What Is the Diencephalon?

Brain tissue located above the midbrain, between the two hemispheres of the brain. The brain between the telencephalon and the midbrain, one on the left and the other on the left, with the third ventricle in between. This chamber is connected downward to the midbrain aqueduct and upward to the lateral ventricle of the telencephalon through the interventricular foramen.

Brain tissue located above the midbrain, between the two hemispheres of the brain. The brain between the telencephalon and the midbrain, one on the left and the other on the left, with the third ventricle in between. This chamber is connected downward to the midbrain aqueduct and upward to the lateral ventricle of the telencephalon through the interventricular foramen.

Chinese name

Interbrain

Foreign name

diencephalon

lie in

Above the brainstem, inside of the caudate nucleus and inner capsule

Also known as

Dorsal thalamus

Interbrain Anatomy

The structure is more complicated, and it is divided into upper thalamus, dorsal thalamus, posterior thalamus, base thalamus and hypothalamus.

(1) The main structure of the hypothalamus is the pineal gland, which is an endocrine gland.

(2) The dorsal thalamus is two oval gray matter masses, one left and one right. Each oval gray matter mass is divided into anterior thalamic nucleus, medial thalamic nucleus, and lateral thalamic nucleus. The anterior thalamic nucleus has functions related to visceral activity. The medial thalamic nucleus may be the integration center of somatic and visceral sensory impulses. The lateral thalamic nucleus is the last-stage relay station of the somatosensory pathway. It transmits skin sensations and proprioceptive urges to the cerebral cortex Central back.

(3) The posterior thalamus includes the medial geniculate body and the lateral geniculate body. The medial geniculate nucleus has the medial geniculate nucleus, which is the last relay station in the auditory pathway. It receives the afferent fibers and sends them to the auditory center of the cerebral cortex. The lateral geniculate nucleus has the lateral geniculate nucleus, which is the last relay station in the visual pathway. It receives the afferent fibers and sends them to the visual center of the cerebral cortex.

(4) The hypothalamus is the transition area between the midbrain and the mesencephalon.

(5) The hypothalamus is the subcortical center of autonomic nerves, and it is related to the secretion of certain hormones, emotional responses, the regulation of certain metabolisms (such as water, salt, sugar, fat, etc.) and body temperature, cardiovascular exercise, and respiratory movement. Regulation and appetite, sleep, awakening, biological clock (or circadian rhythm) and so on are related. Many physiological and psychological studies involve the mesencephalon, especially the hypothalamus.

The midbrain and telencephalon are derived from the forebrain wing in the early stage of the embryo. The midbrain is located in the center of the posterior part of the forebrain, and the telencephalon develops into the left and right cerebral hemispheres. Due to the height expansion of the telencephalon, except for the ventral part of the hypothalamus that is exposed on the surface of the brain, the rest is surrounded by the left and right cerebral hemispheres. On the median sagittal section of the brain, the connection from the posterior commissure to the posterior margin of the papillary body represents the junction between the midbrain and the midbrain, and the connection from the interventricular foramen to the optic cross represents the junction between the mesencephalon and the telencephalon. The ventricular cavity of the interbrain is called the third ventricle.

The medial side of the interventricular brain forms the side wall of the third ventricle. At the junction of the medial side and the back side, there is a raised fiber bundle-the thalamic medullary vein, with the third ventricle choroid tissue attached. The thalamic medullary pattern is connected backward to the zygomatic triangle, and the zygomatic zygomatic connection is between the left and right zygomatic triangles, and the pineal gland is behind the zygomatic. Around the center of the third ventricle wall, there is an interthalamic adhesion (or central block) connecting the left and right ventricle walls. It has a hypothalamic sulcus on its ventral side, from the midbrain water pipe to the interventricular foramen. The structures belonging to the hypothalamus surround the floor of the third ventricle, and from front to back there are optic crosses, funnels, gray nodules, and papillary bodies that connect the endplate. On the dorsal side of the mesencephalon, both sides of the third ventricle are held by oval-shaped gray matter masses belonging to the dorsal thalamus, with an anterior nodules of the thalamus and an enlarged pillow at the rear. There is a caudate nucleus belonging to the telencephalon on the outer side of the dorsal side, and it is a terminal streak between it and the midbrain. On the underside of the pillow, there are medial geniculate bodies and lateral geniculate bodies. The outer side of the midbrain fuses with the inner capsule of the telencephalon. The ventral surface of the mesencephalon is the exposed part of the brain with anterior optic cross and optic bundle, the funnel, pituitary, and gray nodules are centered, and the papillary bodies are paired behind the gray nodules.

Brain damage

Each part of the midbrain has its special function, but the main function is to accept and initially integrate the physical and visceral sensations (except the olfactory sense), relaying to specific sensory regions of the cerebral cortex; it is also the subcortical autonomic nerve And endocrine regulatory center. Therefore, when the brain is damaged, there are sensory disturbances and spontaneous hypersensitivity, especially painful allergies, and autonomic and endocrine disorders such as body temperature, water metabolism, sleep, mood and other abnormal phenomena.