Physiology of Excitable tissue L 5 Skeletal muscles
![Physiology of Excitable tissue L 5 Skeletal muscles Prof. Fakhir Al-Ani fakeralani 2000@yahoo. com Physiology of Excitable tissue L 5 Skeletal muscles Prof. Fakhir Al-Ani fakeralani 2000@yahoo. com](https://slidetodoc.com/presentation_image_h2/0229bc0e842820cf4bc4a0aaea0ea222/image-1.jpg)
Physiology of Excitable tissue L 5 Skeletal muscles Prof. Fakhir Al-Ani fakeralani 2000@yahoo. com
![Neuro-muscular arrangement & Motor Unite Neuro-muscular arrangement & Motor Unite](http://slidetodoc.com/presentation_image_h2/0229bc0e842820cf4bc4a0aaea0ea222/image-2.jpg)
Neuro-muscular arrangement & Motor Unite
![Effect of strength of stimulus on strength of contraction: 1. Sub-minimal stimulus < threshold. Effect of strength of stimulus on strength of contraction: 1. Sub-minimal stimulus < threshold.](http://slidetodoc.com/presentation_image_h2/0229bc0e842820cf4bc4a0aaea0ea222/image-3.jpg)
Effect of strength of stimulus on strength of contraction: 1. Sub-minimal stimulus < threshold. No contraction. 2. Minimal stimulus = threshold. Minimum contraction. 3. Sub-maximum > threshold. Increased force of contraction. 4. Maximal stimulus. Maximum contraction. 5. Supra-maximum: No farther increase in contraction
![Motor Unites & Effect of strength of stimulus: Sub- Minimal Sub- Maximal Maximum Supra-Maximal Motor Unites & Effect of strength of stimulus: Sub- Minimal Sub- Maximal Maximum Supra-Maximal](http://slidetodoc.com/presentation_image_h2/0229bc0e842820cf4bc4a0aaea0ea222/image-4.jpg)
Motor Unites & Effect of strength of stimulus: Sub- Minimal Sub- Maximal Maximum Supra-Maximal Stimulator + Intensity of stimulus So No. of active M. U. the force of contraction
![Muscle Changes during Excitation & Contraction 1. Electrical changes: Action Potential (A. P. ) Muscle Changes during Excitation & Contraction 1. Electrical changes: Action Potential (A. P. )](http://slidetodoc.com/presentation_image_h2/0229bc0e842820cf4bc4a0aaea0ea222/image-5.jpg)
Muscle Changes during Excitation & Contraction 1. Electrical changes: Action Potential (A. P. ) 2. Mechanical changes: Simple Muscle Twitch (SMT) 3. Chemical changes: Metabolism & ATP Hydrolysis 4. Thermal changes: Heat liberation
![1. Electrical Changes (A. P. ) Muscle A. P. is the Same as in 1. Electrical Changes (A. P. ) Muscle A. P. is the Same as in](http://slidetodoc.com/presentation_image_h2/0229bc0e842820cf4bc4a0aaea0ea222/image-6.jpg)
1. Electrical Changes (A. P. ) Muscle A. P. is the Same as in N But the RMP = - 80 m. V. & the duration 10 msec. spick +35 0. 0 Depolariza tion Repolarization Firing Level -80 Hyper polarization 1 2 3 4 5 6 7 8 9 10 msec.
![2. Mechanical changes: It is the work that is produced by the muscle The 2. Mechanical changes: It is the work that is produced by the muscle The](http://slidetodoc.com/presentation_image_h2/0229bc0e842820cf4bc4a0aaea0ea222/image-7.jpg)
2. Mechanical changes: It is the work that is produced by the muscle The record of mechanical changes is called (Simple muscle twitch= SMT) It is recorded by using oscillograph with especial transducer.
![Mechanical changes: Simple muscle twitch. 1. Latent Period = ? ? ? 10% 2. Mechanical changes: Simple muscle twitch. 1. Latent Period = ? ? ? 10% 2.](http://slidetodoc.com/presentation_image_h2/0229bc0e842820cf4bc4a0aaea0ea222/image-8.jpg)
Mechanical changes: Simple muscle twitch. 1. Latent Period = ? ? ? 10% 2. Contraction Time = 40% 3. Relaxation Time = 50 % 1 2 3
![Duration of different phases of S. M. T. 1. Latent period: The time needed Duration of different phases of S. M. T. 1. Latent period: The time needed](http://slidetodoc.com/presentation_image_h2/0229bc0e842820cf4bc4a0aaea0ea222/image-9.jpg)
Duration of different phases of S. M. T. 1. Latent period: The time needed for the impulse to pass from the site of stimulation to the NMJ, till the beginning of the contraction of them. (10% of total duration). 2. Contraction phase: The duration taken by the muscle during contraction. (40% of total duration). 3. Relaxation phase: The duration taken by the muscle during relaxation. (60% of total duration).
