6.4.3 Hypothalamus

Question 1

Answer 1

Question 2

What is the difference between leptins and Ghrelins?

Answer 2

• Leptins: produced in adipose tissue and reduce appetite
• Ghrelins: Produced in gastric mucosa stimulate appetite

Question 3

How can the hypothalamus change the body temperature set point (fever)?

Answer 3

Hypothalamic neurons activated (pre-optic)

-Activation of septum can reduce fever

Question 4

How is temperature info conveyed to the hypothalamus? Which nucleus of the hypothalamus senses temperature

Answer 4

Somatosensory system - temperature sensitive afferents

neurons in anterior nucleus of hypothalamus sense temp

Question 5

What are the two main systems that the hypothalamus uses to carry out endocrine functions?

Answer 5

Neurohypophyseal and Tuberoinfundibular

Question 6

What nucleus in the hypothalamus plays a role in descending control of preganglionic PARA and SYM neurons

Answer 6

Paraventricular nucleus

Question 7

How does the hypothalamus play a role in the circadian rhythm?

Answer 7

Suprachiasmatic nucleus; input from retinal ganglion cells containing melanopsin; project to SCN at chiasm

Regulates core body temp; ACTH levels, slow wave sleep; skin temp

Question 8

What are the four functions of the limbic system?

Answer 8

Homeostasis

Olfaction

Memory

Emotions and Drives

Question 9

Where do the neurohypophyseal system and tuberoinfundibular system project? What endocrine functions are mediated by these systems?

Answer 9

Question 10

What are the afferent inputs into the hypothalamus?

Answer 10

Retina - SCN for circadian function

Fornix - from hippcampus

Amygdala - autonomic component

Medial forebrain bundle

Question 11

What are the functions of the hypothalamus?

Answer 11

Homeostasis

Endocrine

Autonomic

Limbic

Question 12

Answer 12

Question 13

Which regions of the hypothalamus play a role in feeding behavior? What are their effects?

Answer 13

Ventromedial nucleus - satiety stimulation (stimulation reduces food intake, lesions produce overeating and obesity)

Lateral nuclei - feeding center (stimulation produces eating, lesion produce anorexia)

Question 14

Identify these anatomical landmarks for the hypothalamus

Answer 14

Question 15

How does the hypothalamus control thirst/body fluid?

Answer 15

ADH (vasopressin) release by supraoptic nucleus

anterior nucleus involved in coordinating drinking behavior

Question 16

What are the efferent connections of the hypothalamus?

Answer 16

Decending autonomic control - from paraventricular nucleus

Mamillothalamic tract - papez circuit, to anterior n. thalamus

Reciprocal connections

Question 17

Which parts of the hypothalamus coordinated the body’s response to changes in temperature? Warm or cold?

Answer 17

Response to warm: Anterior nucleus

Response to cold: Posterior nucleus