Hypothalamus, Subthalamus and The Third Ventricle (Diencephalon) Flashcards
1
Q
A
2
Q
Hypothalamus and its function
A
- part of the diencephalon
- receives and integrates sensory information from the internal environment and directs actions to control homeostasis
helps regulate 5 basic physiological needs:
- controls BP and electrolyte
- regulates BT
- regulates energy metabolism
- regulates reproduction
- directs stress responses
- weighs 4g
3
Q
Where is the hypothalamus located?
A
- lies below the level of the hypothalamic sulcus, found on the medial surface of the diencephalon
- it includes: chiasma opticum, tuber cinereum with inf. projection infundibulum and mammillary bodies
- surrounded by circle of willis
4
Q
Homeostatic control of Hypothalamus
A
- autonomous control
- thermoregulation
- water regulation
- liberins and statins
5
Q
What 3 systems does the Hypothalamus control?
A
- ANS
- endocrine system
- limbic system
6
Q
Connections of the hypothalamus
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- limbic system
- pituitary gland
- somatic and visceral nuclei
7
Q
Main efferent pathways of Hypothalamus
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- fasciculus mammillothalamicus
- hypothalamo-reticular pathway
8
Q
lateral zone of hypothalamus
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contains two nuclei
- nucleus preopticus lateralis
- nucleus hypothalamicus lateralis
- when stimulated feeling of hunger
9
Q
mammillary bodies of hypothalamus
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- two round pea-like structures, situated just behind the post. perforated substance
- each one consists of a white matter exterior and two grey matter nuclei inside - medial and lateral mammillary nuclei
- the mammillary bodies belong to the limbic system
10
Q
Main afferent pathways of hypothalamus
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- Fasciculus prosencephalicus medialis
- Stria terminalis
- Fornix
11
Q
medial zone of hypothalamus
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regio anterior
- regio tuberalis
- regio posterior
12
Q
Nuclei in regio tuberalis
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- Nucleus dorsomedialis - center of hunger
- Nucleus ventromedialis - center of satiety
- Nucleus arcuatus - secretes releasing factors
13
Q
Nuclei in regio anterior
A
- nucleus preopticus - control paraympathetic function
- nucleus supraopticus - synthesis and secretion of vasopressin, damage causes diabetes
- nucleus suprachiasmaticus - controls circadian rhythm
- nucleus anterior - controls temperature and sexual behaviour
- nucleus paraventricularis - synthesis and secretion of oxytocin
14
Q
Nuclei in regio posterior
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- Nucleu posterior - controls thermoregulation
- Nucleus mamillaris - impulses from hippocampal formation, tegmental nuclei and nucleus anterior thalami
15
Q
The supraoptic and paraventricular nuclei
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- both nuclei are structurally similar, containing large bipolar neurons
- they synthesise the hormones vasopressin (antidieuretic) and oxytocin, which pass along the axons, attached to carrier proteins called neurophysins
- they are released at the axon terminals into the capillary blood-stream of the post. lobe of the hypophysis - neurohypophysis
- medial zone