Podcast
Questions and Answers
Which of the following best describes the role of tendons in skeletal muscle movement?
Which of the following best describes the role of tendons in skeletal muscle movement?
- They directly stimulate muscle fiber contraction.
- They provide nutrients and oxygen to muscle tissue.
- They connect muscles to bones, transferring the tension created by muscle contraction. (correct)
- They act as antagonists to muscle movement.
During a bicep curl, the biceps brachii is the prime mover. What role does the brachialis play in this action?
During a bicep curl, the biceps brachii is the prime mover. What role does the brachialis play in this action?
- Synergist (correct)
- Insertion
- Antagonist
- Fixator
What is the primary function of an antagonist muscle?
What is the primary function of an antagonist muscle?
- To produce the opposite movement of the prime mover. (correct)
- To stabilize the origin of the prime mover.
- To connect muscle to bone.
- To assist the prime mover in performing a specific action.
When extending the knee, the quadriceps femoris muscles are the agonists. Which muscles are the antagonists in this movement?
When extending the knee, the quadriceps femoris muscles are the agonists. Which muscles are the antagonists in this movement?
How do facial muscles differ from most other skeletal muscles?
How do facial muscles differ from most other skeletal muscles?
Which of the following is an example of a skeletal muscle that does NOT cause movement of the skeleton?
Which of the following is an example of a skeletal muscle that does NOT cause movement of the skeleton?
What is the 'origin' of a muscle?
What is the 'origin' of a muscle?
Why is warming up the muscles important before exercising?
Why is warming up the muscles important before exercising?
In the musculoskeletal lever system, what component corresponds to the fulcrum in a hammer removing a nail?
In the musculoskeletal lever system, what component corresponds to the fulcrum in a hammer removing a nail?
How are muscles typically arranged in the body, based on their function?
How are muscles typically arranged in the body, based on their function?
If a muscle attachment is closer to the joint, which of the following is most likely to be favored?
If a muscle attachment is closer to the joint, which of the following is most likely to be favored?
In the context of the musculoskeletal system acting as a lever, what represents the 'load'?
In the context of the musculoskeletal system acting as a lever, what represents the 'load'?
How do the force, speed, and range of movement relate to each other in the context of musculoskeletal mechanics?
How do the force, speed, and range of movement relate to each other in the context of musculoskeletal mechanics?
Why is a proper warm-up important before stretching?
Why is a proper warm-up important before stretching?
Synovial fluid's primary role in a joint is most accurately described as:
Synovial fluid's primary role in a joint is most accurately described as:
Which connective tissue layer directly surrounds each individual muscle fiber (cell)?
Which connective tissue layer directly surrounds each individual muscle fiber (cell)?
A fascicle within a muscle is best described as:
A fascicle within a muscle is best described as:
The arrangement of fascicles within a muscle is known to affect what two primary characteristics of muscle function?
The arrangement of fascicles within a muscle is known to affect what two primary characteristics of muscle function?
In a parallel muscle, where are the fascicles arranged in relation to the long axis of the muscle?
In a parallel muscle, where are the fascicles arranged in relation to the long axis of the muscle?
The 'belly' of a muscle refers to:
The 'belly' of a muscle refers to:
What happens to the size of the opening of a circular muscle (sphincter) when it contracts?
What happens to the size of the opening of a circular muscle (sphincter) when it contracts?
The name of the muscle, orbicularis oris, provides information about its:
The name of the muscle, orbicularis oris, provides information about its:
What characteristic defines a convergent muscle?
What characteristic defines a convergent muscle?
In pennate muscles, how does the arrangement of muscle fibers affect the movement of the tendon?
In pennate muscles, how does the arrangement of muscle fibers affect the movement of the tendon?
Which of the following is an advantage of pennate muscles compared to other muscle arrangements?
Which of the following is an advantage of pennate muscles compared to other muscle arrangements?
What distinguishes a unipennate muscle from a bipennate muscle?
What distinguishes a unipennate muscle from a bipennate muscle?
How does stimulating different portions of a multipennate muscle like the deltoid affect its function?
How does stimulating different portions of a multipennate muscle like the deltoid affect its function?
If only the anterior fascicle of the deltoid muscle is stimulated, what movement(s) will occur at the shoulder joint?
If only the anterior fascicle of the deltoid muscle is stimulated, what movement(s) will occur at the shoulder joint?
A muscle is named 'adductor femoris'. What does 'adductor' in its name suggest about its function?
A muscle is named 'adductor femoris'. What does 'adductor' in its name suggest about its function?
If a muscle's name includes 'biceps', what does this indicate about its structure?
If a muscle's name includes 'biceps', what does this indicate about its structure?
The muscle sternocleidomastoid is named based on its attachments. Which of the following is true regarding its origin?
The muscle sternocleidomastoid is named based on its attachments. Which of the following is true regarding its origin?
A muscle is named based on its attachments. Which part of the name typically indicates the muscle's insertion point?
A muscle is named based on its attachments. Which part of the name typically indicates the muscle's insertion point?
Which function would you expect from a muscle named 'extensor carpi ulnaris'?
Which function would you expect from a muscle named 'extensor carpi ulnaris'?
Why is understanding the etymology of muscle names beneficial in anatomy and physiology?
Why is understanding the etymology of muscle names beneficial in anatomy and physiology?
A muscle named 'fibularis longus' is named based on which of the following criteria?
A muscle named 'fibularis longus' is named based on which of the following criteria?
The term 'rectus' in a muscle name, such as 'rectus abdominis,' indicates what characteristic of the muscle?
The term 'rectus' in a muscle name, such as 'rectus abdominis,' indicates what characteristic of the muscle?
Which of the following is exemplified by muscles named gluteus maximus, gluteus medius and gluteus minimus?
Which of the following is exemplified by muscles named gluteus maximus, gluteus medius and gluteus minimus?
What does the name 'biceps brachii' tell you about the muscle?
What does the name 'biceps brachii' tell you about the muscle?
If a muscle's name includes the word 'oblique', what does this suggest about the muscle's structure?
If a muscle's name includes the word 'oblique', what does this suggest about the muscle's structure?
A muscle described as 'lateralis' is located where?