![Factors affecting SMT 1. Length of the m. fiber. 2. Nutrition of the muscle. Factors affecting SMT 1. Length of the m. fiber. 2. Nutrition of the muscle.](http://slidetodoc.com/presentation_image_h2/0229bc0e842820cf4bc4a0aaea0ea222/image-10.jpg)
Factors affecting SMT 1. Length of the m. fiber. 2. Nutrition of the muscle. 3. Changes in temperature. 4. Strength & Repetitive stimulation.
![1. Length of muscle fiber: Length of the muscle Number of Sarcomers Shortening amplitude 1. Length of muscle fiber: Length of the muscle Number of Sarcomers Shortening amplitude](http://slidetodoc.com/presentation_image_h2/0229bc0e842820cf4bc4a0aaea0ea222/image-11.jpg)
1. Length of muscle fiber: Length of the muscle Number of Sarcomers Shortening amplitude of contraction duration of contraction in same type of the muscle
![2. Nutrition of the muscle: Contraction depends on energy (ATP) coming from nutrients So 2. Nutrition of the muscle: Contraction depends on energy (ATP) coming from nutrients So](http://slidetodoc.com/presentation_image_h2/0229bc0e842820cf4bc4a0aaea0ea222/image-12.jpg)
2. Nutrition of the muscle: Contraction depends on energy (ATP) coming from nutrients So Nutrients ATP shortening tension & Duration of 3 phases of SMT Less fatigability
![3. Changes in temperature: Temperature of a muscle Temperature Amplitude of SMT Duration of 3. Changes in temperature: Temperature of a muscle Temperature Amplitude of SMT Duration of](http://slidetodoc.com/presentation_image_h2/0229bc0e842820cf4bc4a0aaea0ea222/image-13.jpg)
3. Changes in temperature: Temperature of a muscle Temperature Amplitude of SMT Duration of 3 phases of SMT metabolic rate So Energy (APT) production These changes continue up to 43 ºC after which denaturation of muscle proteins (Death) Decreasing the temperature is less defective
![4. Repetitive stimulation. a. Repetitive stimulation with low rate b. Repetitive stimulation with high 4. Repetitive stimulation. a. Repetitive stimulation with low rate b. Repetitive stimulation with high](http://slidetodoc.com/presentation_image_h2/0229bc0e842820cf4bc4a0aaea0ea222/image-14.jpg)
4. Repetitive stimulation. a. Repetitive stimulation with low rate b. Repetitive stimulation with high rate 1. Clonuse. 2. Tetanus. fatigue. Summation of contraction.
![Summation of contraction: Treppe Phenomenon Clonuses Tetanus Summation of contraction: Treppe Phenomenon Clonuses Tetanus](http://slidetodoc.com/presentation_image_h2/0229bc0e842820cf4bc4a0aaea0ea222/image-15.jpg)
Summation of contraction: Treppe Phenomenon Clonuses Tetanus
![The types of contraction Isotonic contraction: Constant tension but there is shortening of the The types of contraction Isotonic contraction: Constant tension but there is shortening of the](http://slidetodoc.com/presentation_image_h2/0229bc0e842820cf4bc4a0aaea0ea222/image-16.jpg)
The types of contraction Isotonic contraction: Constant tension but there is shortening of the muscle. Isometric contraction: Constant length but there is development of tension in the muscle. We cant get pure isometric or isotonic contraction Its mixed type of contraction Because of the presence of two components of the muscle
![Summation of contraction: Tetanus: Complete fusion of contraction. Clonuse: Incomplete fusion of contraction There Summation of contraction: Tetanus: Complete fusion of contraction. Clonuse: Incomplete fusion of contraction There](http://slidetodoc.com/presentation_image_h2/0229bc0e842820cf4bc4a0aaea0ea222/image-17.jpg)
Summation of contraction: Tetanus: Complete fusion of contraction. Clonuse: Incomplete fusion of contraction There is relaxation in between contraction. Occur at a lower rate. Increasing the temperature will change tetanus into Clonus (why? ).
![Components of the muscle 1. Contractile component: = Muscle fiber = Responsible for shortening Components of the muscle 1. Contractile component: = Muscle fiber = Responsible for shortening](http://slidetodoc.com/presentation_image_h2/0229bc0e842820cf4bc4a0aaea0ea222/image-18.jpg)
Components of the muscle 1. Contractile component: = Muscle fiber = Responsible for shortening of the total length of that muscle. 2. Elastic component: = Fibrous & Elastic tissue of the tendon = Responsible for development of tension.
