Flashcards in Physiology Deck (45)
The endocrine system involves ducts. True/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
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
Give an example of glycoprotein/peptide hormones
Give an example of a steroid hormone
Give an example of a tyrosine-derivative hormone
A whole protein is always required to achieve hormonal effect. True/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?
Usually has carrier protein in inactive form
Which carrier protein binds cortisol?
Cortisol-binding protein! FANCY THAT
Which carrier protein binds thyroxine (T4)?
Which hormones normally bind to sex steroid-binding globulin?
Free and bound lipophilic hormone are in equilibrium in the blood. True/False?
What does "tropic" mean with regards to hormones?
Refers to a hormone that acts upon another endocrine gland to regulation secretion of hormone
What are the biggest players in elimination of hormone?
Time taken to reach half life of amine hormones is achieved in seconds/minutes/hours
Time taken to reach half life of protein hormones is achieved in seconds/minutes/hours
Time taken to reach half life of steroid hormones is achieved in seconds/minutes/hours
List the 3 main distinct types of hormone receptor
Which of the 3 main types of hormone receptor are cell surface receptors?
Which of the 3 main types of hormone receptor are intracellular receptors?
Describe class 1 nuclear receptors
Activate by steroid hormones
Usually in cytoplasm bound to heat-shock-proteins
Describe class 2 nuclear receptors
Activate by lipids
Present in nucleus
Describe the hybrid class of nuclear receptors
Activated by T3
Similar function to class 1
Give an example of a hormone that utilises signalling via receptor kinases