5/27- Hypothalamus Flashcards Preview

Term 5: Neuro > 5/27- Hypothalamus > Flashcards

Flashcards in 5/27- Hypothalamus Deck (38):
1

Anterior boundary markers of hypothalamus?

- Lamina terminalis

- Anterior commissure

- Optic chiasm

2

Posterior boundary markers of hypothalamus?

- Posterior comissure

- Mammillary body

3

Major functions of the hypothalamus?

Integrative center (essential for survival and replication)

Maintain homeostasis (interacts w/ 4 major systems):

- Homeostatic mechs (eating, thirst, sleeping, temp reg...)

- Endocrine control (via pituitary)

- Autonomic control

- Limbic mechs (memory, emotion, motivation/drives)

4

4 Regions of medial hypothalamus?

(picture)

Q image thumb

- Posterior region (mammillary)

- Middle region (tuberal)--- most homeostatic

- Anterior region (suprapoptic)

- Preoptic region

The fornix divides the hypothalamus into 2 main halves (medial and lateral)

 

A image thumb
5

Kodachrome pic

Can see lateral and medial hypothalamus divided by the fornix on the angry birds slide

6

Major nuclei (8) in the hypothalamus (picture)?

Q image thumb

Posterior region (mammillary):

1. Posterior nucleus

Middle region (tuberal):

2. Dorsomedial nucleus

3. Ventromedial nucleus

4. Arcuate nucleus

Anterior region (supraoptic):

5. Supraoptic nucleus

6. Suprachiasmatic nucleus

7. Paraventricular nucleus

Preoptic region:

8. Preoptic nucleus

A image thumb
7

Role of mammillary body?

- Connected to limbic system

- Thought to be involved in memory

8

Cross sectional view of anterior hypothalamus (pic)

Q image thumb

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9

Cross sectional view of medial region of hypothalamus (pic)

Q image thumb

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10

Cross sectional view of posterior region of hypothalamus (pic)

Q image thumb

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11

Role of preoptic nucleus?

- Endocrine (releasing hormones [GnRH] in pituitary, sexual, maternal, paternal behaviors)

- Temperature regulation

- Fluid balance

12

Role of paraventricular nucleus?

- Endocrine regulation (stress homeostasis): Vasopressin (ADH), Oxytocin (3Ls: lactation, labor, love)

13

Role of anterior hypothalamus?

PS responses

- Reduced heart rate

- Enhanced GIT secretomotor activity

14

Role of suprachiasmatic nucleus?

Circadian rhythms and sleep/wake cycles

- Vasopressin

- Biological rhythm regulation for hormone release

15

Role of supraoptic nucleus

- Endocrine

- Water homeostasis:

        - Vasopressin (ADH)

        - Oxytocin

16

Role of dorsomedial nucleus?

- Feeding

- Drinking

- Body weight regulation

(Activation promotes obesity and emotional behaviors)

17

Role of ventromedial nucleus?

- Appetitive (hunger and satiety balance)

- Consummatory behaviors (reproduction)

- Rage

18

Role of arcuate nucleus?

- Endocrine regulation (releasing factors into portal system)

- Feeding (hunger and satiety)

19

Role of posterior nucleus?

Sympathetic responses

- Increases HR

- Reduces GIT secretomotor activity

20

Role of mammillary bodies

Memory (Papez Circuit)

- Integrates info from limbic system via fornix

21

Integrative functions of hypothalamus (5)?

1. Controls BP and electrolytes (drinking/appetite)

2. Regulates body temp (via ANS)

3. Regulates energy metabolism (influences feeding, digestion, and metabolism)

4. Regulates reproduction through hormonal control of mating, pregnancy and lactation

5. Directs responses to stress/threatening conditions by influencing blood flow to specific tissues and by stimulating secretion of adrenal stress hormones and activating the ANS

22

What are afferent inputs into the hypothalamus (4)? and major inputs/origins (3)?

1. Limbic system

2. Brain stem

3. Retina

4. Cortex

Major:

1. Fornix (from hippocampus)

2. Stria terminalis (from amygdala)

3. Medial forebrain bundle (from brainstem nuclei)

23

Fornix (afferent) carries information from where to where? (test)

From hippocampus to:

- Medial hypothalamus

- Mammillary body

(- Anterior thalamic nucleus)

(- Pre/postcommissural fornices)

(- Septal area)

24

Stria terminalis (afferent) carries information from where to where? (test)

From amygdala to medial hypothalamus

25

Medial forebrain bundle (afferent) carries information from where to where? (test)

From septal area to:

- (medial) hypothalamus

- Brain stem

26

What are the efferent outputs from the hypothalamus (3)?

1. Limbic system

2. Brainstem nuclei

3. Endocrine system (via pituitary)

27

What are the efferent projections from the mammillary bodies (destination/tracts)?

- Anterior thalamic nucleus (mammillothalamic tract)

- Cingulate gyrus (thalamocortical fibers from anterior thalamic nucleus)

- Midbrain tegmentum and reticular formation (mammillotegmental tract)

28

What are the efferent projections from the medial hypothalamus?

(Like a feedback loop)

Ascending/descending fibers:

- Periaqueductal grey (PAG)

- Amygdala

- Prefrontal cortex

(- Midbrain tegmentum ?)

(- Spinal cord)

(- Hippocampus (different tract))

29

What are the efferent projections from the medial forebrain bundle (lateral hypothalamus)?

- Prefrontal cortex

- Septal area

- Midbrain reticular formation

- Periaqueductal grey (PAG)

30

Hypothalamic- Hypophyseal efferents (2 tracts)?

Hypothalamo-Hypophyseal tract Tuberoinfundibular tract

31

What does the hyopthalamo-hypophyseal tract connect?

From: paraventricular and supraoptic nuclei

To: posterior lobe of pituitary

32

What does the tuberoninfundibular tract connect?

From: medial hypothalamic and arcuate nuclei

To: anterior lobe of pituitary (portal circulation)

33

Anatomical location of disorder:

Feeding (obesity/emaciation)

Obesity: lesions of ventromedial hypothalamus Emaciation: lateral hypothalamus

34

Anatomical location of disorder:

Diabetes insipidus

Supraoptic and paraventricular nuclei (Vasopressin/ADH)

35

Anatomical location of disorder:

Hypertension

Paraventricular nucleus

(excess release of CRH- corticotropin releasing hormone)

36

Anatomical location of disorder:

Endocrine disorders

Pituitary ademonas

(prolactin releasing hormone from arcuate nucleus)

37

Anatomic causes of amnesia?

Damage to:

- Hippocampi

- Mammillary bodies

- Fornices

38

TAKE HOME:

- The hypothalamus is critical for orchestration of endocrine, autonomic, and behavioral responses

- Higher regions of the brain (in limbic forebrain) also participate in these responses

- Hypothalamus is heavily interconnected with the limbic areas

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