Pituitary Gland Flashcards
Define Autocrine signalling
it produces a chemical that stimulates the same cell
Define Paracrine signalling
a chemical substance secreted by 1 cell type that has an effect upon neighbouring cells (local effect)
Describe the glands/organs that make up the endocrine system
- hypothalamus
- pituitary
- parathyroids
- thyroid
- adrenal glands
- pancreas
- testes/ovaries
What hormones are released by the anterior pituitary ?
Glycoproteins & single chain polypeptides
What are some examples of glycoprotein hormones ?
- follicle stimulating hormone
- luteinising hormone
- thyroid stimulating hormone
What are some examples of single chain polypeptide hormones ?
- growth hormone
- prolactin
- adrenocorticotrphin hormone
What are some anterior pituitary cell types ?
lactotrophs, gonadotropins, thyrotrophs, somatotrophs
corticotrophs
Describe the posterior pituitary
- doesn’t synthesise hormones
- stores 2 hypothalamic hormones –> ADH & Oxytocin
What are some hypothalamic hormones ?
CRH, GHRH, somatostatin, dopamine, TRH, GnRH
How is ADH stimulated?
raised osmolarity and low blood volume
How is ADH inhibited ?
lowered osmolarity, alcohol & caffeine
What is the effect of ADH ?
increase permeability of collecting ducts to water
What is the target organ of ADH?
Kidney
How is oxytocin stimulated ?
stretch receptor in the nipple and cervix
How is oxytocin inhibited ?
stress
