Endocrine System Flashcards
Who is Arnold Adolph Berthold?
Founder of Endocrinology
Studied chickens
What was Berthold’s Conclusion?
- A secretory, blood-borne product of the transplanted testes is responsible for the normal development of the birds in the second and third groups.
- Today, this product is called TESTOSTERONE
- A slight problem… it is not know why Berthold performed these experiments in the first place. He never provided a clear rationale for it.
Part 1 Berthold’s Experiment Consisted of what?
To establish that castration would keep the castrated male from developing the four adult factors (aggression, a pronounced crown that attracted females, wattles “beard”, they do not sign the stereotypical “cock-a-doodle-do”)
Part 2 of Berthold’s Experiment
He castrated a set of male chicks and then with a small surgical incision, put the excised testes back into the abdominal wall area of the bird and then sutured the incision site. The bird in this part of the study DID develop those four characteristics described above (aggression, crown, wattle, and song).
Part 3 Berthold’s Experiment
He again castrated a set of male chicks but instead of putting the testes back into the abdominal wall area…. He instead swapped one chick’s testes with that of another chick’s tests and then implanted those swapped testes into a castrated bird. Like in Part 2, the birds in this part of the study DID develop those four characteristics described above (aggression, crown, wattle, and song).
What is Endocrinology?
Chemical communication
What is the Nervous System?
“Electrical” communication
What are the 2 Broad Classes of Hormones?
Steroidal Hormones
- can have a “direct effect”
- some cells have receptors for steroidal hormones that will cause a 2nd messenger protein
Created in endocrine gland
Non-Steroidal Hormones
- have an “indirect effect”
- the hormone DOES NOT enter the cell
- instead the cell stimulated by the hormone releases a 2nd messenger signal that causes change
Created in nervous tissue
How can the Endocrine Gland be regulated?
Hurmonal
- some signal in the blood will regulate a gland
- parathryoid gland
Neural
- a nerve impulse can regulate a gland
- Adrenal gland
(spinal nerve that runs into it- adrenal medulla) and (begins to pump out hormones)
Hormonal
- a hormonal signal will regulate a gland
- pituitary gland
What does the Pineal Gland do?
Produces Melatonin
- regulated sleep/wake cycles
- circadian rhythms
What is the purpose of the Hypothalamus?
Neural site; keeps the body stable: homeostasis
What is the purpose of the Pituitary Gland?
Anterior Pituitary
Posterior Pituitary
Pars Intermedia
- MSH; malochore stimulating hormone
- increae in MSH–> increase in melanin production
Development of the Pituitary and Hypothalamus prenatally is critical for successful growth and development of humans.
What are the 6 Primary Hormonal Signals Produced by the Anterior Pituitary Gland
Growth Hormone (GH)
Follicle Stimulating Hormone (FSH)
Luteinizing Hormone (LH)
Thyroid Stimulating Hormone (TSH)
Prolactin (PRL)
Adrenocorticotropic Hormone (ACTH)
Growth Hormone Details
GH
growth and development especially of the muscles and skeleton
Follicle Stimulating Hormone
FSH
a gonadotropin that is going to stimulate the gonads
Luteinizing Hormone Details
LH
a gonadotropin that is going to stimulate the gonads
FSH + LH are known as Gonadotropins
Thyroid Stimulating Hormone Details
TSH
stimulated the thyroid gland
Prolactin Details
PRL
stimulates the production of milk in the mammary glands and production in the sebaceous glands
Adrenocorticotropic Hormone Details
ACTH
stimulates the production of hormones in the adrenal cortex (outer layer of the adrenal medulla)
What are the 2 Hormones of the Posterior Pituitary Gland?
Oxytocin and Antidiuretic Hormone
What is the purpose of Oxytocin?
- ejection reflexes (mammary glands, sebaceous gland, orgasms)
- milk
What is the purpose of the Antidiuretic Hormone (Vasopressin)?
ADH
- water retention in the body
Purpose of Thyrotropin Releasing Hormone
TRH
- promotes secretion of thyroid stimulating hormone (TSH) and prolactin (PRL)