Lect. 1 Upper Limbs, SM Function, Posterior Shoulder Region Flashcards
What type of joint is the glenohumeral joint?
Synovial, ball, and socket joint
What movements are possible at the glenohumeral joint?
Flexion/extension, abduction/adduction, medial and lateral rotation
Which muscles act on the glenohumeral joint?
Supraspinatus, Teresa major, long head of triceps brachii, short head of bicep
What are the tendons of the rotator cuff?
Supraspinatus, infraspinatus, teres minor, subscapularis
What do the tendons of the rotator cuff reinforce?
The fibrous capsule of the glenohumeral joint
What type of join is the acromioclavicular (AC) joint?
Synovial planar joint
What type of joint is the humeroulnar joint?
Synovial hinge joint
What type of joint is the proximal radio-ulnar joint?
Synovial pivot joint
What type of joint is the interosseous membrane?
Syndesmosis
What type of joint is the intervertebral disc?
Symphyses
What covers the articular surfaces of the synovial joint?
A thin layer of articular cartilage
What can skeletal muscle exert?
Tension
Can skeletal muscle exert tension with or without movement?
With or without movement
What is concentric contraction?
Muscle shortening as it contracts
What is eccentric contraction?
Muscle contracting as it is stretched out
What is the condition for maximal tension production in a muscle?
The sarcomeres are at resting length
What happens to the active tension produced by a muscle if it is too stretched out?
It is reduced
What muscle is located at the shoulder region?
Deltoid
What are the actions of the deltoid muscle?
Abduction of the arm after 15° (middle fibers), flexes the arm (anterior fibers), extend the arm (posterior) fibers
What is the innervation of the deltoid muscle?
Axillary nerve
Where is the subscapularis muscle located?
Subscapular fossa to the lesser tubercle
What is the action of the subscapularis muscle?
Medial rotation of the arm
What are the innervations of the subscapularis muscle?
Upper/lower subscapular nerves
Where is the supraspinatus muscle located?
Supraspinous fossa to greater tubercle
What is the action of the supraspinatus muscle?
Initiates abduction of the arm (0-15°)
What muscle initiates abduction of the arm?
Supraspinatus
What nerve innervates the infraspinatus muscle?
Suprascapular nerve
What is the action of the infraspinatus muscle?
Lateral rotation of the arm
What nerve innervates the teres minor muscle?
Suprascapular nerve
What is the action of the teres minor muscle?
Lateral rotation of the arm
What nerve innervates the teres major muscle?
Lower subscapular nerve
What is the action of the teres major?
Medial rotation, adduction, extension of the arm
What nerve innervates the latissimus dorsi muscle?
Lower subscapular nerve
What is the action of the latissimus dorsi?
Medial rotation, adduction, extension of the arm
What is the innervation of the subscapular nerve?
Thoracodorsal nerve/middle subscapular nerve
What is the innervation of the trapezius muscle?
Accessory nerve & C3/C4
What are the actions of the trapezius muscle?
Elevate scapula (upper fibers), retract scapula (middle fibers), and depress scapula (lower fibers)
What is the innervation of the levator scapula muscle?
Dorsal scapular nerve
What is the origin and insertion of the levator scapula muscle?
Transverse process of cervical vertebrae -> superior angle of scapula
What is the action of the rhomboids?
Retraction and glenoid down rotation of the scapula
What nerve innervates the rhomboids?
Dorsal scapular nerve
What is the action of the serratus anterior?
Protraction and glenoid up rotation of the scapula
What nerve innervates the serratus anterior?
Long thoracic nerve
What is the action of the pectoralis minor?
Depression and protraction of the scapula
What nerve innervates the pectoralis minor?
Medial pectoral nerve
What is the origin and insertion of the pectoralis minor?
Upper 3-5 ribs -> coracoid process
What is the origin and insertion of the serratus anterior?
Upper 8-9 ribs -> medial border of the scapula
What is the origin and insertion of the rhomboids?
Nuchal ligament (minor), thoracic vertebrae (major) -> vertebral border above spine (minor), vertebral border below spine (major)
What is the action of the clavicular head of the pectoralis major muscle?
Adduction, flexion, medial rotation of the arm
What is the action of the sternoclavicular head?
Adduction, medial rotation, & extension when arm is already flexed
What nerves innervate the pectoralis major muscle?
Medial pectoral nerve (sternoclavicular head), & lateral pectoral nerve (clavicular head)
What is the blood supply to the suprascapular artery?
The suprascapular artery arises from the thyrocervical trunk
What is the path of the suprascapular nerve in relation to the superior transverse scapular ligament?
The suprascapular nerve passes inferior to the superior transverse scapular ligament
What is the path of the suprascapular artery in relation to the superior transverse scapular ligament?
The suprascapular artery passes superior to the superior transverse scapular ligament
Where does the dorsal scapular artery often arise from?
The dorsal scapular artery often arises from the 3rd part of the subclavian artery
Where does the axillary artery begin?
The axillary artery begins at the lateral border of the 1st rib
What runs with the posterior circumflex humeral artery in the quadrangular space?
The axillary nerve
What artery is viewed through the triangular space bordered by the long head of the triceps brachii (laterally)?
The circumflex scapular artery
How do the cephalic vein and basilic vein typically communicate?
The cephalic and basilic veins typically communicate via the median cubical vein
What is the location of the quadrangular space?
Deep to the deltoid muscle
What forms the superior border (teres minor) of the quadrangular space?
A muscle innervated by a terminal branch of the brachial plexus (axillary nerve)
What lies superolateral to the triangular space?
The lateral long head of the triceps brachii
What forms the medial border of the quadrangular space?
The long head of the triceps brachii
What forms the lateral border of the quadrangular space?
The surgical neck of the humerus
What innervates or passes through the quadrangular space?
The posterior circuflex humeral artery & the axillary nerve