Pituitary Gland Flashcards
What is a hormone?
A messenger
What are the two main groups of hormones?
Peptide
Steroid
How are peptide hormones synthesised?
As prohormones requiring further processing e.g. cleavage to activate
How are steroid hormones made?
In a series of reactions from cholesterol
How are peptide hormones stored?
In vesicles
Regulatory secretion
How are steroid hormones released?
Immediately
Constitutive secretion
Where are receptors for peptide hormones?
On cell membrane
Where are receptors for steroid hormones?
Intracellular
Change gene expression directly
What makes up the anterior pituitary?
Pars tuberalis
Pars intermedia
Pars distalis
Where does the pituitary gland sit?
In the sella turcica
What are parvocellular neurons?
Short neurons
Release hypothalamic factors into the capillary plexus in median eminence
Regulates anterior pituitary function
What are the 5 subtypes of endocrine cells that make up the anterior pituitary?
Somatotrophs Lactotrophs Corticotrophs Thyrotrophs Gonadotrophs
What is the first step of anterior pituitary regulation?
Axon terminals of hypothalamic neurosecretory cells release hormones into the hypothalamo-pituitary portal system
What is the second step of anterior pituitary regulation?
The RH’s and IH’s travel in the portal system to the anterior pituitary
What is the third step of anterior pituitary regulation?
The RHs and IHs stimulate or inhibit the release of hormones (black dots) from anterior pituitary cells
What is the fourth step of anterior pituitary regulation?
Anterior pituitary hormones leaves gland via the blood
What do the blood vessels make up?
Hypothalamo-pituitary portal system
What are somatotrophs?
Growth hormone
What do lactotrophs make?
Prolactin
What do thyrotrophs make?
Thyroid stimulating hormone
What do gonadotrophs makes?
Lutenising hormones
Follicle stimulating hormone
What do corticotrophs make?
Andrenocorticotrophic hormone
What is different about growth hormone?
What are the regulators?
Has on/off mode
On- growth hormone releasing hormone
Off- Stomatostatin
What is the regulator for prolactin?
Dopamine
Inhibitory
What is the hypothalamic stimulus for TSH?
Thyrotrophin releasing hormone
What is the hypothalmic receptors for LH and FSH?
Gonadotrophin releasing hormone