A&P of Muscular Activities
Excitation
Types of Contractions
MUSCLE ACTION
Phases of Muscular Contraction
Muscle Mechanics
Excitation-Contraction
The Motor Unit
Length-Tension and Muscle Tone
Contraction
Muscle Metabolism
Recruitment
Relaxation
Exercise and its Effects
Sources of ATP
Fast Glycolytic
Fast and Slow Oxidative
Mind Map
Write a great subtitle here to provide context
A great title
A great title
Write a great headline
Write a great headline
A great title
A great title
A great title
A great title
Write a great headline
Write a great headline
A great title
A great title
Mind Map
Write a great subtitle here to give context
A great title
A great title
Write a great headline
Write a great headline
A great title
A great title
A great title
A great title
Write a great headline
Write a great headline
A great title
A great title
A great title
A great title
Write a great headline
Write a great headline
A great title
A great title
Write a great headline
Contextualize your topic with a subtitle
And use this space to describe it. Multimedia content is essential in a presentation to leave everyone speechless. Additionally, this way you will synthesize the content and entertain your audience.
Write a brilliant headline
Contextualize your topic with a subtitle
With Genially templates, you can include visual resources to leave your audience speechless. You can also highlight a specific phrase or fact that will be burned into your audience's memory and even embed external content that surprises: videos, photos, audios... Whatever you want! Do you need more reasons to create dynamic content? Well: 90% of the information we assimilate comes through sight, and we retain 42% more information when the content is moving.
You save time and the concepts stick in your audience's mind.
And use this space to describe it. Multimedia content is essential in a presentation to leave everyone speechless. Furthermore, this way you will synthesize the content and entertain your audience.
‘Including quotes always reinforces our presentation. It breaks the monotony’
Interactivity
Animation
WOW Effect
Write a catchy headline
Contextualize your topic with a subtitle
With Genially templates, you can include visual resources to leave your audience in awe. You can also highlight a specific phrase or piece of information that will be etched in your audience's memory, and even embed external content that surprises: videos, photos, audio... Whatever you want! Need more reasons to create dynamic content? Well: 90% of the information we assimilate comes through sight, and we retain 42% more information when the content is moving.
You save time and the concepts stick in your audience's mind.
Write a catchy headline
Contextualize your topic with a subtitle
With Genially templates, you can include visual resources to leave your audience amazed. You can also highlight a specific phrase or piece of information that will be etched in your audience's memory, and even embed external content that surprises: videos, photos, audios... Whatever you want! Need more reasons to create dynamic content? Well: 90% of the information we assimilate comes through sight, and we retain 42% more information when the content is animated.
You save time and the concepts stick in your audience's mind.
Here is a video that will give you a quick look at how these contractions look in everyday life!
There are three main types of skeletal muscle contractions: isotonic concentric contractions, isotonic eccentric contractions and isometric contractions.
Animation
WOW Effect
Interactivity
And use this space to describe it. Multimedia content is essential in a presentation to leave everyone speechless. Additionally, this way you will synthesize the content and entertain your audience.
Multimedia content is essential to achieve a WOW effect in your creations. Including background music, audio, or sound effects here... it always adds value!
I.Excitation Phase
Skeletal muscle contraction begins with signals from the voluntary (somatic) nervous system. Motor neurons originating in the spinal cord (and some in the brainstem) send action potentials along long axons to muscle fibers. At the neuromuscular junction (NMJ), the motor neuron releases the neurotransmitter acetylcholine (ACh), which crosses the synaptic cleft and binds to receptors on the muscle fiber’s membrane (sarcolemma). This binding opens channels that allow sodium ions (Na⁺) to enter the cell, causing depolarization.
Just a quick introduction to the fundamentals of this unit!
Write a great headline
Contextualize your topic with a subtitle
And use this space to describe it. Multimedia content is essential in a presentation to leave everyone speechless. Additionally, this way you will synthesize the content and entertain your audience.
