximal convoluted tubule a well-stained appearance?

Numerous mitochondria

What structures near the bases of microvilli in the proximal convoluted tubule indicate active endocytosis and pinocytosis?

Numerous pits and vesicles

What features in the proximal convoluted tubule are involved in reabsorption and give the lumen a fuzzy appearance?

Long microvilli forming a brush border

What features are prominent in the basal and lateral parts of the proximal convoluted tubule cells?

Basal folds and lateral interdigitations

Which part of the nephron has numerous mitochondria and vesicles near the basolateral membrane?

PCT

Which part of the nephron has prominent basal folds and lateral interdigitations?

PCT

Which structure has long microvilli that form a surface to facilitate reabsorption?

Brush Border

Which structure gives the lumen of the proximal tubule a "frosted" or "dirty" appearance under histology?

Brush Border

Which nephron segment is located in the cortex and lined by simple cuboidal epithelium?

PCT

The ___ has numerous mitochondria and a brush border (due to long microvilli) which make it look "dirty" or "filled".

PCT

The ___ has a much cleaner lumen with fewer visible contents

DCT

Which segment of the nephron loop is lined with simple squamous epithelium and has few mitochondria?

Thin limbs of the Loop of Henle

Which part of the nephron has a prominent lumen and is involved in passive reabsorption of Na+ and Cl–?

Thin limbs of the Loop of Henle

Which segment of the nephron helps maintain a hyperosmotic interstitium through countercurrent flow?

Thin limbs of the Loop of Henle

Which segment of the Loop of Henle is lined by simple cuboidal epithelium and lacks microvilli?

Thick ascending limb

Which part of the nephron loop has many mitochondria and actively reabsorbs electrolytes?

Thick ascending limb

Which part of the nephron is located in the cortex, has simple cuboidal epithelium, and cells smaller than those in the PCT?

Distal convoluted tubule

Which segment of the nephron has short microvilli, basolateral folds, and more empty lumens than the PCT?

Distal convoluted tubule

Which nephron segment has fewer mitochondria than the PCT and is responsible for electrolyte reabsorption?

Distal convoluted tubule

Which part of the nephron has its Na+ absorption rate regulated by aldosterone?

Distal convoluted tubule

Which structure forms at the contact point between the distal tubule and the vascular pole of the glomerulus?

Juxtaglomerular apparatus

Which kidney structure uses feedback to regulate glomerular blood flow and maintain a constant filtration rate?

Juxtaglomerular apparatus

Which cells within the juxtaglomerular apparatus produce renin?

Juxtaglomerular cells

Which part of the distal tubule becomes columnar and forms a thickened region adjacent to the afferent arteriole?

Macula densa

Which specialized cells are located in the tunica media of the afferent arteriole and contain granules with renin?

Juxtaglomerular granular (JG) cells

Which juxtaglomerular structure is responsible for secreting renin?

Juxtaglomerular granular (JG) cells

Which mesangial cells are located outside the glomerulus, near the macula densa and both arterioles?

Lacis cells

Which component of the juxtaglomerular apparatus is adjacent to the macula densa and modified into a secretory phenotype?

Juxtaglomerular granular (JG) cells

What is the final site of water reabsorption from the filtrate?

Collecting ducts

What tubules from each nephron join in the cortical medullary rays to form collecting ducts?

Connecting tubules

What larger ducts do collecting ducts eventually form before delivering urine to the minor calyx?

Papillary ducts

Where are the collecting ducts primarily located?

Medulla

What type of epithelial transition occurs as collecting ducts enlarge?

Cells become increasingly columnar

What type of cells are the most abundant in the collecting ducts?

Principal cells

What is the primary function of principal cells?

Regulated reabsorption of water and electrolytes

What do principal cells secrete in a regulated manner?

K+

What integral membrane proteins are abundant in principal cells and function as water channels?

Aquaporins

Where are principal cells located?

Medulla

What is a distinguishing histological feature of intercalated cells?

Slightly darker staining

What is the primary function of intercalated cells?

Reabsorption of K+ (low-K+ diet)

How do intercalated cells help maintain acid-base balance?

By secreting either H+ or HCO3–

Which type of intercalated cells secrete H+?

Type A or α intercalated cells

Which type of intercalated cells secrete HCO3–?

Type B or β intercalated cells