1
Q
- These muscles are responsible for moving the scapula and consequently, the upper limb.
- These muscles are known as the extrinsic shoulder muscles because the run from the ribs and vertebral column to the pectoral or shoulder girdle. They have two primary functions: either to fix the scapula in place, or to move the scapula so that the range of motion of the upper limb can be increased.
- The anterior muscles include the pectoralis major and minor, serratus anterior and subclavius.
- The posterior muscles include the latissimus dorsi and trapezius, and the underlying levator scapulae and rhomboids.
A
superficial muscles of the anterior and posterior thorax
2
Q
- is a small muscle that extends from the first rib to the underside of the clavicle (green arrow).
- It helps to stabilize and depress the pectoral girdle to allow for precise movements of the upper limb.
- Under the clavicle, extending from the clavicle to the first rib.
- Steadies the clavicle during movement of the pectoral girdle.
A
The subclavius
3
Q
- draws the scapula forward and downward when the ribs are fixed. However, if the scapula is fixed, contraction of the __ __ pulls the rib cage superiorly. Thus, the ___ __ muscle can be considered an accessory muscle of forced inspiration. Patients suffering from chronic obstructive pulmonary diseases such as emphysema will extend their upper limbs against a table top to brace (fix) the scapula, and use the contractions of the __ __ muscles to help them breathe.
- Thin muscle deep to the pectoralis major.
- With ribs fixed, moves scapula so glenoid cavity can rotate downward
- Assists in forced inspiration when scapula is held fixed because it elevates the ribs.
A
pectoralis minor
4
Q
- gets its name from its jagged or “saw-toothed” appearance.
- Its origin is from slips of muscle arising from the first nine ribs. These join together to insert on the entire anterior surface of the vertebral border of the scapula.
- The main action of the __ __ is to rotate the scapula so that the inferior angle moves laterally and upward. This rotation of the scapula allows you to raise your arm above your head.
- also works to protract and hold the scapula against the posterior rib cage, and permits arm movements such as pushing or punching. That’s why it is nick-named the boxer’s muscle.
A
serratus anterior
5
Q
- Stabilizes, raises, retracts and rotates the scapula.
- is a superficial, flat triangular muscle extending from skull and vertebral column medially to the pectoral girdle. The two ___ muscles form a diamond on the superficial back.
- The action of the ___ depends on which region of this large muscle is active. The middle fibers retract or adduct the scapula; the superior fibers elevate the scapula and work with the levator scapulae to shrug the shoulders or can help extend the head when the scapula is fixed. The inferior fibers depress the scapula and shoulder.
A
The trapezius
6
Q
- Elevate and adduct the scapula
- lie deep to sternocleidomastoid and trapezius. These muscles work along with the superior fibers of the trapezius to elevate the scapula as when shrugging the shoulders or lifting a weight over the head.
A
levator scapulae
7
Q
stabilize the scapula and work with the middle fibers of the trapezius to retract (adduct) the scapula as when “squaring” the shoulders.
A
The rhomboids
8
Q
- Covers the superior thorax
- Two origins: Clavicular head (small) and sternocostal head.
- Prime mover of Arm: flexes, adducts & medially rotates arm
- is a large, flat muscle with convergent fibers that have multiple origins from the clavicle, sternum, costal cartilages of ribs 1-7, and the aponeurosis of the external oblique muscles. The fibers converge to insert by a short tendon into the intertubercular sulcus and greater tubercle of the humerus.
- a prime mover of arm flexion, medial rotation and adduction.
- It functions when climbing, throwing, pushing and in forced inspiration.
A
pectoralis major
9
Q
- Inferior part of back
- Power stroke; strike a blow
- Swimming muscle
- Prime mover of Arm: extension, adduction, medially rotates arm
- is a broad, flat, triangular shaped muscle with numerous origins from the lumbodorsal fascia, spines of the six inferior thoracic vertebrae, lower 3-4 ribs, and iliac crest with a bit coming from the inferior angle of the scapula.
- inserts on the intertubercular sulcus of the humerus. This muscle is a prime mover of arm extension (and so in this action it is an antagonist of the pectoralis major). It is also a powerful arm adductor and medially rotates the arm at the shoulder.
- It functions in common activities such as hammering, swimming, and rowing.
A
The latissimus dorsi
10
Q
- is considered to be a prime mover of the arm.
- is a thick, triangular shaped multipectinate muscle. It has a complex origin with fibers arising from the lateral third of the clavicle, acromion and spine of the scapula. It is the prime mover of arm abduction when all its fibers contract simultaneously. It is an antagonist of the pectoralis major and latissimus dorsi which adduct the arm.
- When only the anterior fibers are active, the ___ can be a powerful flexor and medial rotator of the arm. However, if only the posterior fibers are active, the __ assists in arm extension and lateral rotation.
- It is also active in the swinging of our arms when we walk.
