The Pituitary Gland Flashcards
What are the principal organisers of the endocrine system?
The hypothalamus and the pituitary
What is the hypothalamus a part of and what is it found underneath?
The brain
Under the thalamus
How is the hypothalamus connected to the pituitary gland?
Via a stalk - the infundibulum
Type of communication between hypothalamus and posterior pituitary
Neural
Type of communication between the hypothalamus and the anterior pituitary
Endocrine
What type of function is hypothalamic communication?
Neuroendocrine
What type of tissue is the hypothalamus?
Nervous tissue
Two functions of the hypothalamus
Releases neuroendocrine hormones from the posterior pituitary gland
Causes the anterior pituitary gland to release hormones
What bone is the pituitary gland found in?
Sphenoid bone
Two parts of the pituitary gland
Anterior pituitary
Posterior pituitary
What is the posterior pituitary a continuation of?
Neural tissue from the hypothalamus
What is the anterior pituitary?
A true endocrine gland of epithelial origin
What can cause effects on the hypothalamus?
Cold Stress Metabolic demand Hydration status Exercise Day / night Menstrual cycle Sleep Breastfeeding Pregnancy Puberty
Function of trophic hormones
Govern the release of another hormone
What kind of hormones does the hypothalamus release?
Neurohormones
Where are neurohormones released into?
The blood
What type of hormones does the posterior pituitary release and why?
Neurohormones
Because it is a continuation of the hypothalamus
What is the posterior pituitary?
A mass of nerves and axon terminals that start in the hypothalamus
What type of hormones are released from anterior pituitary?
Endocrine hormones
Two forms of hypothalamic neurohormones
Trophic
Non-trophic
What are trophic hormones?
Neurohormones secreted into capillaries travelling to the anterior pituitary which then govern the release of anterior pituitary hormones
What are non-trophic hormones?
Neurohormones produced in the hypothalamus and travel to posterior pituitary (via axons of hypothalamic neurones) where they are released into the blood
Only what kind of hormones go to the anterior pituitary?
Trophic hormones
How is the anterior pituitary connected to the hypothalamus?
Via a capillary portal system
Another name for the anterior pituitary
Adenohypophysis
How much of the gland does the anterior pituitary make up of the gland?
2/3rds of the gland
Another name for the posterior pituitary
Neurohypophysis
How much of the gland does the posterior pituitary make up?
1/3rd