lab #15 muscles. muscles of the head and neck the axial muscles divisions based on location and...
TRANSCRIPT
The Axial Muscles
• Divisions based on location and function:– muscles of head and neck– muscles of vertebral column– oblique and rectus muscles– muscles of pelvic floor
6 Muscle Groups of the Head and Neck
• 1. Muscles of facial expression:– originate on skull
• 2. Extrinsic (outside) eye muscles:
(don’t need to know)
6 Muscle Groups of the Head and Neck
• 3. Muscles of mastication:– move the mandible
• 4. Muscles of the tongue:– names end in glossus (FYI)
• 5. Muscles of the pharynx:– begin swallowing process (FYI)
• 6. Anterior muscles of the neck:– control position of larynx– depress the mandible– support tongue and pharynx
Muscles of Facial Expression
• Orbicularis oris:– constricts the mouth opening
• Buccinator:– moves food around the cheeks
• Corrugator supercilli – wrinkles forehead
• Orbicularis oculi – sphincter of eye
Others
• Zygomaticus – pull skin of mouth up and out when smiling
• Levator labii superiorus – raises upper lip
• Depressor labii inferiorus – “pouting” muscle
Muscles of the Epicranium (Scalp)
• Temporoparietalis
• Occipitofrontalis:– frontal and occipital bellies– separated by epicranial aponeurosis
• Platysma:– covers anterior surface of neck
3 Muscles of Mastication
• Masseter:– the strongest jaw muscle
• Temporalis:– helps lift the mandible
• Pterygoid muscles (FYI):– position mandible for chewing
Muscles of the Neck
• Digastric:– from chin to hyoid– also hyoid to mastoid
• Platysma:– covers anterior surface of neck
• Sternocleidomastoid:– from clavicle and sternum to mastoid
Lab 19: Muscles of the chest and abdomen
• Remember: if it’s not on the list, you don’t have to locate it or write about it in the lab report
Muscles to know
• pectoralis major• serratus anterior• intercostals (external, internal)• diaphragm• rectus abdominus• obliques (external, internal)• transverse abdominus• trapezius• latissimus dorsi• splenius capitus
Oblique and rectus muscles
• Lie within the body wall
• Generally:– obliques groups are lateral– rectus muscles lie on the anterior midline
Oblique and Rectus Muscles
• Oblique muscles:– compress underlying structures– rotate vertebral column
• Rectus muscles:– flex vertebral column– oppose erector spinae
Thoracic Oblique Muscles
• Thoracic region:– intercostal muscles (external and internal
intercostals):• respiratory movements of ribs
– FYI: transversus thoracis:• cross inner surface of ribs
Thoracic Rectus Group
• Diaphragmatic muscle or diaphragm:– divides thoracic and abdominal cavities– performs respiration
Abdominopelvic Oblique Muscles
• Abdominopelvic region (same pattern as thoracic):– external oblique muscles – internal oblique muscles
• Transversus abdominis – deep to internals
Rectus Group -Abdominopelvic
• Rectus abdominis:– between xiphoid process and pubic
symphysis– divided longitudinally by linea alba– divided transversely by tendinous inscriptions
Muscles that Position the Pectoral Girdle (1 of 3)
• Trapezius:– HUGE– superficial– covers back and neck to base of skull– inserts on clavicles and scapular spines
Muscles that Position the Pectoral Girdle (2 of 3)
• Rhomboid and levator scapulae:– deep to trapezius– attach to cervical and thoracic vertebrae– insert on scapular border
Muscles that Position the Pectoral Girdle (3 of 3)
• Serratus anterior:– on the chest– originates along ribs– inserts on anterior scapular margin– “serrated”
Muscles that Move the Arm (1 of 3)
• Deltoid: – the major abductor of arm
• Supraspinatus: – assists deltoid
• Subscapularis and teres major: – produce medial rotation at shoulder
Muscles that Move the Arm (3 of 3)
• Pectoralis major: – between anterior chest and greater tubercle of
humerus– produces flexion at shoulder joint
• Latissimus dorsi:– between thoracic vertebrae and humerus– produces extension at shoulder joint
The Rotator Cuff
• Muscles involved in shoulder rotation– supraspinatus, subscapularis, infraspinatus,
teres minor,and their tendons
Muscles that Position the Pectoral Girdle
• Rhomboid and levator scapulae:– deep to trapezius– attach to cervical and thoracic vertebrae– insert on scapular border
• Also saw trapezius and serratus anterior
Muscles to know
• supraspinatus• infraspinatus• subscapularis• teres major• rhomboid• levator scapulae• deltoid• biceps brachii• brachialis
• triceps brachii• flexor carpi radialis• flexor carpi ulnaris• flexor digitorum sup.• extensor carpi ulnaris• extensor digitorum• extensor carpi radialis• brachioradialis
Muscles that Move the Arm (1 of 3)
• Deltoid: – the major abductor
• Supraspinatus: – assists deltoid
• Subscapularis and teres major: – produce medial rotation at shoulder
Muscles that Move the Arm (3 of 3)
