Intro Flashcards
The word hormone is derived from the Greek hormao meaning…
To excite
Endocrine
glands ‘pour’ secretions into blood stream (thyroid, adrenal, beta cells of pancreas)
What does exocrine mean?
Glands ‘pour’ secretions through a duct to site of action (pancreas - amylase, lipase)
Endocrine hormone action
Blood-borne, acting at distant sites
Paracrine
Acting on adjacent cells
What does the term “autocrine” mean?
Feedback on the same cell that secreted hormone
Water-soluble hormones are unbound and bind to s______ r______ of target cell
surface receptor
Water-soluble hormones have a _____ half-life and _____ clearance
short, fast
Examples of water-soluble hormones
Peptides (insulin, glucagon), monoamines (histamine, dopamine)
which are stored in vesicles
Fat-soluble hormones are p_____ b____ and diffuse into target cell
protein bound
Fat-soluble hormones have a _____ half life and ____ clearance
long, slow
Fat-soluble hormone examples
Thyroid hormone, steroids
Steroids are s______ on demand
synthesised
Peptides can vary in length and have a l____ or ring structure
linear
Peptides are made of 2 chains and may bind to c______
carbohydrates
Peptides are stored in s_____ g_____, they are hydrophilic and water soluble
secretory granules
Peptides are released in pulses or bursts and cleared by…
tissue or circulating enzymes
After insulin has bound to receptor proteins, it p______ the receptor
phosphorlyates
Phosphorylation of receptor causes t_______ k_____ to become active
tyrosine kinase
Following the activation of tyrosine kinase, phosphorylation of signal molecules triggers cascade of effects resulting in g____ uptake and a_____ reactions
glucose, anabolic
Amines
** look at 14:15?
Are thyroid hormones water soluble?
No
99% of iodothyronines are p____ b___
protein bound
Only 20% of T_ is secreted directly by thyroid
T3
Secretory cells release thyroglobulin into c_____
colloid
Which molecules are incorporated to form the iodothyrosines?
Iodine and tyrosine
C______ of iodothyrosines gives rise to T3 and T4
conjugation
Where are T3 and T4 stored?
In colloid bound to thyroglobulin
___ stimulates the movement of colloid into secretory cell
TSH
T4 and T3 are c______ from thryoglobulin
cleaved
Hormone receptor location
**
Cholesterol derivatives and steroids eg vitamin D are ____ soluble
fat
Vitamin D enters cell directly to nucleus to stimulate ___ production
mRNA
How is Vitamin D transported?
Vitamin D binding protein
A__________ and g______ steroid are 95% protein bound
Adrenocortical
Gonadal
After entering cell, adrenocortical and gonadal steroids pass to nucleus to induce a response, are altered to active m______, bind to a cytoplasmic receptor
metabolite
*** Slide 19
Slide 21 ***
Slide 22 ***
Hormone metabolism means
Reduced function of that hormone
What does synergism mean?
Combined effects of 2 hormones amplified (eg glucagon with adrenaline)
Antagonism
One hormone opposes other hormone (eg glucagon antagonizes insulin)
Hormones controlling the posterior pituitary are synthesised in the…
hypothalamus
What are the 2 hormones which are stored in the posterior pituitary gland?
Oxytocin and ADH
What hormones are associated with the anterior pituitary gland?
TSH, ACTH, FSH, LH, GH and PRL (prolactin)
In periphery T_ is converted to T_
T4 to T3
The half life of T4 is
5 to 7 days
The half life of T3 is
1 day
