Practical 3 Muscles

Is Skeletal muscles voluntary or involuntary

Voluntary they contact when consciously stimulated by specific nerves

Do muscles pull or push

muscles pull on other muscles

What is the muscular system function

movement, maintenance of posture, generation of heat (shriving), compression of the abdomen, storage of glycogen

origin of the muscles

the most stable part of the muscle

insertion of the muscle

the movable attachment of the muscle

action of the muscle

the effect the muscle has on a part of the body

innervation of a muscle

the specific nerve which controls the muscle

Sternocleidomastoid origin (attachment 1)

sternum and the clavicle

Sternocleidomastoid insertion (attachment 2)

mastoid process of the temporal bone

Sternocleidomastoid action

abducts, rotates and flexes the head

Occipitofrontalis Frontal Belly origin (attachment 1)

galea aponeurotica

Occipitofrontalis Frontal Belly insertion (attachment 2)

subcutaneous tissue of eyebrows

Occipitofrontalis Frontal Belly action

scalp is brought forward as in frowning

the eyebrows are raised

Occipitofrontalis Occipital Belly origin (attachment 1)

occipital and temporal bone

Occipitofrontalis Occipital Belly insertion (attachment 2)

galea aponeurotica

Occipitofrontalis Occipital Belly action

retracts scalp

Masseter origin (attachment 1)

zygomatic arch

Masseter insertion (attachment 2)

angle and radius of mandible

Masseter action

elevates (closes) mandible

Temporalis origin (attachment 1)

temporal fossa

Temporalis insertion (attachment 2)

coronoid process and ramus of mandible

Temporalis action

elevates (closes) mandible (chewing muscle)

Orbicularis oculi origin (attachment 1)

frontal and maxilla on medial margin of orbit

Orbicularis oculi insertion (attachment 2)

skin of eyelid

Orbicularis oculi action

closes eyelid

Orbicularis oris origin (attachment 1)

modiolus of mouth

Orbicularis oris insertion (attachment 2)

skin near lips

Orbicularis oris action

closes lips

Zygomaticus major and minor origin (attachment 1)

zygomatic bone

Zygomaticus major and minor insertion (attachment 2)

superolateral angle of the mouth and muscles of upper lip

Zygomaticus major and minor action

elevates corners of mouth in smiling or laughing

Mentalis origin (attachment 1)

anterior mandible

Mentalis insertion (attachment 2)

skin of chin below lower lip

Mentalis action

protrudes lower lip (pouting muscle)

Buccinator origin (attachment 1)

maxilla and mandible near molar teeth

Buccinator insertion (attachment 2)

orbicularis oris

Buccinator action

compresses cheek (tighten the cheek and pushes food towards the molars in chewing)

What is the function of muscles in the abdomen

aid in breathing and food regurgitation

External oblique origin (attachment 1)

ribs 5-12

External oblique insertion (attachment 2)

lliac crest, pubis

External oblique action

compresses abdominal wall, laterally rotates waist

Internal oblique origin (attachment 1)

inguinal ligament, iliac crest

Internal oblique insertion (attachment 2)

pubis, ribs 10-12

Internal oblique action

compresses abdominal wall, laterally rotates waist

Transverse abdominal origin (attachment 1)

inguinal ligament, iliac crest, costal cartilages 7-12

Transverse abdominal insertion (attachment 2)

Linea alba, pubis

Transverse abdominal action

compresses abdominal wall, laterally rotates waist

Rectus abdominis origin (attachment 1)

crest of pubis, pubic symphysis

Rectus abdominis insertion (attachment 2)

costal cartilages 5-7, xiphoid process

Rectus abdominis action

flexes spine, compresses abdominal wall

Serratus anterior origin (attachment 1)

Ribs 1-8

Serratus anterior insertion (attachment 2)

Vertebral boarder and inferior angle of scapula

Serratus anterior action

Abducts scapula (moves scapula away from spinal cord)

External intercostals origin (attachment 1)

inferior border of ribs 1-11

External intercostals insertion (attachment 2)

superior border of rib below

External intercostals action

elevates ribs which increases volume in thorax (inhalation)

Internal intercostals origin (attachment 1)

superior border of a rib

Internal intercostals insertion (attachment 2)

inferior border of next superior rib (2-12)

Internal intercostals action

elevates and depresses ribs (inhalation and exhalation)

Diaphragm origin (attachment 1)

xiphoid process, ribs 7-12, superior lumbar vertebrae

Diaphragm insertion (attachment 2)

central tendon

Diaphragm action

inspiration

Trapezius origin (attachment 1)

posterior occipital bone, nuchal ligament, C7-T4

Trapezius insertion (attachment 2)

clavicle, acromion, and spine of scapula

Trapezius action

extends the abducts head, rotates and adducts scapula, fixes scapula (looks like a diamond on the back between the shoulder blades)

Deltoid origin (attachment 1)

clavicle, acromion, spine of scapula

Deltoid insertion (attachment 2)

deltoid tuberosity of the humerus

Deltoid action

abducts arm, flexes and extends, medially and laterally rotates humerus

Pectoralis major origin (attachment 1)

clavicle, sternum, cartilages of ribs 1-7

Pectoralis major insertion (attachment 2)

crest of greater tubercles of humerus

Pectoralis major action

flexes, adducts, and medially rotates humerus

has fiber which run horizontally across the chest region and is s superficial muscle in the chest

Pectoralis minor origin (attachment 1)

ribs 3-5

Pectoralis minor insertion (attachment 2)

coracoid process of scapula

Pectoralis minor action

depresses glenoid cavity

has fibers which run vertically and is a deep chest muscle

Latissimus dorsi origin (attachment 1)

T7-12, L1-5, crest of ilium, rib 10-12

Latissimus dorsi insertion (attachment 2)

intertubercular sulcus of humerus

Latissimus dorsi action

extends, adducts and medially rotates humerus, draws shoulder inferiorly

Supraspinatus origin (attachment 1)

supraspinous fossa

Supraspinatus insertion (attachment 2)

greater tubercle of the humerus

Supraspinatus action

abducts arms, helps stabilize shoulder joint

Infraspinatus origin (attachment 1)

infraspinous fossa

Infraspinatus insertion (attachment 2)

greater tubercle of humerus

Infraspinatus action

laterally rotates arms, stabilizes shoulder joint

Subscapularis origin (attachment 1)

subscapular fossa

Subscapularis insertion (attachment 2)

lesser tubercle of humerus

Subscapularis action

medially rotates arm, stabilizes shoulder joint

Teres minor origin (attachment 1)

lateral boarder of scapula

Teres minor insertion (attachment 2)

greater tubercle of humerus

Teres minor action

laterally rotates and adducts humerus, stabilizes shoulder joint

Teres major origin (attachment 1)

inferior angle of scapula

Teres major insertion (attachment 2)

crest of lesser tubercle of humerus

Teres major action

extends and medially rotates humerus

Biceps brachii origin (attachment 1)

long head, superior margin of glenoid cavity, short head, coracoid process of scapula

Biceps brachii insertion (attachment 2)

radial tuberosity

Biceps brachii action

flexes arm, flexes forearm, supinates forearm

Triceps brachii origin (attachment 1)

infraglenoid tubercle of scapula, later and posterior surface of humerus

Triceps brachii insertion (attachment 2)

olecranon, tuberosity of ulna

Triceps brachii action

extends and adducts arm, extends forearm

Brachialis origin (attachment 1)

anterior, distal surface of the humerus

Brachialis insertion (attachment 2)

coronoid process of ulna