Due to the key role it plays it maintaining normal body function it is sometimes referred to as the brain within the brain. Some of the important functions of the hypothalamus are listed in the table below. The autonomic nervous system is a system of neurons that automatically regulate function such as heart rate, blood pressure, digestion, etc.
The hypothalamus regulates many of the activities of the activity of the autonomic nervous system by controlling centers in the brain stem and spinal cord.
Select groups of hypothalamic neurons monitor blood temperature directly as well as respond to inputs from other thermoreceptors throughout the body and then send appropriate signals to systems that help regulate body temperature such as sweat glands.
Osmoreceptors modified neurons in the hypothalamus respond to changing salt concentrations in the blood which in turn elicit responses from the kidneys as well as regulate thirst. The hypothalamus regulates the pituitary gland. A major endocrine organ gland that regulates numerous body functions including metabolism and reproduction. The epithalamus is the most dorsal of the structures of the diencephalon.
Within the epithalalmus are several important structures including the habenular nuclei and the pineal gland.
The habenular nuclei have been shown to have involvement in several limbic system type functions including negative reward processing. The diencephalon sits at the top of the brainstem and is closed by the cerebral hemispheres. It consists of four key parts:. Except for these main four parts, some other segments and structures build up the "interbrain" or, scientifically, diencephalon.
Those include the pineal gland, the Stria medullaris thalami , the anterior paraventricular nuclei, the posterior paraventricular nuclei, the posterior commissure, the medial habenular nuclei, and the lateral habenular nuclei 1. It is interesting to describe the borders of the diencephalon to understand its anatomical position and functions. First of all, it has a roof, the lateral walls, as well as anterior and posterior walls.
Moreover, the structure of these borders is important. The roof consists of tela choroidea. This is a Latin scientific name for two membranes. Those are called pia mater and ependyma. The roof of the diencephalon contains two blood vessels. They enter the third ventricle cavity. This is the point where the function of the cerebrospinal fluid production takes place too. The optic chiasm is the key component of the diencephalon floor.
Besides, there is the tuber cinereum, tuber infundibulum, posterior perforated segment, the mammillary bodies, and the top segment of the mesencephalic tegmentum 2. The anterior diencephalon wall contains the fornix column, lamina terminalis, and the anterior commissure. The posterior wall structure contains the Habenular commissures, the stalk of the pineal gland, and the posterior commissure. Medial walls of the thalami build up the diencephalon lateral walls.
Moreover, this part of our brain is directly responsible for connecting the parts of the system of inner secretion glands, i. Moreover, it is interconnected with our limbic system. Namely, it helps manage memories, as well as emotions. We must note that each part of the diencephalon is responsible for a different function. There are communication pathways between its parts and it makes this brain a diverse and connector body in our organism.
Namely, it connects the limbic system, the basal ganglia, and the visual and audio sensory areas. As a result, it plays an important role in our emotions and motoric activities and coordination. The upper part of the thalamus transfers information and processes information from the majority of the sensory organs to the cerebrum. The thalamus surrounds the third chamber and represents a relay station for the sensory impulses. It transfers impulses to the appropriate part of the cortex to be localized and interpreted.
The diencephalon is one of the most highly developed structures of the human central nervous system and consists of two major components: the thalamus , a key structure for transmitting information to the cerebral hemispheres, and the hypothalamus , which integrates the functions of the autonomic nervous system and. The diencephalon relays sensory information between brain regions and controls many autonomic functions of the peripheral nervous system.
This section of the forebrain also connects structures of the endocrine system with the nervous system and works with the limbic system to generate and manage emotions and memories. The pineal gland is an endocrine structure of the diencephalon of the brain, and is located inferior and posterior to the thalamus.
It is made up of pinealocytes. These cells produce and secrete the hormone melatonin in response to low light levels. Asked by: Eudosia Fuerchtenicht medical health brain and nervous system disorders Why is the Diencephalon called Interbrain? Last Updated: 16th February, In development, the forebrain develops from the prosencephalon, the most anterior vesicle of the neural tube that later forms both the diencephalon and the telencephalon.
Gari Quaresima Professional. What does Diencephalon contain? The diencephalon is made up of four main components: the thalamus, the subthalamus, the hypothalamus, and the epithalamus.
The hypothalamus is an integral part of the endocrine system, with the key function of linking the nervous system to the endocrine system via the pituitary gland. Detelina Hughes Professional. Is Diencephalon a midbrain? The diencephalon is a division of the forebrain embryonic prosencephalon , and is situated between the telencephalon and the midbrain embryonic mesencephalon.
