Intro Flashcards
The endocrine system Coordinates hormone signaling pathways that regulate: ?
- Metabolism
- Growth & development
- Water & electrolyte balance
- Reproduction
What other system does the endocrine system work closely with?
Nervous system
Compare the endocrine and nervous systems
1. Endocrine System A. Secretes hormones that travel through bloodstream B. Action relatively slow C. Effects are prolonged D. More general effetcs 2. Nervous System A. Electrochemical impulses via neurons with neurotransmitters B. Rapid response C. Effects are brief and specific
What does the heart secrete?
ANP & BNP
Important in sodium and water balance
What does the kidney secrete?
Secretes erythropoietin
Hormone essential for production of red blood cells
Define hormones
- Chemical substances that regulate activity of certain cells
- Hormones react with specific receptors
- Organs, tissues, or cells lacking the specific receptor do not respond to its stimulating effects
How are hormones secreted? What are the characteristics of each method?
A. Diffusion 1. Continuous release 2. Steroid hormones B. Pulsatile 1. Peak & ebb relative to: -Circadian rhythm -Response to meals -Hormone releasing factors
What is the action of a hormone?
- Once secreted by endocrine organs, hormones travel to their target tissue
A. Bind to specific receptors
B. Initiate chain of events
-Physiologic effects of hormone
Which type of glands have ducts?
Exocrine
Which type of glands do not have ducts?
Endocrine
How are hormones transported?
- Circulate bound to carrier proteins or free
A. Free = active hormone
B. Bound = reservoir to prolong half life
What are circulating levels of hormones regulated by?
- Rate of secretion
- Nature of secretion
- Hormone degradation and/or uptake
- Receptor binding
- Receptor availability
- Affinity of hormones for plasma carriers
What is the action and source of thyroid hormone?
- Thyroid
2. Controls basal metabolism
What is the action and source of cortisol?
- Adrenal cortex
2. Energy metabolism; basis for sex hormones
What is the action and source of mineralcorticoids?
- Adrenal cortex
2. Regulates plasma volume via effects on serum electrolytes