Endocrine System Flashcards
What are hormone and how do they effect target cells?
- specialized chemical substances produced and secreted by an endocrine organ or cell
- effective only at specific target cell
- influence target cells by binding to integral proteins or glycoprotein molecules(receptors)
Circulating hormones
Hormones hat pass into the blood and act on distinct target cells
Circulating hormones are also called…..
Endocrine system
Local hormones
Act locally without first entering the blood stream
Two types of local hormones are…
Paracrines: act on neighboring cells
Autocrines: act on the same cell that secreted them
Hormone
Secreted into the blood to reach their target cells
Neurohormone
Produced by neurons and function like hormones
The type of hormone that influences a post-synaptic cell is…..
Neurotransmitters: released by neurons in the synapse
Pheromone
Chemical signal secreted into the environment that modifies the behavior of other individuals
Chemical classification of hormones
- Amines
- Polypeptides/proteins
- Steroids
- Ecosanoids
Hormones derived from tyrosine and tryptophan and are secreted by the adrenal medulla
Amines
- epinephrine
- thyroid hormones
- serotonin
Class of hormone that is synthesized from rough endoplasmic reticulum and exported from the cell
Polypeptide and protein
Hormones that consist of chains of amino acids are….
Insulin (pancreas)
Erythropoietin (kidney)
Antidiuretic hormone (posterior pituitary)
Ductless glands vs. glands with ducts
Ductless: Endocrine glands
-secrete hormones into extra-cellular spaces and they enter the blood stream and travel to target areas
Glands with ducts: Exocrine glands
-empty into ducts that transport them directly to specific areas
(Ex salivary and sweat glands)
