positive + negative feedback loop + hypothalamus + anterior pituitary

midterm review

what role does Ca+2 play in cellular signaling

Ca+2 acts as an “activator” in various cellular signaling pathways

What is an example of a negative feedback loop in physiology?

Blood sugar regulation, where insulin lowers blood glucose and glucagon raises it to maintain homeostasis

What triggers the release of insulin in the blood sugar regulation pathway?

High blood glucose levels stimulate beta cells in the pancreas to release insulin.

How does a positive feedback loop function in childbirth?

The release of oxytocin causes uterine contractions, which push the baby toward the cervix, further stimulating oxytocin release until birth occurs.

What hormone is released by the posterior pituitary gland that helps in water reabsorption?

Antidiuretic hormone (ADH) is released by the posterior pituitary to promote renal water reabsorption.

Describe the effect of ADH on urine volume and blood osmolarity.

ADH decreases urine volume and reduces blood osmolarity by increasing water reabsorption in the kidneys.

What is a tropic hormone, and give an example.

A tropic hormone stimulates the release of another hormone. An example is Thyroid-Stimulating Hormone (TSH) released from the anterior pituitary.

How does the hypothalamus communicate with the anterior pituitary gland?

The hypothalamus releases trophic neurohormones into the portal system, which signals the anterior pituitary to release specific hormones.

What feedback mechanism controls the release of thyroid hormones?

Negative feedback; high levels of thyroid hormones inhibit the release of TRH and TSH from the hypothalamus and anterior pituitary.