Excitation and contraction of muscle
•Download as PPTX, PDF•
0 likes•237 views
The process of excitation-contraction coupling in muscles begins with the generation of an action potential that spreads into the muscle fiber through T-tubules. This causes the release of calcium from the sarcoplasmic reticulum. The increased calcium concentration in the sarcoplasm allows calcium to bind to troponin-C, exposing actin binding sites for myosin heads to attach and initiate the cross-bridge cycle. This results in the sliding of thin filaments and shortening of sarcomeres, causing muscle contraction. Relaxation occurs when calcium is pumped back into the sarcoplasmic reticulum, detaching from troponin and cessating the interaction between actin and myosin.
Report
Share
Report
Share
Recommended
Superimposed currents
The document discusses superimposed electrical stimulation techniques. It defines superimposition as placing or adding something on top of something else. Superimposing electrical stimulation onto voluntary muscle contractions can theoretically activate more motor units and increase contraction force. Two main techniques are discussed - applying stimulation to nerves or directly to muscles. Superimposition can be used to evaluate central activation failure and distinguish central vs peripheral fatigue. Precautions must be taken when applying electrical stimulation due to risks of electric shock, burns or other issues.
Muscle spindle & muscle c tone
Muscle spindles are proprioceptors that consist of intrafusal muscle fibers enclosed in a sheath (spindle). They run parallel to the extrafusal muscle fibers and act as receptors that provide information on muscle length and the rate of change in muscle length. The spindles are stretched when the muscle lengthens. This stretch causes the sensory neuron in the spindle to transmit an impulse to the spinal cord, where it synapses with alpha motor neurons. This causes activation of motor neurons that innervate the muscle. The muscle spindles determine the amount of contraction necessary to overcome a given resistance. When the resistance increases, the muscle is stretched further, and this causes spindle fibers to activate a greater muscle contraction.
Diadynamic currents
Diadynamic currents are a variation of sinusoidal currents that are produced by rectifying alternating current into monophasic pulses. There are two main types - half wave rectification produces pulses with a duration equal to the interpulse interval at the original frequency, while full wave rectification produces continuous pulses at twice the original frequency. The pulses from diadynamic currents have a duration of 10ms, causing sensations from vibration to pain depending on intensity. Different current types like MF, DF, CP and LP are used for pain relief, muscle stimulation, and preventing accommodation effects. Precautions must be taken due to the electrochemical changes and potential skin damage from the currents.
Neuromuscular junction
This document discusses the neuromuscular junction and several disorders that can affect it. It begins by describing the basic anatomy and physiology of the motor unit and neuromuscular junction. It then reviews several disorders in more depth, including myasthenia gravis, Lambert-Eaton myasthenic syndrome, and neuromyotonia. For each disorder, it discusses the epidemiology, clinical features, diagnostic tests, and treatment options. The goal is to provide clinicians with an overview of these neuromuscular junction disorders.
Rebox current
Rebox electrotherapeutic method is based on non-invasive transcutaneous application of specific electric currents to a living tissue. Main indications for using the Rebox include treatment of acute and chronic pain, immobility, musculoskeletal and neurological disorders and oedema.
Faradic current
Definition, surging, physiological & therapeutic effects,indications & contraindications, techniques of application
Lecture 2 Electrotherapy- pain physiology
Knowledge of pain physiology is very important in understanding of electrotherapy prescription. So, this slide may be useful in understanding the background of the pain processes.
Galvanic-Current.pptx
Galvanic current is a low frequency, interrupted direct current with pulse durations over 1ms up to 300ms and frequencies under 50Hz. It was discovered in the 1780s by Luigi Galvani and can cause contraction of denervated muscles through sluggish contractions, stimulation of sensory nerves resulting in pain sensations, and stimulation of motor nerves at high intensities. Therapeutically, galvanic current is used to retard muscle atrophy and substitute for normal muscle contraction in denervated muscles by slowing structural and functional changes like loss of activity and fibrosis through electrical stimulation. It can also be used facially to reduce dullness, fine lines, wrinkles, and improve elasticity and oxygen supply.
Recommended
Superimposed currents
The document discusses superimposed electrical stimulation techniques. It defines superimposition as placing or adding something on top of something else. Superimposing electrical stimulation onto voluntary muscle contractions can theoretically activate more motor units and increase contraction force. Two main techniques are discussed - applying stimulation to nerves or directly to muscles. Superimposition can be used to evaluate central activation failure and distinguish central vs peripheral fatigue. Precautions must be taken when applying electrical stimulation due to risks of electric shock, burns or other issues.
Muscle spindle & muscle c tone
Muscle spindles are proprioceptors that consist of intrafusal muscle fibers enclosed in a sheath (spindle). They run parallel to the extrafusal muscle fibers and act as receptors that provide information on muscle length and the rate of change in muscle length. The spindles are stretched when the muscle lengthens. This stretch causes the sensory neuron in the spindle to transmit an impulse to the spinal cord, where it synapses with alpha motor neurons. This causes activation of motor neurons that innervate the muscle. The muscle spindles determine the amount of contraction necessary to overcome a given resistance. When the resistance increases, the muscle is stretched further, and this causes spindle fibers to activate a greater muscle contraction.
Diadynamic currents
Diadynamic currents are a variation of sinusoidal currents that are produced by rectifying alternating current into monophasic pulses. There are two main types - half wave rectification produces pulses with a duration equal to the interpulse interval at the original frequency, while full wave rectification produces continuous pulses at twice the original frequency. The pulses from diadynamic currents have a duration of 10ms, causing sensations from vibration to pain depending on intensity. Different current types like MF, DF, CP and LP are used for pain relief, muscle stimulation, and preventing accommodation effects. Precautions must be taken due to the electrochemical changes and potential skin damage from the currents.
Neuromuscular junction
This document discusses the neuromuscular junction and several disorders that can affect it. It begins by describing the basic anatomy and physiology of the motor unit and neuromuscular junction. It then reviews several disorders in more depth, including myasthenia gravis, Lambert-Eaton myasthenic syndrome, and neuromyotonia. For each disorder, it discusses the epidemiology, clinical features, diagnostic tests, and treatment options. The goal is to provide clinicians with an overview of these neuromuscular junction disorders.
