Skeletal Muscular System - Axial Flashcards
5 Superficial Back Muscles
Trapezius Latissimus Dorsi Rhomboid Minor Rhomboid Major Levator Scapulae
Trapezius Muscle
superficial back
Superficial back muscle
Innerviated by CNXI + cervical spinal nerves
3 Components: Ascending, Transverse, + Descending
Ascending Trapezius Muscle
superficial back
Origin: T4-T12
Insertion: upper crest +tubercle of scapular spine
depress scapula
Transverse Trapezius Muscle
superficial back
Origin: C7-T3
Insertion: acromion + spine of scapula
retracts scapula
Descending Trapezius Muscle
superficial back
Origin: occipital bone, C1-C7
Insertion: lateral 1/3 of clavicle
elevates shoulders
Latissimus Dorsi
superficial back
Origin: T7-T1, thoracolumbar fascia, posterior iliac crest, 9-12 ribs
Insertion: intertubercular sulcus of humerus bone
Innervated: thoracodorsal nerve
adduct + medially rotate arm; extend shoulders
Rhomboid Minor
superficial back
Origin: C7-T1
Insertion: medial border of scapula
Innervated: dorsal scapular nerve
retract + medially rotate scapulae
Rhomboid Major
superficial back
Origin: T2-T5
Insertion: medial border of scapula
Innervated: dosral scapular nerve
Levator Scapulae
superficial back
Origin: C1-C4
Insertion: medial border of scapula
Innervated: cervical spinal nerve
laterally flex + rotate head + neck, elevate shoulders
Intermediate Back Muscle
accessory muscles for respiratory + assist in holding tension in the back
branches of thoracic nerves
Serratus Posterior Superior
Serratus Posterior Inferior
Serratus Posterior Superior
Intermediate back muscle
Origin: C7-T3
Insert: 2-5 Ribs
spans laterally+inferiorly; elevates 2-5 ribs during repiration
Serratus Posterior Inferior
Intermediate back muscle
Origin: T11-L2
Insert: 9-12 Ribs
spans laterally + superiorly to depress 6-12 ribs during expiration
Deep Layer of Back Muscles
2 groups: Erector Spinae Group + Multifidus Muscle
Erector Spinae Group
keeps vertebral column erect and hyperetend the spine
I Love Spaghetti (I.L.S.)
Iliocostalis, Longissimus, Spinalis
Iliocostalis
deep back muscle
Origin: sacrum, crest of ilium, spinous process of lumbar + thoracic vertebrae, angles of lower 6 ribs
Insert: angles of upper ribs, transverse processes of cervical vertebrae
Longissimus
deep back muscle
Origin: transverse process of lower vertebrae
Insert: transverse process of thoracic + cervical vertebrae + mastoid process of skull
Spinalis
deep back muscle
Origin: spinous process of lower thoracic vertebrae
Insert: superior cervical vertebrae + base of skull
Multifidus
deep back muscle
makes up transversospinalis muscles
long muscle that spans the length of entire back
Origin: sacrum, transverse process of C2-L5
Insert: spinous process of most spinal vertebrae (C4-L5)
Abdominal Wall
4 muscles: Rectus Abdominis.