- covers shoulder joint and forms the rounded contour of the shoulder. (clavicle, acromion, scapula)
- Common site of intramuscular injections
- Three origins for three sets of muscle fibers.
- Give rise to different movements of the arm
- Prime mover of arm Abduction, aids in flexion, medial rotation, extension and lateral rotation.
- Antagonist of pectoralis major and latissimus dorsi (adduct)
A
deltoid
11
Q
- Helps to form part of posterior axillary wall.
- Extends, medially rotates & adducts the arm.
A
Teres major
12
Q
- Flexion & adduction of the arm; synergist of pectoralis major
- Musculocutaneous nerve pierces belly
A
Coracobrachialis
13
Q
- Fills the subscapular fossa & forms part of posterior wall of axilla.
- Inserts on the lesser tubercle of humerus.
- Helps to hold head of humerus in glenoid cavity.
- Medial rotator of the arm.
A
Subscapularis
14
Q
- (prevents downward dislocation of humerus)
- Supraspinous fossa of the scapula, deep to trapezius.
A
Supraspinatus
15
Q
Infraspinous fossa
A
Infraspinatus
16
Q
Often inseparable from the infraspinatus
A
Teres minor
17
Q
Repetitive overhead motion causes continual pinching of the supraspinatus tendon causes inflammation, pain and eventual degeneration which can result in the muscle pulling away from the humerus.
A
Impingement syndrome
18
Q
- Two heads, long and short
- Originate from scapula (supraglenoid tubercle & coracoid process) and insert on radial tuberosity and bicipital aponeurosis.
- Spans both the shoulder and elbow joint
- Flexes forearm at elbow joint and shoulder joint.
- Supinates the forearm at the radioulnar joints,
A
Biceps brachii
19
Q
- (humerus to ulna)
- Deep to biceps brachii
- Most powerful flexor of the forearm at the elbow joint
A
Brachialis
20
Q
- (above lateral epicondyle of humerus to styloid process of radius)
- Flexes forearm at elbow joint when a quick movement is required or when a weight is lifted slowly during flexion of forearm (stabilizes elbow).
A
Brachioradialis
21
Q
- Posterior surface of arm
- Most powerful of the forearm extensors at the elbow joint.
- Three heads of Origin: Long, lateral and medial heads
- Long head from the scapula and two from the humerus
- Long head crosses the shoulder joint
- Infraglenoid tubercle of scapula to olecranon of ulna
A
Triceps brachii
22
Q
- (= elbow)
- Lateral epicondyle of humerus to olecranon
- Assists triceps in extending the forearm.
A
Anconeus
23
Q
- Forearm pronators
- Medial epicondyle of humerus and coronoid process of ulna to midlateral surface of radius
A
Pronator teres
24
Q
- Forearm pronator
- Distal ulna to distal radius
A
Pronator quadratus
25
* Forearm supinator
* Lateral epicondyle of humerus and near radial notch of ulna to lateral surface of proximal radius.
* Motion: “turning a screw with a screw driver”
Supinator
26
Biceps brachii
Brachialis
Brachioradialis
Flexor compartment
27
Triceps brachii
Anconeus
Extensor compartment
28
Originate on the humerus
Insert typically on the carpals, metacarpals and phalanges
Flexors.
Anterior compartment
29
Originate on humerus
Insert on the metacarpals and phalanges
Extensors.
Posterior compartment
30
From lateral to medial:
Flexor carpi radialis
Palmaris longus (absent in 10% of population)
Flexor carpi ulnaris
Ulnar nerve and artery are just lateral to the tendon of this muscle at the wrist.
Flexor digitorum superficialis
Hand & proximal phalanges
Superficial Anterior Compartment
31
From lateral to medial:
Flexor pollicis longus
Flexor of the distal phalanx of the thumb
Flexor digitorum profundus
Ends in four tendons that insert into the distal phalanges of the fingers.
Deep Anterior Compartment
32
From lateral to medial:
Extensor carpi radialis longus
Extensor carpi radialis brevis
Extensor digitorum
Divides into four tendons that insert into the middle and distal phalanges of the fingers
Extensor digiti minimi
Usually connected to the extensor digitorum
Extensor carpi ulnaris
Superficial Posterior Compartment
33
From lateral to medial:
Abductor pollicis longus
Extensor pollicis brevis
Extensor pollicis longus
Extensor indicis
Supinator
Deep Posterior Compartment
34
Tendons and blood vessels are held close to the bones of the wrist by ___ \_\_
tough fascia.
35
* (= to retain)
* Deep fascia thickened into fibrous bands
Retinacula
36
* (= transverse carpal ligament)
* Located over the palmar surface of the carpal bones.
* Long flexor tendons of the digits and wrist and median nerve pass through this
Flexor retinaculum
37
* (=dorsal carpal ligament)
* Located over the dorsal surface of the carpal bones.
* The extensor tendons of wrist and digits pass through it.
