endocrine system

Question 1

what is a hormone

Answer 1

chemical substance, produced by an endocrine gland, carried by blood, alters activity of one or more specific target organs and then destroyed by liver

Question 2

what is endocrine system

Answer 2

collection of endocrine glands that secrete hormones directly into blood stream to be carried towards target cells or organs

Question 3

what is a gland

Answer 3

a group of cells that produce and secrete chemicals for release.

Question 4

name 6 characteristics of hormones

Answer 4

-small soluble
-effective in low conc
-produced by 1 organ
-secreted into and carried to all parts of body by blood
-has an effect at site different than where synthesised
-specific, so only organs with specific receptors respond to hormone

Question 5

what happens before effects of adrenaline secretion

Answer 5

stimulus detected by hypothalamus in brain, transmission of impulses down to spinal cord

motor neurones transmit nerve impulses to adrenal gland

adrenal gland secretes adrenaline into bloodstream, adrenaline transport to target organs

Question 6

possible stimulus for adrenaline secretion

Answer 6

stress, anxiety, fear, anger