Flashcards in The Adrenal Gland - Lecture 4 Deck (17):
Where are the Adrenal glands located?
On top of the Kidneys, and look like little caps
What are the two tissues that make up the Adrenal gland?
1. Adrenal Medulla
2. Adrenal Cortex
What percentages make up the Adrenal Medulla and Cortex?
Adrenal Medulla makes up the inner 1/4
Adrenal Cortex makes up the outer 3/4
What does the Adrenal Medulla contain?
It is composed of Sympathetic ganglia.
What does the Adrenal Medulla secrete?
Catecholamines, mostly Adrenalin
What type of hormones does the Adrenal Cortex secrete?
What induces the release of Catecholamines from the Adrenal Medulla?
Increased Sympathetic nerve activity.
Exercise or imminent danger (fight or flight)
Where are receptors for Catecholamines found?
Throughout the body
What is Pheochromocytoma?
It is a neuroendocrine tumor of the Adrenal Medulla gland which originates in the chromaffin cells
What occurs when a Pheochromocytoma is present?
It causes Sympathetic nervous system hyperactivity
What are some of the effects of a Pheochromocytoma?
- Elevated heart rate, blood pressure and palpitations
- Diaphoreses (excessive sweating)
- Headaches - most common symptom
- Weight loss
- Elevated blood glucose levels (caused by
Catecholamine stimulation of beta andrenoreceptors
which leads to glycogenolysis and gluconeogenesis)
- Increased Lipolysis (breakdown of stored fat)
How is Pheochromocytoma treated?
How many zones does the Adrenal cortex have?
What does the OUTER zone of the Adrenal Cortex secrete?
It secretes only Aldosterone.
What does the MIDDLE zone of the Adrenal Cortex secrete?
It secretes glucocorticoids; mainly Cortisol. They have the ability to increase plasma glucose concentrations.
What does the INNER zone of the Adrenal Cortex secrete?
It secretes Androgens