Rebox current
Rebox electrotherapeutic method is based on non-invasive transcutaneous application of specific electric currents to a living tissue. Main indications for using the Rebox include treatment of acute and chronic pain, immobility, musculoskeletal and neurological disorders and oedema.
Faradic current
Definition, surging, physiological & therapeutic effects,indications & contraindications, techniques of application
Lecture 2 Electrotherapy- pain physiology
Knowledge of pain physiology is very important in understanding of electrotherapy prescription. So, this slide may be useful in understanding the background of the pain processes.
Galvanic-Current.pptx
Galvanic current is a low frequency, interrupted direct current with pulse durations over 1ms up to 300ms and frequencies under 50Hz. It was discovered in the 1780s by Luigi Galvani and can cause contraction of denervated muscles through sluggish contractions, stimulation of sensory nerves resulting in pain sensations, and stimulation of motor nerves at high intensities. Therapeutically, galvanic current is used to retard muscle atrophy and substitute for normal muscle contraction in denervated muscles by slowing structural and functional changes like loss of activity and fibrosis through electrical stimulation. It can also be used facially to reduce dullness, fine lines, wrinkles, and improve elasticity and oxygen supply.
Golgi tendon organ
This document discusses the Golgi tendon organ and reflex, as well as the withdrawal reflex. It begins by describing the Golgi tendon organ as stretch receptors located in tendons and musculoaponeurotic junctions. It then explains the pathway and function of the Golgi tendon reflex, which protects muscles from overcontraction via autogenic inhibition. Next, it defines the withdrawal reflex as a polysynaptic reflex that causes limb removal in response to painful stimuli, and describes the neural pathway and variations in withdrawal response, including crossed extensor response and widespread withdrawal. It concludes by discussing the protective function of withdrawal reflexes and comparing physiological and pathological clinical reflexes.
Muscle fibre types
This document discusses the different types of muscle fibers: Type 1 slow-twitch fibers, and Type 2 fast-twitch fibers including Type 2a fast oxidative glycolytic fibers and Type 2b fast glycolytic fibers. It aims to describe the structure and function of each fiber type, how recruitment patterns vary, and how fiber types can adapt to long term activity or detraining. The document also analyzes how different sports may require different fiber type compositions and discusses fiber type considerations like potential, training effects, detraining effects, and recovery needs.
Nerves conduction study
This document provides information about nerve conduction studies (NCS). It discusses the basic components of a NCS including compound muscle action potentials, sensory nerve action potentials, F-waves, and H-reflexes. It describes the procedure, techniques, and applications of NCS in evaluating conditions like neuropathies, radiculopathies, and neuromuscular junction disorders. Limitations include NCS only assessing the largest nerve fibers and conditions proximal to the dorsal root ganglia potentially showing normal results.
Sinusoidal current 2
Sinusoidal current is an alternating current that produces smooth, rhythmic muscle contractions at 50 Hz. It is produced from mains electricity reduced to 60-80 volts using a step-down transformer. This current stimulates both motor and sensory nerves, causing tetanic muscle contraction and tingling sensation. It is often used over large areas to relieve pain through sensory stimulation and reduce edema through rhythmic muscle pumping. Sinusoidal current is similar to faradic current but provides deeper penetration and is less irritating, making it well-suited for nervous clients.
Diadynamic current
Diadynamic currents are also called Bernard's currents based on a sine wave with a frequency of 50Hz. Due to the ease of generation of this current shape, they have been known almost from the beginning of electrotherapy, and their influence on the human body has been thoroughly studied.
Galvanic current
This document discusses galvanic current and its use in stimulating denervated muscles. It defines galvanic current as a direct, unidirectional current that can cause pain due to its unidirectional nature. Interrupted galvanic current is introduced to overcome this by providing regular pauses in stimulation. Stimulating denervated muscles with galvanic current can help limit atrophy and edema until reinnervation occurs. Precautions must be taken when applying galvanic current due to potential dangers like burns or electric shock.
Hf uvr
The document discusses different types of ultraviolet generators used to produce ultraviolet radiation, including high pressure mercury vapor lamps, Kromayer lamps, fluorescent tubes, Theraktin tunnels, and PUVA apparatus. It provides information on the structure and functioning of these various lamps and devices used for generating ultraviolet radiation.
Faradic current
This document provides information about faradic current, including its nature, therapeutic and physiological effects, techniques of application, indications, contraindications, and clinical applications. It describes faradic current as an asymmetrical alternating current with a pulse duration of 0.1-1 ms and frequency of 30-100 Hz. The document discusses the effects of faradic current such as stimulation of sensory and motor nerves and reduction of swelling and pain. It outlines various methods and techniques of faradic current application for diagnostic and therapeutic purposes, as well as precautions and potential dangers of its use.
Superimposed current
The document discusses superimposed current (HVPC), a type of neuromuscular stimulation involving a short, microamperage current delivered by a high voltage (up to 300V) in a twin-peak monophasic waveform. It is used clinically to produce muscle contractions and chemical changes. Typical uses include analgesia, muscle contractions, and wound healing. The document lists group members and machines that can deliver HVPC, and discusses its physiological effects such as increasing range of motion and blood flow. It also summarizes studies on using HVPC for wound healing, pain management, muscle strengthening, and edema management.
Skeletal muscle properties
Skeletal muscle makes up 40-50% of total body weight and is attached by tendons to bones. Skeletal muscle cells are multinucleated and striated, have visible banding patterns, and are voluntary muscles under conscious control. Skeletal muscles produce force for locomotion and postural support. Microscopically, skeletal muscle contains myofibrils with thick and thin filaments that slide during muscle contraction and relaxation. Skeletal muscle contraction occurs through summation of motor unit contractions and tetanization at higher stimulation frequencies.
SD curve (Strength Duration Curve)
a detailed description on theory behind Strength duration curve, along with procedure for plotting SD Curve and measuring the Rheobase and Chronaxie of the plotted graph.
Rebox
The Rebox device applies specific electric currents transcutaneously to treat pain, immobility, and musculoskeletal and neurological disorders. It works by restoring microcirculation, reducing inflammation, and improving blood and lymph flow. Treatment sessions last 5-10 minutes using different modes and electrode tips. Rebox is used for conditions like back pain, ankle sprains, and knee ligament injuries. Contraindications include open wounds, pregnancy, and use near pacemakers.