II. Excitation-Contraction
Excitation–contraction (EC) coupling is the process that links a muscle fiber’s electrical signal to its physical contraction. It begins when a muscle action potential travels along the sarcolemma and into structures called T-tubules, which carry the signal deep into the cell. This electrical signal triggers the release of calcium ions (Ca²⁺) from the sarcoplasmic reticulum (SR), the muscle cell’s calcium storage site. The calcium then interacts with regulatory proteins, exposing binding sites on actin so myosin heads can attach and pull, shortening the muscle fiber.
Write a great headline
Contextualize your topic with a subtitle
And use this space to describe it. Multimedia content is essential in a presentation to leave everyone in awe. Additionally, this way you will synthesize the content and entertain your audience.
Write a great headline
Contextualize your topic with a subtitle
With Genially templates, you can include visual resources to leave your audience amazed. You can also highlight a specific phrase or fact that will be etched in your audience's memory, and even embed external content that surprises: videos, photos, audios... Whatever you want! Need more reasons to create dynamic content? Well: 90% of the information we assimilate comes through our sight, and we retain 42% more information when the content moves.
‘Including quotes always reinforces our presentation. It breaks the monotony’
- Always cite the author
The Motor Unit
. A single motor neuron and all the myofibers it innervates is called a motor unit. A small motor unit is an arrangement where a single motor neuron supplies a small number of myofibers in a muscle A large motor unit is an arrangement where a single motor neuron supplies a large number of muscle fibers in a muscle..
Force is directly proportional to size.
With a smile. This will awaken empathy and help you create a special connection.
IV. Relaxation
Undoing what has been done.
The muscle fiber will repolarize, which inactivates DHPR and closes RR where Ca++ was being released. ATP-driven pumps called sarcoplasmic reticulum calcium-ATPase (SERCA) will move Ca++ out of the sarcoplasm back into the SR leading to a decrease in intracellular calcium levels. This lack of available calcium results in regulatory proteins moving back into place and the reshielding of binding sites. Without the ability to form cross-bridges between the thin and thick myofilaments, the muscle fiber loses its tension and relaxes. A muscle also can stop contracting when it runs out of ATP and becomes fatigued.
And use this space to describe it. Multimedia content is essential in a presentation to leave everyone speechless. Moreover, this way you will synthesize the content and entertain your audience.
And use this space to describe it. Multimedia content is essential in a presentation to leave everyone speechless. Additionally, this way you will synthesize the content and entertain your audience.
And use this space to describe it. Multimedia content is essential in a presentation to leave everyone speechless. Moreover, this way you will synthesize the content and entertain your audience.
Multimedia content is essential for achieving a WOW effect in your creations. Including background music, audio, or sound effects here… it always adds value!
A brilliant title
Contextualize your topic
With Genially templates, you can include visual resources to leave your audience speechless. You can also highlight a specific phrase or piece of information that will be etched in your audience's memory and even embed external content that surprises: videos, photos, audios... Whatever you want! Do you need more reasons to create dynamic content? Well: 90% of the information we assimilate comes through sight, and we retain 42% more information when the content is animated.
You save time, and the concepts stick in your audience's mind.
+INFO
A brilliant title
Contextualize your topic
With Genially templates, you can include visual resources to leave your audience speechless. You can also highlight a specific phrase or fact that will be etched in your audience's memory and even embed external content that surprises: videos, photos, audios... Whatever you want! Do you need more reasons to create dynamic content? Well: 90% of the information we assimilate comes through sight, and we retain 42% more information when the content is moving.
You save time and the concepts stick in your audience's brain.
+INFO
Animation
WOW Effect
Interactivity
Write a brilliant headline
Contextualize your topic with a subtitle
With Genially templates, you can include visual resources to leave your audience amazed. You can also highlight a specific phrase or fact that will be etched in your audience's memory and even embed external content that surprises: videos, photos, audios... Whatever you want! Do you need more reasons to create dynamic content? Well: 90% of the information we assimilate comes through sight, and we also retain 42% more information when the content moves.
