Foundational Quizzes Flashcards
The master circadian clock in mammals responds to ambient light via
activation of specialized intrinsically photosensitive retinal ganglion cells.
These specialized retinal ganglion cells, known as ipRGCs (intrinsically photosensitive retinal ganglion cells), contain the photopigment melanopsin and are responsible for conveying light information to the suprachiasmatic nucleus (SCN), which serves as the master circadian clock in mammals. This pathway helps regulate the body’s circadian rhythms in response to light cues.
Does Glucagon causes the breakdown of glycogen in liver to glucose.
True.
Glucagon is a hormone that is released by the pancreas in response to low blood sugar levels. One of its primary functions is to signal the liver to break down glycogen into glucose through a process called glycogenolysis. This results in an increase in blood glucose levels, which can help raise and maintain blood sugar levels when they are too low.
Glucose stimulates pancreatic beta cells to secrete insulin.
True.
Glucose stimulates pancreatic beta cells to secrete insulin. When blood glucose levels rise, such as after a meal, the pancreas detects this increase, and the beta cells respond by releasing insulin into the bloodstream. Insulin helps regulate blood sugar by facilitating the uptake of glucose into cells, which lowers blood glucose levels. This process is a key part of glucose homeostasis in the body.
Which two bacterial metabolites are associated with increased GLP1 activity?
Acetate and lipopolysaccharides.
GLP1 is a hormone that plays a role in regulating blood sugar levels, and these bacterial metabolites can influence its activity.
Which adipokine is a major regulator of satiety?
Leptin.
Leptin is a major regulator of satiety. It is produced by adipose (fat) cells and plays a key role in signaling to the brain about the body’s energy stores. When leptin levels are higher, it signals to the brain that the body has sufficient energy stores, which can lead to reduced appetite and increased feelings of satiety. In cases of leptin deficiency or resistance, individuals may experience increased appetite and obesity due to the lack of this satiety signal.
Which are the most immature cells in spermatogenesis?
spermatogonia
Spermatogonia are the most immature cells in spermatogenesis. They are the stem cells in the testes that give rise to spermatocytes, which then undergo further divisions and differentiation to eventually form spermatozoa (sperm cells).
When is the 2nd polar body is produced:
after fertilization has occurred.
The second polar body is produced during the process of fertilization. It is formed as a result of the second meiotic division of the oocyte (egg) after it is fertilized by a sperm. The formation of the second polar body is part of the process that leads to the formation of a mature egg with a single set of chromosomes, ready for fusion with the sperm’s single set of chromosomes to form a zygote.
Oxytocin is produced by the:
Oxytocin is produced by the hypothalamus but is stored and released from the posterior pituitary gland.
11β hydroxysteroid dehydrogenase type 2 is a placental enzyme that
Protects the fetus from mineralocorticoids.
11β hydroxysteroid dehydrogenase type 2 (11β-HSD2) is an enzyme found in the placenta that plays a crucial role in protecting the fetus from the effects of maternal cortisol (a glucocorticoid) by converting it to an inactive form known as cortisone. This helps prevent excessive exposure of the developing fetus to glucocorticoids, which could have detrimental effects on fetal development.
Capacitation takes place in the oviduct typically in the:
ampulla.
Capacitation is a process where sperm undergo changes in the female reproductive tract, including the oviduct (fallopian tube), that enable them to become capable of fertilizing an egg. The ampulla of the oviduct is the site where fertilization usually occurs, and capacitation prepares the sperm for this process.
Fulvestrant is an estrogen receptor (ER) antagonist that blocks its action in the body, essentially knocking out ER. The immediate effect of this drug on the hormone estrogen would be:
a decrease in estrogen levels.
Fulvestrant is an estrogen receptor (ER) antagonist, which means it blocks the action of estrogen by binding to the estrogen receptors and preventing them from being activated by estrogen. As a result, the immediate effect of fulvestrant is to reduce the biological effects of estrogen in the body, effectively lowering estrogen levels.
Which hormone stimulates red blood cell synthesis?
Erythropoietin.
Erythropoietin (EPO) is the hormone responsible for stimulating the synthesis of red blood cells in the bone marrow. It is released by the kidneys in response to low oxygen levels in the blood, and its primary function is to increase the production of red blood cells to improve oxygen-carrying capacity in the body.
When someone uses the term ‘systolic blood pressure’, they are referring to the blood pressure measured at the time when the
Ventricles are contracting.
Systolic blood pressure is the higher number in a blood pressure reading and represents the pressure in the arteries when the left ventricle of the heart is contracting and pumping blood out into the circulation.
When someone uses the term ‘diastolic blood pressure’, they are referring to the blood pressure at the time when the
Ventricles are relaxed.
Diastolic blood pressure is the lower number in a blood pressure reading and represents the pressure in the arteries when the heart is in its relaxation phase, specifically when the ventricles are relaxed and filling with blood.
The active component of the renin-angiotensin system is
Angiotensin II.
The active component of the renin-angiotensin system is Angiotensin II. It is formed from Angiotensin I through the action of an enzyme called ACE (Angiotensin-Converting Enzyme). Angiotensin II is a potent vasoconstrictor and plays a key role in regulating blood pressure and fluid balance in the body.
