B3.2 The Endocrine System Flashcards
What are hormones? Where are they secreted and how do they travel?
Hormones are chemical messengers which control your body. They are secreted and made in glands and travel in blood plasma to cause a response in the target organ
What do hormones do?
Hormones regulate the function of organs and cells. They are usually long term(EG puberty) but sometimes short term(adrenaline).
They also maintain homeostasis
What does thyroxine do and where is it released from?
Thyroxine - controls metabolic rate, growth and digestion throughout the entire body
It is important because it determines how fats substances are broken down, how much oxygen tissues use and the development of a growing child
Takes iodine and converts it to thyroxine by combining with tyrosine amino acid
Released by the thyroid gland
Where is the master of all hormone production?
The pituitary gland and hypothalamus in the brain which produce hormones to produce other hormones
What does adrenaline do?
If your body is under stress adrenaline is secreted by the adrenal glands. It:
Increases heart rate
Breathes faster to respire more
Respires more
Converts glycogen to glucose in the liver to increase concentration
Dilates your pupils to let in more light
Diverts blood to muscles and limbs from the digestive system
Prepares you for fight or flight
THIS DOES NOT INVOLVE A NEGATIVE FEEDBACK LOOP
How do hormones work?
They diffuse out of the blood and bind to receptors(target cells) on the membrane or cytoplasm of a cell in the target organ. They then stimulate a response
What is the endocrine system?
It is the name given to all the glands and hormones in the body. They control body processes in the nervous system
What are the main differences between the nervous and endocrine system
- the nervous system is very fast in comparison to the endocrine
- nervous signals are transported as electrical impulses using neurones while hormones are transported in the blood
- nerves are short term while hormones are long
- nervous signals target one muscle or area while hormones target a larger area
- Hormones Control homeostasis and keep conditions constant