ELECTRO THERAPY CURRENT USE IN CLINICAL CASES
1. TENS would be used to manage the pain from osteoarthritis of the knee. Specifically, conventional/high TENS with a high frequency of 40-150 Hz, low intensity current of 10-30 mA, and short pulse duration of up to 50 microseconds would be applied for 30-60 minutes.
2. Conventional TENS works by pre-synaptic inhibition to suppress pain signals to the brain and encourage the body's natural painkillers. It can help control arthritis pain without additional drugs.
3. TENS is a safe and effective first-line treatment for many pain conditions, including osteoarthritis of the knee.
Concept of motor unit by sandeep choudhary
it is very useful content for the basic knowledge of motor units .
Dedicated to my father shri satyaveer singh , my mother bateri devi and the entire lnipe family .
Whirlpool Bath - Physiotherapy.pptx
Whirlpool therapy is a physical therapy modality that is used to treat several orthopaedic and neurological dysfunctions.
Low, Medium and High Frequency Current
It is a direct current named after inventor Dr.L. Galvani. 2. Its direction of polarity is constant and passing continuously in one direction only, so termed as constant direct current. 3. Because of its unidirectional property, when applied to a muscle tend to contract and remain in that position till it is brought to zero, which seems to be very painful. GALVANIC CURRENT
Hvpgs
High voltage pulsed galvanic stimulation (HVPGS) is a form of electrical stimulation using very brief high voltage pulses to stimulate nerve and muscle fibers. HVPGS uses pairs of pulses lasting 0.1 milliseconds with peak currents of 2-2.5 amps applied at a frequency of 2-100 Hz. The brief pulses allow the current to pass easily through tissue. HVPGS is used to strengthen muscles, reduce pain, and aid wound healing by increasing blood flow and reducing edema. The document provides details on the parameters and generator of HVPGS and discusses its various applications.
Modified galvanic current
Modified galvanic current, or interrupted direct current, is a type of electrical stimulation where a direct current is pulsed on and off at regular intervals. The document discusses how this current is produced using a source, transistors, and a timer circuit. It describes the physiological effects of interrupted direct current such as sensory stimulation, hyperemia, electrotonus, pain relief, and accelerated healing. The document also provides guidelines for administering interrupted direct current and lists contraindications.
Sinusoidal current
Sinusoidal current produces a sine wave alternating current of 50 Hz, giving 100 pulses per second with durations of 10ms each, alternating direction 50 times in each direction. It is produced from mains power by reducing the voltage to 60-80v using a step down transformer. When passed through the body, sinusoidal current causes changes in ion concentrations at cell membranes, producing muscle contraction in nerves and ionic movement in other tissues. It is commonly used to cause rhythmic muscle contractions and relieve pain and reduce swelling by alternately changing cell membrane permeability. Indications include pain and pain/swelling, while contraindications include skin lesions, infections, and impaired sensation.
HIGH VOLTAGE PULSATING CURRENT (super imposed current)
The document lists the group members working on the topic of super imposed currents. It discusses techniques for electrode placement and polarity in monopolar and bipolar formats. Contraindications that could be dangerous are listed, such as cancer, pregnancy, seizures or heart conditions. Precautions are recommended for impaired sensations, cerebral palsy, inflammation or sensitivity. Potential dangers from the currents include burns, shocks, pain, irritation and muscle soreness.
excitationandcontractionofmuscle-190727143314.pdf
The document discusses the process of excitation-contraction coupling in muscle fibers. It involves the generation of an action potential which spreads into the muscle fiber and triggers the release of calcium from the sarcoplasmic reticulum. The rise in calcium concentration allows myosin heads to bind to actin and initiate the cross-bridge cycle, causing the thin filaments to slide over the thick filaments and shorten the sarcomere, resulting in muscle contraction. Relaxation occurs when calcium is pumped back into the sarcoplasmic reticulum, detaching from troponin and ending the interaction between actin and myosin.
Lec26
The document discusses several topics related to muscle contraction, including:
1. Excitation-contraction coupling, where an action potential causes the release of calcium ions, triggering muscle contraction.
2. Neuromuscular transmission, where a nerve impulse causes the release of acetylcholine at the neuromuscular junction, generating an action potential in the muscle fiber.
3. The sliding filament theory which explains how calcium ions allow the overlapping of actin and myosin filaments, causing sarcomeres to shorten and generate force.
More Related Content
What's hot
Golgi tendon organ
This document discusses the Golgi tendon organ and reflex, as well as the withdrawal reflex. It begins by describing the Golgi tendon organ as stretch receptors located in tendons and musculoaponeurotic junctions. It then explains the pathway and function of the Golgi tendon reflex, which protects muscles from overcontraction via autogenic inhibition. Next, it defines the withdrawal reflex as a polysynaptic reflex that causes limb removal in response to painful stimuli, and describes the neural pathway and variations in withdrawal response, including crossed extensor response and widespread withdrawal. It concludes by discussing the protective function of withdrawal reflexes and comparing physiological and pathological clinical reflexes.
Muscle fibre types
This document discusses the different types of muscle fibers: Type 1 slow-twitch fibers, and Type 2 fast-twitch fibers including Type 2a fast oxidative glycolytic fibers and Type 2b fast glycolytic fibers. It aims to describe the structure and function of each fiber type, how recruitment patterns vary, and how fiber types can adapt to long term activity or detraining. The document also analyzes how different sports may require different fiber type compositions and discusses fiber type considerations like potential, training effects, detraining effects, and recovery needs.
Nerves conduction study
This document provides information about nerve conduction studies (NCS). It discusses the basic components of a NCS including compound muscle action potentials, sensory nerve action potentials, F-waves, and H-reflexes. It describes the procedure, techniques, and applications of NCS in evaluating conditions like neuropathies, radiculopathies, and neuromuscular junction disorders. Limitations include NCS only assessing the largest nerve fibers and conditions proximal to the dorsal root ganglia potentially showing normal results.
Sinusoidal current 2
Sinusoidal current is an alternating current that produces smooth, rhythmic muscle contractions at 50 Hz. It is produced from mains electricity reduced to 60-80 volts using a step-down transformer. This current stimulates both motor and sensory nerves, causing tetanic muscle contraction and tingling sensation. It is often used over large areas to relieve pain through sensory stimulation and reduce edema through rhythmic muscle pumping. Sinusoidal current is similar to faradic current but provides deeper penetration and is less irritating, making it well-suited for nervous clients.