‘Including quotes always reinforces our presentation. It breaks the monotony’
- Always cite the author
Motor units work in teams to get things done. The more units, the more power and movement capacity. The larger units are often going to be slower than smaller ones. Smaller fibers are greater for small movements as well!
See if you can translate this to what we learn about glycolytic and oxidative muscle fibers!
Sources of ATP
Consist of Phosphagen system, anaerobic cellular resp. and aerobic cellular resp.
- Phosphagen system is the use of stored ATP and creatine phosphate for short bursts of activity for 0-10 seconds.
- Anaerobic respiration is the break down of glucose to produce ATP. Short, high intensity for 1-2 minutes.
- Aerobic respiration produces large amounts of ATP from glucose, fats, and sometimes proteins for longer duration and lower intensity activities.
Exercise and its Efffects
Endurance (aerobic) training mainly improves slow oxidative (SO) fibers, making them more efficient by increasing mitochondria, myoglobin, and capillary networks. These changes enhance oxygen delivery and ATP production, allowing muscles to sustain low-force contractions for long periods without fatigue. This is why endurance athletes, like marathon runners, tend to have a higher proportion of SO fibers, though this can be influenced by both genetics and training. However, excessive endurance training can lead to overuse injuries.In contrast, resistance training targets fast glycolytic (FG) fibers, which produce powerful, short bursts of force. This type of training increases muscle size (hypertrophy) by adding myofibrils and structural proteins, but does not significantly increase mitochondria or capillaries. Strength gains require progressively heavier loads, and improper training can cause muscle, tendon, or joint injuries. While some athletes use performance-enhancing substances to boost results, these carry serious health risks and are often banned.
Fast Glycolytic Fibers
Fast contractions and anaerobic glycolysis.
This is the fastest of the three types of fibers. Fast glycolytic fibers (Type IIx/IIb) are muscle fibers specialized for maximum power and speed. They contract very quickly and generate high force, but fatigue rapidly because they rely mainly on anaerobic glycolysis (breaking down glucose without oxygen) for energy.
Key words: Fast and Glycolysis
Fast and Slow Oxidative
Slow oxidative fibers (Type I) are built for endurance. They contract slowly, produce lower force, and resist fatigue because they rely on aerobic respiration. These fibers have many mitochondria, high myoglobin, and a rich blood supply, giving them a darker (red) appearance. They’re used in activities like distance running or maintaining posture.Fast oxidative fibers (Type IIa) are a hybrid. They contract faster and generate more force than slow fibers, but still have moderate fatigue resistance because they can use both aerobic and anaerobic metabolism. They contain a fair amount of mitochondria and myoglobin, making them useful for activities like middle-distance running or repeated bursts of movement.
Length-Tension and Muscle Tone
The cross-bridges can only form where thin and thick filaments already overlap, so that the length of the sarcomere has a direct influence on the force generated when the sarcomere shortens. This is called the length-tension relationship. The ideal length of a sarcomere to produce maximal tension occurs at 80 percent to 120 percent of its resting length, Skeletal muscles are rarely completely relaxed. and are often contracted a small amount even at rest to stabilize and maintain tone. Absence of this little amount is often a result of damage to parts of the CNS.
There is a real relationship here!!
III. Contraction
The contraction phase of skeletal muscle occurs once calcium ions (Ca²⁺) are released into the muscle cell. Calcium binds to regulatory proteins (like troponin), causing a shift that exposes binding sites on actin filaments. This allows myosin heads to attach to actin, forming cross-bridges. Using energy from ATP, the myosin heads pull the actin filaments toward the center of the sarcomere in a “power stroke,” shortening the muscle fiber.This cycle of attachment, pulling, detachment, and reattachment continues as long as calcium and ATP are available. ATP is required both to power the movement and to detach myosin from actin so the cycle can repeat. As many sarcomeres shorten simultaneously, the entire muscle contracts and generates force.
