Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
18 Cards in this Set
- Front
- Back
|
Hormonal Signaling
|
Morphogenesis/tissue development
-cell survival -cell death -regulate cellular proliferation Regulate cellular function -Insulin's role in regulating blood glucose levels Regulate Behaviors -mating behavior -parental care |
|
|
Short vs. Long Range Signaling
|
-Neurotransmitters: short range
-hormones: long-range signaling molecules |
|
|
Hormones
|
-hormones: long-range signaling molecules
-Target cells must have receptors for the hormone -hormones are released into the circulatory system and distributed via bulk transport -Sources of hormones: Nonneural endocrine cells, neursecretory cells |
|
|
More Hormones
|
Source
-specialized secretory cells Mode of transport -released into the circulatory system Physiological role -cell regulators Relative effectiveness -hormones work at low concentrations Blood concentration is regulated -via rate of syntesis, secretion and degradation --Hormones are not defined by their chemical nature |
|
|
Not everything released into blood is a hormone
|
-eg CO2 and O2
-they can act as signaling molecules -cells contain receptors that can bind O2 and CO2 --they mediate physiological response CO2 and O2 are: -not released by specialized cells -found at relatively high concentrations in the blood |
|
|
Classifying Hormones
|
Steroid Hormones
-Synthesized from cholesterol -site of production --gonads --adrenal gland |
|
|
Properties of Steroid Hormones
|
-Steroids Hormones are lipophilic
-can diffuse through membranes -intracellular receptors transport the lipophilic steroid to the nucleus -the receptor-hormone complex binds to specific DNA sequences -When the complex is bound to DNA it can alter the pattern of gene expression |
|
|
Amine Hormones
|
-modified amino acids
|
|
|
Peptide Hormones
|
-Insulin
--consists of 2 peptide chains -peptide hormones are often released as non-active preprohormones -preproinsulin is processed by enzymes to generate active insulin |
|
|
Regulating Hormonal Signaling
|
Multiple Points of regulation
-rate of production of the hormone --both hormonal precursors and active hormones -rate of release -rate of degredation -cellular expression of receptors -Type and density of the receptors |
|
|
Regulating Hormone Signaling
|
Pituitary Gland
-Lies directly below the hypothalamus -Consists of two parts --Anterior Pituitary --Posterior Pituitary |
|
|
Hormones of the Posterior Pituitary
|
-Vasopressin or antidiuretic hormone
--regulates blood pressure and urine production -Oxytocin --uterine contrations -milk production in mammary glands -Neither are synthesized in the posterior pituitary but in neurosecretory neurons located in the hypothalamus and released into the pars nervosa (posterior lobe) |
|
|
Posterior Pituitary
|
-Neural feedback regulates release of the posterior pituitary hormones
|
|
|
Anterior Pituitary
|
Three Regions
-Pars tubueralis -Pars distalis -Pars intermedia -Hormones are synthesized in these structures by nonneural endocrine cells |
|
|
Two classes of hormones generated in the Anterior Pituitary
|
Releasing Hormones/Trophins: target other endocrine glands
-Thyroid Stimulating Horone (THS): targets the thyroid gland Growth Hormones: Promote growth/development of nonendocrine tissues -melanocyte stimulating hormone (MSH): skin cells |
|
|
Regulating the Secretions of the Anterior Pituitary
|
-The endocrine cells of the anterior pituitary are regulated by hormones from the brain
-Neurosecretory neurons located in the hypothalamus release neurohomones into the hypothalamohypohysial portal system --releasing hormones --inhibiting release of hormones |
|
|
Axis of Control
|
-A series of hormonal signals can be involved in the regulation production and secretion of endocrine signals
-hypothalamus to anterior pituitary to adrenal cortex -releasing hormone to stimulating hormones to hormone -negative feedback loops |
|
|
Hormones Modulating Hormones
|
Permissive
-presence of hormone 1 is required in order to respond to hormone 2 Antagonism -hormone 2 antagonizes the response to hormone 1 Synergism -hormone 2 amplifies the response to hormone 1 |
