Endocrine System (unfinished)

Nervous system ➔ rapid precise responses

Endocrine system➔ control of activities requiring duration rather than speed

What's the difference between the Nervous system and the Endocrine system?

- Growth & development (smooth & sequential)

- Metabolism (metabolically controlled)

- Red blood cell production (erythropoietin)

- Core temp

- Water & electrolyte balance

- Reproduction

What internal body functions are under hormonal control?

- Modifying rate of intracellular protein synthesis by stimulating nuclear DNA

- Changing rate of enzyme activity

- Altering plasma membrane transport via a second-messenger system

- Inducing secretory activity

What are the ways that hormones alter cellular reactions of specific target cells?

Depends on the specific receptors that bind the hormone

What does a target cell's response to a hormone depend on?

- Pineal gland

- Hypothalamus

- Pituitary gland

- Thyroid gland

- Parathyroid glands

- Thymus

- Adrenal gland

- Pancreas

- Ovaries

- Testes

What are the Primary endocrine organs?

- Stomach

- Heart

- Liver

- Kidney

- Small intestine

- Skin

What are the Secondary endocrine organs?

"Secondary" means that its just known better for doing something else. But its still an endocrine organ, and they still produce hormones for us.

What does it mean when an endocrine organ is "secondary"?

70+

How many hormones are there in the human body?

- T3

- T4

- Calcitonin

What hormones does the Thyroid gland produce?

False.

A single endocrine gland may produce multiple hormones

True or False:

A single endocrine gland can only produce one hormone

True.

e.g. Somatostatin (secreted from the digestive system & nervous system)

True or False:

A hormone may be secreted by more than one endocrine gland.

True

True or False:

Target cells will respond to hormones so matter the source

False.

Hormones can have more than one target cell.

e.g. Oxytocin (breast & uterus, sperm movement, brain)

True or False:

Hormones can only have one target cell.

True

e.g. menstrual cycle

True or False:

Rate of hormone secretion varies over time in a cyclic pattern.

- Antidiuretic hormone

- Oxytocin

What are the hormones of the posterior pituitary gland?

Oxytocin levels are MUCH lower in men compared to women. The only time that men's oxytocin levels come close to women's is directly after orgasm.

How do oxytocin levels vary per sex?

- Reproductive system

- Adrenocortical system

- Growth hormone system

The "tripartite" endocrine axis is prominent in the control of which systems?

The system uses 3 endocrine glands (Hypothalamus -> Ant pituitary -> 3rd endocrine gland)

What does a "tripartite" endocrine system mean?

Hypothalamic "releasing" hormones are delivered to the anterior pituitary gland via the hypothalamic-pituitary portal system.

Upon arrival, the releasing hormones bind to receptors on the pituitary cells to evoke secretion of the pituitary hormones.

What is the process of making the pituitary gland secrete hormones?

Affect the release of other hormones (can act as releasing or inhibiting hormones)

e.g. Dopamine -> is inhibitory

Inhibits the release of prolactin from the anterior pituitary

What do Tropic hormones do?

- NEURAL INPUT (e.g. cortisol)

- HORMONAL - NEGATIVE FEEDBACK

- CIRCADIAN RHYTHMS (suprachiasmatic nucleus of hypothalamus)

What are the ways that hypothalamic tropic hormone release is controlled?

First intersection happens when the second tropic hormone is released. Tropic hormone turns off the hypothalamus cells that secrete the initial tropic hormone to say "yeah we got released, you can stop now".

IF ITS HAPPENING BETWEEN THE ANTERIOR PIITITARY GLAND AND THE HYPOTHALAMUS, IT'S A SHORT NEGATIVE FEEDBACK LOOP

How do short negative feedback loops work?

Hormone released by the 3rd endocrine gland goes back to turn off anterior pituitary hormone release AND/OR the hypothalamus hormone release.

IF ITS BETWEEN THE ENDOCRINE GLAND AND THE ANT PIT OR HYPO, IT'S A LONG LOOP

How do long negative feedback loops work?

- Glandular tissue in the brain

- Secretes melatonin

What is the Pineal gland?

The suprachiasmatic nuclei

What inhibits melatonin during the day?

- Regulate metabolism

- Regulate core body temp

- Plays a permissive role in skeletal muscle growth

What do T4 and T3 do?

- Autoimmune disease

- Body produces long-acting thyroid stimulator (LATS), causing secretion & growth thyroid at 10-15X the normal rate.

What is Graves Disease?

Regulates calcium & phosphate levels in blood

What does calcitonin do?