Hormones
| English | Chinese | Pinyin |
|---|---|---|
| hormones | 激素 | jī sù |
| gland | 腺体 | xiàn tǐ |
| endocrine system | 内分泌系统 | nèi fēn mì xì tǒng |
| target organs | 靶器官 | bǎ qì guān |
| insulin | 胰岛素 | yí dǎo sù |
| adrenaline | 肾上腺素 | shèn shàng xiàn sù |
Chemical messengers
- Not all the body's messages are electrical. Some are chemicals carried in the blood.
- These are hormones 激素, made by glands 腺体 of the endocrine system 内分泌系统.
A hormone is a chemical messenger carried in the:
Hormones travel in the blood to target organs.
Hormones are produced by organs called ______.
Endocrine glands secrete hormones into the blood.
What hormones are
- A hormone is a chemical messenger made by a gland and carried in the blood.
- It affects specific target organs 靶器官.
Insulin 胰岛素 lowers blood glucose and glucagon raises it, keeping it near a normal level
How hormones work
Hormones are chemical messengers carried in the blood — slower than nerves, but longer-lasting.
Adrenaline prepares the body for:
Adrenaline is the fight-or-flight hormone.
Insulin, made by the pancreas, acts to:
Insulin lowers blood glucose.
Some key hormones
- Adrenaline 肾上腺素 (adrenal glands): prepares the body for action ("fight or flight").
- Insulin (pancreas): lowers blood glucose.
- Testosterone / oestrogen: control development and reproduction.
Hormonal responses are usually slower but longer-lasting than nervous responses.
Nerves are fast and brief; hormones are slower and widespread.
Nerves vs hormones
- Nervous signals are fast and short-lived, sent to a precise place.
- Hormonal signals are slower but longer-lasting, spread through the blood.
Worked example. Facing danger, your adrenal glands release adrenaline into the blood. It reaches the heart (faster beat), muscles and liver — preparing your whole body to fight or flee within seconds.
You've got it
- a hormone is a chemical messenger made by a gland, carried in the blood
- examples: adrenaline (fight or flight), insulin (lowers glucose), sex hormones
- nerves = fast, brief, precise; hormones = slower, longer-lasting, widespread