click below
click below
Normal Size Small Size show me how
Homeostasis/Endocrin
Definitions of key words
Term | Definition |
---|---|
Homeostasis | The maintenance of a constant internal environment |
Stimulus | A 'change' in the internal or external environment |
Sensor | The part of the body that detects a change in conditions either external or internal |
Communication System | The part of the body that receives signals from sensors and reacts in a way that will change the conditions |
Effector | The actions that are carried out that will effect a change in conditions |
Response | The result of the actions of the effectors |
Ectotherm | An organism that cannot maintain it's own body temperature |
Endotherm | An organism that can maintain it's own body temperature |
Negative feedback | The effectors are 'switched off' due to conditions returning to optimum (normal) |
Positive feedback | The effectors are NOT 'switched off' and conditions will continue to be out of control (worsen) |
Endocrine system | Collection of glands of an organism that secrete hormones directly into the circulatory system to be carried towards a distant target organism. |
Hormone | A chemical messenger |
Endocrine gland | A gland that secretes substances directly into the blood |
Exocrine gland | A gland that secretes substances directly into a duct |
Target tissue | The tissue that is affected by a particular hormone |
Pancreas | An organ that contains both endocrine and exocrine tissue |
Insulin | A hormone that lowers the amount of glucose in the blood |
Glucagon | A hormone that raises the amount of glucose in the blood |
Hepatocytes | Liver cells |