Physiology Flashcards
Does the endocrine system involve ducts?
Answer: No it is a ductless system involving glands that secrete directly into blood.
How is specificity of signalling by endocrine glands achieved?
Answer: chemically distinct hormones, specific hormone receptors and distinct distribution of receptors.
List the main endocrine glands of the body
Answer: (1) hypothalamus (2) pituitary (3) parathyroid (4) thyroid (5) adrenal glands (6) pancreas (7) placenta (8) ovaries and testes.
What is meant by autocrine gland?
Answer: hormone release acts back on the structure that released it.
What is meant by a paracrine gland?
Answer: hormone release acts on neighbouring structures.
List the 3 main classes of hormones
Answer (1) glycoproteins and peptides (2) steroids (3) tyrosine derivatives.
Give an example of glycoprotein/peptide hormones
Answer: (1) insulin (2) growth hormone (3) oxytocin and (4) prolactin.
Give an example of a steroid hormone?
Cortisol and Testosterone
Give an example of a tyrosine-derivative hormone?
Adrenaline, Thyroid Hormone and Melatonin
A whole protein is always required to achieve hormonal effect. Is this statement true or false?
Answer: False as a protein can be cleaved into active hormonal units
On a basic level how are amines, peptides and proteins released from their respective endocrine cell?
Synthesised then packaged into vesicles and released in response to a 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 and rate of conversion into pregnenolone which is then used to build steroids to be released
Steroid hormones travel freely in blood. True or false?
False as usually has a carrier protein in inactive form.
Which carrier protein binds cortisol?
Cortisol binding protein
Which carrier protein binds thyroxine (T4?)
Thryoxine-binding globulin
Which hormone usually binds to sex steroid-binding protein?
Testosterone and Oestradiol
What does topic mean with regards to hormone action?
Refers to a hormone that acts upon another endocrine gland to regulate secretion of hormone.
What organs in the body have the greatest role in elimination of hormones?
Answer: Liver and Kidney
Time taken to reach half life of amine hormones is achieved in?
Answer: Seconds
Time taken to reach half life of protein hormones
Minutes
Time taken to reach half life of steroid hormones is achieved in?
Hours
List the 3 main distinct types of hormone receptors
GPCR
Receptor Kinases
Nuclear Receptors
Which of the 3 main types of hormone receptor are cell surface receptors?
GPCR and Receptor Kinases
Which of the 3 main types of hormone receptors are intracellular receptors?
Nuclear Kinases
