Subject: "Reception. The system organization of carrying-out ways, nervous fibers, types, the mechanism of carrying out excitement. Physiological properties of nervous fibers. N. E. Vvedensky's doctrine about a parabiosis. Action of a direct current on excitable fabrics. Polar laws, electrotone, katodichesky depression". Lecture plan: 1. Structurally – physiological features of nervous fiber 2. Physiological properties of nervous fiber. 3. Excitement distribution on nervous fibers. 4. Speed of carrying out excitement. 5. Laws of carrying out excitement. Relative not fatigue of a nerve. 6. Parabiosis, phases. 7. Action of a direct current.
Neuron structure
Физиологические свойства Physiological properties of nervous fiber нервного волокна Excitability. 2. Conductivity. 1.
Laws of carrying out excitement in nerves. Anatomic and physiological integrity of nervous fiber. 2. Bilateral carrying out excitement. 3. The isolated carrying out excitement. 1.
Relative not fatigue of nervous fiber ► Relative not fatigue of nervous fiber is caused by low power expenditure of a nerve at excitement and fast the resintezy. ► In the nitrogen atmosphere the nerve gets tired.
The mechanism of carrying out excitement in nervous fibers I. Bezmiyelinovye of fiber; - excitement extends continuously. II. Myelin fibers. - excitement extends skachkoobrazno, i. e. saltatorno.
Speed of carrying out excitement on nervous fibers Group of fibers А Аα Аβ Аγ Аδ В С Diameter of fibers (micron) Speed of carrying out (m/s) 12 -22 8 -12 4 -8 1 -4 1 -3 0, 5 -1, 0 70 -120 40 -70 15 -40 5 -15 3 -14 0, 5 -2
Parabiosis and its phases The parabiosis (para – near, bios – life) is a condition between life and death, in a basis - the decrease in lability caused by action of an alteriruyushchy factor. Parabiosis phases: 1. Leveling phase; 2. Paradoxical phase; 3. Brake phase. At a full parabiosis the special condition of not extending excitement localized on a site of action of the alteriruyushchy agent ("stationary excitement") develops.
Action of a direct current on excitable fabric current (Pflyuger 1759) ► Laws of polar action of a direct current ► 1. The irritant action occurs only at the time of short circuit and disconnection. ► 2. At short circuit of excitement arises on the cathode, at disconnection on the anode. ► 3. The switching blow of a direct current is stronger than the razmykatelny.
►Katelektroton is an increase of excitability and conductivity under the cathode at action of a direct current ►Anelektroton is a decrease in excitability and conductivity under the anode at action of a direct current
► The Katodichesky depression is a decrease in excitability and conductivity under the cathode at long action of a direct current. ► Anodichesky exaltation is an increase of excitability and conductivity under the anode at long action of a direct current.
Скачать презентацию Subject Reception The system organization of carrying-out ways
3- Рецепция. нервные волокна.ppt