YTTanatomy

Question 2

what is the Sternocleidomastoid

Answer 2

largest & most important anterior neck muscle

Question 3

what is the origin of the Sternocleidomastoid

Answer 3

dual origins: on the sternum & claviclesuperior occipital line

Question 4

what is the insertion point of the Sternocleidomastoid

Answer 4

inserts: on the mastiod process & curved

Question 5

what is the action of the Sternocleidomastoid

Answer 5

actions: when skull is fixed SCM elevates the sternum & clavicle - assists in inspirationwhen htoracic cage is fixed: contraction of SCM causes ipsilateral sidebending and contralateral rotation of the head as well as extension

Question 6

where does the diaphragm insert?

Answer 6

inserts on its own central tendon

Question 7

diaphragm - origins?

Answer 7

three major origins, all inserting on the central tendon-sternal origin from the xiphoid process-costal origin - from the deep surfaces of ribs 7-12 and their cartilages-vertebral origin - a ‘right crus’ arising from the bodies of L1-L3 and a ‘left crus’ from the bodies of L1-L2

Question 8

diaphragm - action?

Answer 8

the diaphragm is the principal muscle of inspiration

Question 9

Psoas Major - origin

Answer 9

the psoas major arises from the bodies of T12-L5 and from arches of fascia which connect the boney parts of the vertebral bodies but do not attach to the intervertebral disks

Question 10

Psoas Major - insertion

Answer 10

the psoas major run anterior to the pelvis, posterior to the inguinal ligament and inserts on the lessor trocanter

Question 11

Psoas Major - action

Answer 11

when the vertebrae are fixed, the psoas flexes the hip and works as a weak adductor and lateral rotatorwhen spine is fixed: straightens the spine (act to erect) the lumbar spine. in unilateral contraction - the unilateral action pulls the spine into a sidebend, flexion and rotation of the side opposite of the contraction

Question 12

External oblique - O I A

Answer 12

Origin: the external oblique is attached above to the outer surfaces of ribs 5-12 & the ilioinguinal ligament. Insertion: In front & below it ends at the linea alba & inguinal ligamentAction: unilateral contraction of the exteral oblique results in sidebending and contralateral rotation of the spine & ribcageBilateral contraction causes flexion of the trunkfixed pelvis: lowers the ribs - expiratory muscle

Question 13

Rectus abdominis OIA

Answer 13

O: the crrest and symphysis of the pubusI: the xiphoid process and cartilages of ribs 5-7A: flexor of the trunk (moving the sternum toward the pelvis

Question 14

Levator scapulae OIA

Answer 14

O: the transverse processes of C1-C4I: superior angle of the scapulaA: elevates the scapula and rotates it downward.When scapula is fixed it acts on the cervical spine (reinforce splenius cervicis)

Question 15

Rhomboids OIA

Answer 15

O: the spinous process of C7 and T1-T4I: the medial border of the scapulaA: adduct the scapula and rotate it downwardwhen the scapula is fixed they act the contraction of these muscles pulls the vertebrae laterally

Question 16

Subscapularis OIA

Answer 16

O: the anterior surface of the scapulaI: on the lesser tubercle of the humerusA: principal muscle of medial rotation of the arm

Question 17

Supraspinatus OIA

Answer 17

O: suprapinous fossa on the posterior scapulaI: highest point on the greater tubercleA:abducts the arm (with the deltoid)

Question 18

Infraspinatus OIA

Answer 18

O: from the infrespinous fossaI: the greater tubercle (at a point posterinferior to the insertition of the supraspinatus)A;lateral rotation and participates in abduction

Question 19

what are the Rotator cuff muscles?

Answer 19

four deep muscles: subscapularis, supraspinatus, infraspinatus and teres minorapart from their action of mobilizing the humerus, they play an important role as “active ligaments” in providing mobility to the joint

Question 20

what do the Rotator cuff muscles do?

Answer 20

apart from their action of mobilizing the humerus, they play an important role as “active ligaments” in providing mobility to the jointsupraspinatus - prevents the humerus from being dislocated/displaced upwardsubscapularis prevents the head of the humerus from gliding backwardthe infraspinatus and teres minor prevent it from being dislocated forward and from gliding forward & backward

Question 21

Biceps brachii OIA

Answer 21

O: 2 (bi) origins the long head arises from a tubercle about the glenoid cavity of the scapulathe short head starts as a tendon at the coracoid process on the lateral edge of the scapula. the two tendons continue downward & form one tendonI: bicipital tuberosity of the radiusA: the primary elbow flexorI:

Question 22

Triceps brachii OIA

Answer 22

O: 3 (tri) origins the long head - a tubercle below the glenoid cavity of the scapulathe lateral head - from the lateral posterosuperior shaft of the humerusthe medial head - from the posteroinferior humerusI: singl ebroad insertion by a tendon onto the olecranonA:major elbow extensor

Question 23

Pectoralis major OIA

Answer 23

O: clavivle head from the anterior, medial clavicle and a sternocostal head from the sternum and costal cartilages 1-6 and rib 7I: the tendon is twisted such that the fibers from the clavicular head insert below those from the sternocoastal head on teh lateral aspect of the bicipital grooveA: ribcage fixed - all the fibers adduct and medially rotate the arm - the “hugging muscle” flexionshoulder fixed: inspiration

Question 24

Latissimus dorsi OIA

Answer 24

“widest back muscle”O: the scral & iliac crests, thoracolumbar fascia, spinous processes of T7-T12 and the posterior surfaces of the four lower ribsI: the tendon(wraps around the medial side of the humerus, makes a twist &) inserts on the bicipital grooveA: extension, adduction and medial rotation of the arm