Extensor retinaculum
38
* Psoas major and iliacus muscles share a common insertion on the lesser trochanter of the femur. These two muscles are collectively referred to as the \_\_
* Flex the thigh at hip joint
* Rotate thigh laterally and flex trunk on the hip (sit ups)
iliopsoas
39
* (largest and heaviest)
* Main extensor of the femur
* Rotates thigh laterally & abducts
Gluteus maximus
40
* (deep to gluteus maximus):
* Powerful abductor (medially rotates) of the femur at the hip joint.
* Common site for intramuscluar injections
* insert on greater trochanter
Gluteus medius
41
* Smallest and lies deep to the gluteus medius
* Abducts and medially rotates thigh
* inserts on greater trochanter
Gluteus minimus
42
* Fascia lata: Deep fascia encircling the entire thigh.
* Fascia lata and the tendons of the __ \_\_ __ and gluteus maximus form iliotibial tract which inserts into the lateral condyle of the tibia.
* arise from the lateral surface of thigh originating from the iliac crest and inserting on tibia by way of the iliotibial tract.
* Flexes, medially rotates and abducts thigh at hip joint.
* Supports the knee
Tensor fasciae latae
43
\_\_ __ of the femur at the hip joint.
Piriformis
Obturator internus
Obturator externus
Superior gemellus
Inferior gemellus
Quadratus femoris
Lateral rotators
44
* Flex and adduct the thigh
Adductor magnus
Adductor longus
Adductor brevis
Pectineus
Gracilis: adducts the thigh and flexes the leg at the knee joint.
Medial (adductor) compartment
45
Quadriceps femoris and sartorius:
Quadriceps femoris includes four muscles:
Rectus femoris
Vastus lateralis
Vastus medialis
Vastus intermedius
* Insert on patella via quadriceps tendon and then tibial tuberosity via patellar ligament. Extend leg at knee joint.
Anterior (extensor) compartment
46
forms a band across the thigh from the ilium to the medial aspect of the tibia. Cross-legged sitting position gives it its name as the “tailor’s” muscle.
The sartorius
47
also flexes thigh at hip joint when acting alone.
The rectus femoris
48
Hamstrings: Consists of three separate muscles:
Biceps femoris
Semitendinosus
Semimembranosus
* Span two joints (hip and knee): Extend the thigh and flex the leg
Posterior (flexor) Compartment
49
is bordered laterally by the tendons of the biceps femoris and medially by the tendons of the semitendinosus and semimembranosus.
Popliteal fossa
50
* masculature of the leg
```
Muscles that dorsiflex the foot.
Tendons are held firmly to the ankle by superior extensor retinaculum (transverse ligament of the ankle), and inferior extensor retinaculum (cruciate ligament of ankle).
Tibialis anterior
Extensor hallucis longus
Extensor digitorum longus
Peroneus tertius (part of the extensor digitorum longus)
```
Anterior compartment
51
* masculature of the leg
Muscles that plantar flex and evert the foot:
Peroneus (fibularis) longus and brevis
Lateral compartment
52
Gastrocnemius
Soleus
Plantaris (may be absent in some individuals, or there may be two per side)
* insert into the calcaneus via the calcaneal (Achilles) tendon.
* Plantar flex the foot at the ankle.
Superficial muscles include
53
Popliteus
Tibialis posterior
Flexor digitorum longus
Flexor hallucis longus
Deep Muscles
54
* are characterized by pain along the medial and distal two-thirds of the tibia.
Causes:
Tendinitis of the anterior compartment muscles.
Related to poor conditioning, poor shoes or running on hard or banked surfaces.
Inflammation of the periosteum (periostitis).
Stress fractures.
Shinsplints
55
* Originate, insert and act on the foot.
* Support and locomotion (not precise movements)
Intrinsic muscles
56
Extends from the calcaneus to phalanges and supports the longitudinal arch of the foot and encloses the flexor tendons of the foot.
Plantar aponeurosis
57
* dorsal
* Has four parts deep to the tendons of the extensor digitorum longus .
* Extends toes 2-5
Extensor digitorum brevis
58
* Abductor hallucis
* Flexor digitorum brevis: Middle of the sole, flexes toes 2-5
* Abductor digiti minimi:Lateral border of sole, Abducts the small toe
Plantar: First Layer
59
* Quadratus plantae:two heads and flexes toes 2-5
* Lumbricals: Originate from the tendons of the flexor digitorum longus; Flex the proximal phalanges and extend the distal joints of toes 2-5.
Plantar: Second layer
60
Flexor hallucis
Adductor hallucis
Flexor digiti minimi brevis
Plantar: Third layer
61
* Dorsal interossei: four muscles that adduct toes 2-4, flex the proximal phalanges and extend the distal phalanges
* Plantar interossei: three muscles which adduct toes 3-5, flex the proximal phalanges and extend the distal phalanges.
Plantar: Fourth (deep) layer
The Muscular System
flashcards
Decks in class (3)
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