Diadynamic current
Diadynamic currents are also called Bernard's currents based on a sine wave with a frequency of 50Hz. Due to the ease of generation of this current shape, they have been known almost from the beginning of electrotherapy, and their influence on the human body has been thoroughly studied.
Galvanic current
This document discusses galvanic current and its use in stimulating denervated muscles. It defines galvanic current as a direct, unidirectional current that can cause pain due to its unidirectional nature. Interrupted galvanic current is introduced to overcome this by providing regular pauses in stimulation. Stimulating denervated muscles with galvanic current can help limit atrophy and edema until reinnervation occurs. Precautions must be taken when applying galvanic current due to potential dangers like burns or electric shock.
Hf uvr
The document discusses different types of ultraviolet generators used to produce ultraviolet radiation, including high pressure mercury vapor lamps, Kromayer lamps, fluorescent tubes, Theraktin tunnels, and PUVA apparatus. It provides information on the structure and functioning of these various lamps and devices used for generating ultraviolet radiation.
Faradic current
This document provides information about faradic current, including its nature, therapeutic and physiological effects, techniques of application, indications, contraindications, and clinical applications. It describes faradic current as an asymmetrical alternating current with a pulse duration of 0.1-1 ms and frequency of 30-100 Hz. The document discusses the effects of faradic current such as stimulation of sensory and motor nerves and reduction of swelling and pain. It outlines various methods and techniques of faradic current application for diagnostic and therapeutic purposes, as well as precautions and potential dangers of its use.
Superimposed current
The document discusses superimposed current (HVPC), a type of neuromuscular stimulation involving a short, microamperage current delivered by a high voltage (up to 300V) in a twin-peak monophasic waveform. It is used clinically to produce muscle contractions and chemical changes. Typical uses include analgesia, muscle contractions, and wound healing. The document lists group members and machines that can deliver HVPC, and discusses its physiological effects such as increasing range of motion and blood flow. It also summarizes studies on using HVPC for wound healing, pain management, muscle strengthening, and edema management.
Skeletal muscle properties
Skeletal muscle makes up 40-50% of total body weight and is attached by tendons to bones. Skeletal muscle cells are multinucleated and striated, have visible banding patterns, and are voluntary muscles under conscious control. Skeletal muscles produce force for locomotion and postural support. Microscopically, skeletal muscle contains myofibrils with thick and thin filaments that slide during muscle contraction and relaxation. Skeletal muscle contraction occurs through summation of motor unit contractions and tetanization at higher stimulation frequencies.
SD curve (Strength Duration Curve)
a detailed description on theory behind Strength duration curve, along with procedure for plotting SD Curve and measuring the Rheobase and Chronaxie of the plotted graph.
Rebox
The Rebox device applies specific electric currents transcutaneously to treat pain, immobility, and musculoskeletal and neurological disorders. It works by restoring microcirculation, reducing inflammation, and improving blood and lymph flow. Treatment sessions last 5-10 minutes using different modes and electrode tips. Rebox is used for conditions like back pain, ankle sprains, and knee ligament injuries. Contraindications include open wounds, pregnancy, and use near pacemakers.
ELECTRO THERAPY CURRENT USE IN CLINICAL CASES
1. TENS would be used to manage the pain from osteoarthritis of the knee. Specifically, conventional/high TENS with a high frequency of 40-150 Hz, low intensity current of 10-30 mA, and short pulse duration of up to 50 microseconds would be applied for 30-60 minutes.
2. Conventional TENS works by pre-synaptic inhibition to suppress pain signals to the brain and encourage the body's natural painkillers. It can help control arthritis pain without additional drugs.
3. TENS is a safe and effective first-line treatment for many pain conditions, including osteoarthritis of the knee.
Concept of motor unit by sandeep choudhary
it is very useful content for the basic knowledge of motor units .
Dedicated to my father shri satyaveer singh , my mother bateri devi and the entire lnipe family .
Whirlpool Bath - Physiotherapy.pptx
Whirlpool therapy is a physical therapy modality that is used to treat several orthopaedic and neurological dysfunctions.
Low, Medium and High Frequency Current
It is a direct current named after inventor Dr.L. Galvani. 2. Its direction of polarity is constant and passing continuously in one direction only, so termed as constant direct current. 3. Because of its unidirectional property, when applied to a muscle tend to contract and remain in that position till it is brought to zero, which seems to be very painful. GALVANIC CURRENT
Hvpgs
High voltage pulsed galvanic stimulation (HVPGS) is a form of electrical stimulation using very brief high voltage pulses to stimulate nerve and muscle fibers. HVPGS uses pairs of pulses lasting 0.1 milliseconds with peak currents of 2-2.5 amps applied at a frequency of 2-100 Hz. The brief pulses allow the current to pass easily through tissue. HVPGS is used to strengthen muscles, reduce pain, and aid wound healing by increasing blood flow and reducing edema. The document provides details on the parameters and generator of HVPGS and discusses its various applications.
Modified galvanic current
Modified galvanic current, or interrupted direct current, is a type of electrical stimulation where a direct current is pulsed on and off at regular intervals. The document discusses how this current is produced using a source, transistors, and a timer circuit. It describes the physiological effects of interrupted direct current such as sensory stimulation, hyperemia, electrotonus, pain relief, and accelerated healing. The document also provides guidelines for administering interrupted direct current and lists contraindications.
Sinusoidal current
Sinusoidal current produces a sine wave alternating current of 50 Hz, giving 100 pulses per second with durations of 10ms each, alternating direction 50 times in each direction. It is produced from mains power by reducing the voltage to 60-80v using a step down transformer. When passed through the body, sinusoidal current causes changes in ion concentrations at cell membranes, producing muscle contraction in nerves and ionic movement in other tissues. It is commonly used to cause rhythmic muscle contractions and relieve pain and reduce swelling by alternately changing cell membrane permeability. Indications include pain and pain/swelling, while contraindications include skin lesions, infections, and impaired sensation.
HIGH VOLTAGE PULSATING CURRENT (super imposed current)
The document lists the group members working on the topic of super imposed currents. It discusses techniques for electrode placement and polarity in monopolar and bipolar formats. Contraindications that could be dangerous are listed, such as cancer, pregnancy, seizures or heart conditions. Precautions are recommended for impaired sensations, cerebral palsy, inflammation or sensitivity. Potential dangers from the currents include burns, shocks, pain, irritation and muscle soreness.
