Anatomy and Physiology 1 Updated Study Guide Human Anatomy & Physiology 1 . 1 / 4
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Endocrine System
What are the 4 principles that cells communicate with each other?• Cells communicate with each other through • (1) gap Junctions, which join single-unit smooth muscle, cardiac muscle, epithelial and other cells to each other. They let cells pass nutrients, electrolytes, and signaling molecules directly from the cytoplasm of one cell to the cytoplasm of the NXT thru pores in their plasma membrane.• (2) Neurotransmitters help cells communicate with ea. other by letting go neurons, the neurons spread across a narrow synaptic cleft, & bind to receptors on the surface of the next cells.• (3) Paracrine are sometime called local hormones, they are secreted by one cell and spread to other cells close by in the same tissue, & stimulate their physiology.• (4) Hormones are chemical messengers that secrete cells into the blood stream.
Vocab:
1. Endocrine sys: compromised by glands, tissues, & cells that secrete
hormones
2. Endocrinology: study of the treatment / diagnosis of its disorder
- What are the differences b/w the endocrine and exocrine glands?
1) Exocrine Glands
a) Secrete their products thru DUCTS onto an epithelial surface like the skin or the mucosa
of the digestive tract.
- they have EXTRACELLULAR EFFECTS such as digestion of food
2) Endocrine Glands
a) DUCTLESS release their secretion into the BLOODSTREAM
b) INTRACELLULAR EFFECTS - change cell metabolism What are the differences b/w
nervous and endocrine system?
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What are the functions of hormones?• Hormones help regulate the chemical structure/ volume of its internal environment (interstitial fluid), metabolism and energy balance, contraction of smooth muscle and cardiac muscle fibers.• Glandular secretions and some immune system activities.• Controls growth/development • Regulate operation of reproductive systems • Helps establish circadian (Sleep) rhythms
Why is the is the target-cell concept essential for understanding hormone function?• Only target cells and organs respond to certain hormones that are sent thru the blood stream b/c they have receptors that will bind to it. W/o these receptors the hormones will not bind, and no effect will be made to the body.What is down-regulation?• When a hormone is present in excess the # of target- cell- receptors may decrease.What is up-regulation?• When a hormone is lacking the # of receptors may increase. This makes the target cell more Sensitive.What are the hormone receptors?• Protein or glycoprotein molecules (on plasma membrane, in the cytoplasm, or nucleus) • Act like switches turning the metabolic pathways when hormones bind to them • Receptor- hormone interactions show specificity & saturation • Specific receptors for ea. Hormone • Saturated when all receptor molecules are taken by a hormone molecule
Signal Amplification
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