It consists of structures that are on either side of the third ventricle, including the thalamus, the hypothalamus, the epithalamus and the subthalamus. Peggie Piercey Professional. What is the largest part of the human brain? This is the cerebrum. It's the largest part of the human brain. The cerebrum also called telencephalon sits on top of the brain.
Calin Thirumalai Explainer. What is Interbrain? See also brainstem. More medially is the parahippocampal gyrus, which is involved in learning and memory.
Portions of the frontal, parietal, and temporal lobes, which are adjacent to the lateral sulcus and overlie the insular cortex, are known as the operculum. The inferomedial surface of the temporal lobe is made up of the uncus and the parahippocampal gyrus medially. The inferior surface of the temporal lobe rests on the tentorium cerebelli. The occipital lobe is the most caudal part of the brain, lies on the tentorium cerebelli Figure 1. On its medial surface, there is a prominent fissure — the calcarine fissure and parieto-occipital sulcus.
The calcarine fissure sulcus and the parieto-occipital sulcus also define a cortical region known as the cuneus. The cuneus sulcus divides the occipital lobe into the cuneus dorsally and ventrally into the lingual gyrus.
The occipital lobe contains the primary and higher-order visual cortex. The insula lobe is located deep inside the lateral fissure and can be seen only when the temporal and the frontal lobes are separated Figures 1. The insula is characterized by several long gyri and sulci, the gyri breves and gyri longi. There is some evidence that the insular cortical areas are involved in nociception and regulation of autonomic function.
The limbic lobe is not a true lobe and is comprised of several cortical regions such as the cingulate and parahippocampal gyri, some subcortical areas like the hippocampus, amygdala, septum, and other areas with their respective ascending and descending connections Figures 1. The limbic lobe is involved in memory and learning, drive related behavior, and emotional function.
There are subcortical areas in the telencephalon like the basal ganglia and the amygdaloid nucleus complex.
The corpus callosum is a collection of nerve fibers that connect the two hemispheres. The corpus callosum is divided into rostrum head , body, the most rostrally part is the genu knee with connecting the rostrum and the body, and the splenium at the caudal extremity Figure 1. The corpus callosum plays an important role in transferring information from one hemisphere to the other. The second major derivative of the prosencephalon is the diencephalon.
The diencephalon is the most rostral structure of the brain stem; it is embedded in the inferior aspect of the cerebrum. The posterior commissure is the junctional landmark between the diencephalon and the mesencephalon. Caudally, the diencephalon is continuous with the tegmentum of the midbrain.
During development the diencephalon differentiates into four regions: thalamus, hypothalamus, subthalamus and epithalamus Figure 1.
The brain stem consists of mesencephalon midbrain , metencephalon, and myelencephalon. The metencephalon and myelencephalon together compose the rhombencephalon hindbrain , which divides into pons, and medulla oblongata Figures 1. Mesencephalon midbrain is continuous with the diencephalon rostrally and with the pons caudally. The midbrain is the smallest part of the brain stem, being about 2 cm in length.
It consists of a tectum posteriorly, a tegmentum inferiorly, and a base anteriorly. The tectum forms the roof of the cerebral aqueduct, which connects the third ventricle with the fourth ventricle and the tegmentum its floor.
The base of the midbrain consists of the cerebral peduncle, which contain nerve fibers descending from the cerebral cortex. The nuclei of the 3rd oculomotor , the 4th trochlear and part of the 5th trigeminal are located in the midbrain tegmentum.
The red nucleus and the substantia nigra, two prominent nuclei, are also found in the midbrain tegmentum. The midbrain tectum is formed by two pairs of rounded structures: the superior and inferior colliculi. The superior and inferior colliculi Figure 1. Pons is continuous with the midbrain and is composed of two parts, the pontine tegmentum located internally and the basilar pons. At the level of the pons, the cerebral aqueduct has expanded to form the fourth ventricle Figure 1.
The cerebellum is situated posterior to the pons and forms part of the roof tectum of the forth ventricle. The pons contains nuclei that receive axons from various cortical areas. Projections from the axons of these pontine neurons form large transverse fiber bundles that traverse the pons and ascend to the contralateral cerebellum via the middle cerebellar peduncles. Also, within the pons base and tegmentum are longitudinally ascending and descending fibers. The nuclei of the 5th trigeminal , 6th abducens , 7th facial and the 8th vestibulocochlear nerves are located in the pons tegmentum.
Medulla Oblongata myelencephalon is also known as the medulla. The medulla lies between the pons rostrally and the spinal cord caudally. It is continuous with the spinal cord just above to foramen magnum and the first spinal nerve. The posterior surface of the medulla forms the caudal half of the fourth ventricle floor and the cerebellum, its roof Figure 1.
The base of the medulla is formed by the pyramidal-descending fibers from the cerebral cortex.
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