A muscle described as 'lateralis' is located where?
A muscle's name contains the word 'quadriceps.' What does this imply about the muscle?
A muscle's name contains the word 'quadriceps.' What does this imply about the muscle?
Which of the following accurately distinguishes between axial and appendicular muscles?
Which of the following accurately distinguishes between axial and appendicular muscles?
How does the insertion point of facial expression muscles contribute to their unique function?
How does the insertion point of facial expression muscles contribute to their unique function?
What functional challenge is addressed by the epicranial aponeurosis connecting the frontalis and occipitalis muscles, given their location?
What functional challenge is addressed by the epicranial aponeurosis connecting the frontalis and occipitalis muscles, given their location?
Which action does contraction of the buccinator muscle directly facilitate?
Which action does contraction of the buccinator muscle directly facilitate?
How does the corrugator supercilii contribute to facial expression?
How does the corrugator supercilii contribute to facial expression?
How do extrinsic eye muscles differ functionally from intrinsic eye muscles?
How do extrinsic eye muscles differ functionally from intrinsic eye muscles?
What is the functional significance of the orbicularis oris being a circular muscle?
What is the functional significance of the orbicularis oris being a circular muscle?
If a patient has difficulty closing their eyes, which muscle is most likely affected?
If a patient has difficulty closing their eyes, which muscle is most likely affected?
Which of the following actions would be MOST compromised by damage to the entire erector spinae group?
Which of the following actions would be MOST compromised by damage to the entire erector spinae group?
How do the iliocostalis, longissimus, and spinalis groups of the erector spinae muscles differ in their anatomical location relative to the vertebral column?
How do the iliocostalis, longissimus, and spinalis groups of the erector spinae muscles differ in their anatomical location relative to the vertebral column?
A patient is experiencing difficulty laterally flexing their cervical region. Which of the following muscles is LEAST likely to be involved in this specific movement?
A patient is experiencing difficulty laterally flexing their cervical region. Which of the following muscles is LEAST likely to be involved in this specific movement?
What is the MOST significant difference in function between the erector spinae muscles and the interspinales/intertransversarii muscles?
What is the MOST significant difference in function between the erector spinae muscles and the interspinales/intertransversarii muscles?
If a person is performing deep inhalation, which of the following muscles is MOST likely assisting in this process?
If a person is performing deep inhalation, which of the following muscles is MOST likely assisting in this process?
How does the arrangement of the transversospinales muscles, running from the transverse processes to the spinous processes, relate to their function?
How does the arrangement of the transversospinales muscles, running from the transverse processes to the spinous processes, relate to their function?
A weightlifter is performing an exercise that requires maintaining a strong lumbar curve. Which muscle group is primarily responsible for this?
A weightlifter is performing an exercise that requires maintaining a strong lumbar curve. Which muscle group is primarily responsible for this?
What role do the interspinales and intertransversarii muscles play in the movement of the spine?
What role do the interspinales and intertransversarii muscles play in the movement of the spine?
During an eye exam, a doctor asks a patient to follow a moving finger. What is the primary purpose of this test?
During an eye exam, a doctor asks a patient to follow a moving finger. What is the primary purpose of this test?
The masseter and temporalis muscles are crucial for mastication. What is their primary action during this process?
The masseter and temporalis muscles are crucial for mastication. What is their primary action during this process?
While the masseter is the primary muscle for chewing, the temporalis assists in this action. What specific movement does the temporalis contribute?
While the masseter is the primary muscle for chewing, the temporalis assists in this action. What specific movement does the temporalis contribute?
Besides the masseter and temporalis, which other muscles significantly contribute to the process of mastication?
Besides the masseter and temporalis, which other muscles significantly contribute to the process of mastication?
The tongue plays a multifaceted role in the oral cavity. Beyond taste, which functions does the tongue directly contribute to?
The tongue plays a multifaceted role in the oral cavity. Beyond taste, which functions does the tongue directly contribute to?
What is the key functional difference between the extrinsic and intrinsic muscles of the tongue?
What is the key functional difference between the extrinsic and intrinsic muscles of the tongue?
The genioglossus muscle is named for its origin and function. What does the name 'genioglossus' suggest about its origin and action?
The genioglossus muscle is named for its origin and function. What does the name 'genioglossus' suggest about its origin and action?
During general anesthesia, the anesthesiologist takes over control of the patient's respiration. Why is this intervention necessary?
During general anesthesia, the anesthesiologist takes over control of the patient's respiration. Why is this intervention necessary?
What is the primary purpose of endotracheal intubation during general anesthesia?
What is the primary purpose of endotracheal intubation during general anesthesia?
The suprahyoid and infrahyoid muscles are grouped based on their position relative to which structure?
The suprahyoid and infrahyoid muscles are grouped based on their position relative to which structure?
What is the collective action of the suprahyoid muscles during deglutition?
What is the collective action of the suprahyoid muscles during deglutition?
The sternocleidomastoid muscle is a key landmark in the neck. What is its primary action when acting unilaterally?
The sternocleidomastoid muscle is a key landmark in the neck. What is its primary action when acting unilaterally?
How do the actions of the sternocleidomastoid muscles differ when they contract bilaterally compared to unilaterally?
How do the actions of the sternocleidomastoid muscles differ when they contract bilaterally compared to unilaterally?
The sternocleidomastoid muscle divides the neck into anatomical triangles. What is the significance of this division?
The sternocleidomastoid muscle divides the neck into anatomical triangles. What is the significance of this division?
What is the primary function of the splenius muscles located in the posterior neck?
What is the primary function of the splenius muscles located in the posterior neck?
How does the brain prevent rapid fatigue in muscles responsible for maintaining posture?
How does the brain prevent rapid fatigue in muscles responsible for maintaining posture?
What is the functional advantage of having three layers of anterolateral abdominal muscles with fibers running in different directions?
What is the functional advantage of having three layers of anterolateral abdominal muscles with fibers running in different directions?
Why is the arrangement of the transversus abdominis muscle described as being 'similar to the front of a belt'?
Why is the arrangement of the transversus abdominis muscle described as being 'similar to the front of a belt'?
What is the primary function of the linea alba?
What is the primary function of the linea alba?