What's hot (20)
HIGH VOLTAGE PULSATING CURRENT (super imposed current)
HIGH VOLTAGE PULSATING CURRENT (super imposed current)
Similar to Excitation and contraction of muscle
excitationandcontractionofmuscle-190727143314.pdf
The document discusses the process of excitation-contraction coupling in muscle fibers. It involves the generation of an action potential which spreads into the muscle fiber and triggers the release of calcium from the sarcoplasmic reticulum. The rise in calcium concentration allows myosin heads to bind to actin and initiate the cross-bridge cycle, causing the thin filaments to slide over the thick filaments and shorten the sarcomere, resulting in muscle contraction. Relaxation occurs when calcium is pumped back into the sarcoplasmic reticulum, detaching from troponin and ending the interaction between actin and myosin.
Lec26
The document discusses several topics related to muscle contraction, including:
1. Excitation-contraction coupling, where an action potential causes the release of calcium ions, triggering muscle contraction.
2. Neuromuscular transmission, where a nerve impulse causes the release of acetylcholine at the neuromuscular junction, generating an action potential in the muscle fiber.
3. The sliding filament theory which explains how calcium ions allow the overlapping of actin and myosin filaments, causing sarcomeres to shorten and generate force.
Muscle contraction
The document describes various aspects of muscle contraction including:
1) Excitation-contraction coupling which involves depolarization of the muscle membrane leading to calcium release and muscle contraction.
2) The roles of the sarcoplasmic reticulum, t-tubules, and troponin-tropomyosin complex in regulating calcium levels and exposing actin binding sites during contraction.
3) The sliding filament theory of how myosin heads binding to actin causes muscle shortening through an ATP-driven cycling of cross-bridge formation and breaking.
skeletal muscle.pptx
1) Skeletal muscle contraction is initiated by an action potential that travels along the sarcolemma and T-tubules, causing the release of calcium from the sarcoplasmic reticulum.
2) The increase in intracellular calcium concentration triggers the interaction between actin and myosin cross-bridges through troponin C, resulting in the sliding of thin filaments over thick filaments and muscle contraction.
3) Muscle relaxation occurs as calcium is re-uptaken into the sarcoplasmic reticulum by SERCA pumps, reducing calcium levels and ending the cross-bridge cycling between actin and myosin.
Excitation - Contraction coupling
The document summarizes the mechanism of skeletal muscle contraction. It describes how an action potential leads to a rise in intracellular calcium levels through excitation-contraction coupling. This triggers the sliding filament theory where actin and myosin filaments slide past each other through cross-bridge cycling powered by ATP hydrolysis. Calcium binds to troponin C, allowing the power stroke to occur as myosin heads pull the actin filaments towards the center of the sarcomere. Relaxation occurs as calcium is re-sequestered in the sarcoplasmic reticulum, breaking the cross-bridges.
CONTRACTILE TISSUES. medical physiologyptx
The document provides information on the three types of contractile tissues: skeletal, cardiac, and smooth muscle. It describes their structures, functions, and the physiology of excitation and relaxation. Skeletal muscle is striated and voluntary, found attached to bones. Cardiac muscle is also striated and located in the heart, contracting involuntarily. Smooth muscle lacks striations and is found in organs and passageways, with involuntary contraction. Contraction is powered by the sliding of the skeletal muscle's thick and thin filaments, triggered by calcium ion release from the sarcoplasmic reticulum in response to an action potential. Relaxation occurs when calcium is pumped back into the sarcoplasmic reticulum.
Graduate Physiology 503 Muscle Phy.docx
Graduate Physiology 503 Muscle Physiology Hurley
1
MUSCLE PHYSIOLOGY
Part 2: Excitation-contraction coupling
Learning Objectives:
1. Compare the role of extracellular and intracellular calcium in excitation contraction
coupling in skeletal and cardiac muscle.
2. Describe the role of the T‐tubule and the sarcoplasmic reticulum membrane systems in
excitation‐contraction coupling.
3. Describe how calcium is removed from the cytoplasm for relaxation.
4. Describe how force can be graded in cardiac and skeletal muscles.
A. OVERVIEW
Skeletal Muscles are the effector organs of the voluntary locomotor system. The striated
appearance of both skeletal and cardiac muscle is because of the ordered arrangement of the
contractile elements within the muscle fibers. Skeletal muscle, unlike cardiac muscle, has no
intrinsic spontaneous electrical activity and therefore relied upon neural impulses to initiate
activity. Most activation of skeletal muscle takes place at specialized nerve ending called
motor end plates. There are a few exceptions: facial muscles, for example, are diffusely
innervated along the length of the muscle providing multifocal innervation of these skeletal
muscles.
B. STRUCTURE OF SKELETAL MUSCLE
The neural electrical impulse is amplified at the neuromuscular junction producing an end
plate potential that is the first step in muscle contraction.
Figure 1. Key structures of skeletal muscle fiber.
Graduate Physiology 503 Muscle Physiology Hurley
2
Like neurons, muscle fibers are excitable cells. Their plasma membranes (sarcolemma) express ion channels
and pumps necessary to support a very negative resting membrane potential as well as the voltage gated ion
channels required to generate an action potential. At any given time, the membrane potential of muscle cells
is the result of the net electrochemical gradients of ions that the membrane is permeable to. (Recall Nernst
equation; Table 1). The resting membrane potential in skeletal muscle at 37°C is similar to neurons (~-70 –
90 mV). However, there is an importance difference between the ion species that dominate the resting
membrane potential in neurons and skeletal muscle.
Question:
In contrast to skeletal muscle, what ion species dominates the resting potential of neurons? Explain.
Chloride makes a significant contribution to the resting membrane potential of skeletal
muscle. The physiological relevance of the Cl- current stems from a need to maintain
muscle activity during repeated stimulation. When muscle contracts, there is leakage of K+
from the cell. With repeated activity, there is run-down of the K+ concentration gradient
across the sarcolemma. Without the Cl- current to maintain resting membrane potential,
the muscle would not repolarize suffi ...
