Physiology Flashcards
The endocrine system involves ducts. True/False?
False
It is a ductless system involving glands that secrete directly into blood
How is specificity of signalling by endocrine glands achieved?
Chemically distinct hormones
Specific hormone receptors
Distinct distribution of receptors
List the main endocrine glands of the body
Hypothalamus Pituitary Parathyroid Thyroid Adrenal gland Pancreas Placenta Ovaries/testes
What is meant by an autocrine gland?
Hormone released acts back on the structure that released it
What is meant by a paracrine gland?
Hormone released acts on neighbouring structures
List the 3 main classes of hormones
Glycoproteins + peptides
Steroids
Tyrosine derivatives
Give an example of glycoprotein/peptide hormones
Insulin
Growth hormone
Oxytocin
Prolactin
Give an example of a steroid hormone
Cortisol
Testosterone
Give an example of a tyrosine-derivative hormone
Adrenaline
Thyroid hormone
Melatonin
A whole protein is always required to achieve hormonal effect. True/False?
False
Protein can be cleaved into active hormonal units
On a basic level, how are amines, peptides and proteins released from the endocrine cell?
Synthesised, packaged into vesicles and then released in response to stimuli via exocytosis
On a basic level, how are steroid hormones released from the endocrine cell?
Synthesised upon demand, then stimuli increases cellular uptake and availability of cholesterol + rate of conversion into pregnenolone, which is then used to build steroid to be released
Steroid hormones travel freely in blood. True/False?
False
Usually has carrier protein in inactive form
Which carrier protein binds cortisol?
Cortisol-binding protein!
FANCY THAT
Which carrier protein binds thyroxine (T4)?
Thyroxine-binding globulin
Which hormones normally bind to sex steroid-binding globulin?
Testosterone
Estradiol
Free and bound lipophilic hormone are in equilibrium in the blood. True/False?
True
What does “tropic” mean with regards to hormones?
Refers to a hormone that acts upon another endocrine gland to regulation secretion of hormone