Brain of birds: structure and functions

The brain is the main regulator of all functional departures of the body, as well as its behavioral acts, which are aimed at adapting to the external conditions of life.

The medulla oblongata is an extension of the spinal cord. He has a gray substance outside and a white substance inside. Clusters of neuronal cell bodies form nuclei in the medulla oblongata. The medulla oblongata is a vital organ. With its defeat, there is a violation of reflex somatic and vegetative acts, and when it is destroyed, death occurs. The medulla oblongata performs a conductive and reflex function. The cerebrum regulates the following reflexes: cardiac activity, vascular tone, breathing, coughing, sneezing, salivation, swallowing, gastric and pancreatic secretion, vomiting, metabolism, lacrimation, blinking and eyelid closing, tonic reflexes of skeletal muscles.

The activity of the centers of the medulla oblongata is associated with the manifestation of the postural reflexes of the posture. The reflexes of the posture are those reflexes that cause a redistribution of the tonus of the muscles of the limbs when the position of the head changes.

The brain and cerebellum are connected by afferent and efferent fibers with all parts of the central nervous system, and through them with muscles and many receptors of the body, as well as with the autonomic nervous system.

The main functions of the cerebellum include: 1) the regulation of motor acts; 2) regulation of vegetative processes. These functions of the cerebellum were established in experiments using the techniques of extirpation, stimulation, registration of cerebellar biocurrents, and clinical observations.

The cerebellum is well developed in birds and is of great importance for a highly developed sense of balance. In the first period after removal of the cerebellum, the bird can not fly and walk. When you try to move, convulsions appear, and the bird falls on its side. However, she can take food and drink. After a while the condition improves and the bird is able, although with difficulty, to stand, walk and fly. Scientific research has established that in the cerebellum there are centers that regulate the activity of the autonomic nervous system.

The brain of birds (middle brain) is well developed and consists of two parts: dicholmia and legs. Dichotomy has anterior and posterior lobes and is formed by the nuclei of sensitive neurons.

The main functions of the midbrain are: 1. The front part of the dichotomy is the primary visual center. Here the primary analysis of light stimuli occurs. With the help of these centers, an approximate reaction to light stimulation is performed (turning the head toward the light stimulus). The centers of the anterior part of the diorhythm regulate the narrowing of the pupil. 2. The back part of the dichotomy carries out an approximate reaction to sound stimuli (turning the head toward the sound stimulus). 3. Black substance is involved in the regulation of contractions of skeletal muscles. It also regulates the act of swallowing and the rhythm of breathing. 4. The brain, or rather the middle brain, has the centers of the rectifying reflexes. Straightening reflexes are called reflexes, which restore the normal position of the body after its violation.

The brain of reptiles, in contrast to the brain of birds, has poorly developed cerebral hemispheres.

The intermediate brain consists of the thalamus, epithalamus, and hypothalamus. The intermediate brain performs many functions. 1. The thalamus is a collector that collects impulses from all body receptors (visual, auditory, taste, tactile, temperature, pain, proprioceptors) and directs them to the larger hemispheres. 2. In the nuclei of the thalamus, the afferent impulses are subjected to initial analysis and synthesis. 3. In the thalamus afferent impulses acquire emotional coloring. There is a feeling of pain, a feeling of pleasant and unpleasant. 4. The thalamus regulates the plastic muscle tone, thanks to which the birds can take and maintain various poses. 5. In the epithalamus there are centers that regulate the activity of the olfactory analyzer. 6. In the hypothalamus, the centers regulating the dilatation of the pupil, blood pressure, respiration, motor and secretory functions of the digestive tract are localized. 7. The hypothalamus regulates body temperature.