![Type of muscle contraction: - isotonic contraction - isometric contraction Do we use Isotonic Type of muscle contraction: - isotonic contraction - isometric contraction Do we use Isotonic](http://slidetodoc.com/presentation_image_h2/0229bc0e842820cf4bc4a0aaea0ea222/image-19.jpg)
Type of muscle contraction: - isotonic contraction - isometric contraction Do we use Isotonic & Isometric contraction in our daily work? Can we get Pure isotonic or Isometric cont?
![Effect of Muscle training: 1. Muscle size by 2. Force of contraction. 3. Blood Effect of Muscle training: 1. Muscle size by 2. Force of contraction. 3. Blood](http://slidetodoc.com/presentation_image_h2/0229bc0e842820cf4bc4a0aaea0ea222/image-20.jpg)
Effect of Muscle training: 1. Muscle size by 2. Force of contraction. 3. Blood supply & mitochondria. thickness of muscle fibers. 4. May speed of contraction.
![Effects of exercise on the muscle Aerobic long sustained exercises Oxidative capacity m. f. Effects of exercise on the muscle Aerobic long sustained exercises Oxidative capacity m. f.](http://slidetodoc.com/presentation_image_h2/0229bc0e842820cf4bc4a0aaea0ea222/image-21.jpg)
Effects of exercise on the muscle Aerobic long sustained exercises Oxidative capacity m. f. B. V. supply & mitochondria so muscle efficiency High intensity, short burst exercise: glycolytic activity synthesis of glycolytic enzymes, synthesis of myofibrils muscle size
![Effect of muscle denervation: 1. Paralysis. 2. Atrophy of the muscle (decreased size) 3. Effect of muscle denervation: 1. Paralysis. 2. Atrophy of the muscle (decreased size) 3.](http://slidetodoc.com/presentation_image_h2/0229bc0e842820cf4bc4a0aaea0ea222/image-22.jpg)
Effect of muscle denervation: 1. Paralysis. 2. Atrophy of the muscle (decreased size) 3. Fibrosis of the muscle. 4. Fibrillation (Spontaneous invol. Contr. )
![Changes in the muscle during Excitation & Contraction 1. Electrical changes: Action Potential (A. Changes in the muscle during Excitation & Contraction 1. Electrical changes: Action Potential (A.](http://slidetodoc.com/presentation_image_h2/0229bc0e842820cf4bc4a0aaea0ea222/image-23.jpg)
Changes in the muscle during Excitation & Contraction 1. Electrical changes: Action Potential (A. P. ) 2. Mechanical changes: Simple Muscle Twitch (S. M. T. ) //////////////////////////////// 3. Chemical changes: Metabolism & ATP generation 4. Thermal changes: Heat liberation
![3. Chemical Changes Muscle is a machine that convert one type of energy to 3. Chemical Changes Muscle is a machine that convert one type of energy to](http://slidetodoc.com/presentation_image_h2/0229bc0e842820cf4bc4a0aaea0ea222/image-24.jpg)
3. Chemical Changes Muscle is a machine that convert one type of energy to the other Chemical energy present in the food is converted to mechanical energy in the muscle This energy is represented by ATP There are 2 types of chemical changes to produce energy: -
![Types of metabolism 1. Aerobic: Need Oxygen = Oxidative Glucose 40 ATP Mol. 2. Types of metabolism 1. Aerobic: Need Oxygen = Oxidative Glucose 40 ATP Mol. 2.](http://slidetodoc.com/presentation_image_h2/0229bc0e842820cf4bc4a0aaea0ea222/image-25.jpg)
Types of metabolism 1. Aerobic: Need Oxygen = Oxidative Glucose 40 ATP Mol. 2. Anaerobic: little or no O 2 - Glucose 4 ATP Mol. During Metabolism there is consumption of 2 ATP Mole So the net result Synthesis of 38 ATP Mol in aerobic Met. & 2 Mol of ATP in Anaerobic Met. So Aerobic is more efficient than the anaerobic
![Chemical Changes Diet (Carb. , Fat, & Prot. ) Metabolism in the Muscle ATP Chemical Changes Diet (Carb. , Fat, & Prot. ) Metabolism in the Muscle ATP](http://slidetodoc.com/presentation_image_h2/0229bc0e842820cf4bc4a0aaea0ea222/image-26.jpg)
Chemical Changes Diet (Carb. , Fat, & Prot. ) Metabolism in the Muscle ATP Mechanical Energy (Movement & Force)
![Metabolism: The energy comes mainly from ATP + H 2 O Triphosphotase ADP + Metabolism: The energy comes mainly from ATP + H 2 O Triphosphotase ADP +](http://slidetodoc.com/presentation_image_h2/0229bc0e842820cf4bc4a0aaea0ea222/image-27.jpg)
Metabolism: The energy comes mainly from ATP + H 2 O Triphosphotase ADP + 7. 3 Kcal Lactic acid & toxic material of anaerobic metabolites Cause vasoconstriction of blood vessels so there is insufficient blood supply So fatigue occurs early in anaerobic metabolism & May cause Muscle spasm
