14.1 Hormonal Communication Flashcards
What is the endocrine system
It uses hormones to send info about changes to the environment around the body
What are the endocrine glands
A group of specialised cells that secrete hormones directly into the bloodstream
What are the roles of hormones
They are chemical messengers that carry info from 1 part of the body to the other
They are secreted directly into the blood when glands are stimulated
How do hormones travel around the body
They are transported in blood plasma and diffuse out of the blood and bind to a specific receptor on target cells
These target cells will be stilmulated by the hormones to produce a response
What do steroid hormones do and where are they in the body
They are lipid soluble so can pass through lipid components of cells forming a hormone receptor complex
They are present in the cytoplasm or nucleus
What does it mean by steroid hormones acting as transcription factors
They facilitate or inhibit the transcription of a particular gene
What are non-steroid hormones and what do they do
They are hydrophilic so cannot pass directly through the cell membrane
So they bind to receptors on cell surface of target cells and trigger a cascade reaction mediated by second messengers
What are the adrenal glands
Where are they located
2 small glands located on the top of each kidney
Adrenal cortex
Adrenal medulla
What is the adrenal cortex abs where is it located
On the outer region of the glands
Produces hormones that are vital for life
What is the adrenal medulla abs where is it located
It’s in the inner region of the glands and the hormones are released when the sympathetic nervous system is stimulated
Produces non essential hormones
What hormones are secreted by the adrenal cortex
Glucocorticoids - help regulate blood pressure and metabolism
Mineralacorticoids - control blood pressure and maintains salt and water balance
Androgens - small amounts of male and female sex hormones are released
What hormones are secreted by adrenal medulla
Adrenaline - increases heart rate and raises blood glucose concentration
Noradrenaline - works with adrenaline in response to stress
Increases HR
Widens pupils
Widens air passages