EXCITATION CONTRACTION COUPLING physiology
This document summarizes the process of muscle excitation and contraction. It discusses how an action potential triggers the release of calcium ions, which then bind to troponin and allow the myosin heads to interact with actin filaments. The myosin heads undergo an ATP-powered power stroke that causes the filaments to slide past each other, resulting in muscle shortening and contraction. Muscle relaxation occurs when calcium ions are pumped back into the sarcoplasmic reticulum, detaching the myosin heads from actin and allowing the muscle fibers to return to their resting state.
part 7
Excitation-contraction coupling refers to the process by which an action potential in the skeletal muscle plasma membrane leads to muscle contraction. The action potential causes calcium release from the sarcoplasmic reticulum, which increases cytosolic calcium levels and allows cross-bridge cycling between actin and myosin filaments, causing contraction. Calcium is then actively transported back into the sarcoplasmic reticulum by calcium ATPases, lowering cytosolic calcium and allowing muscle relaxation.
Muscular system_powerpoint
The document summarizes the structure and function of the muscular system. It describes the three types of muscles, with a focus on skeletal muscles. Skeletal muscles produce movement by pulling on tendons attached to bones. The document then details the anatomy of skeletal muscles including their gross anatomy, blood supply, and microanatomy down to the level of the sarcomere. It explains how skeletal muscle contraction occurs through the sliding filament theory involving the interaction of actin and myosin filaments.
Muscular system_powerpoint
The document summarizes the structure and function of the muscular system. It describes the three types of muscles, with a focus on skeletal muscles. Skeletal muscles produce movement by pulling on tendons attached to bones. The document details the anatomy of skeletal muscles including their gross anatomy, blood vessels and nerves. It then describes the microanatomy of skeletal muscle fibers including myofibrils, sarcomeres, and the sliding filament theory of contraction.
Muscular system
The document summarizes the structure and function of the muscular system. It describes the three types of muscles, with a focus on skeletal muscles. Skeletal muscles produce movement by pulling on tendons attached to bones. The document then details the anatomy of skeletal muscles including their gross anatomy, blood supply, and microanatomy down to the level of the sarcomere. It explains how skeletal muscle contraction occurs through the sliding filament theory involving the interaction of actin and myosin filaments.
Right Atrial Contractions
The document discusses skeletal muscle contraction which begins when an action potential arrives at the neuromuscular junction. This causes acetylcholine to be released into the synaptic cleft which binds to nicotinic receptors on the muscle fiber membrane, triggering an endplate potential that depolarizes the fiber. This leads to the release of calcium ions from the sarcoplasmic reticulum which initiates the sliding filament mechanism of contraction through interactions between actin and myosin fibers.
Muscle contraction with medecine
The document defines key terms related to muscle contraction such as sarcomeres, myofibrils, and cross-bridges. It then summarizes the sliding filament model of muscle contraction which involves calcium binding to troponin, exposing actin binding sites, ATP binding to myosin heads, power strokes that cause actin to slide over myosin, and cross-bridge detachment. It also describes muscle twitches, summation that results from high stimulation frequencies, tetanus which is a sustained contraction, and recruitment where additional motor neurons are activated to involve more muscle fibers and produce more force.
Muscle Contraction Lab
The lab experiment tested the muscle reaction of a psoas muscle fiber to three different solutions by measuring the fiber size before and after adding each solution. The fiber size did not change with any of the solutions, not supporting the hypothesis that ATP solution would cause muscle contraction. The purpose was to determine if the solutions would cause contraction. The introduction provided background on muscle contraction and the role of ATP.
8_MUSCLE TISSUE.pptx
This document provides an overview of muscle tissue, including the three main types - skeletal, cardiac, and smooth muscle. It discusses the anatomy, location, functions and examples of each type of muscle. For skeletal and cardiac muscle, it describes the sarcomere structure and sliding filament model of contraction. For smooth muscle, it explains the role of calcium and calmodulin in excitation-contraction coupling. The document aims to describe the fundamental differences between muscle types at the cellular and molecular level.
muscle7-smoothmuscle-180414110808.pptx
- Smooth muscle fibers are much smaller in diameter and length compared to skeletal muscle fibers. Smooth muscle lacks striations and is located within organs like the intestines and blood vessels.
- Smooth muscle contraction is initiated by an increase in intracellular calcium ions which can be triggered by nerve stimulation, hormones, stretch of the fiber, or chemical changes. Calcium then binds to calmodulin instead of troponin to drive contraction.
- Smooth muscle exhibits a slow cycling of myosin cross-bridges, requiring less energy for sustained contraction compared to skeletal muscle. Its contraction and relaxation is also slower than skeletal muscle.
MUSCLE CONTRACTION.ppt
Muscle contraction occurs via a sliding filament mechanism where actin filaments slide inward among myosin filaments. This occurs when calcium ions bind to troponin C, allowing the myosin cross-bridges to attach to actin and generate force as they detach. The strength of muscle contraction depends on factors like stimulus strength, temperature, and load. Repeated stimulation can cause fatigue, summation, or tetanus depending on frequency.
PHYSIOLOGY OF MUSCLE CONTRACTION
Muscle movement plays an important role in day to day life where the contraction and relaxation of muscle is significant. The current slide has been developed with the focus on different phases during muscle contraction and the physiological change involved on it.
NMP-6.pptx
The document summarizes the molecular mechanisms of muscle contraction. It describes how actin, tropomyosin, and troponin proteins in the thin filament regulate muscle contraction by exposing binding sites on actin for myosin cross bridges. Calcium released from the sarcoplasmic reticulum in response to an action potential triggers contraction by causing troponin and tropomyosin to move, exposing actin binding sites. Repeated cycling of myosin cross bridges binding to and detaching from actin causes the thin filaments to slide, shortening the sarcomere and producing muscle contraction via the sliding filament mechanism. ATP provides energy for cross bridge cycling.
Similar to Excitation and contraction of muscle (20)
Recently uploaded
A Classical Text Review on Basavarajeeyam
Basavarajeeyam is a Sreshta Sangraha grantha (Compiled book ), written by Neelkanta kotturu Basavaraja Virachita. It contains 25 Prakaranas, First 24 Chapters related to Rogas& 25th to Rasadravyas.
Light House Retreats: Plant Medicine Retreat Europe
Our aim is to organise conscious gatherings and retreats for open and inquisitive minds and souls, with and without the assistance of sacred plants.
