Lab #15 Muscles

Muscles of the Head and Neck

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

Muscles of Facial Expression Figure 11–4a

Muscles of Facial Expression Figure 11–4b

Summary: Muscles of Facial Expression Table 11–2 (1 of 2)

Summary: Muscles of Facial Expression Table 11–2 (2 of 2)

3 Muscles of Mastication Masseter: the strongest jaw muscle Temporalis: helps lift the mandible Pterygoid muscles (FYI): position mandible for chewing

Muscles of Mastication Figure 11–6

Summary: Muscles of Mastication Table 11–4

Muscles of the Tongue Don’t need to know any of these Figure 11–7

Muscles of the Neck Digastric: Platysma: Sternocleidomastoid: from chin to hyoid also hyoid to mastoid Platysma: covers anterior surface of neck Sternocleidomastoid: from clavicle and sternum to mastoid

Anterior Muscles of the Neck Figure 11–9

Summary: Anterior Muscles of the Neck Table 11–7

Muscles of the chest and abdomen

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

Cervical Oblique Muscles FYI: Cervical region: scalene muscles flex the neck

Oblique and Rectus Muscles of the Thoracic region Figure 11–11a, b

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

Oblique and Rectus Muscles of the Abdominopelvic region Figure 11–11a, c

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

Summary: Oblique and Rectus Muscles Table 11–9 (1 of 2)

Muscles that Position the Pectoral Girdle Figure 11–14b

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”

Summary: Muscles that Position the Pectoral Girdle Tables 11–11

Muscles that Move the Arm Figure 11–15b

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 (2 of 3) Infraspinatus: produce lateral 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

Shoulder flexion vs extension Lats and portion of delts Pecs and portion of delts

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 of the shoulders, arm, and hand

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 Figure 11–15a

Muscles that Move the Arm Figure 11–15b

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 (2 of 3) Infraspinatus: produce lateral 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

Summary: Muscles that Move the Arm Table 11–12

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: Flexors: 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 -Extensors Figure 11–16a

Muscles that Move the Forearm and Hand - Flexors Figure 11–16b

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

Figure 11–16a

Figure 11–16b

Summary: Muscles that Move the Forearm and Hand Table 11–13 (1 of 2)

Muscles of the Pelvis, Leg and Foot

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 Muscles that move the thigh Muscles that move the leg 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 that Move the Thigh Gluteal muscles Lateral rotators Adductors Iliopsoas group

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

Muscles that Move the Thigh Figure 11–19a, b

Muscles that Move the Thigh Figure 11–19c, d

Adductors Adductor longus: Gracilis (UPPER LEG): hip flexion and adduction Gracilis (UPPER LEG):

Iliopsoas group 2 hip flexors insert on the same tendon: psoas major originates on lumbar vetebrae, inserts on femur iliacus originates on illium/fossa

Summary: Muscles that Move the Thigh Table 11–16 (1 of 2)

Summary: Muscles that Move the Thigh Table 11–16 (2 of 2)

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: All are knee flexors biceps femoris (long and short heads) semimembranosus semitendinosus All are knee flexors

Muscles that Move the Leg Figure 11–20a

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 Leg Figure 11–20b, c

Summary: Muscles that Move the Leg Table 11–17 (1 of 2)

Summary: Muscles that Move the Leg Table 11–17 (2 of 2)

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

Muscles that Move the Foot and Toes Figure 11–21a, b

Muscles that Move the Foot and Toes Figure 11–21c, d

The Achilles Tendon The calcaneal tendon (Achilles tendon): shared by the gastrocnemius and soleus

Muscles that Produce Flexion at the Ankle Tibialis anterior: opposes the gastrocnemius

Muscles that Move the Foot and Toes Figure 11–21a, b

Muscles that Move the Foot and Toes Figure 11–21c, d

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)

The Intrinsic Muscles of the Foot Figure 11–22a

Muscles that Produce Flexion at the Toes Flexor digitorum longus Flexor hallucis longus: oppose the extensors Toe flexors are on bottom of foot

The Intrinsic Muscles of the Foot Figure 11–22b, c

Summary: Muscles that Move the Foot and Toes Table 11–18

Lab 15 This is a huge lab (it covers ~3-4 labs worth of material) Due on day of practical (11/22)