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UDK 004.02:004.5:004.9
Salimova S.F. teacher
Department of Biology Bukhara State University
GENERAL STRUCTURE OF SPINAL ANIMALS FEATURES
Annotation: Vertebrates- (Vertebrata or Craniata) are a subspecies of chordates. The number of species is less than that of invertebrates; however, they play an important role in the modern biosphere. They have a highly structured, changeable habitat. They live in different layers of the ocean, in high mountains, deserts and other places. In the evolution of these animals, it is observed that their structure develops according to a single general plan. Such development has led to the emergence of forms that have improved in terms of morphological, biochemical and physiological properties, behavior and mental activity.
Keywords: Vertebrates, body structure, nervous system, digestive organs, development, biological growth.
The shape of the body is different. Aquatic lowland vertebrates. The body is divided into head, body and tail parts. They have a single back, tail and under the tail and a pair of thoracic and ventral fins. A terrestrial vertebrate in the body of the animal again a part of the neck is formed, the odd fin wings will not appear, instead of a pair of finned wings appear five-toed type structured legs will be.
Leather covers. The skin is an important organ in terms of function. Because skin participation in body defense, thermoregulation, multiplication and sensation processes reaches The skin is composed of outer epidermis and inner chin skin layers. Epidermis composed of multilayered epithelium. A circle whose life depends on the aquatic environment mucous substance in the epidermis of larvae of oral fish and amphibians secretory glands. Mucous substances affect the movement of these animals in water relieves. The outer part of the epidermis in terrestrial vertebrates layer is branched. On their skin faces are various horny products, coins, shield, feather, wool, etc. are formed. Chin leather is a hard fibrous binder made of tissue. In this tissue are the bones that cover the uncle and the bone marrow located.
Skeletons. The skeletons of vertebrates are divided into bullet skeletons, head skeletons, and divided into foot skeletons.
The skeleton of a bullet consists of a chord in the embryos of vertebrates. Chord segments does not divide. Tissue that connects the chord and the central nervous system the curtain surrounds the outside. This membrane is a skeletogenic membrane. Due to the membrane, vertebrae made of bone or bone develop. Of lightning the vertebrae are convex and the spine is not divided into
sections. The vertebrae of fish are divided into two parts - the rib body and the tail without ribs divided into sections. The vertebrae of terrestrial vertebrates are divided into five sections: neck, chest, waist, tail, and tail. In this case, the ribs of the thoracic cavity move with the chest to form the thorax. The spine supports the entire body on one side, on the other hand, the spinal cord and internal organs serve as a protective sheath.
The skull consists of the cerebral cortex and the surface or visceral sections. Brain box protects the brain and sensory organs from mechanical impact.
In fish, the visceral skeleton is composed of uncle lattices in round mouths from the visceral arch: 1) the jaw arch 2) the sublingual arch 3) the jaw arch. On land the upper part of the jaw arch of living vertebrates to the auditory bone, the lower part again the remnants of the jaw arches become the sublingual apparatus. From round-mouthed all vertebrates except have a pair of legs and their girdle skeleton. Fish have a skeleton of two swimming wings, while terrestrial animals have five the toe will be the skeleton of the foot.
Nervous system. Nervous system of vertebrates 1) head and back to the central nervous system consisting of the brain 2) originating from the brain and spinal cord to the peripheral nervous system composed of nerves and 3) along the arch of the spine divided into the lying autonomic nervous system.
The brain is in the anterior part of the neural tube during the early stages of embryonic development comes in the form of three bubbles. Then before and after the first bubble the brain, the midbrain is formed from the second cerebral bladder, and the cerebellum from the third. At the base of the brain is the elongated brain. A total of 10-12 from the brain a pair of brains emerge.
The spine is in the shape of a lifelong reed. Its interior is gray exterior and white matter. The metamer in the spinal cord is the back of it brain nerves come out. They start with two roots, the sensory back and the driving force is the abdomen. These roots merge after leaving the spinal cord, forms spinal nerves.
The peripheral nervous system of vertebrates is the brain and spinal cord is a complex system of nerves and these nerves are different from the body goes to the organs.
The autonomic nervous system is the work of the internal organs of the animal, the heart controls palpitations, bowel contractions, glandular secretions.
The sense organs are diverse and complex. Skin sensory organs consists of nerve endings that receive mechanical stimuli, such as the skin on the face and on the surface of the mucous membranes of the intestine and other organs scattered.
Lateral organs are found only in primary aquatic vertebrates specific. In round-mouthed amphibians and amphibians, these organs are located on the surface of the skin. In fish, on both sides of the body in the form of longitudinal stripes located on the side. Due to the lateral line bodies the flow rate of water to the animal and feels the direction of the movement of his body.
The auditory organ is always paired and acts as a balance organ. Round in lizards and fish it consists only of the inner ear. The inner ear is oval consists of
a pouch and a bottom round pouch. Oval bags are round three semicircular canals in all vertebrates except vertebrates turns out. An endolymphatic canal with a closed tip emerges from the sac.
From amphibians, the middle ear is formed. Inside it is the sternum, and in mammals the outer ear appears again.
Respiratory organs. Round-mouthed, fish and amphibians. If the respiratory organs of the larvae are oppressed, the breathing of the remaining vertebrates serves as an organ. In some cases, the skin is involved in respiration The organ of vision consists of a pair of eyelids. In front of it is the cornea. The eyeball is the center of the eyeball. Eye contact the wall is vascular, pigmented, and composed of a retina.
The olfactory organ is paired in all vertebrates except the round-mouthed will be. This organ consists of two olfactory sacs in the lower vertebrae and the nose. The inner nose, which does not connect to the medium through the nostrils through the nostrils it also connects to the oral cavity and the respiratory tract through holes or holes.
The digestive system is tubular and consists of the following parts: 1) the mouth cavity, 2) larynx - In fish, when the jaw cracks open in the larynx, on land In living vertebrates, a larynx is located in the larynx, 3) the esophagus, 4) stomach, 5) small intestine, colon and rectum, 6) posterior outlet or cloaca. Digestive glands include the liver, pancreas, and others.
References:
1. Animal Life, in 7 volumes. T. 4. 5. 6 7. - M.: "Education", 1983- 1989
2. Jupanov M. A. Life is an anthropogenic transformation in the conditions of the southern island vertebrates. Doctor of Biological Sciences (D S e) d i ss e r ta i n ya si avtoreferat !!.
3. Zoology ku ren (edited by B. S. Matveev. Acad. T. Z. Zoxidov translation) 11 vols, - T. : 1966.
4. Zoxidov T. Z Encyclopedia of Zoology. Fish and lower chordates. - T. : «Fan», 1966,
5. Zoxidov T. Z. I am in encyclopedia of zoology. Amphibians and reptiles. -T. : «Fan», 1969
