Endocrine System Flashcards
Paracrine hormones
Act on neighboring cells
Endocrine hormones
Act on distant cells
Lipid soluble hormones
Cross thro plasma membrane and bind to intracellular receptors
It has a quick process and circulates in blood bound to a transport protein
Water soluble hormones
React with transmembrane receptors which activates a cascade of second messengers
It has a slow process and it circulates in plasma in a free form
Feedback mechanisms
Negative feedback to hypothalamus and pituitary glands limits releasing of signal, while positive feedback stimulates further release
Releasing hormones
From hypothalamus to act on pituitary gland
Stimulating / tropic hormones
From pituitary to stimulate another endocrine gland to release hormones
Non -tropic hormones
From endocrine glands to act directly on target cells
Hypothalamus
Located at the top of the brain stem and is the communications center for the pituitary gland
Secretes releasing hormones (stimulating), somatostatin and dopamine (inhibiting)
Pituitary gland
Secrete hormones to regulate functions and control other glands
Anterior pituitary gland
Glandural tissue that has 5 types of endocrine cells defined by the hormones they secrete
Can be somatotropes, lactotropes, gonadotopes, corticotropes, thyrotropes
Posterior pituitary gland
Neural tissue that secretes neurohypophysical hormones to blood like oxytocin and vasopressin
It doesn’t produce its own hormones, it secretes hormones from hypothalamus
Pancreas
Has endocrine cells called the Islets of Langerhans
The beta cells secrete insulin to initiate the uptake of glucose
The alpha cells secrete glucagon to stimulate the break down of glycogen to glucose
Type l diabetes
When pancreas can’t produce insulin
Type II diabetes
When the insulin receptor isn’t functioning, its the more common one
