endocrine system Flashcards
what is a hormone
a chemical messenger released by an endocrine gland. they travel in the bloodstream to a specific target organ or tissue where they have an effect.
what is the purpose of the endocrine system
chemical communication in the body
what do endocrine glands regulate?
- metabolism
- growth/development
- reproduction/sexual function
- sleep/mood
gland
An organ or group of specialised cells in the body that produces and secretes a specific substance, such as a hormone
why are only target cells affected by hormones
because they have receptors in their cell membranes
Why must levels of glucose in the blood be controlled?
To provide cells with glucose for respiration/ To stop osmosis of water out of body (somatic) cells into the blood (see diabetes symptoms and issues)
What two hormones control the level of glucose in the blood? Explain the effect of each on blood glucose levels
Insulin (stimulates target cells in the liver to absorb glucose and make Glycogen).
Glucagon (stimulates receptors in target cells in the liver to hydrolyse Glycogen to glucose and release it into the blood stream)
What glandular organ secretes glucagon and insulin?
the pancreas
What endocrine tissue within this glandular organ contains the alpha and beta cells that secrete these hormones?
islets of langerhans
Which cell (alpha or beta) secretes insulin? Which secretes glucagon?
Alpha cells produce Glucagon; Beta cells produce insulin
What disease does someone have if they are unable to produce insulin or their cells are not sensitive to insulin?
diabetes
Why are glucagon and insulin known as antagonistic hormones?
they work in opposite ways
What kind of biological molecule is glycogen?
Polysaccharide (carbohydrate) that serves as a form of energy storage in animals
If the glycosidic bonds in glycogen are broken, what are the monomers that are released?
(Alpha) glucose – can be used in respiration to make energy (ATP)
Insulin regulates levels of what molecule in the blood?
glucose
What disease would be caused if insulin cannot be produced/cells are not sensitive to it?
diabetes