Endocrine System Flashcards
what is the definition of endocrinology
the study of hormones, their receptors, their intracellular signalling pathways and the diseases associated with them
define the difference between endocrine and exocrine glands
endocrine - does not have a duct system and secretes into the blood
exocrine - has a duct system
give an example of an endocrine gland
thyroid
give an example of an exocrine gland
salivary gland
what is an example of a gland that is both endo and exocrine
pancreas
match the characteristic to the type of gland
acts in short distances
exocrine
match the characteristic to the type of gland
very target specific
exocrine
match the characteristic to the type of gland
slow in response
endocrine
which hormones are water soluble
protein hormones and catecholamines
what are the three types of protein hormones
small peptides, polypeptides and glycoproteins
what are the three lipid soluble hormones
steroids, thyroid hormones and eicosanoids
true or false - protein hormones are not stored after they are made
false - they are, steroid hormones are not stored
pick the correct pathway
a) hormone -> prehormone -> prohormone
b) prohormone -> prehormone -> hormone
c) prehormone -> prohormone -> hormone
c
what are the two types of receptors
cell surface and intracellular receptors
which type of receptors bind to lipid soluble hormones
intracellular receptors
adrenaline and glucagon are examples of what subtype of receptor
G protein linked receptors
explain the steps of the activation mechanism
- enzyme binds to G protein
- 2nd messenger comes in
- protein kinase turns it on
- protein phosphorylation
- response of target cells
insulin and GH are examples of what subtype of receptors
catalytic receptors
what are the most common signalling mechanisms for cellular receptors
- second messengers
- enzyme activation by receptors
- intrinsic enzymatic activity of receptor
define up regulation
an increase in the number of receptors for a hormone
describe the negative feedback loop of PTH secretion and Ca concentration in blood
- low Ca -> endocrine cell is activated
- release of PTH -> target cell
- increase calcium in blood
what is an example of a positive feedback loop mentioned in this lecture
uterine contraction and oxytocin secretion from the posterior pituitary
a _____ hormone is a hormone that controls the secretion of another hormone
tropic
what happens when there is hypo-responsiveness
abnormal receptors -> Dwarfism
defective cell signalling
defective enzyme function in target cells
what is the difference between paracrine and autocrine cells
autocrine -> acts on itself
paracrine -> acts on other cells surrrounding
what are the two anterior pituitary hormones that target the ovaries and testes
FSH and LH
true or false - FSH and LH are secreted from different cell types
false - from same cell types
what is the main target of prolactin
mammary glands
what kind of family do the hormones of the anterior pituitary gland belong to
protein family
state the effect this hormone has on the anterior pituitary hormones
thryotropin releasing hormone
increases TSH secretion
state the effect this hormone has on the anterior pituitary hormones
gonadotropin releasing hormone
increases LH and FSH secretion
state the effect this hormone has on the anterior pituitary hormones
somatostatin
decreases Prolactin
where are the posterior pituitary hormones released from
they are released from nerve endings in the posterior pituitary
where is oxytocin and ADH produced
in the cell bodies of the hypothalamus
what is the most abundant APH
growth hormone
when does the GH mainly promote growth
after birth
how does GH affect fats
increases lipolysis -> increases free fatty acids for energy
true or false - acute stress can decrease GH secretion
false -> it increases it
what are the two disorders that can occur with too much GH
gigantism and acromegaly
what is the specific disorder that stems from the mutation of the GH receptor
Laron dwarfism
major source for ADH and vasopressin
supraoptic nucleus
major source for oxytocin
paraventricular nucleus
