This is an MCQ-based quiz for GRE on the topic of Endocrine System.
This includes Metabolism (the way you break down food and get energy from nutrients), Growth and development, Emotions and mood, Fertility and sexual function, Sleep, and Blood pressure
A person with low blood calcium will have increased activity in which gland?
Which endocrine gland releases aldosterone?
Adrenocorticotropic hormone will enter the blood stream, and act on which structure in the body?
Which gland releases oxytocin and antidiuretic hormone?
Which gland releases hormones that help regulate blood glucose levels?
Which of the following features would you expect to see in an individual with a deficient posterior pituitary gland?
Which of the following hormones will increase cortisol secretion in a normal individual?
What is the purpose of antidiuretic hormone in the body?
What is the name of the hormone responsible for raising blood calcium levels?
The interaction between blood pressure and kidney function in humans requires coordination by the renin-angiotensin-aldosterone system (RAAS). This system involves the dynamic interplay of the kidneys, lungs, and blood vessels to carefully regulate sodium and water balance.
A normal human kidney has cells adjacent to the glomerulus called juxtaglomerular cells. These cells sense sodium content in urine of the distal convoluted tubule, releasing renin in response to a low level. Renin is an enzyme that converts angiotensinogen to angiotensin I (AI). AI is converted to angiotensin II (AII) by angiotensin converting enzyme (ACE) in the lung.
AII stimulates aldosterone secretion in the zona glomerulosa of the adrenal gland. Aldosterone then acts to upregulate the sodium-potassium pump on the basolateral side of distal tubule epithelial cells to increase sodium reabsorption from the urine, as well as increasing potassium excretion.
Renin is most likely to drive the formation of angiotensin I from angiotensinogen by doing which of the following?
I. Increasing the concentration of angiotensinogen
II. Lowering the activation energy of the reaction from angiotensinogen to angiotensin I
III. Stabilizing the angiotensin I molecule to lower the energy of the products
I,II, and III
II and III