chemical co-ordination Flashcards
what is chemical co-ordination?
described as a slow, prolonged process of communicating information throughout the body, by ways of chemicals called hormones.
what do endocrine glands secrete?
a variety of hormones
which system does the endocrine system work with ?
the nervous system
how are chemical co-ordination and nervous co-ordination similar ?
they both transfer information
how is chemical co-ordination and nervous co-ordination different ?
by means of speed + response time
characteristics of chemical co-ordination?
- brought about by endocrine system
- influences metabolic activities of all cells by hormones
- hormones travel in bloodstream
- conduction is slow
- causes widespread response in target organs
- response is slow but long lasting
characteristics of nervous co-ordination?
- brought about by nervous system
- regulates activities of muscle glands by means of electrical impulse
- impulses conducted by neurons
- conduction is very fast
- causes specific response in one target organ (effector)
- response is rapid and short lasting
what is a hormone ?
a chemical substance, usually a protein ( sometimes a steroid )
that is secreted but the endocrine gland
+ carried into the bloodstream to is target organs.
what does a hormone do?
regulates metabolic reactions
why don’t hormones last long ?
they are broken down by enzymes
how do hormones operate ?
not on their own
they form integrated systems with other hormones + the nervous system
how are hormones carried and what do they effect ?
hormones are carried in the blood throughout the body
only affect certain cells
how do specific cells respond to hormones ?
they have receptor sites for that hormone
where are the target organs/tissues located ?
in a single gland/ organ
in some cases they are scattered throughout the body as many areas are affected
what is the endocrine gland ?
a small vascular, ductless gland
that secretes hormones that are carried in the bloodstream to their target organs
how are the endocrine glands stimulated?
by changes in the composition of blood
how do stimulated endocrine glands respond ?
by secreting more or less of their hormone
what is the difference between the exocrine and endocrine systems ?
endocrine glands do not have ducts, secretions are carried in the bloodstream to their target organs
eg: adrenal gland
secretion if exocrine glands are carried in ducts to where they are needed
eg: salivary glands, liver + pancreas
what are the endocrine glands in the body ?
hypothalamus
pituitary gland
thyroid gland
islet of langerhans in pancreas
adrenal glands