• Pectoralis major: – between anterior chest and greater tubercle of
humerus– produces flexion at shoulder joint
• Latissimus dorsi:– between thoracic vertebrae and humerus– produces extension at shoulder joint
The Rotator Cuff
• Muscles involved in shoulder rotation– supraspinatus, subscapularis, infraspinatus,
teres minor,and their tendons
Muscles that Position the Pectoral Girdle
• Rhomboid and levator scapulae:– deep to trapezius– attach to cervical and thoracic vertebrae– insert on scapular border
Muscles that Move the Forearm and Hand
• Originate on humerus and insert on forearm
• Exceptions:– the major flexor (biceps brachii)– the major extensor (triceps brachii)
Extensors and Flexors
• Extensors:– mainly on posterior and lateral surfaces of
arm
• Flexors:– mainly on anterior and medial surfaces
Muscles that Move the Forearm and Hand
• Biceps brachii:– flexes elbow– stabilizes shoulder joint– originates on scapula and humerus– inserts on radial tuberosity
Muscles that Move the Forearm and Hand
• Triceps brachii:– extends elbow– originates on scapula (three spots)– inserts on olecranon
• Brachialis and brachioradialis:– assist in flexing elbow (synergists)
Muscles that Move the Forearm and Hand
• Flexor carpi ulnaris: – superficial– flexes wrist– adducts wrist
Muscles that Move the Forearm and Hand
• Flexor carpi radialis: – superficial– flexes wrist– abducts wrist
Muscles that Move the Forearm and Hand
• Extensor carpi radialis:– superficial– extends wrist– abducts wrist
Muscles that Move the Forearm and Hand
• Extensor carpi ulnaris:– superficial– extends wrist– adducts wrist
Muscles to know
• psoas major• iliacus• gluteus maximus• gluteus medius• sartorius• quadriceps femoris (4)• gracilus• adductor longus• biceps femoris• semitendinosis• semimembranosus
• tibialis anterior• ext hallucis longus• ext digitorum longus• fibularis (peroneus)
longus• gastrocnemius• soleus• flexor hallucis longus• flexor digitorum longus
Muscles of the Pelvis and Lower Limbs
• Pelvic girdle is tightly bound to axial skeleton:– permits little movement– has few muscles
Muscles that Position the Lower Limbs
1. Muscles that move the thigh
2. Muscles that move the leg
3. Muscles that move the foot and toes
Generally…
• Muscles that are lateral are abductors
• Muscles that are medial are adductors
• flexors are on inner surface of joint
• extensors are on outer surface of joint
Note: in legs and feet, look at each joint individually (cf. arms)
Muscles of hip and thigh
• psoas major
• iliacus
• gluteus maximus
• gluteus medius
• adductor longus
Gluteal Muscles (1 of 2)
• Cover lateral surfaces of ilia
• Gluteus maximus:– largest, most posterior gluteal muscle– produces extension and lateral rotation at
hip– Originates on illiac crest, etc., inserts on
illiotibial tract and femur
Gluteal Muscles (2 of 2)
• Gluteus medius and [gluteus minimus]: – originate anterior to gluteus maximus– insert on trochanter of femur
Adductors
• Adductor longus:– hip flexion and adduction
• Gracilis (UPPER LEG):– hip flexion and adduction
Iliopsoas group
• 2 hip flexors insert on the same tendon: – psoas major
• originates on lumbar vetebrae, inserts on femur
– iliacus• originates on illium/fossa
Muscles that Move the Leg
• Flexors of the knee:– originate on the pelvic girdle– generally: hamstrings
• Extensors of the knee:– originate on the femoral surface– insert on the patella– generally: quads
Flexors of the Knee
• Biceps femoris
• Semimembranosus
• Semitendinosus
• Sartorius:– originates superior to the acetabulum– long, ribbon-like muscle– traverses the quads and wraps around to the
back of the knee
Hamstrings
• Made up of:– biceps femoris (long and short heads)– semimembranosus– semitendinosus
• All are knee flexors
Extensors of the Knee
• 4 muscles of the quadriceps femoris: – 3 vastus muscles:
• vastus lateralis • vastus medialis• vastus intermedius
– rectus femoris muscle
Muscles that Move the Foot and Toes
• Extrinsic muscles that move the foot and toes include:– muscles that produce extension at the ankle
(Plantar flexion)– muscles that produce flexion at the ankle– muscles that produce extension at the toes– muscles that produce flexion at the toes
Muscles that Produce Extension at the Ankle (Plantar flexion)
Calf muscles
Large posterior calf muscles, both insert on Achilles):
• Gastrocnemius
• Soleus
• Fibularis longus
The Achilles Tendon
• The calcaneal tendon (Achilles tendon):– shared by the gastrocnemius and soleus
Muscles that Produce Extension at the Toes
• Extensor digitorum longus
• Extensor hallucis longus
Toe extensors are on top of foot
Note: there are no muscles in toes themselves (only tendons)
Muscles that Produce Flexion at the Toes
• Flexor digitorum longus
• Flexor hallucis longus:– oppose the extensors
Toe flexors are on bottom of foot