BIOL1040 MOdule 6 L2: Hypothalamys and Pituitary

What two systems control long-distance regulation in the body?

The nervous system and the endocrine system.

How does the nervous system interact with the endocrine system?

Neural signals can initiate and regulate hormonal signals.

What type of feedback maintains homeostasis?

Negative feedback.

What is a hormone cascade pathway?

A series of hormonal activations in which one hormone stimulates another endocrine gland to release more hormones, amplifying the response.

What is meant by “antagonistic pairs of hormones”?

Two hormones with opposing effects that maintain homeostasis by balancing each other’s actions - glucagon and insulin

How does insulin maintain glucose homeostasis?

It lowers blood glucose by promoting glucose uptake and storage as glycogen. - acts on pancreatic beta cells

How does glucagon maintain glucose homeostasis?

It raises blood glucose by promoting glycogen breakdown and glucose release from the liver - acts on pancreatic alpha cells

What is diabetes mellitus?

A disorder caused by problems in insulin production or response, leading to elevated blood glucose levels.

What causes Type I diabetes mellitus?

An autoimmune destruction of pancreatic beta cells, resulting in insulin not being produced

What causes Type II diabetes mellitus?

Insulin deficiency or reduced sensitivity of target cells due to receptor changes - insulin not functioning properly

Insulin deficiency or reduced sensitivity of target cells due to receptor changes.

The Renin–Angiotensin–Aldosterone System, which regulates blood pressure and fluid balance.

outline of RAAS

Low blood pressure triggers renin release from the kidneys, which converts angiotensinogen (from the liver) into angiotensin I.
Angiotensin I is converted to angiotensin II by ACE (mainly in the lungs).
Angiotensin II causes vasoconstriction and stimulates aldosterone release from the adrenal cortex.
Aldosterone increases sodium and water reabsorption in the kidneys, restoring blood pressure and volume.