14/ hypothalamus and autonomic control

Question 1

areas of hypothalamus and what they’re involved in

Answer 1

• 11 major nuclei
• lateral area involved in motivated behaviour, deciding to do something
• medial, periventricular links body to mind via ANS and pituitary

Question 2

4 key nuclei of the hypothalamus

Answer 2

• paraventricular nucleus. link anterior pituitary, posterior pituitary and brain stem to influence ANS
• supraoptic nucleus. output to posterior pituitary
• anterior pituitary/ adenohypophysis
• posterior pituitary/ neurohypophysis

Question 2

how does the hypothalamus broadly control homeostasis

Answer 2

• disruption to a vital parameter
• sensory inputs and contextual inputs
• integration by hypothal
• controls autonomic ns, neuroendocrine system and behaviour
• restoration of vital parameter

Question 3

adenohypophysis stimulation of troph cells

Answer 3

• troph cells stimulated by releasing hormones from paraventricular neurons of hypothalamus
• releasing hormones travel through portal system into blood vessels
• hormones released by troph cells taken upp into blood vessel system in anterior pituitary and transported around body

Question 4

neurohypophysis - how are hormones released

Answer 4

• releases hormones from magnocellular neurons (paraventricular nucleus and supraoptic nucleus) directly into systemic circulation

Question 5

ANS - voluntary or involuntary, 2 efferent pathways, what is innervated

Answer 5

• involuntary
• sympathetic and parasympathetic - efferent (motor - output)
• smooth muscle, cardiac muscle, glands

Question 6

afferent/sensory division of ans, what does it feed into

Answer 6

• receptors in internal organs and blood vessels
• afferent fibres: visceral nerves, cranial nerves
• brainstem nuclei (degree of hypothalamic control)

Question 7

when is the hypothalamus most involved

Answer 7

• contextual responses - behavioural responses
• eg temp - v conscious of your body temp

Question 8

general organisation of ans

Answer 8

• preganglionic neurons (brainstem and spinal tube) derived from neural tube project to
• postganglionic neurons derived from neural crest. ganglia project to
• effector cells

Question 9

sympathetic organisation - spinal cord grey matter see diagram flashcard

Answer 9

• dorsal horn - top
• intermediate grey zone - middle
• intermediolateral cell column - circle in middle
• lateral horn - middle
• ventral horn - bottom

Question 10

true or false the ventrolateral medulla important in controlling sympathetic preganglionic neurons

Answer 10

true

Question 11

types of effectors in sympathetic vs parasympathetic ns

Answer 11

• symp: adrenergic
• para: muscarinic

Question 12

cranial parasympathetic organisation

Answer 12

• midbrain: contains edinger-westphal nucleus which the oculomotor nerve (cn 3) leaves from
• medulla: contains dorsal motor nucleus of the vagus and the nucleus ambiguus which the vagus nerve (cn 10) leaves from

Question 13

what % of total parasympathetic outflow is carried by vagus nerve, what else does it carry lots of

Answer 13

• 80%
• visceral afferents - vagal nerve stimulation