Endocrine 🧠

What is a negative feedback loop in the endocrine system?

A process where the final hormone inhibits its own production

What is paracrine signaling?

Hormones act on nearby cells

What is autocrine signaling?

Hormones act on the same cell that released them

What are eicosanoids (like prostaglandins)?

Local signaling molecules derived from fatty acids

What are synergistic hormones?

Hormones that work together to enhance an effect

What are antagonistic hormones?

Hormones that oppose each other’s effects

What are the three types of hormonal release?

Humoral, neural, hormonal

What triggers humoral release?

Changes in blood levels (ions/nutrients)

What triggers neural release?

Nerve stimulation

What triggers hormonal release?

Hormones stimulating other glands

What are water-soluble hormones?

Hormones that bind to membrane receptors

What do water-soluble hormones use to act in the cell?

Second messengers

What are G proteins?

Proteins that relay signals from receptors to enzymes

What pathway uses cAMP?

Adenylate cyclase → cAMP → protein kinase A

What pathway uses DAG and IP3?

Phospholipase C → PIP2 → DAG + IP3 → protein kinase C

What are examples of water-soluble hormones?

Peptides and modified amino acids

What are lipid-soluble hormones made from?

Cholesterol

How do lipid-soluble hormones travel in blood?

Bound to protein carriers

How do lipid-soluble hormones affect cells?

Enter cell and activate genes

What does the hypothalamus release to control the anterior pituitary?

Releasing and inhibiting hormones

What does the hypothalamus send to the posterior pituitary?

ADH and oxytocin

What are anterior pituitary hormones often called?

Tropic hormones

What does “target cell specificity” mean?

Only cells with receptors respond to a hormone

What does the adrenal cortex produce?

Salt (aldosterone), sugar (cortisol), sex hormones

What does the adrenal medulla produce?

Catecholamines (epinephrine/norepinephrine)

What hormone lowers blood calcium?

Calcitonin

What hormone raises blood calcium?

Parathyroid hormone (PTH)

What role does vitamin D play in calcium regulation?

Increases calcium absorption

What hormone lowers blood glucose?

Insulin

What hormone raises blood glucose?

Glucagon

What disorder involves too much growth hormone in adults?

Acromegaly

What disorder involves insulin resistance?

Type 2 diabetes

Name an organ besides glands that has endocrine function.

Heart, kidneys, adipose tissue (any example)