Endocrinology Flashcards
What does the posterior pituitary gland produce?
ADH and oxytocin
What are the carrier proteins for ADH and oxytocin called?
Neurophisins
Difference between anterior and posterior pituitary glands?
Anterior has no direct neural connection to hypothalamus
How does the hypothalamus communicate with the anterior gland
By small regulatory hormones synthesised by the hypothalamus via hypothalamic portal system
How do ADH and oxytocin reach the posterior gland?
Via nerve axons
What does oxytocin do?
Controls interuterine contractions and lactation
What does ADH do?
Enhances reabsorption of water from kidney collecting ducts
What is the hypothalamic portal system?
System allowing communication between hypothalamus and anterior
Name 6 hormones produced by anterior pituitary gland (FLATPG)
Growth hormone Prolactin Thyroid stimulating hormone Follicular stimulating hormone Leutinising hormone Adrenocorticotrophic hormone
What organ does growth hormone act on?
Liver
What organ does FSH act on and what does it do?
Ovary and testes- oestrogen synthesis, oogenesis and spermatogenesis
What does LH act on?
Ovary and testes - ovulation, corpus leutheum development and testosterone synthesis
What does adrenocortictrophic hormone do (acth)
Adrenal cortex of skin- glucocorticoid synthesis- pigmentation
How are thyroid hormones formed?
In thyroid gland by iodination and coupling of tow molecules of the amino acid tyrosine
What is iodine in the diet used for?
1/3 used by thyroid gland and small amount in salivary glands- rest excreted
What initiates uptake of iodine from diet?
TSH
What halpens iodide within the thyroid gland?
It is converted to iodine
What happens thyroglobulin?
The thyrosine residues of thyroglobulin are iodine see to form mono and di-iodotyrosine (MIT and DIT)
What is thyroxine (T4) made of?
DIT and DIT coupled
What is triiodothyronine (T3) made of?
MIT and DIT
How are thyroid hormones released into blood? Clue= follicular cells
Thyroglobulin taken up into follicular cells that fuse with lysosomes to form phagocytic vacuoles. Subsequent proteolysis releases thyroid hormone
What is TSH?
28kda glycoprotein made up of an alpha and beta subunit