What is the role of the tendinous intersections?
What is the role of the tendinous intersections?
Which of the following structures primarily contributes to the stability of the posterior abdominal wall?
Which of the following structures primarily contributes to the stability of the posterior abdominal wall?
If an individual has a compromised quadratus lumborum muscle, what functional deficit would MOST likely be observed?
If an individual has a compromised quadratus lumborum muscle, what functional deficit would MOST likely be observed?
The external oblique muscle extends in the direction of sliding your fingers into your pockets. How does this orientation relate to its function?
The external oblique muscle extends in the direction of sliding your fingers into your pockets. How does this orientation relate to its function?
During an initial physical therapy session for a shoulder injury, what is the PRIMARY goal of assessing the joint's functionality?
During an initial physical therapy session for a shoulder injury, what is the PRIMARY goal of assessing the joint's functionality?
Why is icing typically recommended as a follow-up to exercises in physical therapy?
Why is icing typically recommended as a follow-up to exercises in physical therapy?
What is the MOST likely reason a PT would apply a heat pack to an injury site at the beginning of a session?
What is the MOST likely reason a PT would apply a heat pack to an injury site at the beginning of a session?
How does the contraction and relaxation of the diaphragm contribute to breathing?
How does the contraction and relaxation of the diaphragm contribute to breathing?
What is the physiological basis of the Valsalva maneuver during defecation?
What is the physiological basis of the Valsalva maneuver during defecation?
How do the external and internal intercostal muscles work together to facilitate breathing?
How do the external and internal intercostal muscles work together to facilitate breathing?
What role does the levator ani play in maintaining proper pelvic function?
What role does the levator ani play in maintaining proper pelvic function?
How is the perineum anatomically divided, and what structures define its boundaries?
How is the perineum anatomically divided, and what structures define its boundaries?
How does the diaphragm contribute to the rise and fall of the chest during breathing?
How does the diaphragm contribute to the rise and fall of the chest during breathing?
What is the functional result of the fusion of the pericardial sac and pleural membranes to the central tendon of the diaphragm?
What is the functional result of the fusion of the pericardial sac and pleural membranes to the central tendon of the diaphragm?
How do the intercostal muscles facilitate changes in the dimensions of the rib cage during breathing?
How do the intercostal muscles facilitate changes in the dimensions of the rib cage during breathing?
In what way does the levator ani contribute to the processes of defecation and childbirth?
In what way does the levator ani contribute to the processes of defecation and childbirth?
How do the muscles within the urogenital triangle of the perineum differ functionally between males and females?
How do the muscles within the urogenital triangle of the perineum differ functionally between males and females?
How does the arrangement of the diaphragm's muscle fibers and openings impact its function?
How does the arrangement of the diaphragm's muscle fibers and openings impact its function?
Why does childbirth involve cooperation between the diaphragm and abdominal muscles?
Why does childbirth involve cooperation between the diaphragm and abdominal muscles?
If a patient has difficulty moving their scapula medially, which of the following muscles is MOST likely impaired?
If a patient has difficulty moving their scapula medially, which of the following muscles is MOST likely impaired?
A bodybuilder is performing a bench press, which primarily uses the pectoralis major to move the arm anteriorly. Which other muscle assists in adducting the humerus during this exercise?
A bodybuilder is performing a bench press, which primarily uses the pectoralis major to move the arm anteriorly. Which other muscle assists in adducting the humerus during this exercise?
How does the location of the latissimus dorsi, on the inferior part of the back, relate to its function in moving the humerus?
How does the location of the latissimus dorsi, on the inferior part of the back, relate to its function in moving the humerus?
Which muscle is MOST likely responsible for initiating the action of reaching overhead to grab an object from a high shelf?
Which muscle is MOST likely responsible for initiating the action of reaching overhead to grab an object from a high shelf?
A patient reports shoulder pain and limited range of motion, specifically struggling to rotate their arm laterally. Which muscle is MOST likely affected?
A patient reports shoulder pain and limited range of motion, specifically struggling to rotate their arm laterally. Which muscle is MOST likely affected?
A gymnast performing the iron cross on rings requires significant shoulder adduction strength. Which of the following muscles is MOST crucial for providing this stability and force?
A gymnast performing the iron cross on rings requires significant shoulder adduction strength. Which of the following muscles is MOST crucial for providing this stability and force?
During a boxing match, a fighter throws a powerful overhand punch. Which muscle(s) are primarily responsible for the initial protraction and rotation of the scapula to maximize reach?
During a boxing match, a fighter throws a powerful overhand punch. Which muscle(s) are primarily responsible for the initial protraction and rotation of the scapula to maximize reach?
A rock climber is hanging from a hold with one arm. Which group of muscles is primarily engaged to maintain the stability of the pectoral girdle against the pull of gravity?
A rock climber is hanging from a hold with one arm. Which group of muscles is primarily engaged to maintain the stability of the pectoral girdle against the pull of gravity?
Which of the following rotator cuff muscles is responsible for medially rotating the arm?
Which of the following rotator cuff muscles is responsible for medially rotating the arm?
A baseball pitcher is diagnosed with a rotator cuff tear. Which group of muscles is MOST likely affected by this injury?
A baseball pitcher is diagnosed with a rotator cuff tear. Which group of muscles is MOST likely affected by this injury?
Which of the following muscles is NOT located in the anterior compartment of the forearm?
Which of the following muscles is NOT located in the anterior compartment of the forearm?
Which of the following muscle groups allows for precise movements of the fingers, such as those required for typing?
Which of the following muscle groups allows for precise movements of the fingers, such as those required for typing?
What action is performed by the supinator muscle?
What action is performed by the supinator muscle?
How does the flexor digitorum superficialis contribute to hand and finger movement?
How does the flexor digitorum superficialis contribute to hand and finger movement?
What is the MOST likely consequence of poor ergonomics and repetitive movements involving the flexor muscles of the forearm?
What is the MOST likely consequence of poor ergonomics and repetitive movements involving the flexor muscles of the forearm?
If a patient has difficulty extending their wrist and fingers, which compartment of the forearm is MOST likely affected?
If a patient has difficulty extending their wrist and fingers, which compartment of the forearm is MOST likely affected?
