The hypothalamus and the pituitary (Mainly posterior pituitary gland)

What is the pituitary and the hypothalamus?

Pituitary: the “master” endocrine gland that controls many of the endocrine systems in our body

Hypothalamus: the site in our CNS that collects and integrates information from different inputs

What property is all hormones made in the pituitary?

• all hormones made in the pituitary are hydrophilic

Describe the glandular portion of the pituitary

• hormones of the glandular/anterior pituitary are produced in the pituitary in response to hypothalamic releasing and inhibiting hormones

Describe the neural portion of the pituitary

• hormones of the neural/posterior pituitary are synthesized in the hypothalamus and stored in vescicles in the pituitary where they are released into circulation

• no endocrine

When are hormones of the posterior pituitary released? Describe the pathway

• released in response to neural input from the hypothalamus

Process

often secrete in reponse to plasma osmolarity or large fall in blood pressure → neurosecretory neuronal cell bodies in hypothalamus → hypothalamic posterior pituitary stalk → synapse directly onto capillary (neuronal terminals in posterior pituitary)

What hormones are released by the posterior pituitary galnd?

Vasopressin

• nephrons in kidney → increase permeability of distal collecting tubules to H2O

• arterioles throughout the body → cause vasoconstriction

Oxytocin (Love hormone)

• Uterus → stimulate uterine contraction during birth

• Mammary glands - stimulate milk ejection during breast feeding

• influences pair-bonding and parent-offspring bonds