Class Notes (1,016,374)
CA (584,266)
UTM (26,740)
Biology (2,556)
BIO310H5 (142)
Lecture 17

BIO310H5 Lecture Notes - Lecture 17: Macula Densa, Afferent Arterioles, Juxtaglomerular CellPremium

2 pages92 viewsFall 2018

Department
Biology
Course Code
BIO310H5
Professor
Nagham Abdalahad
Lecture
17

This preview shows half of the first page. to view the full 2 pages of the document.
BIO310 Lecture 17
Juxtaglomerular Apparatus
Macula densa cells: Chemoreceptors (monitor [Na+ ]) ,
also detect rate of flow of filtrate in DCT (act to cause
vasoconstriction/vasodilation of afferent arteriole)
Juxtaglomerular cells (granular cells) in wall of afferent
arteriole: Baroreceptor (monitors pressure) and releases
renin
Sympathetic innervation: Stimulates JGA cells to
release renin (direct effect) or causes vasoconstriction of
the afferent arteriole which drops pressure and leads to
renin release (indirect effect).
Renin liberated into blood in response to:
1 Drop in plasma Na+ concentration (monitored by macula densa cells)
2 Local stimuli - loss of distension, ie. Drop in blood pressure
3 Circulating catecholamines
Renin-Angiotensin System
Antidiuretic hormone(ADH)/vasopressin
ADH regulates water permeability in the collecting duct -is secreted by
hypothalamic neurons at the posterior pituitary
Factors regulating ADH secretion
Major: osmoreceptors in the brain & cardiovascular baroreceptors
Other: Angiotensin II stimulates ADH release & ANP inhibits ADH
release
Regulation of Blood Volume
You're Reading a Preview

Unlock to view full version

Subscribers Only

Loved by over 2.2 million students

Over 90% improved by at least one letter grade.