A&P of Muscular Activities
Joseph Brescia
Created on April 28, 2026
Start designing with a free template
Discover more than 1500 professional designs like these:
View
Essential Map
View
Akihabara Map
View
Discover Your AI Assistant
View
Match the Verbs in Spanish: Present and Past
View
Syllabus Organizer for Higher Education
View
Pollution Post
View
Hand-Drawn Infographic
Explore all templates
Transcript
A&P of Muscular Activities
Excitation
Types of Contractions
MUSCLE ACTION
Phases of Muscular Contraction
Muscle Mechanics
Excitation-Contraction
The Motor Unit
Length-Tension and Muscle Tone
Contraction
Muscle Metabolism
Recruitment
Relaxation
Exercise and its Effects
Sources of ATP
Fast Glycolytic
Fast and Slow Oxidative
Mind Map
Write a great subtitle here to provide context
A great title
A great title
Write a great headline
Write a great headline
A great title
A great title
A great title
A great title
Write a great headline
Write a great headline
A great title
A great title
Mind Map
Write a great subtitle here to give context
A great title
A great title
Write a great headline
Write a great headline
A great title
A great title
A great title
A great title
Write a great headline
Write a great headline
A great title
A great title
A great title
A great title
Write a great headline
Write a great headline
A great title
A great title
Write a great headline
Contextualize your topic with a subtitle
And use this space to describe it. Multimedia content is essential in a presentation to leave everyone speechless. Additionally, this way you will synthesize the content and entertain your audience.
Write a brilliant headline
Contextualize your topic with a subtitle
With Genially templates, you can include visual resources to leave your audience speechless. You can also highlight a specific phrase or fact that will be burned into your audience's memory and even embed external content that surprises: videos, photos, audios... Whatever you want! Do you need more reasons to create dynamic content? Well: 90% of the information we assimilate comes through sight, and we retain 42% more information when the content is moving.
You save time and the concepts stick in your audience's mind.
And use this space to describe it. Multimedia content is essential in a presentation to leave everyone speechless. Furthermore, this way you will synthesize the content and entertain your audience.
‘Including quotes always reinforces our presentation. It breaks the monotony’
Interactivity
Animation
WOW Effect
Write a catchy headline
Contextualize your topic with a subtitle
With Genially templates, you can include visual resources to leave your audience in awe. You can also highlight a specific phrase or piece of information that will be etched in your audience's memory, and even embed external content that surprises: videos, photos, audio... Whatever you want! Need more reasons to create dynamic content? Well: 90% of the information we assimilate comes through sight, and we retain 42% more information when the content is moving.
You save time and the concepts stick in your audience's mind.
Write a catchy headline
Contextualize your topic with a subtitle
With Genially templates, you can include visual resources to leave your audience amazed. You can also highlight a specific phrase or piece of information that will be etched in your audience's memory, and even embed external content that surprises: videos, photos, audios... Whatever you want! Need more reasons to create dynamic content? Well: 90% of the information we assimilate comes through sight, and we retain 42% more information when the content is animated.
You save time and the concepts stick in your audience's mind.
Here is a video that will give you a quick look at how these contractions look in everyday life!
There are three main types of skeletal muscle contractions: isotonic concentric contractions, isotonic eccentric contractions and isometric contractions.
Animation
WOW Effect
Interactivity
And use this space to describe it. Multimedia content is essential in a presentation to leave everyone speechless. Additionally, this way you will synthesize the content and entertain your audience.
Multimedia content is essential to achieve a WOW effect in your creations. Including background music, audio, or sound effects here... it always adds value!
I.Excitation Phase
Skeletal muscle contraction begins with signals from the voluntary (somatic) nervous system. Motor neurons originating in the spinal cord (and some in the brainstem) send action potentials along long axons to muscle fibers. At the neuromuscular junction (NMJ), the motor neuron releases the neurotransmitter acetylcholine (ACh), which crosses the synaptic cleft and binds to receptors on the muscle fiber’s membrane (sarcolemma). This binding opens channels that allow sodium ions (Na⁺) to enter the cell, causing depolarization.
