Mechanisms of the Juxtaglomerular Apparatus [Part 1] | Macula Densa

What are the two main components of the juxtaglomerular apparatus?

• Afferent and efferent arterioles

• Renal corpuscle and loop of Henle

• Macula densa and JG cells

• Proximal and distal convoluted tubules

Which part of the nephron makes contact with the renal corpuscle?

• Collecting duct

• Distal convoluted tubule

• Loop of Henle

• Proximal convoluted tubule

What do macula densa cells primarily sense in the filtrate?

• Calcium ions

• Sodium ions

• Chloride ions

• Potassium ions

What does a high sodium level near the macula densa indicate?

• High potassium level

• Low glomerular filtration rate

• High blood pressure

• Low blood pressure

How do macula densa cells respond to low sodium levels?

• Constrict the afferent arteriole

• Release renin

• Decrease glomerular filtration rate

• Increase blood pressure

What is the role of renin in blood pressure regulation?

• Has no effect on blood pressure

• Initiates processes that increase blood pressure

• Directly increases blood pressure

• Decreases blood pressure

What happens to renin release when sodium levels are high?

• Renin is converted to aldosterone

• Renin release decreases

• Renin release remains unchanged

• Renin release increases

Which enzyme is inhibited when sodium levels are high in the macula densa?

• Cyclooxygenase (Cox 2)

• ATPase

• Adenylate cyclase

• Nitric oxide synthase

What triggers vasoconstriction in the granular cells?

• Influx of chloride

• Influx of sodium

• Influx of calcium

• Influx of potassium

What is the effect of elevated sodium on the afferent arteriole?

• Dilation

• No change

• Bursting

• Constriction