Identification and nursing management of congenital malformations .pptx
Identification and nursing management of congenital malformations .pptxMGM SCHOOL/COLLEGE OF NURSING
Identification and nursing management of congenital malformations Top-Vitamin-Supplement-Brands-in-India List
Swisschem Dermacare provides the Top 10 Vitamin Supplement Brands in India. To know more about us give us call at our official number
Phone Us ❤8107221448❤ #ℂall #gIRLS In Dehradun By Dehradun @ℂall @Girls Hotel...
Phone Us ❤8107221448❤ #ℂall #gIRLS In Dehradun By Dehradun @ℂall @Girls Hotel...chandankumarsmartiso
Phone Us ❤8107221448❤ #ℂall #gIRLS In Dehradun By Dehradun @ℂall @Girls Hotel With 100% Satisfaction
Hemodialysis: Chapter 4, Dialysate Circuit - Dr.Gawad
- Video recording of this lecture in English language: https://youtu.be/kqbnxVAZs-0
- Video recording of this lecture in Arabic language: https://youtu.be/SINlygW1Mpc
- Link to download the book free: https://nephrotube.blogspot.com/p/nephrotube-nephrology-books.html
- Link to NephroTube website: www.NephroTube.com
- Link to NephroTube social media accounts: https://nephrotube.blogspot.com/p/join-nephrotube-on-social-media.html
ABDOMINAL TRAUMA in pediatrics part one.
Abdominal trauma in pediatrics refers to injuries or damage to the abdominal organs in children. It can occur due to various causes such as falls, motor vehicle accidents, sports-related injuries, and physical abuse. Children are more vulnerable to abdominal trauma due to their unique anatomical and physiological characteristics. Signs and symptoms include abdominal pain, tenderness, distension, vomiting, and signs of shock. Diagnosis involves physical examination, imaging studies, and laboratory tests. Management depends on the severity and may involve conservative treatment or surgical intervention. Prevention is crucial in reducing the incidence of abdominal trauma in children.
8 Surprising Reasons To Meditate 40 Minutes A Day That Can Change Your Life.pptx
8 Surprising Reasons To Meditate 40 Minutes A Day That Can Change Your Life.pptxHolistified Wellness
We’re talking about Vedic Meditation, a form of meditation that has been around for at least 5,000 years. Back then, the people who lived in the Indus Valley, now known as India and Pakistan, practised meditation as a fundamental part of daily life. This knowledge that has given us yoga and Ayurveda, was known as Veda, hence the name Vedic. And though there are some written records, the practice has been passed down verbally from generation to generation.Local Advanced Lung Cancer: Artificial Intelligence, Synergetics, Complex Sys...
Overall life span (LS) was 1671.7±1721.6 days and cumulative 5YS reached 62.4%, 10 years – 50.4%, 20 years – 44.6%. 94 LCP lived more than 5 years without cancer (LS=2958.6±1723.6 days), 22 – more than 10 years (LS=5571±1841.8 days). 67 LCP died because of LC (LS=471.9±344 days). AT significantly improved 5YS (68% vs. 53.7%) (P=0.028 by log-rank test). Cox modeling displayed that 5YS of LCP significantly depended on: N0-N12, T3-4, blood cell circuit, cell ratio factors (ratio between cancer cells-CC and blood cells subpopulations), LC cell dynamics, recalcification time, heparin tolerance, prothrombin index, protein, AT, procedure type (P=0.000-0.031). Neural networks, genetic algorithm selection and bootstrap simulation revealed relationships between 5YS and N0-12 (rank=1), thrombocytes/CC (rank=2), segmented neutrophils/CC (3), eosinophils/CC (4), erythrocytes/CC (5), healthy cells/CC (6), lymphocytes/CC (7), stick neutrophils/CC (8), leucocytes/CC (9), monocytes/CC (10). Correct prediction of 5YS was 100% by neural networks computing (error=0.000; area under ROC curve=1.0).
How STIs Influence the Development of Pelvic Inflammatory Disease.pptx
STIs may cause PID. For the both disease, herbal medicine Fuyan Pill can be a solution.
Integrating Ayurveda into Parkinson’s Management: A Holistic Approach
Explore the benefits of combining Ayurveda with conventional Parkinson's treatments. Learn how a holistic approach can manage symptoms, enhance well-being, and balance body energies. Discover the steps to safely integrate Ayurvedic practices into your Parkinson’s care plan, including expert guidance on diet, herbal remedies, and lifestyle modifications.
Adhd Medication Shortage Uk - trinexpharmacy.com
The UK is currently facing a Adhd Medication Shortage Uk, which has left many patients and their families grappling with uncertainty and frustration. ADHD, or Attention Deficit Hyperactivity Disorder, is a chronic condition that requires consistent medication to manage effectively. This shortage has highlighted the critical role these medications play in the daily lives of those affected by ADHD. Contact : +1 (747) 209 – 3649 E-mail : sales@trinexpharmacy.com
TEST BANK For Community Health Nursing A Canadian Perspective, 5th Edition by...
