Introduction (1) Flashcards
What do the nervous and endocrine systems enable animals to respond to?
External changes and to control conditions inside their bodies.
What is chemical co-ordination?
Chemical co-ordination may be described as a slow, prolonged process of communicating information throughout the body by way of chemicals called hormones.
A variety of hormones are secreted by special glands or tissue called _____ glands.
endocrine
What system does the endocrine system work with?
The endocrine system works with the nervous system.
What is a hormone?
A hormone is an organic chemical substance, usually a protein but sometimes a steroid, secreted by an endocrine gland and carried in the blood stream to its target organ / s where it regulates metabolic reactions.
Why do hormones not last long in the body?
Hormones do not last long in the body as they are broken down by enzymes.
Do hormones affect all cells?
No, although hormones are carried in the blood throughout the body, they only affect certain cells.
What do the specific cells that respond to a given hormone have?
The specific cells that respond to a given hormone have receptor sites for that hormone. These cells are known as target tissue or target organs. They can be a single gland or organ or scattered throughout the body.
What is an endocrine gland?
An endocrine gland is a vascular, ductless gland that secretes hormones which are carried in the bloodstream to their target organs. vascular = richly supplied with blood vessels.
How do exo- and endocrine glands differ?
The secretions of an exocrine gland are carried in ducts to where they are needed, e.g. salivary glands, liver, pancreas. Endocrine glands do not have ducts and their bloodstream to their target organs.