Just a quick introduction to the fundamentals of this unit!
Write a great headline
Contextualize your topic with a subtitle
And use this space to describe it. Multimedia content is essential in a presentation to leave everyone speechless. Additionally, this way you will synthesize the content and entertain your audience.
II. Excitation-Contraction
Excitation–contraction (EC) coupling is the process that links a muscle fiber’s electrical signal to its physical contraction. It begins when a muscle action potential travels along the sarcolemma and into structures called T-tubules, which carry the signal deep into the cell. This electrical signal triggers the release of calcium ions (Ca²⁺) from the sarcoplasmic reticulum (SR), the muscle cell’s calcium storage site. The calcium then interacts with regulatory proteins, exposing binding sites on actin so myosin heads can attach and pull, shortening the muscle fiber.
Write a great headline
Contextualize your topic with a subtitle
And use this space to describe it. Multimedia content is essential in a presentation to leave everyone in awe. Additionally, this way you will synthesize the content and entertain your audience.
Write a great headline
Contextualize your topic with a subtitle
With Genially templates, you can include visual resources to leave your audience amazed. You can also highlight a specific phrase or fact that will be etched in your audience's memory, and even embed external content that surprises: videos, photos, audios... Whatever you want! Need more reasons to create dynamic content? Well: 90% of the information we assimilate comes through our sight, and we retain 42% more information when the content moves.
‘Including quotes always reinforces our presentation. It breaks the monotony’
- Always cite the author
The Motor Unit
. A single motor neuron and all the myofibers it innervates is called a motor unit. A small motor unit is an arrangement where a single motor neuron supplies a small number of myofibers in a muscle A large motor unit is an arrangement where a single motor neuron supplies a large number of muscle fibers in a muscle..
Force is directly proportional to size.
With a smile. This will awaken empathy and help you create a special connection.
IV. Relaxation
Undoing what has been done.
The muscle fiber will repolarize, which inactivates DHPR and closes RR where Ca++ was being released. ATP-driven pumps called sarcoplasmic reticulum calcium-ATPase (SERCA) will move Ca++ out of the sarcoplasm back into the SR leading to a decrease in intracellular calcium levels. This lack of available calcium results in regulatory proteins moving back into place and the reshielding of binding sites. Without the ability to form cross-bridges between the thin and thick myofilaments, the muscle fiber loses its tension and relaxes. A muscle also can stop contracting when it runs out of ATP and becomes fatigued.
And use this space to describe it. Multimedia content is essential in a presentation to leave everyone speechless. Moreover, this way you will synthesize the content and entertain your audience.
And use this space to describe it. Multimedia content is essential in a presentation to leave everyone speechless. Additionally, this way you will synthesize the content and entertain your audience.
And use this space to describe it. Multimedia content is essential in a presentation to leave everyone speechless. Moreover, this way you will synthesize the content and entertain your audience.
Multimedia content is essential for achieving a WOW effect in your creations. Including background music, audio, or sound effects here… it always adds value!
A brilliant title
Contextualize your topic
With Genially templates, you can include visual resources to leave your audience speechless. You can also highlight a specific phrase or piece of information that will be etched in your audience's memory and even embed external content that surprises: videos, photos, audios... Whatever you want! Do you need more reasons to create dynamic content? Well: 90% of the information we assimilate comes through sight, and we retain 42% more information when the content is animated.
You save time, and the concepts stick in your audience's mind.
+INFO
A brilliant title
Contextualize your topic
With Genially templates, you can include visual resources to leave your audience speechless. You can also highlight a specific phrase or fact that will be etched in your audience's memory and even embed external content that surprises: videos, photos, audios... Whatever you want! Do you need more reasons to create dynamic content? Well: 90% of the information we assimilate comes through sight, and we retain 42% more information when the content is moving.
You save time and the concepts stick in your audience's brain.
