Cerebellum & Diencephalon

Pineal gland can secret melatonin. Melatonin is important in the regulation of day-night cycles, with secondary effects on reproductive function. habenula

Subthalamic nucleus

Intermediate adhesion ： a medial projection of gray matter , extends into the ventricle fro the thalamus on either side; 70% the two fuse in the midline.

Intermediat e adhesion

Dorsal thalamus

Cerebellum & Diencephalon Xu Jin Department of Anatomy Chongqing Medical University

overview

cerebellum

diencephalon

cerebellum Function It is involved in equilibrium, in muscle tone and postural control, and in the coordination of voluntary movements. It covers most of post. surface of the brainstem , anchored there by three pairs of fiber bundles called cerebellar peduncles.

Superior cerebellar peduncle

Inferior cerebellar peduncle

Middle cerebellar peduncle

External features Divided in transversely

cerebell Posteriolateral fissure um

Flocculonodular lobe Body of cerebellum

Primary fissure

Ant. lobe Post. lobe

Divided in functionally Vermis Intermediate

vermis

Intermediate zone

zone

Hemisphere

Tonsils are two elevated massed on the inf. surface. It’s close to the magnum foramen and can be developed into tonsillar herniation

hemisphere

Flocculonodular lobe

vestibulocerebellum ; archicerebellum

To maintain the equilibrium

Ant. lobe

paleocerebellum; spinocerebellum

To influence muscle tone and synergy of muscle during stereotyped movement

Post. lobe

neocerebellum pontocerebellum

To ensure the coordination of muscles fro accuracy of nonstereotyped movement

Internal features Gray

matter ( cortex) share common organization White matter (medullary center) deep nuclei; cerebellar peduncles

*arbor vitae The arbor vitae (Latin for " Tree of Life") is the cerebellar white matter, so called for its branched, tree-like appearance. It brings sensory and motor information to and from the cerebellum.

Deep cerebellar nuclei dentate

nucleus emboliform / globose nucleus: interposed nucleus fastigial nucleus

Dentate nucleus

Fastigial nucleus

Globose and emboliform nuclei

Inf. cerebellar peduncle ( restiform body)

Mainly of afferents ; From the spinal cord and brainstem

Mid. cerebellar peduncle ( brachium pontis)

Largest of the three; Exclusively of afferents; From the pontine nuclei

Sup. cerebellar peduncle (brachium conjunctivum)

Major efferents; To the red nucleus and thalamus

Diencephalon It’s mostly hidden from view between the cerebral hemispheres. It has extremely widespread and important connections, and the great majority of sensory, motor, and limbic pathways involve one of more relays in the diencephalons.

It lies between the brainstem and cerebrum and can be divided into: 

Epithalamus ----- pineal gland and habenular nuclei



Subthalamus ----- subthalamic nucleus



Metathalamus ----- medial and lateral geniculate bodies (put them in the dorsal thalamus to study



Dorsal thalamus ----- also called thalamus



Hypothalamus

Dorsal thalamus It is a large, egg-shaped nuclear mass which makes up about 80% of the diencephalons. The thalamic nuclei provides relay centers for both sensory and motor pathways. Between the 2 thalami , it is the 3rd ventricle. Intermediate adhesion

Thalamic nuclei can be distinguished from each other both by their topographical locations within the thalamus and by the patterns of their inputs and outputs.

Dorsal thalamus Subdivisi Ant on group Medial group Lateral group

Nuclei

Specific inputs

anterior

Cortical output

Dorsomedial (DM) Dorsal tier Lateral dorsal ( Lateral LD) post. ( LP) Pulvinar Ventral tier Ventral ant. (VA) Ventral lat. (VL) Ventral posterolateral (VPL) Ventral posteromedial(VPM ) Medial geniculate (Lateral MGN) geniculate ( LGN)

Basal ganglia; cerebellum

Motor areas

Medial lemnisus (body) ; spinothalamic tract (body) Medial lemnisus

Somatosenso ry cortex

(face) ; spinothalamic tract (face) Brachium of the inf. colliculus Optic tract

Somatosenso ry cortex Auditory cortex Visual cortex

Hypothalamus The hypothalamus links the nervous system to the endocrine system via the pituitary gland (hypophysis). The hypothalamus is located below the thalamus, just above the brain stem . This brain region occupies the major portion of the ventral diencephalon. It is found in all mammalian brains. In humans, it is roughly the size of an almond. The hypothalamus is responsible for certain metabolic processes and other activities of the Autonomic Nervous System. It synthesizes and secretes neurohormones, often called hypothalamic-releasing hormones, and these in turn stimulate or inhibit the secretion of pituitary hormones.

Hypothalamus

The hypothalamus controls body temperature, hunger, thirst, fatigue, anger, and circadian cycles. Suggested website http://en.wikipedia.org/wiki/Hypothalamus#cite_note-0

Some of the formation are: Optic chiasma Optic tract Tube cinereum Infundibulum Mamillary body

Mamillary body

Optic chiasma

infundibulum

Some of the nuclei are: Paraventricular nucleus Supraoptic nucleus Suprachiasma nucleus Mamillary nucleus

Paraventricular nucleus

Supraoptic nucleus

Mamillary nucleus

Suprachiasma nucleus

The end