Podcast
Questions and Answers
Which of the following best describes the combined action of the pectoralis minor muscle?
Which of the following best describes the combined action of the pectoralis minor muscle?
- Retracts and elevates the scapula.
- Retracts and depresses the scapula.
- Protracts and depresses the scapula. (correct)
- Protracts the scapula, drawing it anteriorly, and elevates the scapula.
The subclavius muscle plays a role in stabilizing which joint?
The subclavius muscle plays a role in stabilizing which joint?
- Acromioclavicular joint
- Sternoclavicular joint (correct)
- Scapulothoracic joint
- Glenohumeral joint
What is the origin and insertion of the subclavius muscle?
What is the origin and insertion of the subclavius muscle?
- Originates from the clavicle and inserts on the first rib.
- Originates from the sternum and inserts on the coracoid process of the scapula.
- Originates from the second rib and inserts on the clavicle's inferior surface.
- Originates from the first rib at the junction with its costal cartilage and inserts into the subclavius groove of the clavicle. (correct)
Which nerve directly innervates the pectoralis minor muscle?
Which nerve directly innervates the pectoralis minor muscle?
What is the main function of the pectoral fascia?
What is the main function of the pectoral fascia?
Which muscle lies deep to the pectoralis major muscle?
Which muscle lies deep to the pectoralis major muscle?
What is the nerve supply for the subclavius muscle?
What is the nerve supply for the subclavius muscle?
Which of the following is the correct action of the subclavius muscle on the clavicle?
Which of the following is the correct action of the subclavius muscle on the clavicle?
Which layer of the pectoral region directly encloses the mammary glands?
Which layer of the pectoral region directly encloses the mammary glands?
A patient experiences paralysis of the ability to adduct and medially rotate the arm. Which muscle is MOST likely affected?
A patient experiences paralysis of the ability to adduct and medially rotate the arm. Which muscle is MOST likely affected?
Which of the following muscles is NOT located in the pectoral region?
Which of the following muscles is NOT located in the pectoral region?
If a person has difficulty depressing their shoulder and moving it inferiorly and anteriorly, which muscle is MOST likely affected?
If a person has difficulty depressing their shoulder and moving it inferiorly and anteriorly, which muscle is MOST likely affected?
A weightlifter strains a muscle during a bench press. The injury impairs their ability to adduct their arm and rotate it medially. Which part of the pectoralis major is MOST likely affected?
A weightlifter strains a muscle during a bench press. The injury impairs their ability to adduct their arm and rotate it medially. Which part of the pectoralis major is MOST likely affected?
During a physical exam, a doctor palpates the anterior surface of the sternum and upper costal cartilages to assess the origin of which muscle?
During a physical exam, a doctor palpates the anterior surface of the sternum and upper costal cartilages to assess the origin of which muscle?
A surgeon needs to access deeper structures in the pectoral region and cuts through the pectoralis major. Which muscle will they encounter immediately after?
A surgeon needs to access deeper structures in the pectoral region and cuts through the pectoralis major. Which muscle will they encounter immediately after?
A person is involved in a car accident and sustains a clavicle fracture. Which muscle's origin could be directly affected by this fracture?
A person is involved in a car accident and sustains a clavicle fracture. Which muscle's origin could be directly affected by this fracture?
A patient reports difficulty adducting their arm. Which muscle is MOST likely affected?
A patient reports difficulty adducting their arm. Which muscle is MOST likely affected?
During a physical exam, a doctor asks a patient to flex, adduct, and medially rotate their arm. Which muscle's function is the doctor MOST likely assessing?
During a physical exam, a doctor asks a patient to flex, adduct, and medially rotate their arm. Which muscle's function is the doctor MOST likely assessing?
If the medial pectoral nerve is damaged, which action would be the LEAST affected?
If the medial pectoral nerve is damaged, which action would be the LEAST affected?
Which anatomical landmark serves as the insertion point for the pectoralis minor muscle?
Which anatomical landmark serves as the insertion point for the pectoralis minor muscle?