+INFO
Animation
WOW Effect
Interactivity
Write a brilliant headline
Contextualize your topic with a subtitle
With Genially templates, you can include visual resources to leave your audience amazed. You can also highlight a specific phrase or fact that will be etched in your audience's memory and even embed external content that surprises: videos, photos, audios... Whatever you want! Do you need more reasons to create dynamic content? Well: 90% of the information we assimilate comes through sight, and we also retain 42% more information when the content moves.
‘Including quotes always reinforces our presentation. It breaks the monotony’
- Always cite the author
Motor units work in teams to get things done. The more units, the more power and movement capacity. The larger units are often going to be slower than smaller ones. Smaller fibers are greater for small movements as well!
See if you can translate this to what we learn about glycolytic and oxidative muscle fibers!
Sources of ATP
Consist of Phosphagen system, anaerobic cellular resp. and aerobic cellular resp.
Exercise and its Efffects
Endurance (aerobic) training mainly improves slow oxidative (SO) fibers, making them more efficient by increasing mitochondria, myoglobin, and capillary networks. These changes enhance oxygen delivery and ATP production, allowing muscles to sustain low-force contractions for long periods without fatigue. This is why endurance athletes, like marathon runners, tend to have a higher proportion of SO fibers, though this can be influenced by both genetics and training. However, excessive endurance training can lead to overuse injuries.In contrast, resistance training targets fast glycolytic (FG) fibers, which produce powerful, short bursts of force. This type of training increases muscle size (hypertrophy) by adding myofibrils and structural proteins, but does not significantly increase mitochondria or capillaries. Strength gains require progressively heavier loads, and improper training can cause muscle, tendon, or joint injuries. While some athletes use performance-enhancing substances to boost results, these carry serious health risks and are often banned.
Fast Glycolytic Fibers
Fast contractions and anaerobic glycolysis.
This is the fastest of the three types of fibers. Fast glycolytic fibers (Type IIx/IIb) are muscle fibers specialized for maximum power and speed. They contract very quickly and generate high force, but fatigue rapidly because they rely mainly on anaerobic glycolysis (breaking down glucose without oxygen) for energy.
Key words: Fast and Glycolysis
Fast and Slow Oxidative
Slow oxidative fibers (Type I) are built for endurance. They contract slowly, produce lower force, and resist fatigue because they rely on aerobic respiration. These fibers have many mitochondria, high myoglobin, and a rich blood supply, giving them a darker (red) appearance. They’re used in activities like distance running or maintaining posture.Fast oxidative fibers (Type IIa) are a hybrid. They contract faster and generate more force than slow fibers, but still have moderate fatigue resistance because they can use both aerobic and anaerobic metabolism. They contain a fair amount of mitochondria and myoglobin, making them useful for activities like middle-distance running or repeated bursts of movement.
Length-Tension and Muscle Tone
The cross-bridges can only form where thin and thick filaments already overlap, so that the length of the sarcomere has a direct influence on the force generated when the sarcomere shortens. This is called the length-tension relationship. The ideal length of a sarcomere to produce maximal tension occurs at 80 percent to 120 percent of its resting length, Skeletal muscles are rarely completely relaxed. and are often contracted a small amount even at rest to stabilize and maintain tone. Absence of this little amount is often a result of damage to parts of the CNS.
There is a real relationship here!!
III. Contraction
The contraction phase of skeletal muscle occurs once calcium ions (Ca²⁺) are released into the muscle cell. Calcium binds to regulatory proteins (like troponin), causing a shift that exposes binding sites on actin filaments. This allows myosin heads to attach to actin, forming cross-bridges. Using energy from ATP, the myosin heads pull the actin filaments toward the center of the sarcomere in a “power stroke,” shortening the muscle fiber.This cycle of attachment, pulling, detachment, and reattachment continues as long as calcium and ATP are available. ATP is required both to power the movement and to detach myosin from actin so the cycle can repeat. As many sarcomeres shorten simultaneously, the entire muscle contracts and generates force.