What is the function of the retinacula found at the wrist?
What is the function of the retinacula found at the wrist?
The rounded contour at the base of the thumb, known as the thenar eminence, is formed by which group of muscles?
The rounded contour at the base of the thumb, known as the thenar eminence, is formed by which group of muscles?
If a patient is unable to oppose their thumb (bring it across the palm to touch the little finger), which muscle is MOST likely affected?
If a patient is unable to oppose their thumb (bring it across the palm to touch the little finger), which muscle is MOST likely affected?
Which muscles are located on the medial aspect of the palm and act on the little finger?
Which muscles are located on the medial aspect of the palm and act on the little finger?
A pianist is experiencing pain and weakness in the hand, specifically affecting the ability to abduct and adduct the fingers. Which group of intrinsic hand muscles is MOST likely involved?
A pianist is experiencing pain and weakness in the hand, specifically affecting the ability to abduct and adduct the fingers. Which group of intrinsic hand muscles is MOST likely involved?
Regarding the deltoid, what movements at the shoulder joint are facilitated by stimulating ONLY the anterior fascicle of the Deltoid?
Regarding the deltoid, what movements at the shoulder joint are facilitated by stimulating ONLY the anterior fascicle of the Deltoid?
Which muscle extends the arm and assists in adduction and medial rotation of it?
Which muscle extends the arm and assists in adduction and medial rotation of it?
What is the primary reason the pelvic girdle has less range of motion compared to the pectoral girdle?
What is the primary reason the pelvic girdle has less range of motion compared to the pectoral girdle?
If the pelvic girdle had the same range of motion as the pectoral girdle, what would be the MOST likely consequence?
If the pelvic girdle had the same range of motion as the pectoral girdle, what would be the MOST likely consequence?
Which functional trade-off exists between the leg muscles and the muscles of the pectoral girdle?
Which functional trade-off exists between the leg muscles and the muscles of the pectoral girdle?
How do the origins of muscles that move the femur typically differ from the origins of muscles that move the lower leg?
How do the origins of muscles that move the femur typically differ from the origins of muscles that move the lower leg?
Which of the following BEST describes the iliopsoas muscle group's primary action?
Which of the following BEST describes the iliopsoas muscle group's primary action?
What is the correct order, from superficial to deep, of the three gluteal muscles?
What is the correct order, from superficial to deep, of the three gluteal muscles?
How do the anterior and posterior muscles of the femur differ regarding their primary actions on the thigh and lower leg?
How do the anterior and posterior muscles of the femur differ regarding their primary actions on the thigh and lower leg?
What is the MOST accurate description of the tensor fascia latae's role in movements of the thigh and stabilization of the knee?
What is the MOST accurate description of the tensor fascia latae's role in movements of the thigh and stabilization of the knee?
Considering their attachments and location, what action would you expect the muscles of the anterior compartment of the thigh to perform?
Considering their attachments and location, what action would you expect the muscles of the anterior compartment of the thigh to perform?
How do the actions of the adductor longus and adductor magnus muscles differ regarding flexion and extension of the thigh?
How do the actions of the adductor longus and adductor magnus muscles differ regarding flexion and extension of the thigh?
Which group of muscles primarily contributes to the formation of the popliteal fossa, and what is its general function?
Which group of muscles primarily contributes to the formation of the popliteal fossa, and what is its general function?
How do the superior and inferior extensor retinacula contribute to the function of the anterior leg muscles?
How do the superior and inferior extensor retinacula contribute to the function of the anterior leg muscles?
If an individual has plantar fasciitis, which anatomical structure is primarily affected, and what is its typical function?
If an individual has plantar fasciitis, which anatomical structure is primarily affected, and what is its typical function?
What is the functional significance of the arrangement of muscles in the four layers of the plantar aspect of the foot?
What is the functional significance of the arrangement of muscles in the four layers of the plantar aspect of the foot?
Which action at the hip joint would be MOST affected by damage to the muscles in the medial compartment of the thigh?
Which action at the hip joint would be MOST affected by damage to the muscles in the medial compartment of the thigh?
How does the sartorius muscle enable the cross-legged sitting position?
How does the sartorius muscle enable the cross-legged sitting position?
What is the primary functional difference between the muscles in the anterior compartment and those in the posterior compartment of the leg?
What is the primary functional difference between the muscles in the anterior compartment and those in the posterior compartment of the leg?
The femoral triangle is a crucial anatomical region in the thigh. Which of the following structures are located within it?
The femoral triangle is a crucial anatomical region in the thigh. Which of the following structures are located within it?
Which of the following muscles resides on the lateral aspect of the thigh, and what is its action?
Which of the following muscles resides on the lateral aspect of the thigh, and what is its action?
A patient has difficulty plantar flexing their foot, especially when trying to stand on their tiptoes. Which muscle(s) is MOST likely affected?
A patient has difficulty plantar flexing their foot, especially when trying to stand on their tiptoes. Which muscle(s) is MOST likely affected?
How does the arrangement of deep fascia in the thigh contribute to its overall function?
How does the arrangement of deep fascia in the thigh contribute to its overall function?
If a person has an absent plantaris muscle, what is a potential implication for surgical procedures?
If a person has an absent plantaris muscle, what is a potential implication for surgical procedures?
What is the role of the quadriceps tendon and patellar ligament in knee extension?
What is the role of the quadriceps tendon and patellar ligament in knee extension?
How does the skeletal system primarily contribute to maintaining calcium homeostasis in the body?
How does the skeletal system primarily contribute to maintaining calcium homeostasis in the body?
Which of the following best describes the interaction between the skeletal system and the endocrine system in regulating calcium levels?
Which of the following best describes the interaction between the skeletal system and the endocrine system in regulating calcium levels?
How does the digestive system interact with the skeletal system to maintain calcium homeostasis?
How does the digestive system interact with the skeletal system to maintain calcium homeostasis?
What role does the urinary system play in calcium homeostasis, in conjunction with the skeletal system?
What role does the urinary system play in calcium homeostasis, in conjunction with the skeletal system?
How does the nervous system indirectly influence calcium homeostasis via its interaction with the skeletal system and other organ systems?