Question 25

Deltoid OIA

Answer 25

three groups of fibers:middle fibers attach to the lateral border of the acromionposterior fibers attache to the spine of the scapulathe anterior fibers attach to the claviclesI: (the three fibers converge) on the lateral surface of the humerusA: contraction of anterior fibers: flexion & medial rotation of armcontraction of middle fibers: abduction of the armcontraction of posterior fibers: extension of the arm

Question 26

Trapezius OIA

Answer 26

O:occiput, nuchal ligament and spinous processes of the cervical vertebrae and the thoracic vertebrae down to T12I:- the lateral third of the clavicle and acromion (upper fibers)-scapular spine (middle fibers)-a tubercle at the medial end of the scapular spine (lower fibers)A: simultaneous contraction of all the fibers adducts the scapula- upper fibers alone=elevation and upward rotation of the scapula-lower fibers=act in depression and upward rotation of the scapula

Question 27

Gluteus minimus OIA

Answer 27

O: exteral iliac fossaI:anterior aspect of the greater trochanterA: reinforce those of the anterior part of gluteus mediusIn addition to abduction of the thigh, it assists in flexion and medial rotation

Question 28

Gluteus medius OIA

Answer 28

O: broad origin on the external iliac fossaI: It’s fibers converge and insert on the lateral aspect of the greater trochanterA: hip fixed: major action=abduction of the hip but can also assist in flexion and extensionfemur fixed: involved in both flexion and extension of the pelvis. Main action is visble when standing on one leg:acts in lateral flexion of the pelvis

Question 29

Piriformis OIA

Answer 29

O: on the anterior sacrumI: on top of the greater trochanterA: fixed sacrum=laterally rotates, abducts and flexes the femurfixed femur: contributes to extension of the pelvis or medial rotation of the pelvis

Question 30

Quadricepts femoris - what are the three parts?

Answer 30

massive muscle w/ four bodies which converge into a single quadriceps tendonvastus intermedius- the deepest muscle originates from the upper two thirds of the anterior femoral shaftvastus interedius is covered by vastus lateralis and medialis

Question 31

rectus femoris OIA

Answer 31

rectus femoris - covers the hip as well as O: anterior inferior iliac spine (& part of the iliumI: the common (quad) tendon (also crosses knee & hip & acts on both joints)A: pelvis fixed= flexes the hip & extends the kneefemur fixed= flexion of the pelvis and extends knee(to stretch hip must be in extention and knee in flexion)

Question 32

Hamstrings OIA

Answer 32

O: ischium (posterior to the hip bone)I: on the bones of the lower legA:primary actions are extension of the thigh and flexion of the kneethigh fixed= act in extension of the pelvis

Question 33

Semitendinosus OIA

Answer 33

a hamstring muscle O: located medially (posterior to the semimembranosus) and inserts (via a long thin tendon to the superomedial tibial shaft) on the tibiaA: also acts to medially rotate the knee (with the semitendinosus)

Question 34

Semimembranosus OIA

Answer 34

a hamstring muscleO: from the ischiumI: inserts on the posteromedial aspect of the tibial condyleA: with the semimembranosus, medially rotates the knee

Question 35

Biceps femoris OIA

Answer 35

hamstring muscle, two headsO:ischium (posterior to hip bone)I:via common tendon to the head of the fibulaA: also acts in lateral rotation

Question 36

Adductors OIA

Answer 36

a group of five muscles having their bodies on the medial thighI: on the linea aspera of the femurA:adduction of the hip

Question 37

Pectinus OIA

Answer 37

an adductor muscleO: runs from the lateral pubis to a line connecting the lesser trochanter to the linea aspera of the femur

Question 38

Adductor magnus OIA

Answer 38

the largest and strongest of the adductor group - a compund muscleanterior portion originates from the ischiopubic ramus and inserts on the linea asperathe posterior portion originates from the ischial tuberosity and inserts just above the medial femoral condyle.A: also involved in medial rotation of the pelvis when femur is fixed

Question 39

Tensor fasciae latae OIA

Answer 39

O: anterior iliac crestI: not on a bone but on the fascia lata (aka the iliotibial tract). on a band of strong fibrous tissueA: abducts, flexes and medially rotates the femur. Plays small part in knee extension or lateral rotation of the flexed kneethigh & leg fixed=flexion, lateral flexion or lateral rotation of the pelvis

Question 40

Gluteus Maximus OIA

Answer 40

O: posterior sacrum and coccyx (as well as the posterolateral iliac fossa)I: the deep layer inserts on the superior linea aspera of the femursuperficial layer inserts on the fascia lataA (deep layer): hip bone fixed=pulls femur backward (hip extension) into lateral rotation and slight adductionfemur fixed= acts in extension of the pelvis and in extension, medial rotation and medial flexion of the pelvisA: superficial layer: acts on the femur by extending, externally rotating and abducting it. works with the tensor facia latae

Question 41

what is the femur?

Answer 41

thigh bone

Question 42

what is the humerus?

Answer 42

upper arm bone

Question 43

what is the tibia?

Answer 43

lower leg bone (along with the fibula)

Question 44

what is the radius?

Answer 44

the lower arm bone (along with the ulna)

Question 45

what is the lumbar spine?

Answer 45

vertebrae of the lower spine

Question 46

what is kyphosis?

Answer 46

forward curvature of the spine