L2 Pituitary Gland Flashcards
Infundibulum
connects pituitary gland to hypothalamus
Posterior pituitary glands
-what hormones are secreted
a.k.a Neurohypophysis
ADH
Oxytocin
What hormones are secreted by the anterior pituitary glands
Growth Hormone Prolactin TSH ACTH FSH LH
Describe the synthesis of ADH and oxytocin
synthesis by neurones of the hypothalamus
(supraoptic nuclei and paraventricular nucleus)
hormones are initially inactive in these nuclei
travel along the hypothalamico-neurohypophyseal tract.
then stored in the posterior pituitary and activated here
Antidiuretic Hormone
Secretion of ADH is influenced by plasma osmolarity.
Stimulation of v2 receptors causes translocation of aquaporins to the membrane of the kidney tubule, thus allowing water reabsorption.
Stimulation of V1 receptors causes vasoconstriction but this does not occur at normal physiological conditions
Oxytocin
- how does it act
- what stimulates its secretion
- when is it important
Oxytocin acts via IP3 to cause contraction of the smooth muscle of the genital tract (uterus) and breast.
Secretion of oxytocin is stimulated by stimulation of the genitals and nipples.
Oxytocin is most important at parturition and during lactation.
Thyroid Stimulating Hormone is synthesised by what cells?
thyrotrophe cells
Adrenocorticotrophic Hormone is synthesised by what cells?
corticotrophe cells
Follicle stimulating Hormone is synthesised by what cells?
gonadotrophe cells
Prolactin
-synthesis
peptide hormone
synthesised in the lactotrophe cells of the anterior pituitary.
Name 3 things that stimulate prolactin secretion
Mild stress
Nipple stimulation
Coitus
Growth hormone
- synthesis
- control
- synthesised in the somatotrophe cells of the anterior pituitary gland
- control by GHRH and GHRIH and somatostatin
How can growth hormone be stimulated?
stimulated by decreased carbohydrates and fatty acids and increased amino acids
What is the primary effect of growth hormone?
to promote linear growth of adolescence and by increasing protein synthesis and collagen deposition
this is mediated via the nucleus
What effect does growth hormone have on foetal growth
independent of GH
