The Diencephalon 间脑 山东大学医学院 解剖教研室 李振华

Position of Diencephalon Position: Lies between midbrain and cerebrum, almost entirely surrounded by cerebral hemisphere Diencephalon

Subdivision of Diencephalon Doral thalamus 背侧丘脑 Metathalamus 后丘脑 Epithalamus 上丘脑 Subthalamus 底丘脑 Hypothalamus 下丘脑

Dorsal Thalamus 背侧丘脑

Dorsal Thalamus 背侧丘脑 External features A large egg-shaped nucleus mass Anterior end －anterior thalamic tubercle 丘脑前节结 Posterior end － pulvinar 丘脑枕 Right and left portion of thalamus are joined by interthalamic adhesion 丘脑间粘合 Floor－hypothalamic sulcus

Classification of Nuclei of Dorsal Thalamus Three nuclear group－divided by internal medullary lamina 内髓板 Anterior nuclear group 前核群 Medial nuclear group 内侧核群 Lateral nuclear group 外侧核群

Internal medullary lamina Med. nuclear group Ant. nuclear group Lateral nuclear group Medial geniculate body (MGN) Ventral anterior nucleus Ventral lateral nucleus Ventral posterior nucleus (VP) Lateral geniculate body (LGN) Ventral posterolateral (VPL) Ventral posteromedial (VPM )

Subdivision Principal Nuclei Common abbreviation Ant. nuclear group Med. nuclear group Lat. nuclear group Dorsal tier of the nuclei Lateral dorsal LD Lateral posterior LP Pulvinar Ventral tier of the nuclei Ventral anterior VA Ventral lateral VL Ventral posterior VP Ventral posterolateral VPL Ventral posteromedial VPM

Functional Subdivision of Dorsal Thalamus Nonspecific relay nuclei 非特异性中继核团－receive afferents from rhinencephalon and reticular formation of brain stem, project mainly to hypothalamus and corpus striatum Midline nucleus group Intralaminar nuclear group Thalamic reticular nucleus Association nuclei 联络核团－receive input from many converging sours and in turn project widely to the association areas of cerebral cortex Anterior nuclear group Medial nuclear group Dorsal tier of lateral nuclear group

Functional Subdivision of Dorsal Thalamus Special relay nuclei 特异性中继核团 Vent. anterior nucleus (VA) 腹前核 Vent. intermediate nucleus (VI) 腹中间核 Receiving dentate nucleus, globus pallidus and substantia nigra to motor cortex Vent. posteromedial nucleus (VPM ) 腹后内侧核★ Receives trigeminal lemniscus and taste fibers Vent. posterolateral nucleus (VPL ) 腹后外侧核★ Receives medial lemniscus and spinal lemniscus Projects to first somatic sensory area via central thalamic radiation 丘脑中央辐射

Metathalamus 后丘脑 Lateral geniculate body (LGN) 外侧膝状体 Medial geniculate body (MGN) 内侧膝状体

Metathalamus 后丘脑 Medial geniculate body (MGN) 内侧膝状体★ Relay station of audition Receive fibers from inferior colliculus Projects to auditory area via acoustic radiation 听辐射 Lateral geniculate body (LGN)外侧膝状体★ Relay station of vision Receive fibers from optic tract Projects to visual area via optic radiation 视辐射

Epithalamus 上丘脑 Consist of: Thalamic medullary stria 丘脑髓纹 Habenular trigone 缰三角 Habenular commissure 缰连合 Pineal body 松果体 posterior commissure 后连合

Subthalamus 底丘脑 Position: transition zone between diencephalons and tegmentum of midbrain Content: subthalamic nucleus 底丘脑核, parts of red nucleus and substantia nigra

Hypothalamus 下丘脑 Position－lies ventral to thalamus Boundaries Superiorly: hypothalamic sulcus Inferiorly: optic chiasma 视交叉 tuber cinereum 灰结节 Infundibulum 漏斗 mamillary body 乳头体 Anterior: lamina terminalis 终板 Posterior: continues with midbrain tegmentum

Hypothalamus 下丘脑 Subdivisions Preoptic region 视前区 Supraoptic region 视上区 Tuberal region 结节区 Mamillary region 乳头体区

Important Nuclei of Hypothalamus Supraoptic region 视上区 Supraoptic nucleus 视上核－produce antidiuretic hormone 抗利尿激素(ADH， vasopressin 加压素) Paraventricular nucleus 室旁核－produce oxytocin 催产素 Tuberal region 结节区 Infundibular nucleus 漏斗核 Ventromedial nucleus 腹内侧核 Dorsomedial nucleus 背内侧核 Mamillary region 乳头体区 Mamillary nucleus 乳头体核 Posterior hypothalamic nucleus 下丘脑后核

Paraventricular nucleus Paraventriculohypophyeal tract Supraoptic nucleus Supraopticohypophyseal tract infundibulum anterior lobe of hypophsis posterior lobe of hypophysis

Connections of Hypothalamus Supraoptic nucleus → antidiuretic hormone (ADH) →supraopticohypophyseal tract →posterior lobe of hypophysis Paraventricular nucleus → produce oxytocin (oxytocin) →paraventriculohypophyseal tract→posterior lobe of hypophysis Parvicellular neurons in the arcuate nucleus and nearby region of the walls of the third ventricle secrete releasing and inhibiting hormones → tuberoinfundibular tract →portal vein of hypophysis → anterior lobe of hypophysis

Paraventricular nucleus Paraventriculohypophyseal tract Supraoptic nucleus Supraopticohypophyseal trac Inferior hypophyseal a. posterior lobe of hypophysis Hypophyseal v.

Parvicellular neurons in the arcuate nucleus and nearby region of the walls of the third ventricle secrete releasing and inhibiting hormones → tuberoinfundibular tract →portal vein of hypophsis → anterior lobe of hypophsis Tuberoinfundibular tract Median eminence Portal v. Superior hypophyseal a. anterior lobe Hypophyseal v.

Connections of Hypothalamus Connects with limbic system Connects with brainstem and spinal cord Connects with dorsal thalamus Connects with hypophysis

Functions of Hypothalamus Autonomic control Endocrine control Temperature regulation Regulation of food and water intake Emotion and behavior Control of circadian rhythms （生理节奏）

Third ventricle 第三脑室 Communication Position: a narrow ventricle cleft lies within diencephalons Boundaries Roof: choroids plexus Floor: optic chiasma tuber cinereum infundibulum and mamillary body Anterior: lamina terminalis Posterior: continuous with mesencephalic aqueduct Lateral wall: dorsal thalamus and hypothalamus Communication Third ventricle →mesencephalic aqueduct → fourth ventricle