TEST BANK For Community Health Nursing A Canadian Perspective, 5th Edition by Stamler, Verified Chapters 1 - 33, Complete Newest Version Community Health Nursing A Canadian Perspective, 5th Edition by Stamler, Verified Chapters 1 - 33, Complete Newest Version Community Health Nursing A Canadian Perspective, 5th Edition by Stamler Community Health Nursing A Canadian Perspective, 5th Edition TEST BANK by Stamler Test Bank For Community Health Nursing A Canadian Perspective, 5th Edition Pdf Chapters Download Test Bank For Community Health Nursing A Canadian Perspective, 5th Edition Pdf Download Stuvia Test Bank For Community Health Nursing A Canadian Perspective, 5th Edition Study Guide Test Bank For Community Health Nursing A Canadian Perspective, 5th Edition Ebook Download Stuvia Test Bank For Community Health Nursing A Canadian Perspective, 5th Edition Questions and Answers Quizlet Test Bank For Community Health Nursing A Canadian Perspective, 5th Edition Studocu Test Bank For Community Health Nursing A Canadian Perspective, 5th Edition Quizlet Test Bank For Community Health Nursing A Canadian Perspective, 5th Edition Stuvia Community Health Nursing A Canadian Perspective, 5th Edition Pdf Chapters Download Community Health Nursing A Canadian Perspective, 5th Edition Pdf Download Course Hero Community Health Nursing A Canadian Perspective, 5th Edition Answers Quizlet Community Health Nursing A Canadian Perspective, 5th Edition Ebook Download Course hero Community Health Nursing A Canadian Perspective, 5th Edition Questions and Answers Community Health Nursing A Canadian Perspective, 5th Edition Studocu Community Health Nursing A Canadian Perspective, 5th Edition Quizlet Community Health Nursing A Canadian Perspective, 5th Edition Stuvia Community Health Nursing A Canadian Perspective, 5th Edition Test Bank Pdf Chapters Download Community Health Nursing A Canadian Perspective, 5th Edition Test Bank Pdf Download Stuvia Community Health Nursing A Canadian Perspective, 5th Edition Test Bank Study Guide Questions and Answers Community Health Nursing A Canadian Perspective, 5th Edition Test Bank Ebook Download Stuvia Community Health Nursing A Canadian Perspective, 5th Edition Test Bank Questions Quizlet Community Health Nursing A Canadian Perspective, 5th Edition Test Bank Studocu Community Health Nursing A Canadian Perspective, 5th Edition Test Bank Quizlet Community Health Nursing A Canadian Perspective, 5th Edition Test Bank Stuvia
Cell Therapy Expansion and Challenges in Autoimmune Disease
There is increasing confidence that cell therapies will soon play a role in the treatment of autoimmune disorders, but the extent of this impact remains to be seen. Early readouts on autologous CAR-Ts in lupus are encouraging, but manufacturing and cost limitations are likely to restrict access to highly refractory patients. Allogeneic CAR-Ts have the potential to broaden access to earlier lines of treatment due to their inherent cost benefits, however they will need to demonstrate comparable or improved efficacy to established modalities.
In addition to infrastructure and capacity constraints, CAR-Ts face a very different risk-benefit dynamic in autoimmune compared to oncology, highlighting the need for tolerable therapies with low adverse event risk. CAR-NK and Treg-based therapies are also being developed in certain autoimmune disorders and may demonstrate favorable safety profiles. Several novel non-cell therapies such as bispecific antibodies, nanobodies, and RNAi drugs, may also offer future alternative competitive solutions with variable value propositions.
Widespread adoption of cell therapies will not only require strong efficacy and safety data, but also adapted pricing and access strategies. At oncology-based price points, CAR-Ts are unlikely to achieve broad market access in autoimmune disorders, with eligible patient populations that are potentially orders of magnitude greater than the number of currently addressable cancer patients. Developers have made strides towards reducing cell therapy COGS while improving manufacturing efficiency, but payors will inevitably restrict access until more sustainable pricing is achieved.
Despite these headwinds, industry leaders and investors remain confident that cell therapies are poised to address significant unmet need in patients suffering from autoimmune disorders. However, the extent of this impact on the treatment landscape remains to be seen, as the industry rapidly approaches an inflection point.
Basavarajeeyam - Ayurvedic heritage book of Andhra pradesh
Basavarajeeyam is an important text for ayurvedic physician belonging to andhra pradehs. It is a popular compendium in various parts of our country as well as in andhra pradesh. The content of the text was presented in sanskrit and telugu language (Bilingual). One of the most famous book in ayurvedic pharmaceutics and therapeutics. This book contains 25 chapters called as prakaranas. Many rasaoushadis were explained, pioneer of dhatu druti, nadi pareeksha, mutra pareeksha etc. Belongs to the period of 15-16 century. New diseases like upadamsha, phiranga rogas are explained.
Recently uploaded (20)
Tests for analysis of different pharmaceutical.pptx
Tests for analysis of different pharmaceutical.pptx
Light House Retreats: Plant Medicine Retreat Europe
Light House Retreats: Plant Medicine Retreat Europe
Identification and nursing management of congenital malformations .pptx
Identification and nursing management of congenital malformations .pptx
Phone Us ❤8107221448❤ #ℂall #gIRLS In Dehradun By Dehradun @ℂall @Girls Hotel...
Phone Us ❤8107221448❤ #ℂall #gIRLS In Dehradun By Dehradun @ℂall @Girls Hotel...
Hemodialysis: Chapter 4, Dialysate Circuit - Dr.Gawad
Hemodialysis: Chapter 4, Dialysate Circuit - Dr.Gawad
8 Surprising Reasons To Meditate 40 Minutes A Day That Can Change Your Life.pptx
8 Surprising Reasons To Meditate 40 Minutes A Day That Can Change Your Life.pptx
Local Advanced Lung Cancer: Artificial Intelligence, Synergetics, Complex Sys...
Local Advanced Lung Cancer: Artificial Intelligence, Synergetics, Complex Sys...
How STIs Influence the Development of Pelvic Inflammatory Disease.pptx
How STIs Influence the Development of Pelvic Inflammatory Disease.pptx
Integrating Ayurveda into Parkinson’s Management: A Holistic Approach
Integrating Ayurveda into Parkinson’s Management: A Holistic Approach
TEST BANK For Community Health Nursing A Canadian Perspective, 5th Edition by...
TEST BANK For Community Health Nursing A Canadian Perspective, 5th Edition by...
Cell Therapy Expansion and Challenges in Autoimmune Disease
Cell Therapy Expansion and Challenges in Autoimmune Disease
Basavarajeeyam - Ayurvedic heritage book of Andhra pradesh
Basavarajeeyam - Ayurvedic heritage book of Andhra pradesh
Excitation and contraction of muscle
- 1. Objective Discuss the process of excitation – contraction coupling
- 2. The process by which depolarization of the muscle fiber initiates contraction is called excitation–contraction coupling
- 3. Process.. Generation of action potential in muscles fiber Inward spread of depolarization along T-tubules into the muscle Release Calcium from the terminal cisternae
- 5. Increasing Sarcoplasmic Ca2+ concentration Binding of Ca2+ to troponin-C that uncover the myosin binding sites on Actin Attachment of myosin head to actin initiating cross-bridge cycle
- 8. Contd… Sliding of thin filament over thick filament towards the center of the sarcomere Decrease sarcomere length producing muscle shortening Contraction
- 10. Relaxation Ca2+ pumped back into sarcoplasmic reticulum Released of Ca2+ from troponin Cessation of interaction between actin and myosin
- 11. summary
- 13. Reference Guyton and Hall-Textbook of medical physiology- 13th edition Understanding Medical Physiology-4th edition Ganong’s Review of Medical physiology-23th edition
- 14. Prepared by Nilshan Rai MBBS Student