WEEK 6: Endocrine Control and Metabolic Processes Flashcards
what is the endocrine system?
Series of glands that synthesise and secrete hormones or chemical messengers
what does positive feedback aim to do?
response sustains or enhances stimulus
what does negative feedback aim to do?
response reduces stimulus
what is the pituitary gland?
body’s ‘master gland’ – controls the activity of most other hormone-secreting glands/cells
what regulates the pituitary gland?
hypothalamus
what are steroid hormones derived from?
cholesterol
what is the humoral mechanism?
hormones are released in response to changing levels of something like ions in the blood
what is the hormonal mechanism?
what is the neural mechanism?
slide 8
how does a water soluble hormone cell signal?
binds target cell receptors and induces cellular response
how does a lipid soluble hormone cell signal?
diffuses into target cell/nucleus and binds target receptor - directly triggers cell response. Receptor enters nucleus and binds to (i) DNA binding protein or (ii) hormone response element in DNA
what are the 3 types of hormone signalling?
endocrine, panacrine, autocrine
what is endocrine signalling?
secreted hormones diffuse into blood and act on target cells anywhere in the body
what is paracrine signalling?
secreted hormones diffuse locally and act on nearby cells
what is autocrine signalling?
secreted hormones act on the same cell that produced it
structure of the pituitary gland?
PG consists of two lobes – posterior and anterior
what are neurohormones released by?
neuroendocrine cells
slide 11 adm 12
Anterior pituitary secretes multiple hormones that regulate which various cellular?
metabolism, osmoregulation, reproduction.
what are tropic hormones?
they target other endocrine glands – regulate the activity of other endocrine glands – e.g. FSH and TSH
what are non-tropic hormones?
they target non-endocrine cells - cellular growth, metabolism etc – e.g. prolactin and MSH
slide 15??? dk if u need to know
what cells produce insulin?
beta cells
what cells produce glucagon?
alpha cells
what does insulin do? (3)
Stimulates glucose uptake (e.g. GLUT4 translocation to plasma membrane of liver and muscle cells)
Halts gluconeogenesis
Promotes glycogenesis (conversion of glucose to glycogen)
what does glucagon do? (4)
Stimulates glycogenolysis (conversion of glycogen to glucose)
Promotes gluconeogenesis
Reduces glucose consumption by the liver
Promotes lipolysis
