-
What are the components of the diencephalon?
- Thalamus
- Epithalamus
- Hypothalamus
-
Describe the epithalamus.
- Roof of diencephalon, superior to third ventricle
- Anterior portion - Contains extensive area of choroid plexus that extends into interventricular foramina
- Posterior portion - Pineal gland: Secretes melatonin (hormone regulating day-night cycles and some reproductive functions)
-
Describe the Thalamus.
- On each side of brain, superior to midbrain.
- Final point for ascending sensory information to be relayed or projected to cerebral cortex. Acts as a filter, only passing on small portion of sensory information.
- Has regions that contain nuclei or groups of nuclei that connect to specific regions of cerebral cortex
-
What are the components of the Thalamus?
- Interthalamic adhesion: Connects thalamic hemispheres, but no neural fibers cross.
- Lateral geniculate nucleus: Receives visual information from optic tract and relays signals to midbrain and occipital lobe.
- Medial geniculate nucleus: Relays auditory information from inner ear receptors to appropriate cerebral cortex area.
-
Describe the Hypothalamus.
- Contains important control and integrative centers
- Centers may be stimulated by:
- -Sensory information from cerebrum, brain stem, and spinal cord.
- -Changes in CSF and interstitial fluid composition.
- -Chemical stimuli from blood because this area lacks blood–brain barrier.
-
Describe the components of the Hypothalamus.
- Infundibulum: Connects to pituitary gland
- Mammillary bodies: Control feeding reflexes like licking and swallowing, Relay station for olfaction
- Hormonal centers: Secrete chemical messengers that control endocrine cells in anterior pituitary, Secrete two hormones released by posterior pituitary
- Nuclei: autonomic centers that control cardiovascular and vasomotor centers of medulla oblongata
- Preoptic area: Regulates body temperature through adjustments in blood flow and sweat gland activity
- Suprachiasmatic nucleus: Coordinates day-night cycles of activity/inactivity
- Hormonal centers
|
|
