What is endomysium
connective tissue that wraps individual muscle fibers
What is perimysium
Connective tissue that wraps around multiple muscle fibers
What is a fasciculus or what are fasciculi
A bundle of muscle fibers wrapped in perimysium
What is epimysium
Connective tissue that wraps around multiple fasciculus
What are the fascial wrapping continuous with
tendons, periosteum, and other connective tissue structures
What is superficial fascia
subdermal loose connective tissue that contains blood vessels, fat, and nerves (reticular)
What is deep fascia
Thick connective tissue that forms various protective structures
What is an investing layer
fascia that surrounds muscle groups
What is intermuscular septa
Fascia that separates functional muscle groups
What is a bursa
A flattened sac located in a region where friction needs to be reduced between muscle/tendon and bone
What are synovial sheaths
bursae surrounding tendons
What are bursae made of
connective tissue and bursal fluid on the inside
What is bursitis
The swelling/inflammation of a bursa
what is a motor unit
muscle fibers controlled by a single motor neuron
What detects the stretch of a particular muscle to prevent over stretching/tearing
specialized sensory nerves such as Golgi tendon organs and muscle spindle fibers
If an axon innervates very few muscle fibers, will it have power or finesse in its contraction
finesse (think ocular muscles)
If an axon innervates many muscle fibers, will it have power or finesse in its contraction
Power (think latissima dorsi)
What is the origin and insertion of the latissimus dorsi
Spine of T6-L5, intertubercular groove
What muscle(s) does the Thoracodorsal nerve innervate
Latissimus Dorsi
What is the action of the Latissimus Dorsi
Extend, adduct, and medially rotate the humerus (handcuffs!)
What is the origin and insertion of the levator Scapulae
Origin: Transverse processes of C1-4
Insertion: Medial border of the scapula superior to the spine
What is the origin and insertion of the rhomboid minor
Origin: Spinous processes of C7-T1
insertion: medial border of scapula, at the level of the spine
What is the origin and insertion of the rhomboid major
Origin: Spinous processes of T2-5
insertion: Medial border of scapula, below level of the spine
What does the Dorsal scapular nerve innervate
Levator scapulae, rhomboid minor, and rhomboid major
What is the action of the rhomboids and levitator scapulae
Elevate, retract, and medially rotate the scapula
Where is the Dorsal scapular nerve located
It decends from C5 and passes deep to the rhomboids and levitator scapulae
What are the 7 muscles on the scapula that move the humerus
Deltoid, supraspinatus, infraspinatus, subscapularis, teres major, teres minor, triceps
What are the origins of the deltoid
Posterior deltoid: spine of the scapula, intermediate deltoid: acromion, anterior deltoid: lateral 1/3 of the clavicle
What is the insertion of the deltoid
deltoid tuberosity of the humerus
What does the axillary nerve innervate
deltoid and teres minor
Where is the axillary nerve located
It branches from the brachial plexus and passes through the quadrangular space.