![Sources of ATP There are 3 main sources of ATP: 1. Phosphorylation of creatine Sources of ATP There are 3 main sources of ATP: 1. Phosphorylation of creatine](http://slidetodoc.com/presentation_image_h2/0229bc0e842820cf4bc4a0aaea0ea222/image-28.jpg)
Sources of ATP There are 3 main sources of ATP: 1. Phosphorylation of creatine phosphate: Protein which rich energy substance present in the muscle mainly as a storage component. 2. CHO: Glycogen Lactic acid Glucose + O 2 CO 2 + H 2 O 3. F. F. A. : Usually utilize O 2 for production of ATP. Fatty acid + O 2 CO 2 + H 2 O 4. Protein is not used in normal conditioned Amino acid + O 2 CO 2 + H 2 O + Urea
![Creatine phosphate metabolism During exercise: Creatine phosphate + ADP ATP+ creatine This reaction occurs Creatine phosphate metabolism During exercise: Creatine phosphate + ADP ATP+ creatine This reaction occurs](http://slidetodoc.com/presentation_image_h2/0229bc0e842820cf4bc4a0aaea0ea222/image-29.jpg)
Creatine phosphate metabolism During exercise: Creatine phosphate + ADP ATP+ creatine This reaction occurs when there is increase exercise & decrease O 2 supply During Rest: Creatinine + ATP Creatine Phosphate This reaction occurs when there is: blood flow & nutrition & O 2 To store ATP & use it during sudden strenuous exercise & in anaerobic phase.
![The sequence of energy production: Energy Produced in the muscles firstly from Creatine Phosphate. The sequence of energy production: Energy Produced in the muscles firstly from Creatine Phosphate.](http://slidetodoc.com/presentation_image_h2/0229bc0e842820cf4bc4a0aaea0ea222/image-30.jpg)
The sequence of energy production: Energy Produced in the muscles firstly from Creatine Phosphate. Then from the carbohydrate Then from fat And the least is from protein.
![Fatigue Gradual in amplitude & gradual in duration of SMT induced by slow repetitive Fatigue Gradual in amplitude & gradual in duration of SMT induced by slow repetitive](http://slidetodoc.com/presentation_image_h2/0229bc0e842820cf4bc4a0aaea0ea222/image-31.jpg)
Fatigue Gradual in amplitude & gradual in duration of SMT induced by slow repetitive stimuli. Fatigue occurs: 1. Firstly at the neuromuscular junction. 2. Then fatigue occurs in muscle. 3. Then in the nerve. At the end of fatigue if more stimulation there is failure of relaxation no more contraction of muscle
![Fatigue Fatigue](http://slidetodoc.com/presentation_image_h2/0229bc0e842820cf4bc4a0aaea0ea222/image-32.jpg)
Fatigue
![To prove that fatigue appears firstly in neuromuscular junction by removing stimulation from nerve To prove that fatigue appears firstly in neuromuscular junction by removing stimulation from nerve](http://slidetodoc.com/presentation_image_h2/0229bc0e842820cf4bc4a0aaea0ea222/image-33.jpg)
To prove that fatigue appears firstly in neuromuscular junction by removing stimulation from nerve fibers and applying it directly on the muscle. There will be response in the muscle.
![Causes of fatigue: 1. Decrease in the neurotransmitter: Ach. 2. Decrease in energy of Causes of fatigue: 1. Decrease in the neurotransmitter: Ach. 2. Decrease in energy of](http://slidetodoc.com/presentation_image_h2/0229bc0e842820cf4bc4a0aaea0ea222/image-34.jpg)
Causes of fatigue: 1. Decrease in the neurotransmitter: Ach. 2. Decrease in energy of muscle or nerve. 3. Accumulation of metabolites & waste products like lactic acid, CO 2. 4. Failure of repolarization due to loss of energy.
![Failure of repolarization: In resting condition: (there is R. M. P. ) All excitable Failure of repolarization: In resting condition: (there is R. M. P. ) All excitable](http://slidetodoc.com/presentation_image_h2/0229bc0e842820cf4bc4a0aaea0ea222/image-35.jpg)
Failure of repolarization: In resting condition: (there is R. M. P. ) All excitable tissues (n. & m. ) are in polarized state On stimulation : (No R. M. P. ) There will be process of depolarization as a result of influx of Na+. Later on: (Regaining the R. M. P. ) The muscle & nerve are repolarized. This can take place by the effect of Na-K pump, which needs energy in the form of (ATP). During fatigue due to in ATP So Na-K pump will be in efficient in repolarization.
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