Endocrinology

What is the neuroendocrine system

A regulatory system linking the nervous and endocrine systems, combining rapid and slow signaling.

How do peptide and amine hormones differ from steroid hormones in storage?

Peptide and amine hormones are stored in secretory vesicles; steroid hormones are synthesized on demand.

What type of receptor do steroid hormones bind?

Intracellular receptors that act as regulatory transcription factors.

Intracellular receptors that act as regulatory transcription factors.

TSH and ACTH.

What does insulin do?

Promotes glucose uptake by cells, lowering blood glucose levels.

What hormone is released during low blood sugar levels?

Glucagon.

How does negative feedback maintain glucose homeostasis?

By adjusting insulin and glucagon release to keep blood glucose within a tight range.

What is the role of LH and FSH in sex hormone regulation?

They stimulate steroid biosynthesis (estrogen/testosterone) and gametogenesis.

How does positive feedback affect sex hormone development?

It reinforces male or female hormone patterns during development.

Why is epinephrine released faster than cortisol?

Because epinephrine is pre-stored in vesicles, while cortisol needs to be synthesized.

What are some effects of cortisol during stress?

Increased gluconeogenesis, lipolysis, suppressed inflammation, heightened memory.

What type of feedback regulates cortisol levels?

Negative feedback

What hormones are released from the posterior pituitary?

Oxytocin and ADH.

What does the adrenal medulla release?

Epinephrine.

What is post-translational regulation?

Regulation of proteins after they are made, allowing rapid cellular responses.

peptide hormones

Made of chains of amino acids (small or large).
Examples: Insulin, glucagon, oxytocin.
They are water-soluble and act on receptors on the cell surface.

amine hormones

Derived from a single amino acid (like tyrosine or tryptophan).
Examples: Epinephrine (adrenaline), thyroxine (T4).
Some are water-soluble (like epinephrine), and some are lipid-soluble (like thyroid hormones).

steroid hormone

Made from cholesterol (lipid-based).
Examples: Cortisol, testosterone, estrogen.
They are lipid-soluble and pass through the cell membrane to act inside the cell.

steroid hormone receptor

Proteins inside cells that bind steroid hormones and regulate gene expression.

Insulin, glucagon, pancreas

The pancreas releases insulin and glucagon to control blood sugar levels.

Testosterone, estrogen:

Testosterone and estrogen are steroid hormones that regulate male and female reproductive development, respectively

Positive, negative feedback:

• Positive feedback amplifies a response, while negative feedback reduces or stops it to maintain balance.

Epinephrine

Epinephrine (adrenaline) is a hormone that triggers the body's "fight-or-flight" response.

Cortisol

a steroid hormone that helps regulate metabolism, stress response, and immune function.

Adrenal gland

The adrenal glands sit above the kidneys and produce hormones like cortisol and epinephrine.

Adrenal cortex

Outer part of adrenal gland

Gonads, ovaries:

Gonads (testes in males, ovaries in females) produce sex hormones and gametes (sperm or eggs)

Pituitary, hypothalamus:

The hypothalamus controls the pituitary gland, which releases hormones that regulate many body processes.