How does the nervous system indirectly influence calcium homeostasis via its interaction with the skeletal system and other organ systems?
Flashcards
Tendons
Tendons
Connect muscles to bones; strong, dense regular connective tissue bands.
Insertion
Insertion
Moveable muscle end attached to bone being pulled.
Origin
Origin
Fixed muscle end attached to a stabilized bone.
Prime mover (agonist)
Prime mover (agonist)
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Synergist
Synergist
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Fixator
Fixator
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Antagonist
Antagonist
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Examples of skeletal muscles not attached to the skeleton
Examples of skeletal muscles not attached to the skeleton
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Muscle Arrangement
Muscle Arrangement
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Fulcrum
Fulcrum
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Load (in musculoskeletal system)
Load (in musculoskeletal system)
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Effort (Applied Force)
Effort (Applied Force)
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Bones as Levers
Bones as Levers
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Endomysium
Endomysium
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Epimysium
Epimysium
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Fascicle
Fascicle
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Perimysium
Perimysium
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Parallel Muscles
Parallel Muscles
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Muscle Belly
Muscle Belly
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Fusiform Muscle
Fusiform Muscle
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Circular Muscles (Sphincters)
Circular Muscles (Sphincters)
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Orbicularis Oris
Orbicularis Oris
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Orbicularis Oculi
Orbicularis Oculi
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Convergent Muscle
Convergent Muscle
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Pectoralis Major
Pectoralis Major
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Pennate Muscles
Pennate Muscles
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Unipennate Muscle
Unipennate Muscle
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Bipennate Muscle
Bipennate Muscle
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Prefix 'bi-' in muscle names
Prefix 'bi-' in muscle names
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Prefix 'tri-' in muscle names
Prefix 'tri-' in muscle names
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Order of attachments in muscle names
Order of attachments in muscle names
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Sternocleidomastoid
Sternocleidomastoid
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Flexor
Flexor
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Etymology
Etymology
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Frontalis Muscle
Frontalis Muscle
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Orbicularis
Orbicularis
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Gluteus Maximus
Gluteus Maximus
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Gluteus Medius
Gluteus Medius
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Gluteus Minimus
Gluteus Minimus
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Brevis
Brevis
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Longus
Longus
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Axial Muscles
Axial Muscles
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Appendicular Muscles
Appendicular Muscles
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Epicranial Aponeurosis
Epicranial Aponeurosis
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Buccinator Muscle
Buccinator Muscle
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Corrugator Supercilii
Corrugator Supercilii
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Extrinsic Eye Muscles
Extrinsic Eye Muscles
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Head Extensors
Head Extensors
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Erector Spinae Group
Erector Spinae Group
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Erector Spinae Subgroups
Erector Spinae Subgroups
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Iliocostalis Divisions
Iliocostalis Divisions
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Longissimus Divisions
Longissimus Divisions
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Spinalis Divisions
Spinalis Divisions
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Transversospinales Muscles
Transversospinales Muscles
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Scalene Muscles
Scalene Muscles
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Mastication
Mastication
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Masseter Muscle
Masseter Muscle
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Temporalis Muscle
Temporalis Muscle
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Medial and Lateral Pterygoid Muscles
Medial and Lateral Pterygoid Muscles
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Deglutition
Deglutition
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Extrinsic Tongue Muscles
Extrinsic Tongue Muscles
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Intrinsic Tongue Muscles
Intrinsic Tongue Muscles
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Genioglossus
Genioglossus
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Styloglossus
Styloglossus
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Palatoglossus
Palatoglossus
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Hyoglossus
Hyoglossus
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Endotracheal Intubation
Endotracheal Intubation
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Suprahyoid Muscles
Suprahyoid Muscles
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Trunk Muscles
Trunk Muscles
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Deep Core Muscles
Deep Core Muscles
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Muscle Control of Posture
Muscle Control of Posture
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Anterolateral Abdominal Muscles
Anterolateral Abdominal Muscles
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External Oblique Direction
External Oblique Direction
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Internal Oblique Direction
Internal Oblique Direction
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Transversus Abdominis Arrangement
Transversus Abdominis Arrangement
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Linea Alba
Linea Alba
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Physical Therapists (PTs)
Physical Therapists (PTs)
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Range of Motion
Range of Motion
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Abduction
Abduction
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Adduction
Adduction
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Circumduction
Circumduction
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Extension
Extension
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Heat Pack Use (in PT)
Heat Pack Use (in PT)
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Icing (in PT)
Icing (in PT)
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Diaphragm Muscle
Diaphragm Muscle
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Valsalva Maneuver
Valsalva Maneuver
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Intercostal Muscles
Intercostal Muscles
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External Intercostals
External Intercostals
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Internal Intercostals
Internal Intercostals
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Pelvic Floor
Pelvic Floor
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Pectoral Girdle
Pectoral Girdle
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Anterior Pectoral Girdle Muscles
Anterior Pectoral Girdle Muscles
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Posterior Pectoral Girdle Muscles
Posterior Pectoral Girdle Muscles
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Rhomboid Action
Rhomboid Action
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Muscles Moving the Humerus
Muscles Moving the Humerus
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Axial Muscles of the Arm
Axial Muscles of the Arm
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Latissimus Dorsi
Latissimus Dorsi
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Deltoid Muscle
Deltoid Muscle
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Subscapularis
Subscapularis
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Supraspinatus
Supraspinatus
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Infraspinatus
Infraspinatus
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Teres Major
Teres Major
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Teres Minor
Teres Minor
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Coracobrachialis
Coracobrachialis
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Rotator Cuff
Rotator Cuff
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Forearm Flexors
Forearm Flexors
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Forearm Extensors
Forearm Extensors
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Pronators
Pronators
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Supinator
Supinator
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Flexor Carpi Radialis, Ulnaris, and Flexor Digitorum Superficialis
Flexor Carpi Radialis, Ulnaris, and Flexor Digitorum Superficialis
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Flexor Pollicis Longus and Flexor Digitorum Profundus
Flexor Pollicis Longus and Flexor Digitorum Profundus
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Thenar Muscles
Thenar Muscles
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Appendicular Muscles (Lower Body)
Appendicular Muscles (Lower Body)
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Pelvic Girdle Stability
Pelvic Girdle Stability
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Muscles Moving Femur
Muscles Moving Femur
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Iliopsoas Group
Iliopsoas Group
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Gluteal Muscle Group
Gluteal Muscle Group
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Tensor Fascia Latae
Tensor Fascia Latae
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Lateral Hip Rotators
Lateral Hip Rotators
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Pectineus Muscle
Pectineus Muscle
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Medial Thigh Compartment
Medial Thigh Compartment
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Gracilis Muscle
Gracilis Muscle
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Anterior Thigh Compartment
Anterior Thigh Compartment
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Quadriceps Femoris
Quadriceps Femoris
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Patellar Ligament
Patellar Ligament
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Sartorius Muscle
Sartorius Muscle
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Posterior Thigh Compartment
Posterior Thigh Compartment
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Hamstring Group
Hamstring Group
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Popliteal Fossa
Popliteal Fossa
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Anterior Leg Compartment
Anterior Leg Compartment
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Extensor Retinaculum
Extensor Retinaculum
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Lateral Leg Compartment
Lateral Leg Compartment
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Calcaneal (Achilles) Tendon
Calcaneal (Achilles) Tendon
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Intrinsic Foot Muscles
Intrinsic Foot Muscles
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Calcium Homeostasis
Calcium Homeostasis
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Skeletal System
Skeletal System
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Study Notes
- Balancing the body on two feet and walking upright involves a complex process.
