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Flashcards in Hypothalamus Deck (38)
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1

The Central Autonomic Network Includes

  • Insular Cortex
  • Amygdala
  • Hypothalamus
  • Periaqueductal gray matter
  • Parabrachial complex
  • Solitary nucleus
  • Ventrolateral Medulla

2

Satiety Centers

  • Hypothalamus
  • Cortex
  • Limbic System

3

Direct control of autonomic preganglionic neurons arises from?

  • Hypothalamus
  • Parabrachial Nucleus
  • Solitary Nucleus
  • Ventrolateral medulla

4

Indirect control of atonoimc responses arises from?

  • Cortex
  • Amygdala
  • Periaqueductal gray matter

5

CNS regulation of the peripheral ANS: Centers

-location

-function of centers

  • Hypothalamus
    • Heat Control (temp)
    • Water balance
    • Feeding control
  • Brainstem
    • Urinary Bladder control
    • Pneumotaxic center (another respiratory center)
    • Cardiac acceleration and vasoconstriction
    • Cardiac slowing
    • Respiratory center

6

Hypothalamus:

  • Part of Diencephalon and Limbic system
    • connnected to structures in limbic system and barinstem
  • Hypothalamus + Limbic system
    • control endocrine system and autonomic nervous to maintain homeostasis
      • Stability of the internal enviroment 
  • Integrative functions:
    • Controls:
      • BP and electrolyte (Drinking and salt appetite)
      • Body temperature
    • Regulates:
      • energy metabolism
      • reproduction
      • Circadiam rhythm and sleep-wake cycle
    • Direct responses to stress
      • by influencing blood flow ot specific tissues
      • by  stimulating the secertion of adrenal stress hormone
    • Secretes trophic hormones 
      • control release of hormones from anterior pituitary gland
    • Interacts with limbic system
      • influence behavior, emotions, learning and memory 

7

Limbic System

  • Controls emotional behavior and learning memory
  • consists of:
    • hypothalamus
    • thalamus
    • Forntal lobe
    • olfactory bulb
    • Amygdala
    • Hippocampus

8

Hypothalamus: Anatomic Organization

  • Above the pituitary gland
  • Surrounds 3rd ventricle
  • divided into medial and lateral regions by the fornix

9

Hypothalamic nuclei

  • Lateral preoptic nucleus
  • medial preoptic nucleus 
  • Suprachiasmatic nucleus
  • Paraventricular nucleus
  • Lateral nucleus
  • Periventricular nucleus 
  • Supraoptic nucleus
  • Dorsal nucleus
  • Dorsomedial nucleus
  • Ventromedialnucleus
  • Posterior Nucleus

10

Hypothalamus: Preoptic Area

Medial Preoptic Nucleus

  • Produces Gonadotropin Releasing Hormone (GnRH)
    • transported to anterior pituitary to release Gonadotropins 
      • Lutenzing hormone (LH)
      • Follicle Simulating Hormone (FSH)
  • Sexually dimorphic nucleus
    • larger in males than females
  • influences behavior related eating, reproduction, and locomotion 

11

Hypothalamus: Lateral Zone

  • Contains
    •  medial forebrain bundle
      • diffuse system
      • connects hypothalamus to septal nuclei and brainstem (Reticular formation)
    • Lateral Hypothalamic Nucleus:
      • feeding center
      • stimulation causes feeding
      • destruction causes weight loss

12

Hypothalamus: Media Zone

  • Supraoptic Region
    • paraventricular nucleus
      • Antidiuretic hormone (ADH, Vasopressin)
      • Oxytocin
    • suprachiasmatic nucleus
      • circadian rhythm
    • Anterior Nucleus
      • Body temperature 
  • Tuberal Region
    • Ventromedial nucleus
      • satiety center
    • Dorsomedial nucleus
      • aggressive behavior
    • Arcuate nucleus
      • Origion of majoring of releasing hormones including beta endorphins
  • Mammillary region
    • connects to
      • limbic system
      • thalamus (mammilothalamic tract)
        • conversion of short to longer term memory
        • anterograde amnesia

13

Hypothalamus: Major Inputs

  • Cortical areas
  • Ventral Striatum 
  • Septal Nuclei
  • Hippocampus
  • Amygdall 
  • Brainstem and spinal cord
  • retina
  • orbital cortex

14

Hypothalamus: Major Outputs

  • Cortical Areas
  • Septal Nuclei
  • Anterior Nucleus
  • Mammillothalamic Tract
  • Amygdala 
  • Brainstem and spinal cord
  • Pituitary gland
    • adenohypophysis
    • neurohypophysis