What is the origin of the sternocostal head of the pectoralis major?
What is the origin of the sternocostal head of the pectoralis major?
A weightlifter strains a muscle, and an MRI reveals damage to the lateral lip of the bicipital groove of the humerus. Which muscle is MOST likely affected?
A weightlifter strains a muscle, and an MRI reveals damage to the lateral lip of the bicipital groove of the humerus. Which muscle is MOST likely affected?
Which of the following is the origin of the pectoralis minor muscle?
Which of the following is the origin of the pectoralis minor muscle?
If a patient has a condition that selectively impairs the function of the lateral pectoral nerve, what specific movement would be MOST affected, considering the combined actions of both heads of the pectoralis major?
If a patient has a condition that selectively impairs the function of the lateral pectoral nerve, what specific movement would be MOST affected, considering the combined actions of both heads of the pectoralis major?
What is the primary role of the clavipectoral fascia in relation to the subclavius and pectoralis minor muscles?
What is the primary role of the clavipectoral fascia in relation to the subclavius and pectoralis minor muscles?
The costo-coracoid ligament, a thickening of the clavipectoral fascia, connects which two structures?
The costo-coracoid ligament, a thickening of the clavipectoral fascia, connects which two structures?
Which of the following structures does NOT typically pierce the clavipectoral fascia?
Which of the following structures does NOT typically pierce the clavipectoral fascia?
A surgeon is performing a procedure in the pectoral region and needs to ligate the thoracoacromial artery. Knowing the anatomy of the clavipectoral fascia, where would the surgeon expect to find this artery in relation to the fascia?
A surgeon is performing a procedure in the pectoral region and needs to ligate the thoracoacromial artery. Knowing the anatomy of the clavipectoral fascia, where would the surgeon expect to find this artery in relation to the fascia?
What is the combined action of the two heads of the pectoralis major muscle?
What is the combined action of the two heads of the pectoralis major muscle?
If the medial pectoral nerve is damaged, which of the following muscle actions would be MOST affected?
If the medial pectoral nerve is damaged, which of the following muscle actions would be MOST affected?
A patient presents with difficulty stabilizing their sternoclavicular joint. Which muscle is MOST likely affected?
A patient presents with difficulty stabilizing their sternoclavicular joint. Which muscle is MOST likely affected?
A weightlifter strains their pectoral region during a bench press. They experience pain and weakness when adducting and medially rotating their arm. Which muscle is MOST likely injured?
A weightlifter strains their pectoral region during a bench press. They experience pain and weakness when adducting and medially rotating their arm. Which muscle is MOST likely injured?
Flashcards
Pectoral Region
Pectoral Region
The front of the upper part of the chest.
Layers of Pectoral Region
Layers of Pectoral Region
Skin, superficial fascia (containing mammary glands, cutaneous vessels, and nerves), and deep fascia & muscles.
Muscles of Pectoral Region
Muscles of Pectoral Region
Pectoralis major, pectoralis minor, and subclavius.