- Muscles of the vertebral column, thorax, and abdominal wall extend, flex, and stabilize the trunk.
- The brain sends electrical impulses to muscle groups for posture control through alternating contraction and relaxation.
- Posture is compromised if any single muscle group fails.
Anterolateral Abdominal Wall Muscles
- Four pairs of abdominal muscles cover the anterior and lateral abdominal region, meeting at the anterior midline.
- These muscles include the external obliques, internal obliques, transversus abdominis, and rectus abdominis.
- External obliques extend inferiorly and medially.
- Internal obliques extend superiorly and medially, perpendicular to external obliques.
- Transversus abdominis is arranged transversely around the abdomen.
- The arrangement of these three muscle bands allows trunk movements, rotations, and protects internal abdominal organs where there is no bone.
- The linea alba is a fibrous band where the rectus sheaths join at the anterior midline.
- Rectus abdominis muscles originate at the pubic crest and symphysis.
- Segmented by three transverse tendinous intersections, which can lead to the appearance of "six-pack abs."
Posterior Abdominal Wall
- Formed by the lumbar vertebrae, ilia of the hip bones, psoas major and iliacus muscles, and quadratus lumborum muscle.
- Plays a key role in stabilizing the body and maintaining posture.
Physical Therapy
- Physical therapists (PTs) are experts in body movement mechanics.
- PTs assess joint functionality, such as range of motion (normal movements a joint performs).
- PTs create physical therapy plans based on injury assessment.
- Initial steps in physical therapy may include heat application to enhance healing.
- Patients perform exercises at home, followed by icing to decrease inflammation.
- PTs conduct exit exams and provide reports on improved range of motion.
- PTs work with patients to help them return to their normal level of physical activity.
Muscles of the Chest
- Facilitate breathing by changing the thoracic cavity size.
- Chest rises during inhalation as the cavity expands.
- Chest falls during exhalation as the thoracic cavity decreases in size.
- The diaphragm separates the thoracic and abdominal cavities.
- The diaphragm is dome-shaped at rest, with a convex superior surface and a concave inferior surface.
- Defecation, urination, and childbirth involve cooperation between the diaphragm and abdominal muscles (Valsalva maneuver).
- Holding breath involves steady contraction of the diaphragm.
- The inferior surface of the pericardial sac and pleural membranes fuse onto the central tendon of the diaphragm.
- Skeletal muscle portions of the diaphragm insert into the central tendon.
- Origins include the xiphoid process, inferior six ribs, lumbar vertebrae, and 12th ribs.
- The diaphragm includes the caval opening (inferior vena cava), the esophageal hiatus (esophagus and nerves), and the aortic hiatus (aorta, thoracic duct, and azygous vein).
Intercostal Muscles
- Three sets of muscles span each of the intercostal spaces.
- They assist in breathing by changing the rib cage dimensions.
- Eleven pairs of external intercostal muscles aid in inspiration by raising the rib cage
- Eleven pairs of internal intercostal muscles aid in expiration by drawing the ribs together to constrict the rib cage.
- Innermost intercostal muscles act as synergists for the action of the internal intercostals.
Pelvic Floor
- The pelvic floor is a muscular sheet defining the inferior portion of the pelvic cavity.
- The pelvic diaphragm, spanning from the pubis to the coccyx, comprises the levator ani and the ischiococcygeus.
- Openings include the anal canal, urethra, and vagina in females.
- The levator ani consists of the pubococcygeus and iliococcygeus muscles.
- The levator ani supports the pelvic viscera and creates skeletal muscle sphincters at the urethra and anus, and aids in defecation and childbirth.
- The ischiococcygeus pulls the coccyx anteriorly.
Perineum
- The perineum is the diamond-shaped space between the pubic symphysis, coccyx, and ischial tuberosities.
- It lies just inferior to the pelvic diaphragm.
- Divided transversely into the urogenital triangle (anterior) and anal triangle (posterior).
- The urogenital triangle includes the external genitals, and the anal triangle contains the anus
- The perineum is divided into superficial and deep layers with shared muscles.
- Females have the compressor urethrae and the sphincter urethrovaginalis to close the vagina.
- Males possess the deep transverse perineal muscle, which plays a role in ejaculation.
Muscles of the Shoulder and Upper Limb
- Divided into four groups: muscles that stabilize and position the pectoral girdle, move the arm, move the forearm, and move the wrists, hands, and fingers.
- The pectoral girdle (shoulder girdle) consists of the lateral ends of the clavicle and scapula, along with the proximal end of the humerus.
- Muscles cover these three bones to stabilize the shoulder joint.
- The girdle provides a base for the head of the humerus to move the arm in multiple directions within the glenoid fossa of the scapula.
