Ch:25 The Endocrine System Flashcards
An endocrine gland has NO ______; thus, their secretions are picked up and transported to their site by the bloodstream.
ducts
Endocrine has NO ducts
Steroid hormones are synthesized from _________.
Cholesterol
Steroid hormones are lipid _____… thus can pass through the cell membrane and bind to nuclear receptors.
soluble
What is an example of a peptide hormone?
Insulin
Amine hormones are called _______.
catecholamines
Catecholamines are made from the amino acid ______.
Tyrosine
Are amine hormones hydrophobic or hydrophilic?
Hydrophilic (H2O soluble)
A neurohormone called _______ is also a catecholamine.
Dopamine
ESSENTIAL CONCEPT: An endocrine gland secretes a hormone, it travels through the ______ to its target site. At the site, the hormone enters the cell by passing through the membrane. The hormone binds to a receptor and it likely enters the nucleus. In the nucleus, activation of ______ synthesis occurs. mRNA then can enter cytoplasm to make proteins.
Blood; mRNA
Hormones are often involved what is called a _______. This simply refers to a series of chemical rxns which are initiated by a molecular binding on a receptor.
cascade
What is the difference between H2O-soluble hormones and Lipid-soluble hormones? (hint: receptors)
“A VERY IMPORTANT CONCEPT, FOLKS!!”
H2O-soluble hormones bind to cell-surface receptors
Lipid-soluble hormones bind to intracellular receptors
What is the link between the nervous and endocrine systems?
Hypothalamus (located in the brain)
What hormones does the hypothalamus synthesize?
ADH (vasopressin) and Oxytocin
Where is vasopressin (ADH) and oxytocin synthesized and where are they stored?
ADH (vasopressin) and Oxytocin are synthesized in the hypothalamus but stored in the POSTERIOR pituitary
What is the function of Oxytocin?
STIMULATES MILK SECRETION
stimulates contractions of the uterus and stimulates mammary glands to assist in milk ejection
What is the function of ADH (vasopressin)?
Involved with H2O retention by the kidneys.
If there is severe blood loss (hemorrhage), by retaining more H2O, this increases the blood volume, hence the blood pressure. Thus, this hormone decreases urine volume.
Some hormones of the anterior pituitary are called tropic hormones, meaning ____________.
stimulate other endocrine glands to release their hormones
What 7 hormones are secreted by the anterior pituitary?
- Growth Hormone (GH): Somatotropin
- LH: (Luteinizing Hormone)
- FSH (Follicle Stimulating Hormone)
- TSH (Thyroid Stimulating Hormone)
- ACTH (Adrenocorticotropic Hormone)
- Prolactin: NON-tropic
- MSH (Melanocyte-Stimulating Hormone): NON-tropic
What is another name for Growth Hormone?
Somatotropin
What is the purpose of Growth Hormone?
- involved in bone growth
- increases DNA, RNA and protein synthesis
- Stimulates the liver to release IGFs… insulin growth factors which allow for bone and cartilage growth
- Increases blood sugar
What is the purpose of FSH?
Ovarian follicle in women, spermatogenesis in males
What is the purpose of LH?
Stimulates ovulation, progesterone secretion, corpus luteum formation in women, and stimulates testosterone secretion in men?
What is the purpose of TSH?
Stimulates thyroid to make hormones and release them
Which hormone from the anterior pituitary stimulates ovulation, progesterone secretion, corpus luteum formation in women and testosterone secretion in men?
LH
Which of the 7 anterior pituitary hormones are NOT TROPIC?
Prolactin and MSH
MEANING THEY DON’T CAUSE CASCADES
What are the 5 TROPIC-hormones of the anterior pituitary?
- GH
- LH
- FSH
- TSH
- ACTH
(ALL CAUSE CASCADES)
“A VERY IMPORTANT CONCEPT”