What are the 4 borders of the quadrangular space
teres major and minor, humerus, and the long head of the triceps
What does SITS stand for
The rotator cuff muscles: supraspinatus, infraspinatus, teres minor, subscapularis
What is the origin and insertion of the supraspinatus
Origin: supraspinous fossa
Insertion: greater tubercle of the humerus
what is the origin and insertion of the infraspinatus
Origin: infraspinous fossa
insertion: greater tubercle of the humerus
What is the origin and insertion of the Teres minor
Origin: lateral border of the scapula
Insertion: greater tubercle of the humerus
What is the origin and insertion of the subscapularis
Origin: subscapular fossa
Insertion: lesser tubercle of the humerus
What does the suprascapular nerve innervate
Supraspinatus, infraspinatus
Where is the suprascapular nerve located
It decends from C5, passes through the suprascapular notch under the transverse ligament, and passes into the infra/supraspinatus muscles
What does the upper subscapularis nerve innervate
The subscapularis
What does the lower subscapularis nerve innervate
The subscapularis and teres major
What is the most common pathology of the rotator cuff muscles
The suprasinatus gets inflamed, and the swelling makes it rub against the acromion and surrounding ligaments, leading to a tear
What is the origin and insertion of the teres major
Origin: Lateral border of the scapula
Insertion: intertubercular groove
What is the origin and insertion of the pectoralis major
Origin: medial 1/2 of the clavicle and upper 6 costal cartilages
Insertion: Bicipital groove on the humerus
What is the origin and insertion of the pectoralis minor
Origin: Ribs 3,4,5
Insertion: Coracoid process
What is the action of the pectoralis minor
protract,depress, and medial rotation of the scapular
What innervates the pectoralis minor
The medial pectoral n
What is the origin and insertion of the subclavius
Origin: first costal cartilage
Insertion: infer. groove of clavicle
What is the action of the subclavius
to depress and stabilize the clavicle
What is the innervation of the subclavius
n to subclavius (Haha, laaame)
What innervates the pectoralis Major
lateral and medial pectoral nn
where is the medial pectoral nerve located
It branches from the brachial plexus and passes through the minor into the major pec
What is the origin and insertion of the serratus anterior
Origin: upper 8 ribs
Insertion: medial border of the scapula
What does the long thoracic n innervate
The serratus anterior
What is the action of the serratus
protract and laterally rotate the scapula
Where is the long thoracic n located
it decends from C5,6,7 and passes under the clavicle to the serratus anterior
What is scapular winging
Weakness in either the rhomboids or serratus anterior that causes lateral or medial rotation, respectively.
What is the origin of the trapezius
Superior nuchal line, external occipital protuberance, nuchal ligament, spines of C7-T12
What is the insertion of the trapezius
Spine of the scapula (top), acromion, and lateral 1/3 of the clavicle (top)
What does the accessory n (CN XI) innervate?
The sternocleidomastoid and the trapezius
What is the action of the trapezius on the scapula
elevation, depression, retraction, lateral rotation
Where is the accessory n located
It decends from the base of the skull, out of the posterior triangle of the neck, and passes down the side of the neck deep to the trapezius
What are the 3 joint types
Fibrous, cartilaginous, and synovial
What are the three types of fibrous joints
Syndesmoses, Sutures, and Gomphosis
What are the 2 types of cartilaginous joints
Symphysis and synchondrosis
What are the 5 key characteristics of a synovial joint
- articulating ends are covered in hyaline cartilage. 2. synovial space between the bones and within the joint capsule
- articular capsule consisting of CT that is continuous with the periosteum of the bones
- Synovial membrane on inner lining of joint capsule that creates a lubricating synovial fluid
- occasionally there is a fibrocartilage articulating disc or meniscus between the bones
What type of joint is formed if the interzonal mesenchyme dies off
As it dies, it signals the formation of hyaline cartilage, and forms a synovial joint
What type of joint it formed if mesenchyme turns into chondrocytes?
Chondrocytes are cartilage forming cells, so it become a cartilaginous joint
What type of joint is formed if mesenchyme turns into fibroblasts
Fibroblasts make connective tissue, so a fibrous joint will form.
Which muscles retract the scapula
Traps, rhomboids, and lev. scap
Which muscles protract the scapula
Pec. minor and serratus anterior
Which muscles elevate the scapula
Trap, rhomboids, and lev. scap
Which muscles depress the scapula
Trap and pec. minor
Which muscles laterally rotate the scapula
Trap and serratus anterior
Which muscles medially rotate the scapula
Rhomboids, lev scap, and pec. minor
Which muscles flex the humerus
Pec. major, deltoid, biceps br. and corocobrachius
Which muscles extend the humerus
Latissimus, teres major, deltoid, and triceps brac.
Which muscles abduct the humerus
Deltoid and supraspinatus
Which muscles adduct the the humerus
Pec major, latissimus, teres major, and corocobrac.
Which muscles medially rotate the humerus
Pec major, latissimus, teres major, deltoid, and subscapular
Which muscles laterally rotate the humerus
Deltoid, infraspinatus, and teres minor