- Muscles that position the pectoral girdle are on the anterior or posterior thorax.
- Anterior muscles include the subclavius, pectoralis minor, and serratus anterior.
- Posterior muscles include the trapezius, rhomboid major, and rhomboid minor.
- When the rhomboids contract, the scapula moves medially, pulling the shoulder and upper limb posteriorly.
- Muscles that cross the shoulder joint and move the humerus include axial and scapular muscles.
- The two axial muscles are the pectoralis major and the latissimus dorsi.
- The pectoralis major is thick and fan-shaped, covering much of the superior portion of the anterior thorax.
- The latissimus dorsi is broad and triangular, located on the inferior part of the back, inserting into the aponeurosis.
- Muscles that move the humerus anteriorly are located on the anterior side of the body and originate from the sternum (e.g., pectoralis major) or the anterior side of the scapula (e.g., subscapularis).
- Muscles that move the humerus superiorly originate from the superior surfaces of the scapula and/or the clavicle (e.g., deltoids).
- Muscles that move the humerus inferiorly originate from the middle or lower back (e.g., latissimus dorsi).
- Muscles that move the humerus posteriorly are located on the posterior side of the body and insert into the scapula (e.g., infraspinatus).
- The deltoid is the major abductor of the arm, also facilitates flexing and medial rotation, as well as extension and lateral rotation.
- The subscapularis originates on the anterior scapula and medially rotates the arm.
- The supraspinatus (superior to the spine of the scapula) abducts the arm.
- The infraspinatus (inferior to the spine of the scapula) laterally rotates the arm.
- The teres major is inferior to the teres minor, extends the arm, and assists in adduction and medial rotation.
- The teres minor laterally rotates and extends the arm.
- The coracobrachialis flexes and adducts the arm.
- Tendons of the subscapularis, supraspinatus, infraspinatus, and teres minor connect the scapula to the humerus.
- These tendons form the rotator cuff (musculotendinous cuff), the circle of tendons around the shoulder joint.
- Shoulder surgery on baseball pitchers often addresses the rotator cuff, which can become pinched, inflamed, and torn due to repetitive overhead arm motions.
Forearm Muscles
- The forearm, made of the radius and ulna bones, has four main types of action at the hinge of the elbow joint: flexion, extension, pronation, and supination.
- Forearm flexors include the biceps brachii, brachialis, and brachioradialis.
- Extensors are the triceps brachii and anconeus.
- Pronators are the pronator teres and the pronator quadratus.
- The supinator turns the forearm anteriorly.
- When the forearm faces anteriorly, it is supinated; when it faces posteriorly, it is pronated.
- The biceps brachii, brachialis, and brachioradialis flex the forearm.
- The biceps brachii crosses the shoulder and elbow joints to flex the forearm, supinate the forearm at the radioulnar joints, and flex the arm at the shoulder joint.
- The brachialis, deep to the biceps brachii, provides additional power in flexing the forearm.
- The brachioradialis can flex the forearm quickly or help lift a load slowly.
- These muscles and their associated blood vessels and nerves form the anterior compartment of the arm (anterior flexor compartment of the arm).
Wrist, Hand, and Finger Muscles
- Wrist, hand, and finger movements are facilitated by two groups of muscles: extrinsic muscles of the hand (originating in the forearm) and intrinsic muscles of the hand (originating in the palm).
- The muscles in the anterior compartment of the forearm originate on the humerus and insert onto different parts of the hand.
- The superficial anterior compartment of the forearm includes the flexor carpi radialis, palmaris longus, flexor carpi ulnaris, and flexor digitorum superficialis.
- The flexor digitorum superficialis flexes the hand and the digits at the knuckles, allowing for rapid finger movements.
- Poor ergonomics can irritate the tendons of these muscles as they slide back and forth within the carpal tunnel of the anterior wrist and pinch the median nerve, leading to Carpal Tunnel Syndrome.
- The deep anterior compartment produces flexion and bends fingers to make a fist; it includes the flexor pollicis longus and the flexor digitorum profundus.
- The muscles in the superficial posterior compartment of the forearm originate on the humerus and include the extensor radialis longus, extensor carpi radialis brevis, extensor digitorum, extensor digiti minimi, and the extensor carpi ulnaris.
- The muscles of the deep posterior compartment of the forearm originate on the radius and ulna and include the abductor pollicis longus, extensor pollicis brevis, extensor pollicis longus, and extensor indicis.
- Tendons of the forearm muscles attach to the wrist and extend into the hand, sheathed at the wrist by fibrous bands called retinacula.
- The flexor retinaculum extends over the palmar surface, and the extensor retinaculum extends over the dorsal surface.
- The intrinsic muscles of the hand both originate and insert within it, allowing for precise finger movements.
- These muscles are divided into three groups: thenar muscles (radial aspect of the palm), hypothenar muscles (medial aspect of the palm), and intermediate muscles (midpalmar).
- The thenar muscles include the abductor pollicis brevis, opponens pollicis, flexor pollicis brevis, and the adductor pollicis.
- These muscles form the thenar eminence, the rounded contour of the base of the thumb, and act on the thumb.
- The movements of the thumb play an integral role in most precise movements of the hand.
- The hypothenar muscles include the abductor digiti minimi, flexor digiti minimi brevis, and the opponens digiti minimi.
- These muscles form the hypothenar eminence, the rounded contour of the little finger, and act on the little finger.
- The intermediate muscles act on all the fingers and include the lumbrical, the palmar interossei, and the dorsal interossei.
- Appendicular muscles of the lower body position and stabilize the pelvic girdle.
- The pelvic girdle serves as a foundation for the lower limbs.
- There is less movement at the pelvic girdle than at the pectoral girdle due to the pelvic girdle's connection with the sacrum.
- The pelvic girdle is designed to stabilize and support the body.
- The body's center of gravity is in the area of the pelvis.
- Leg muscles lack range of motion and versatility, but make up for it in size and power, which facilitates the body's stabilization, posture, and movement.
- Most muscles that insert on the femur originate on the pelvic girdle.
- The psoas major and iliacus make up the iliopsoas group.
- The gluteal muscles (gluteal group) are some of the largest and most powerful muscles in the body.
