Neuroendocrinology Flashcards
(37 cards)
What is neuroendocrinology?
A branch of life sciences dealing with neurosecretion and the physiological interaction between the CNS and endocrine system
What are the 2 types of neurones in the hypothalamus?
- Parvocellular (small) neurones interact with ANTERIOR pituitary (via hypo-physical portal system)
- Magnocellular (large) neurones interact with the POSTERIOR pituitary
What are the 4 different outcomes of pituitary hormones?
Secreted into circulation and then go into either:
- Target tissues
- Adrenal axis (stress)
- Thyroid axis(metabolism)
- Gonads axis(reproduction)
What is the function of the hypothalamus?
To integrate autonomic responses and endocrine function with behaviour, especially behaviour concerned with basic homeostatic requirements of every day life
What are the 3 ways in which homeostasis is controlled?
- Behaviour
- Neuronal control through the ANS
- Hormonal control through hormone release from the pituitary gland initially (gets signal from hypothalamus)
How does the hypothalamus get signals from other brain centres?
Through its leaky BBB, the optics, limbic system and visceral ANS input for example can signal to the hypothalamus via certain molecules allowing the endocrine system to feedback to it
What are the 6 major homeostatic needs that the hypothalamus maintains?
- BP/electrolyte composition: control of drinking, salt appetite, blood osmolality + vasomotor tone
- Body temp: metabolic thermoregulation + behaviours like seeking appropriate environment
- Energy metabolism: feeding, digestion + metabolic rate
- Reproduction: hormonal control of mating, pregnancy + lactation
- Stress response: adrenal stress hormones e.g. cortisol
- Growth: e.g. GH
The hypothalamus does not just control the neuroendocrine system but also the ___.
ANS
How does the hypothalamus have a role in emotional behaviour?
Anatomically it is close to the amygdala which gets signals from the pre-frontal cortex allowing it to get signals from here
What are the roles of the paraventricular nucleus (PVN) of the hypothalamus?
Autonomic control:
- Stress (CRH)
- Energy balance (TRH)
- Osmoregulation (AVP)
- Maternal control (Oxy)
- BP (AVP)
What are the roles of the supraoptic nucleus (SON) of the hypothalamus?
Osmoregulation (AVP)
Maternal control (Oxy)
What are the roles of the arcuate (ARC) nucleus of the hypothalamus?
Reproduction (GnRH)
Growth (GHRH)
Lactation (dopamine)
What are the roles of the ventromedial nucleus of the hypothalamus?
Energy and glucose balance
What are the roles of the dorsomedial nucleus of the hypothalamus?
Diurnal rhythms
What are the roles of the suprachiasmatic nucleus of the hypothalamus?
Circadian rhythms
What are the roles of the anterior nucleus of the hypothalamus?
Thermoregulation
What are the roles of the mamillary body of the hypothalamus?
Sleep/wake cycle
What are the 4 areas of the hypothalamus?
- Preoptic area
- Anterior (supraoptic) region
- Middle (tuberal region)
- Posterior (mammillary) region
What connects the hypothalamus to the pituitary gland?
Pituitary stalk
What is narcolepsy associated with?
Loss of hypothalamic orexin neurons
Describe the hypophysial portal system.
Hypophysical portal vessels are on anterior surface of pituitary stalk where vessels arise from primary capillary bed on the median eminence fanning out over the anterior pituitary gland at the pituitary stalk junction
What artery supplies blood to the posterior pituitary?
Tubero-infundibular artery (branch of superior hypophysial artery) arches across top of stalk-pituitary junction where it enters the anterior pituitary gland passing through to supply blood to posterior pituitary
Where is the pituitary gland located?
Sella turcica = bony cavity at base of brain
What are the key features of the anterior pituitary gland?
Develops from pharyngeal epithelium
Contains glandular cells
Parvocellular neurones
Releasing/inhibiting factors via portal system
