Anatomy Lab Practical 2

#1

endomysium (white)

#2

myofibril (bundle of filaments)

#3

transverse tubules (blue)

#4

terminal cisterna (tan area on sides of t-tubules)

#5

sarcoplasmic reticulum (tan, net-like)

#6

sarcolemma (pink)

#7

motor end plate (folded area of sarcolemma)

#8

synaptic vesicles (contain neurotransmitter)

#9

synaptic cleft (gap between nerve and muscle)

#10

nucleus

#11

axon of motor neuron

skeletal muscle

cardiac muscle

smooth muscle

origin

the attachment of a muscle to the stationary bone

insertion

the attachment of a muscle to the movable bone

action

the movements that occur when the muscle contracts

#1

occipitofrontalis

#2

orbicularis oculi

• origin: medial wall of orbit

• insertion: circular path around orbit

• action: closes eye

#3

zygomaticus minor

• origin: zygomatic bone

• insertion: skin of upper lip

• action: raises upper lip, exposing upper teeth

#4

zygomaticus major

• origin: zygomatic bone

• insertion: skin at corner of mouth and orbicularis oris

• action: draws angle of mouth superiorly and laterally (smiling)

#5

masseter

• origin: maxilla and zygomatic arch

• insertion: angle and ramus of mandible

• action: elevates mandible, as in closing mouth

#6

orbicularis oris

• origin: muscle fibers surrounding opening of mouth

• insertion: skin at corner of the mouth

• action: closes and protrudes lips (kissing), compresses lips against teeth, and shapes lips during speech

#7

sternocleidomastoid

• origin: sternum and clavicle

• insertion: mastoid process of temporal bone

• action: bilateral (flex the cervical portion of the vertebral column), unilateral (rotates the head to the opposite side and laterally flexes the neck to the same side

#8

trapezius

• origin: occipital bone, nuchal ligament, spinous processes of C7 - T12

• insertion: clavicle, acromion and spine of scapula

• action: superior (elevates scapula), middle (abduct scapula), inferior (depress scapula), reverse muscle action (extends head at next when scapula is stabilized)

#9

latissimus dorsi

• origin: spinous processes of T7 - L5 vertebrae, sacrum, iliac crest

• insertion: intertubercular sulcus of humerus

• action: extends, adducts, and medially rotates arm at shoulder, reverse muscle action (elevates vertebral column when humerus is strabilized)

#11

pectoralis major

• origin: clavicle, sternum, and costal cartilages of ribs 2-6

• insertion: greater tubercle of humerus

• action: flexes, adducts, and medially rotates arm at shoulder

#18

rectus abdominus

• origin: pubis and pubic symphysis

• insertion: cartilage of ribs 5-7 and xiphoid process

• action: flexes vertebral column; compresses abdomen

#19

external oblique

• origin: ribs 5-12

• insertion: iliac crest of ilium, pubis, and linea alba

• action: bilateral (flexes vertebral column; compresses abdomen), unilateral (laterally flexes and rotates vertebral column)

#10

deltoid

• origin: clavicle, acromion and spine of scapula

• insertion: deltoid tuberosity of humerus

• action: anterior fibers (flex and medially rotate arm at shoulder), middle fibers (abduct arm at shoulder), posterior fibers (extend and laterally rotate arm at shoulder)

#12

biceps brachii

• origin: long head (supraglenoid tubercle of scapula), short head (coracoid process)

• insertion: radial tuberosity of radius and bicipital aponeurosis

• action: flexes forearm at elbow, supinates forearm at radioulnar joints and flexes arm at shoulder

#17

subscapularis

• origin: subscapular fossa of scapula

• insertion: lesser tubercle of humerus

• action: medially rotates arm at shoulder

#13

triceps brachii

• origin: long head (scapula), lateral head (lateral and posterior surface of humerus), medial head (posterior surface of humerus)

• insertion: olecranon of ulna

• action: extends forearm at elbow and extends arm at shoulder

#14

supraspinatus

• origin: supraspinatus fossa of scapula

• insertion: greater tubercle of umerus

• action: assists deltoid in abducting arm at shoulder

#15

infraspinatus

• origin: infraspinatus fossa of scapula

• insertion: greater tubercle of humerus

• action: laterally rotates arm at shoulder

#16

teres minor

• origin: lateral border of scapula

• insertion: greater tubercle of humerus

• action: laterally rotates arm at shoulder

#22

sartorius

#23

gracilis

#24

rectus femoris

#25

vastus lateralis

#26

vastus medialis

#28

biceps femoris

#29

semitendinosus

#30

semimembranosus

#31

tibialis anterior

#32

gastrocnemius

#33

soleus