- The gluteus maximus is the largest gluteal muscle.
- Deep to the gluteus maximus is the gluteus medius.
- Deep to the gluteus medius is the gluteus minimus, the smallest of the trio.
- Large and powerful muscles of the hip that move the femur generally originate on the pelvic girdle and insert into the femur.
- Muscles that move the lower leg typically originate on the femur and insert into the bones of the knee joint.
- Anterior muscles of the femur extend the lower leg and aid in flexing the thigh.
- Posterior muscles of the femur flex the lower leg and also aid in extending the thigh.
- A combination of gluteal and thigh muscles adduct, abduct, and rotate the thigh and lower leg.
- The tensor fascia latae is a thick, squarish muscle in the superior aspect of the lateral thigh.
- The tensor fascia latae acts as a synergist of the gluteus medius and iliopsoas in flexing and abducting the thigh.
- It also helps stabilize the lateral aspect of the knee by pulling on the iliotibial tract (band), and making it taut.
- The piriformis, obturator internus, obturator externus, superior gemellus, inferior gemellus, and quadratus femoris laterally rotate the femur at the hip.
- These muscles are deep to the gluteus maximus.
- The adductor longus, adductor brevis, and adductor magnus can both medially and laterally rotate the thigh depending on foot placement.
- The adductor longus flexes the thigh.
- The adductor magnus extends the thigh.
- The pectineus adducts and flexes the femur at the hip.
- The pectineus is located in the femoral triangle.
- The femoral triangle is at the junction between the hip and the leg.
- The femoral triangle also includes the femoral nerve, the femoral artery, the femoral vein, and the deep inguinal lymph nodes.
- Deep fascia in the thigh separates it into medial, anterior, and posterior compartments.
- Muscles in the medial compartment of the thigh are responsible for adducting the femur at the hip.
- Along with the adductor longus, adductor brevis, adductor magnus, and pectineus, the strap-like gracilis adducts the thigh and flexes the leg at the knee.
- Muscles of the anterior compartment of the thigh flex the thigh and extend the leg.
- This compartment contains the quadriceps femoris group, which comprises four muscles that extend and stabilize the knee.
- The four muscles are: the rectus femoris, the vastus lateralis, the vastus medialis, and the vastus intermedius.
- The rectus femoris is on the anterior aspect of the thigh.
- The vastus lateralis is on the lateral aspect of the thigh.
- The vastus medialis is on the medial aspect of the thigh.
- The vastus intermedius is between the vastus lateralis and vastus medialis and deep to the rectus femoris.
- The tendon common to all four quadriceps femoris muscles is the quadriceps tendon (patellar tendon), which inserts into the patella and continues below it as the patellar ligament.
- The patellar ligament attaches to the tibial tuberosity.
- The sartorius is a band-like muscle that extends from the anterior superior iliac spine to the medial side of the proximal tibia.
- The sartorius flexes the leg at the knee and flexes, abducts, and laterally rotates the leg at the hip.
- Muscles in the posterior compartment of the thigh flex the leg and extend the thigh.
- The three long muscles on the back of the knee are the hamstring group, which flexes the knee.
- The hamstring group includes the biceps femoris, semitendinosus, and semimembranosus.
- The tendons of the hamstring muscles form the popliteal fossa, the diamond-shaped space at the back of the knee.
- Muscles of the leg are divided by deep fascia into the anterior, lateral, and posterior compartments.
- The anterior compartment of the leg includes the tibialis anterior, extensor hallucis longus, and extensor digitorum longus, which raise the front of the foot when they contract.
- The tibialis anterior is a long and thick muscle on the lateral surface of the tibia.
- The extensor hallucis longus is deep under the tibialis anterior.
- The extensor digitorum longus is lateral to the tibialis anterior.
- The fibularis tertius is a small muscle associated with the extensor digitorum longus, which may be fused to it, but is not present in all people.
- The fibularis tertius originates on the anterior surface of the fibula.
- Thick bands of connective tissue called the superior extensor retinaculum (transverse ligament of the ankle) and the inferior extensor retinaculum, hold the tendons of the anterior leg muscles in place during dorsiflexion.
- The lateral compartment of the leg includes the fibularis longus (peroneus longus) and the fibularis brevis (peroneus brevis).
- The superficial muscles in the posterior compartment of the leg all insert onto the calcaneal tendon (Achilles tendon).
- The calcaneal tendon (Achilles tendon) is a strong tendon that inserts into the calcaneal bone of the ankle.
- The muscles in the posterior compartment of the leg are large and strong and keep humans upright.
- The most superficial and visible muscle of the calf is the gastrocnemius.
- Deep to the gastrocnemius is the wide, flat soleus.
- The plantaris runs obliquely between the gastrocnemius and soleus.
- Some people may have two plantaris muscles, and no plantaris is observed in about seven percent of other cadaver dissections.
- The plantaris tendon is a desirable substitute for the fascia lata in hernia repair, tendon transplants, and repair of ligaments.
- There are four deep muscles in the posterior compartment of the leg: the popliteus, flexor digitorum longus, flexor hallucis longus, and tibialis posterior.
- The foot also has intrinsic muscles, which originate and insert within it.
- These muscles primarily provide support for the foot and its arch and contribute to movements of the toes.
- The principal support for the longitudinal arch of the foot is a deep fascia called plantar aponeurosis.
- The plantar aponeurosis runs from the calcaneus bone to the toes.
- Inflammation of the plantar aponeurosis is the cause of "plantar fasciitis".
- The intrinsic muscles of the foot consist of two groups: the dorsal group and the plantar group.
- The dorsal group includes only one muscle, the extensor digitorum brevis.
- The plantar group consists of four layers, starting with the most superficial.
- The muscles along the dorsal side of the foot generally extend the toes.
- The muscles of the plantar side of the foot generally flex the toes.
- The plantar muscles exist in four layers, providing the foot the strength to counterbalance the weight of the body.
- Calcium Homeostasis involves interactions of the skeletal system and other organ systems.
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Description
Understand how skeletal muscles create movement through tension on tendons. Learn about the roles of the origin (fixed bone attachment) and insertion (moveable bone attachment). Explore prime movers, synergists, and antagonists in muscle actions.
