Endocrine System Flashcards
How does the Negative Feedback System/Mechanism work?
This mechanism reverses changes that occurred
Brings body back to homeostasis
How does the Positive Feedback System/Mechanism work?
This mechanism reinforces changes that occurred
What regulatory hormones does the hypothalamus produce? What organ do these hormones act on?
Releasing hormones and Inhibiting hormones
These hormones act on the Anterior Pituitary Gland and tell it to release or inhibit release of hormones
What two hormones are synthesized in the hypothalamus?
Antidiuretic hormone
Oxytocin
What gland stores and releases Antidiuretic hormone and Oxytocin?
Posterior Pituitary Gland
The Anterior Pituitary Gland is regulated by which gland?
Hypothalamus
What are tropic hormones?
Hormones that send messages to other glands and tell those glands to release their specific hormones
What hormones are classified as tropic hormones?
Thyroid Stimulating Hormone
Adrenocorticotropic Hormone
Follice Stimulating Hormone
Luteinizing Hormone
What hormones come from the Anterior Pituitary Gland?
Thyroid Stimulating Hormone Adrenocorticotropic Hormone Follice Stimulating Hormone Luteinizing Hormone Growth Hormone Prolactin
How does Thyroid Stimulating Hormone (TSH) work?
Stimulates the thyroid to release thyroid hormones (T3 and T4)
How does Adrenocorticotropic Hormone (ACTH) work?
Stimulates the adrenal cortex to release glucocorticoids (cortisol)
If there is a malfunction of the Anterior Pituitary Gland, what will happen with secretion of its hormones?
There will either be too little or too much of various hormones released
The Posterior Pituitary Gland is an extension of what?
Extension of the hypothalamus
Does the Posterior Pituitary Gland synthesize its hormones?
No
It only stores and releases hormones (Antidiuretic Hormone and Oxytocin)
When would increased levels of Adrenocorticotropic Hormone be present in the body?
During periods of stress, trauma, infection, illness, etc.
Levels of Adrenocorticotropic Hormone (ACTH) would be increased because this hormone is stimulating the Adrenal Cortex to release glucocorticoids (cortisol)
How does Antidiuretic Hormone (ADH) - also known as Vasopressin) - work?
It regulates fluid volume within the body
When released, it tells the kidneys to reabsorb water, thus conserving water within the body
Which endocrine gland can possibly be palpated?
Thyroid Gland
What hormone stimulates the thyroid to release T3 and T4?
Thyroid Stimulating Hormone
What three hormones come from the thyroid?
Triiodothyronine (T3)
Thyroxine (T4)
Calcitonin
What do T3 and T4 do within the body?
Regulate cellular respiration of glucose and fatty acids
Control metabolism throughout entire body and all bodily processes
In order for T3 and T4 to be synthesized by the thyroid, what must be in the diet?
Protein and Iodine
What does calcitonin do within the body?
Inhibits reabsorption of calcium
Lowers serum calcium levels
When is calcitonin stimulated?
When serum calcium levels are too high (hypercalcemia)
It will take excess calcium and store it in the bones and teeth
What hormone is produced by the Parathyroid Gland?
Parathyroid Hormone (PTH)
What does Parathyroid Hormone (PTH) do?
Raises serum calcium levels:
Pulls calcium from bones
Encourages small intestine to absorb more calcium
Encourages the kidneys to reabsorb more calcium
When is Parathyroid Hormone (PTH) secreted?
During hypocalcemia
The Adrenal Medulla releases what hormones?
Epinephrine and Norepinephrine
What effect do Epinephrine and Norepinephrine have on the body?
Act on alpha one, beta one and beta two receptors
Increase the heart rate, increase the force of cardiac contraction, bronchodilation, vasoconstriction of peripheral arteries, vasodilates skeletal muscle arterioles, tells the liver to convert glycogen to glucose for energy
When are Epinephrine and Norepinephrine released?
Released during stressful times (flight or fight) to manage stress response and keep body safe
The Adrenal Cortex releases what hormones?
It releases corticosteroids, which include:
Glucocorticoids (Cortisol)
Mineralocorticoids (Aldosterone)
Gonadocorticoids (Androgens)
What hormones released by the Adrenal Cortex are essential for life?
Mineralocorticoids
Glucocorticoids
What tropic hormone is released to promote the release of Cortisol from the Adrenal Cortex?
Adrenocorticotropic Hormone (ACTH)
What is the target organ of Mineralocorticoids (Aldosterone)?
Kidneys