The brain is located in the skull, which protects it from mechanical damage. As the spinal cord, he is covered by three membranes of connective tissu

Brain stem structure and functions

The brain is located in the skull, which protects it from mechanical damage. As the spinal cord, he is covered by three membranes of connective tissue: hard, soft and arachnoid (vascular). In most cases the irritation of these membranes (in inflammation, poisoning, lack of oxygen) is accompanied by a headache. Between the sheath and in the four ventricles (cavities) of the brain contains a cerebrospinal fluid (CSF). The average weight of the human brain is about 1.5 kg.

The direct continuation of the spinal cord is a medulla. The fourth ventricle of the brain is located in it. The next parts of the brain are a bridge and midbrain. These three sections form the brain stem (diagram 149). It consists predominantly of white matter and its main function is to conduct excitation from the spinal cord to the cerebral cortex, and vice versa. The white matter is the accumulation of gray matter, which forms the core, in particular the cores of 12 cranial nerves pairs. Taken from http://worldofschool.org

Diagram 149. The structure of the cerebellum and diencephalon: 1 — thalamus; 2 — the brain stem; 3 — the midbrain; 4 — bridge; 5 — the medulla oblongata; 6 — the spinal cord; 7 — the cerebellum; 8 — bark of the cerebellum; 9 — the nucleus of the cerebellum

There are the nerve centers in the brain stem that regulate different unconditioned autonomic (cardiovascular, respiratory, etc.) and motor reflexes (e.g. indicative, posture reflexes) and ensure the conduction of the sensitive information to the brain regions placed above (in particular, from the visual and auditory receptors). The brain stem has a reticular formation — a network of huge amount of neurons. The axons of each form two branches — one descends to the spinal cord neurons, and the other — is raises to the neurons of intermediate brain and to the cerebral cortex. Dendrites of these cells get the excitation of all sensitive formations. Due to afferent revenue from different receptor, neurons of the reticular formation are constantly in a state of excitement. By sending nerve impulses to all departments of the central nervous system, neurons of reticular formation provide support of excitability and tonus maintenance of all its departments.

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  • What is the structure and functions of the medulla oblongata and the bridge?