Download Muscles of the abdominal wall, trunk muscles

Muscles of the abdominal wall, trunk muscles
1. Muscles that move the vertebral column
2. Muscles of the thorax
3. Muscles of the abdominal wall
1. muscles of vc, bend, twist, stretch the trunk
erector spinae: deep to trapezius and latissimus dorsi
either side of vc
2. muscles of thorax: involved in breathing
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external intercostals(most lateral) elevate ribs
internal intercostals(most medial) depress ribs
diaphragm: large horizontal muscle that separates
thoracis and abdominal cavities
contracts – pushes down on abdom. Cav
expands thoracic cav(pressure
decreases, inhalation results.
3. Muscles of abdominal wall
Flex and rotate vc and compress abdominal cav
Shields the organs of ac
Linea alba: (ridge of CT) vertical line from sternum to
Navel
Rectus abdominis: each side of linea alba
Tendinous inscriptions create the 6
pack look( inserts at xyphoid, origin pubic symphysis)
Acts in opposition to the erector spinae
External oblique, lateral to rectus abdominis, most
Superficial,(
Internal oblique: beneath external oblique
Transverse abdominis, most deep
These 3 groups are named for the orientation of the
muscle.
Lower limb muscles
Muscles that move the thigh, leg and foot and toes
Located in pelvic region, origin = coxal bones, insertion = femur
Iliopsoas(ilium(hip)and loin(psoas)) – flexes thigh
Tensor fasciae latae – most lateral to thigh
Abducts, flexes medially rotates thigh
Tenses the iliotibial-tract tendon(ct from
ilium to tibia) the tensor fasciae latae tightens the ittt . the tfl is a
short band of muscle anterior to the ittt and extends down just to
top of thigh.
Posterior to pelvis: gluteus maximus: biggest butt muscle
Extends the thigh when thigh is flexed
Gluteus medius: superior and lateral to maximus
Site for injections
Abducts, medially rotates thigh
Muscles that move thigh as primary function, to adduct the thigh
Located in medial portion of thigh
Adductor longus(most lateral),
Adductor magnus(mid)
Gracilis(most medial)
Muscles that move the leg
Dual functions, move the thigh and move the leg
Located in thigh
Anterior group: extend the leg, flex the thigh
Posterior group: flex the leg, extend the thigh
Anterior group(extend the leg, flex the thigh)
Sartorius: long narrow muscle, extends from ilium to
proximal end of tibia, allows us to sit cross-legged
Quadriceps femoris: primary extensors of leg
4 different origins but one common tendinous insertion
(insert on the patella via quadriceps tendon, then onto the
patellar tendon which attaches to the tibial tuberosity)
3 vastus muscles along shaft of femur
vastus lateralis, vastus intermedius(deep to rf)
and vastus medialis
all 3 vastus muscles cradle the rectus femoris like a hotdog in
a bun.
Posterior thigh muscles: (flex the leg, extend the thigh)
Biceps femoris, semismembranosus, and semitendinosus
Origin along edge of pelvis , insert on tibia and fibula
Contractions produce flexion at knee
Bf, Sm, and st, collectively called hamstring muscles
Hyperextension at the hip, as in a sprint, can “pull a hamstring”
Locking of the knee
During full extension
Slight lateral rotation of tibia
Popliteus muscle – origin on lateral condyl of femur, inserts
on posterior tibial shaft( a crosses from anterior to posterior)
, – relaxes to lock knee, allowing tibia to rotate
Contraction, slight medial rotation of tibia, knee flexes