7.1 Hormones Flashcards
What are hormones, what secretes them, and what is their purpose?
chemical messengers secreted into the blood by specialized epithelial cells that regulate long-term body functions such as metabolism, internal environment, and growth.
What are the three basic ways hormones act on target cells?
1) By controlling enzymatic reactions
2) By controlling ion or molecule transport across membranes
3) By controlling gene expression and protein synthesis.
what was done back then to study endocrine function in male sexuality and what did Berthold’s experiment with roosters demonstrate?
Castration of animals and men decreased sex drive and fertility. Berthold’s experiment with roosters demonstrated that testes secrete something into the blood affecting the body.
What are the classic steps for identifying an endocrine gland?
1) Remove the suspected gland and observe for deficiencies.
2) Replace the hormone to see if symptoms resolve.
3) Create hormone excess to observe symptoms.
What is the traditional definition of a hormone?
a chemical secreted into the blood by cells to act on distant target cells at very low concentrations.
Where are ectohormones secreted?
Ectohormones are secreted into the external environment.
What are Pheromones a type of and what is their job?
Pheromones are a type of ectohormone that influences other organisms of the same species.
How are hormones terminated in the body (what are they degraded by, what happens to their activity)?
Hormones are degraded by enzymes in the liver and kidneys, and their activity is terminated by removal or inactivation, such as through receptor endocytosis or intracellular enzyme metabolism.
