Flashcards in Pituitary Gland Deck (35):
What is the pituitary gland?
"Master" endocrine glands because it secretes several hormones that control other endocrine glands
Where is the pituitary gland?
Small region of the brain below the thalamus
Lies in the hypophyseal fossa of the sella turcica of the sphenoid bone
What does the pituitary gland link?
The nervous and endocrine system
How many cells does the hypothalamus synthesise?
At least 9 different hormones
How many cells does the pituitary gland synthesise?
What is the shape and size of the pituitary?
Pea shaped structure
What does the pituitary gland attach to?
The hypothalamus by a stalk (infundibulum)
What are the two portions of the pituitary gland?
Anterior pituitary gland
Posterior pituitary gland
What are the two parts of the anterior pituitary gland in an adult?
Pars distalis (larger portion)
Pars tuberalis (forms sheath around infundibulum)
What is the posterior pituitary composed of?
What does the posterior pituitary consist of?
What's the third part of the pituitary gland?
Pars Intermedia (only in fetal development)
What are the six major anterior pituitary hormones?
TSH (Thyroid stimulating hormone)
ACTH (Adrenocorticotropic hormone)
FSH (Follicle stimulating hormone)
LH (Luteinising hormone)
What is GH (Somatotropin) involved in?
Insulin-like growth factor (IGF-1) & metabolic effects
What is TSH (Thyroid stimulating hormone) involved in?
Secretion of thyroid hormones
What is ACTH (Adrenocorticotropic hormone) involved in?
Cortisol from adrenal cortex
What is FSH (Follicle stimulating hormone) involved in?
Inhibin from Sertoli cells, Corpus luteum
Oestrogen from granulosa cells of follicle
What is LH (Luteinising hormone) involved in?
Testosterone from Leydig cells
Progesterone from Corpus luteum
What is prolactin involved in?
Breast development & milk production
What are the six hypothalamic releasing factors?
GnRH (Gonadotropin Releasing Hormone)
GHRH (Growth hormone releasing hormone)
TRH (Thryotropin, TSH-releasing hormone)
CRH (corticotropin releasing hormone)
Dopamine (amine not a peptide hormone)
What is GnRH (Gonadotropin Releasing Hormone) for?
Stimulates release of LH and FSH (production of gametes)
What is GHRH (Growth hormone releasing hormone) for?
Stimulates release of growth hormone, GH
What is SST (Somatostatin) for?
Inhibits release of growth hormone, GH
What is TRH (Thryotropin, TSH-releasing hormone) for?
Increase release of thyroid stimulating hormone, TSH
What is CRH (corticotropin releasing hormone) for?
Increases release of corticotropin (ACTH) may stimulate prolactin release
What is Dopamine (amine not a peptide hormone) for?
Decreases prolactin release
What is the anterior pituitary hormone feedback long and short control loops?
Stress and Non-stress neural inputs
Corticotropin releasing hormone (CRH)
Adrenocorticotropic hormone (ACTH)
Cortisol (end product feedbacks)
What can the two additional hypothalamic hormones of the posterior pituitary hormones?
ADH (Anti-Diuretic Hormone)
What is ADH released as a posterior pituitary hormone?
Also known as Vasopressin (two functions)
Causes production of hypertonic urine (dilute)
Causes increase in systemic mean arterial blood pressure
What is Oxytocin released as a posterior pituitary hormone?
Released as part of the suckling reflex
Causes contraction of smooth muscle cells (myo-epithelial cells and smooth muscle in breast duct cells to enhance milk flow- let down reflex)
What is Oxytocin also involved with?
Other sex hormones
Oestrogen- causes breast duct development in puberty
Progesterone and prolactin cause breast alveoli development
Prolactin stimulates breast milk production by alveolar cells
What are the two phases of the LH and FSH in female reproductive system?
What is the follicular phase for LH and FSH in female reproduction?
Thecal cells -> Androgens -> Granulosa cells
Inhibits FSH only Inhibits ant pit FSH & LH
What is the luteal phase in female reproduction?
Granulosa cells develop LH receptors and combine with thecal cells to produce progesterone which continues to inhibit LH production