hypothal Flashcards
Anterior hypothalamus
above the optic chiasm
supraoptic
medial hypothalamus
above the pituitary
tuberal
posterior hypothalamus
above and including the mammillary bodies
Anterior HT region nuclei
- Lateral preoptic nucleus
- Medial preoptic nucleus
- Suprachiasmatic nucleus
Tuberal Hypothalamic Nuclei (posterior)
- Dorsal nucleus
- Dorsmedial nucleus
- Lateral nucleus
- Supraoptic nucleus
- Ventromedial nucleus
- Periventricular nucleus
Tuberal HT nuclei (ant)
- Paraventricular nucleus
- Anterior nucleus
- Lateral nucleus
- Periventricular nucleus
Posterior Hypothalamic Nuclei
- Posterior nucleus
- Subthalamic nucleus
- Lateral nucleus
- Mammillary body
Autonomic System:
ability of HT to regulate ANS is critical for its role in maintaining homeostasis and inducing emotional expression.
Efferent/afferent pathways from the hypothalamus to the ANS travel in the following tracts:
- Dorsal longitudinal fasiculus:
- Medial forebrain bundle:
- Mammillotegmental tract
Dorsal longitudinal fasiculus:
to ANS nuclei in the brainstem reticular system
Medial forebrain bundle:
to brainstem reticular formation
Mammillotegmental tract:
from mammillary bodies to midbrain reticular formation (tegmentum)
In general, stimulation of the anterior hypothalamus results in:
increases PNS activity (or SNS actions) stimulation of the posterior hypothalamus increases SNS activity.
Somatic Motor System:
- ability of HT to coordinate somatic motor activity leads to the organization of complex activities requiring both somatic and autonomic responses (vomiting, laughing, crying, facial expression
- organizes motor activities required for homeostasis (chewing and swallowing).
HT neurons innervate neurons in:
the reticular formation of the brainstem near the motor nuclei of the cranial nerves. These somatic neurons in turn innervate skeletal muscle.
Use same pathways as those used for the ANS