Pectoralis Major
Pectoralis Major
Signup and view all the flashcards
Pectoralis Major Origin (Clavicular Head)
Pectoralis Major Origin (Clavicular Head)
Signup and view all the flashcards
Pectoralis Major Origin (Sternocostal Head)
Pectoralis Major Origin (Sternocostal Head)
Signup and view all the flashcards
Muscle Origin Definition
Muscle Origin Definition
Signup and view all the flashcards
Muscle Insertion Definition
Muscle Insertion Definition
Signup and view all the flashcards
Pectoralis Major Insertion
Pectoralis Major Insertion
Signup and view all the flashcards
Pectoralis Major Origin
Pectoralis Major Origin
Signup and view all the flashcards
Pectoralis Major Nerve Supply
Pectoralis Major Nerve Supply
Signup and view all the flashcards
Pectoralis Major Action
Pectoralis Major Action
Signup and view all the flashcards
Pectoralis Minor Muscle
Pectoralis Minor Muscle
Signup and view all the flashcards
Pectoralis Minor Insertion
Pectoralis Minor Insertion
Signup and view all the flashcards
Pectoralis Minor Origin
Pectoralis Minor Origin
Signup and view all the flashcards
Pectoralis Minor Action
Pectoralis Minor Action
Signup and view all the flashcards
Subclavius Muscle
Subclavius Muscle
Signup and view all the flashcards
Subclavius Origin & Insertion
Subclavius Origin & Insertion
Signup and view all the flashcards
Subclavius Nerve Supply
Subclavius Nerve Supply
Signup and view all the flashcards
Subclavius Action
Subclavius Action
Signup and view all the flashcards
Pectoral Fascia
Pectoral Fascia
Signup and view all the flashcards
Clavipectoral Fascia
Clavipectoral Fascia
Signup and view all the flashcards
Costo-coracoid ligament
Costo-coracoid ligament
Signup and view all the flashcards
Structures piercing the Clavipectoral fascia
Structures piercing the Clavipectoral fascia
Signup and view all the flashcards
Study Notes
- The pectoral region forms the front of the upper chest and is part of the upper limb.
- The lecture aims to explain the anatomy of the pectoral region, covering the fascia and muscles.
- Contents will cover definition of the pectoral region, contents, superficial and deep fascia, and muscles.
- The muscles include the pectoralis major, pectoralis minor, and subclavius, with focus on their origin, insertion, nerve supply, and action.
Contents/Layers of the Pectoral Region
- Skin.
- Superficial fascia: encloses the mammary glands, cutaneous vessels, and nerves.
- Deep fascia and Muscles.
Muscles of the Pectoral Region
- The muscles are pectoralis major, pectoralis minor, and subclavius.
- Nerve supply to the upper limb muscles provided by the Brachial plexuses.
Pectoralis Major
- It is the largest and the most superficial muscle in the pectoral region.
- Clavicular head origin: anterior surface of the medial half of the clavicle.
- Sternocostal head origin: anterior surface of the sternum and the upper seven costal cartilages.
- Insertion: lateral lip of the bicipital groove (intertubercular sulcus) of the humerus.
- Nerve supply: lateral and medial pectoral nerves.
- Muscle action when both heads act together is to flex, adduct, and medially rotate the arm at the shoulder joint.
Pectoralis Minor Muscle
- Characteristics include that it's a small triangular muscle and lies deep to the pectoralis major.
- Insertion: coracoid process of the scapula (medial border and upper surface).
- Origin: ribs 3 to 5 by anterior surfaces and superior borders.
- Nerve supply: medial pectoral nerve.
- Action: protracts and depresses the scapula (drawing it anteriorly and inferiorly at the tip of the shoulder).
Subclavius Muscle
- Characteristics include that it is a small muscle and lies deep to the pectoralis major muscle.
- Insertion: subclavius groove.
- Origin: the first rib, specifically at the junction between the rib and its costal cartilage.
- Nerve supply: nerve to subclavius.
- Action: stabilizes the sternoclavicular joint and depresses the clavicle.
Deep Fascia
- Pectoral fascia: thin lamina of connective tissue covering the surface of the pectoralis major muscle.
- Clavipectoral fascia: thick sheet of connective tissue that connects the clavicle to the floor of the axilla, acting as the suspensory ligament of the axilla.
- The clavipectoral fascia encloses the subclavius and pectoralis minor muscles, covering the gap between them.
- The clavipectoral fascia is thickened at its upper border to form the costo-coracoid ligament, which spans from the first rib to the coracoid process.
- Structures piercing the clavipectoral fascia include the cephalic vein, thoraco-acromial artery, lateral pectoral nerve, and lymphatics,.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
Explore the anatomy of the pectoral region, including its layers, fascia, and muscles such as the pectoralis major, pectoralis minor, and subclavius. This lesson covers their origins, insertions, nerve supply, and actions. Focus is given on key areas like the clavicular and sternocostal heads.