External Oblique,
Internal Oblique,
Transversus Abdominis
Rectus Abdominis
long, straight, vertical (6 pack)
surrounded by rectus sheath formed by aponeuroses of flat abdominal muscle
has TENDINOUS INTERSECTIONS that divide muscles into individual sections that increase range of motions
EXTERNAL OBLIQUE
Origin: 5-12 ribs
Insert: Linea Alba, pubic crest, anterior superior iliac spine, iliac crest
INTERNAL OBLIQUE
Origin: deep layer of thoracolumbar fascia, anterior 2/3 of iliac crest, lateral 2/3 of inguinal ligament, iliopsas
Insert: 10-12 ribs, pubic crest, anterior + posterior layers of the linea alba
TRANSVERSUS ABDOMINIS
Origin: 7-12 cartilage, deep thoracolumbar fascia, anterior 2/3 iliac crest, lateral 1/3 inguinal ligament
Insert: linea alba, pubic crest, pecten pubis
Posterior Abdominal Wall
Iliacus (hip flexer) Psoas Minor Psoas Major (hip flexer) Quadratus Lumborum Diaphragm Transversus Abdominis Internal Oblique External Oblique`
Iliacus
posterior abdominal wall
Origin: internal pelvis, iliac fossa on ala of ilium
Insert: femur
Psoas Major
posterior abdominal wall
Origin: T12-L5 transverse process
Insert: femur
Psoas Minor
posterior abdominal wall
anterior of psoas major. sometimes absent in some individuals
Quadratus Lumborum
Origin: Iliac crest inferior
Insert: 12th rib superiorly
important for back support and posture
Functions of Pelvic Floor
bowl shaped structure that connects lower limbs inferiorly to the trunk superiorly
- provides attachment sires for muscles of abdomen, back, lower limb
- protecting organs of urogenital system
- allowing passage of a newborn
Pelvic Floor Muscles
pelvic diaphragm, Perineal Membrane, Perineal Body, Deep Perineal Pouch
Pelvic Diaphragm
composed of COCCYGEUS muscle posteriorly, LEVATOR ANI muscles anteriorly and laterally
arranged like a bowl that separates pelvis from perineum
Right + Left Coccygeus
posteosuperior part of pelvic diaphragm
Levator Ani
large part of pelvic diaphragm
3 parts: Iliococcygeus, Pubococcygeus, Puborectalis muscles
originate + inset into hip bones to seal up pelvic outlet
Puborectalis
part of Levator ani that creates a U shape opening for urethra
Obturator Internus
anterior to pelvic diaphragm on both sides.
has tough membrane layer that closes obturator foramen on each hip.
Perineal Membrane + Deep Perineal Pouch
forms boundary bw pelvic cavity and perineum
perineal membrane is flat triangular fibrous tissue that extends bw ischiopubic rami
in males, has aperture that transmists urethra
in females, has aperture for urethra and another aperture for vagina
Perineal Body
attached to posterior aspect of perineal membrane
serves as attachment site for superficial/deep perineal muscles, external anal sphincter, and bulbospongiosus muscle
SCALP
Skin Connective Tissue Aponeuroses Loose Connective Tissue Pericranium
Circular Facial Muscles
Orbicularis Oculi
Orbicularis Oris
Orbicularis Oculi
Origins: medial aspect of orbital margin, palpebral part, and lacrimal bone
Inserts: skin surrounding orbit, lateral palpebral raphe, upper + lower eyelids
responsible for controlling gap bw eyelids (voluntary action of blinking)
ORBICULARIS ORIS
surrounds oral cavity
Origin: anteromedial surface of maxilla + anteromedial surface of mandible
Insert: skin and fascias of the lips
5 Straight Facial Muscles
Buccinator Muscle Platysma Zygomaticus Muscle Depressor Anguli Oris Frontal Belly of Occipitofrontalis
Buccinator Muscle
small, flat muscle of facial expression and mastification
alveolar process of mandible to pterygomandibular raphe + alveolar process of maxilla
Platysma
Origin: pectoral fascia overlying pectoralis major + deltoid muscles
Insert: inferior morder of mand`ible + parotid fascia
large, broad, think sheet like muscle in anterior aspect of neck. deprsses angle of mouth + tenses neck
more prominent in men
Zygomaticus Muscle
Major - more lateral
Origin: lateral surface of zygomatic bone. Insert: skin of angle of mouth
Minor - Origin: anterior surface of zygomatic bone. Insert: lateral upper lip + angle of mouth
Depressor Anguli Oris
Origin: anterolateral part of inferior border of mandible + platysma
Insert: angle of mouth + merges w fibers of orbicularis oris
Frontal Belly of Occipitofrontalis
part of layer of scalp
Origin: epicranial aponeurosis
Insert: skin of eyebrows + forehead
4 Muscles of Mastification
innervated by mandibular branch of trigeminal nerve
Responsible for elevation:
Temporalis, Masseter, + Medial Pterygoid
Responsible for depression:
Lateral Pterygoid
Temporalis
large fan shape.
Arises from temporal fossa and inserts into anterior ramus of mandible
Masseter
deep masseter is smaller from posterior third of zygomatic arch
superficial masseter is larger/broader arising from anterior 2/3 of zygomatic arch. inserts low down to mandibular ramus, on lateral side of angle
Medial Pterygoid
Origin: medial surface of lateral prerygoid plate, pyramidal process of palatine bone, tuberosity of maxilla
Inserts: medial surface of angle + ramus of mandible
Lateral Pterygoid
Origin: superior head-infratempora surface of greater wing of sphenoid + inferior head-lateral surface of pterygoid plate
Inserts: condylar process of mandble