MAP CABS

15

Hypothalamus: Zones

  • Anterior Region
    • Lateral preoptic nucleus
    • medial preoptic nucleus
    • Suprachiasmatic nucleus
  • Tuberal Region
    • paraventricular nucleus
    • Anterior Nucleus
    • Supraoptic nucleus 
    • Dorsomedial nucleus
    • Ventromedial nucleus
    • Arcuate nucleus 
  • Lateral-posterior region
    • posterior area
    • mamillary body 

16

Hypothalamus: Neurohumoral regulation

  • Secretes different releasing hormones and factors
    • Median Eminence (ME)
      • secretion of releasing hormones
    • Posterior Pituitary 
      • secretion of ADH/Vasopressin and Oxytocin
    • Subfornical Organ (SFO)
      • control of fluid balance and drinking behavior
    • Vascular Organ of the lamina terminalis (OVLT)
      • control of fluid balance
    • Pineal Gland:
      • melatonin-sleep regulation
    • Area postrema-induces vomitting
  • Part of circumventricular organs (CVOs)
    • highly vascularized
    • no BBB
    • areas of communication between the blood, brain parenchyma, and the CSF by monitoring blood chemistry and releasing hormones into the blood stream

17

Paraventricular Nucleus and Supraoptic Nuclei: Fxn

  • Reglate water balance
  • Produce ADH and oxytocin
  • destruction causes diabetes insipidus 
  • paraventricular nucleus projects to autonomic nuclei of brainstem and spinal cord

18

Anterior Nucleus: Fxn

  • Thermal regulation (dissipation of heat)
  • Stimuluates parasympathetic NS
  • Destruction=hyperthermia

19

Preoptic Area

  • contains sexually dimporphic nucleus
  • Medial Preoptic area regulates release of gonadotropic hormones 
  • Thermal Regulation (heat Dissipation)??

20

Suprachiasmatic nucleus

  • Receives input from retina
  • Controls circadian rhythyms
  • projects to pineal gland which releases melatonin 

21

Dorsomedial nucleus

  • Aggresive Behavior
  • Stimulation results in obesity and savage behavior 

22

Posterior nucleus

  • Thermal regulation (conservation of heat)
  • destruction-inability to thermoregulate
  • Simulates the symathetic NS

23

Lateral Nucleus

  • Feeding center 
  • Stimulation induces eating/feeding
  • destruction=starving/weight loss
    • anorexia 

24

Mammillary Body

  • Receives input from hippocampal formation by fornix
  • Projects to anterior nucleus of thalamus
  • Contains hemorrhagic lesions in Wernicke's encephalopathy

25

Ventromedial Nucleus

  • Satiety center
  • Destruction-obesity and savage behavior

26

Arcuate Nucleus

  • Origin of releasing hormones/factors
    • including B-endorphins
  • contains DOPA-ergic neurons that inhibit prolactin release

27

Posterior Pituitary vs Anterior Pituitary: Neuroendocrine Function

  • Posterior Pituitary
    • Axon Projections
    • Secrete
      • Vasopress/ADH-->kidney tubules
      • oxytocin-->uterine muscles/mammary glands
  • Anterior Pituitary
    • Axon secretions carried by portal vein to anterior pituitary capillaries
    • Secrete:
      • Growth Hormone-->entire body 
      • Prolactin-->mammary glands
      • Thyroid Stimulating hormone-->thyroid
      • Corticotropin Releasing hormone-->Adrenal Cortex?
      • Gonadotropine releasing Hormon->testes/ovaries
        • FSH & LH
      • Endorphins-controls pain receptors in the brain
        • part of endogenous opioid system

28

Neurosecretory Cells

  • secrete releasing horones from hypothalamus

29

How does the hypothalamus control the endocrine system?

  • secreting oxytocin and vasopressin from posterior pituiatry into general circulation

30

Hypothalamic Control: Anterior Pituitary

  • Parvocellular neurons of Arcuate Nucleus
    • secrete hypothalamic releasing and inhibiting hormones
    • travel down Tuberoinfundibular tract 
    • Secreted into Median Eminence
      • first capillary bed
    • then Hypophyseal Portal System
    • second capillary bed in anterior pituitary 
    • absorbed by endocrine cells
  • Faciliate or inhibit the release of:
    • ACTH
    • GH
    • FSH
    • LH
    • TSH
    • MSH
    • Prolactin 

 

Neurons of the Medial Preoptic Nucelus

  • secrete Gonadotropine Releasing Factor
  • faciliates the release of FSH and LH