6.1 Anatomy of the Endocrine System Flashcards
What does the Endocrine system do in coordination with the nervous system?
coordinates the various activities of the body parts utilizing chemical messengers
How does the nervous system coordinate activities of the body?
neurons release neurotransmitters that influence the excitability of other neurons
How does the Endocrine system coordinate the various activities of the body?
hormones that are typically released directly into the bloodstream
Which system reacts quickly to external and internal stimuli?
nervous system
What system reacts slowly to external and internal stimuli?
endocrine system
Why is the Endocrine system slow to respond?
takes a while for the hormone to travel through the bloodstream to its target organ
How do the cells that can react to a hormone work?
that have receptors on their cell surface that combined with the hormone in a lock and key method
What is a hormone?
organic chemical produced by one set of cells that acts on a different set of cells
How do hormones function?
mechanical messengers that influence the metabolism of the recipient cell
What do all hormones have?
specific organ/gland of origin
specific target organ/gland
specific actions
What are many hormones classified as and how are the made?
protein; coded for by genes and synthesized within the cytoplasm at ribosomes
Once hormones are synthesized by ribosomes what occurs to them?
packaged by the Golgi into vesicles and secreted at the plasma membrane
What are the two main categories of hormones?
peptide hormones
steroid hormones
What are peptide hormones derived from?
proteins, peptides, or catecholamines
What is the function of peptide hormones?
activate existing enzymes in the cell
How long does it take for peptide hormones to act/how long does their influence last?
act relatively quickly but only for a short period of time
What are steroid hormones derived from?
cholesterol by a series of metabolic reactions
How long does it take for steroid hormones to act/how long does their influence last?
act slower than peptide hormones but their effect lasts longer
Why does it take longer for steroid hormones to act as compared to peptide hormones?
takes longer to synthesize new proteins than to activate enzymes that are already present in the cell
Where are steroid hormones stored?
fat droplets in the cytoplasm
