Block C Flashcards
(48 cards)
what are the two main types of hormone
chemically- peptide vs steroid
functionally- short-term vs long-term regulation of function
what are peptide hormones
two amino acid residue molecules joined by disulphide bridges. rapid onset and offset of action, secret in bursts when requires. short term regulation, secreted when needed
example of steroid hormones
cortisol and testosterone
example of steroid-like hormones
thyroxine
what do pituitary glands influence
the thyroid which produces steroid-like hormone thyroxine, adrenal cortex- which produces steroid hormone cortisol, gonads- which produce sex hormones
thyrotrophin path from pituitary gland
thyrotropin -> thyroid -> thyroxine
corticotrophin path from pituitary gland
corticotrophin -> adrenal cortex -> cortisol
gonadotrophin path from pituitary gland
gonadotrophin -> gonads -> sex hormones
growth hormone path from pituitary gland
growth hormone -> liver -> IGF-1
where is insulin produced
pancreas
what do growth hormones effect
growth, calcium ion and phosphate retention, increased protein synthesis, increased blood glucose, increased circulating free fatty acids
steps in the growth of bones
production of cartilage by chondrocytes pf epiphyseal plate
conversion of cartilage to bone at shaft edge of plate
epiphyseal plate becomes converted to bone
then growth stops at this point
what happens when growth hormones go to accelerated lipolysis
increased circulating free fatty acids, resulting in reduced tissue glucose uptake
what happens if growth hormone deficiency occurs before epiphyseal closure
dwarfism
what happens if there is growth hormone excess
if its before growth cessation -> gigantism
if after growth cessation -> acromegaly
what do thyroids secrete
thyroxine and tridothyronine
which influence activity of almost every body system -> required for synthesis of various key enzymes involved in cellular functions
where is the thyroid located
between larynx and trachea
action of thyroid hormones
influence activity of almost every body system -> required for synthesis of various key enzymes involved in cellular functions
what are required for synthesis of various key enzymes involved in cellular functions
cardiac sarcoplasmic ca2+-ATPase, Na-K ATPase, glyceraldehyde 3-phosphate dehydrogenase, beta-adrenoceptors, enzymes involved in fatty acid synthesis
consequences of thyroid hormone deficiency
marked reduction in metabolic rate of tissues, reduced function of most organ systems
what does thyroid deficiency in newborns lead to
congenital hypothyroidism (cretinism) -> impaired growth and development, mental retardation
adults with congenital hypothyroidism
severe mental retardation, dwarfism, impaired sexual development
consequences of thyroid hormone excess
marked increase in metabolic rate of tissues, increased function of most organ systems
structure of testes
interstitial cells, seminiferous epithelium, seminiferous tubules
