Review Sheet #1 B Test 3 Biology 1108 Dr. Adams
Hormonal Control - Endocrine System; one of two control systems in animals
Concepts:
Hormone Classes: your book talks about four types, but I will simplify this to two.
Mechanism of Action B you will learn that the mechanism of action is quite different for lipid versus protein-based hormones (know what the different mechanisms are), but the end result is the same B active proteins in cells that did not have this activity previously.
Hormonal control in other organisms B an example
Control of growth/molting/metamorphosis in insects.
Involves the release of two series of semi-antagonistic
(neuro)hormones:
1. Juvenile hormone released from corpus allatum that stimulates maintenance of juvenile
characteristics (maintains larval state)
2. Brain hormone (released from brain!) that stimulates release of ecdysone (molting
hormone) from prothoracic glands B stimulates molting.
Stretch receptors respond to growth by stimulating brain to release brain hormone periodically. As larva gets bigger, proportionally less and less juvenile hormone is released, so eventually a molt occurs into the pupal, and then adult stages.
Human Endocrine Organs SEE BOOK and HANDOUT
Actually includes a number of different organs in the body, including such organs as the heart, stomach, intestines, etc. Covered here are the Aclassic@ endocrine organs.
I. Pancreas B Islets of Langerhans
two types of cells: α cells - glucagon; β cells - insulin - glucose metabolism
II. Adrenal (Aat kidney@) glands B compound gland
A. Medulla: epinephrine/norepinephrine B many stimulatory effects
B. Cortex: around 2 dozen hormones; 3 types of corticosteroids
1. glucocorticoids B glucose metabolism
2. mineral corticoids B regulation of ion (Na+/K+) balance
3. gonadocorticoids B androgens (supplementary sexual hormones)
III. Thyroid gland
A. thyroid hormones B stimulates increase in metabolism (increases temperature); growth (protein
synthesis/distribution)
B. calcitonin B Ca+2 excretion and uptake by bones
IV. Parathyroid glands - PT hormone - Ca+2 retention from kidneys, absorption from digestive tract
(through activation of vitamin D), and release from bones
V. Pineal Gland - melatonin - metabolic depressant, whose
release is inhibited by light. Therefore,
involved in circadian rhythms/moods;
also inhibits release of GnRH from Hypothalamus
VI. The Pituitary Gland and the Hypothalamus
A. The Pituitary - compound gland
1. Posterior (Neurohypophysis)
-- hormones released from here are produced in the hypothalamus
a. oxytocin - uterine contraction/ejection of milk from breasts
b. ADH (antidiuretic) - water resorption in kidney
2. Anterior (adenohypophysis): 6 major hormones; most are tropic hormones
a. Growth hormone
(GH)
b. Prolactin - milk production
c. Thyroid stimulating hormone
(TSH)
d. Adrenocorticotropic hormone (ACTH)
e. Gonadotropic hormones - stimulates ovaries/testes
i. follicle stimulating hormone (FSH)
ii. luteinizing hormone (LH)
B. The Hypothalamus (a neuroendocrine organ): the true Amaster@ gland; produces
releasing/inhibiting hormones
1. Growth hormone releasing hormone (GHRH) and GH inhibiting hormone
(GHIH)
2. Prolactin RH (PRH) and PIH
3. Thyroid RH (TRH)
all control precise timing and
4. Corticotropic RH (CRH)
release of (stimulating) hormones
5. Gonadotropic RH (GnRH)
from the anterior pituitary
VII. Gonads:
A. Ovaries - estrogen and progesterone
B. Testes - testosterone