What Is the Forebrain?

The two hemispheres of the brain and the mesencephalon are called the forebrain. The forebrain (Prosencephalon) anatomical structure includes the telencephalon and the interbrain. It is the largest area of the human brain, divided into two hemispheres, and each is divided into four brain lobes, namely the occipital lobe, parietal lobe, temporal lobe, and frontal lobe. Part of the brain. It mainly includes the telencephalon and the interbrain. The telencephalon consists mainly of two symmetrical hemispheres and the corpus callosum. The cerebral hemisphere covered by the cerebral cortex includes the limbic system and basal ganglia. The midbrain is located between the midbrain and the telencephalon and surrounds the third ventricle. The main structures are the thalamus and hypothalamus. The thalamus forms the back of the midbrain, near the center of the hemisphere. The hypothalamus is located at the base of the brain and controls the autonomic nerve, endocrine system, and tissue-related behaviors of germline survival.

The two hemispheres of the brain and the mesencephalon are called the forebrain. The forebrain (Prosencephalon) anatomical structure includes the telencephalon and the interbrain. It is the largest area of the human brain, divided into two hemispheres, and each is divided into four brain lobes, namely the occipital lobe, parietal lobe, temporal lobe, and frontal lobe. Part of the brain. It mainly includes the telencephalon and the interbrain. The telencephalon consists mainly of two symmetrical hemispheres and the corpus callosum. The cerebral hemisphere covered by the cerebral cortex includes the limbic system and basal ganglia. The midbrain is located between the midbrain and the telencephalon and surrounds the third ventricle. The main structures are the thalamus and hypothalamus. The thalamus forms the back of the midbrain, near the center of the hemisphere. The hypothalamus is located at the base of the brain and controls the autonomic nerve, endocrine system, and tissue-related behaviors of germline survival.

Chinese name

Forebrain

Foreign name

Prosencephalon

Nature

science

Category

biological

Forebrain forebrain composition:

1. Viewing mound:

Opal mound (thalamus) Opal mound is oval-shaped, composed of white matter nerve fibers, one left and one right, located below the corpus callosum. Nerve impulses transmitted from the spinal cord, brain stem, and cerebellum first terminate in the optic cumulus and are transmitted to relevant areas of the cerebral cortex through the optic cumulus. Therefore, the optic mound is an important transmission station of sensory nerves. In addition, the visual mound has the function of controlling emotions.

2. Downward view mound:

The hypothalamus (hypothalamus) is located below the hypothalamus and is the main control center of the autonomic nervous system. It is directly connected to various regions of the brain, and is connected to the pituitary and medulla. The main function of the hypothalamus is to regulate the endocrine system, maintain normal metabolism, regulate body temperature, and have close relations with physiological motivations such as hunger, thirst, and sex in physiological activities.

3. Edge system:

The limbic system is generally considered to include the parietal mast, hypothalamus, and midbrain. The main functions of the limbic system are smell, viscera, autonomic nerve, endocrine, sex, feeding, learning, memory and so on. The limbic system has two neural tissues, the amygdala and the hippocampus. The former is related to emotional performance and the latter is related to memory.

4, cerebral cortex:

The cerebral cortex is the surface layer of the brain. It is composed of gray matter and has a thickness of about 1 to 4 mm. There is a fissure in the middle of the brain. The brain is divided into left and right hemispheres from front to back, called the cerebral hemisphere. The two hemispheres are connected by the corpus callosum, so that nerve conduction in the two hemispheres can communicate.

Forebrain Anatomy:

1. Hemisphere:

The cerebral hemisphere is composed of the cerebral cortex, medulla and basal nucleus. The left and right cerebral hemispheres are connected by the corpus callosum. The surface of the cortex is covered with brain grooves of varying depths, with raised brain gyrus between the grooves. The medulla is located on the deep side of the cortex and is composed of nerve fibers. It is the fiber that connects the two hemispheres of the brain and the brain with the brainstem and spinal cord. The basal nucleus is located deep in the medulla and consists of dense neurons.

Each hemisphere can be divided into three faces, namely the broad and convex dorsal outer side, the flatter inner side and the irregular bottom side. The front of the hemisphere is called the frontal pole; the back is called the occipital pole; the front of the temporal lobe is called the temporal pole; The boundary between the medial and bottom surfaces is irregular, and is divided into two parts: the front is located between the medial and orbital surfaces, called the inner orbital margin, and the back is located between the medial and cerebellar surfaces, called the inner pillow The surface of the rim and cerebral hemisphere is a complex undulation and is separated by many grooves of varying depth and apparent degree. The grooves of the cerebral hemisphere divide the hemisphere into several leaves, and each leaf is divided into several times. The longitudinal groove separating the left and right hemispheres is called the hemisphere longitudinal fissure; the bottom of the longitudinal groove is the fiber connecting the left and right hemispheres, which is called the corpus callosum.

2. Interbrain:

The midbrain is located between the midbrain and the telencephalon. 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.

The mesencephalic is divided into five parts: The upper thalamus mainly includes the sacroiliac triangle, the medullary stratum of the thalamus, and the pineal gland. Dorsal thalamus is the two large gray matter masses that hold the third ventricle, also called thalamus. The posterior thalamus includes the medial and lateral geniculate bodies. The hypothalamus is located between the dorsal thalamus and the hypothalamus, and is connected to the midbrain cover. The hypothalamus is the part below the hypothalamus sulcus, including the optic cross, optic bundle, funnel, pituitary, gray nodules, and papillary body.

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.