Exercise 9 Muscular System - identify muscle

Adductor group

Lies under anterior border of gracilis

Origin: pubis

Insertion: femur

Antagonist: gluteus maximus/ medius

Action: adduct the thigh

biceps brachii

Origin: scapula

Insertion: radius

Antagonist: triceps brachii

Action: flexion of the elbow

biceps femoris

very large superficial muscle on lateral surface of the thigh

Origin: ischium

Insertion: tibia & fibula

Antagonist: quadriceps group

Action: flex the knee

• part of the hamstring group

deltoid

Origin: scapula & clavicle

Insertion: humerus

Antagonist: latissimus dorsi

Action: abduct the arm

*may not see in cat

digastric

Origin: mastoid process

Insertion: mandible

Antagonist: masseter & temporalis

Action: lower the mandible

external oblique

Outer layer of abdominal wall; fibers run obliquely downward & backward

Origin: ribs & lumbodorsal fascia

Insertion: aponeurosis to linea alba (connective tissue line)

Antagonist: itself

Action: constrict abdomen (flexing)

gastrocnemius

Large calf muscle

Origin: femur

Insertion: calcaneous by way of Achilles tendon

Antagonist: tibialis anterior

Action: plantar flexion or rising of toes

gracilis

Origin: symphysis pubis

Insertion: tibia

Antagonist: gluteus maximus

Action: adductor of the thigh

gluteus maximus

Origin: pelvic girdle

Insertion: femur & fascia of thigh

Antagonist: adductor group/ gracilus

Action: abducts the thigh & extends the hip

gluteus medius

Origin: ileum

Insertion: greater trochanter of femur

Antagonist: gracilus

Action: abduction & medial rotation of thigh

infraspinatus

Origin: scapula

Insertion: humerus

Antagonist: supraspinatus

Action: lateral rotation of the humerus

latissimus dorsi

Broad muscle extends from middle of the back to humerus

• Origin: Vertebrae & lumbodorsal fascia

• Insertion: Humerus

• Antagonist: Pectoralis group

• Action: pull forelimb dorsally & posteriorly

masseter

Thick muscle of the jaw, inferior to the ear

Origin: zygomatic arch

Insertion: mandible

Antagonist: digastric

Action: raises mandibles as in chewing

orbicularis oculi

Origin: orbit

Insertion: eyelids (mucus membrane)

Antagonist: itself

Action: closes eyelids

orbicularis oris

Origin: maxilla & mandible

Insertion: mucus membrane

Antagonist: itself

Action: purses lips

rectus abdominis

Origin: pubis

Insertion: sternum & costal cartilages

Antagonist: itself

Action: flexes the body & compresses the abdomen

pectoralis (pectoralis group)

Origin: sternum

Insertion: humerus

Antagonist: latissmus dorsi

Action: adduct (toward midline) the forelimb anteriorly

rectus femoris

Origin: ileum and femur

Insertion: tibia

Antagonist: hamstring group

Action: extend the knee

sartorius

Origin: iliac crest

Insertion: tibia & patella

Antagonist: gluteus maximus

Action: pull one leg across the other

semimembranosus

bulky muscle under gracilis & posterior to adductors

Origin: ischium

Insertion: tibia & fibula

Antagonist: quadriceps group

Action: flex the knee & extend hip

semitendinosus

long muscle posterior to semimembranosus

Origin: ischium

Insertion: tibia & fibula

Antagonist: quadriceps group

Action: flex the knee & extend hip

serratus ventralis

Origin: ribs

Insertion: scapula

Antagonist: rhomboideus

Action: pulls scapula ventrally

soleus

Origin: fibula

Insertion: calcaneous by way of Achilles tendon

Antagonist: tibialis anterior

Action: plantar flexion, rising of toes

sternocleidomastoid

Origin: manubrium & clavicle

Insertion: mastoid process

Antagonist: splenius

Action: turn the head (one part) or flex the neck (when both parts contracted)

*two separate muscles in the cat & one w/t two parts in man

supraspiratus

Origin: scapula

Insertion: Humerus

Antagonist: infraspinatus

Action: abduct or to extend the humerus

teres major

Origin: scapula

Insertion: humerus

Antagonist: deltoid/ supraspinatus

Action: extend, adduct, or medially rotate humerus

temporalis

Bulk of the muscle lies above the ear; synergist to mandible

Origin: temporal bone

Insertion: mandible

Antagonist: digastric

Action: raises mandible as in chewing

tibialis anterior

Origin: tibia

Insertion: first metatarsal

Antagonist: gastrocnemius

Action: dorsiflexion of foot

trapezius

Origin: occipital bone & upper vertebrae

Insertions: scapula & clavicle

Antagonist: latissimus dorsi

Action: extension of the neck & raising or lowering of the shoulders

triceps brachii

Origin: scapula & humerus

Insertion: olecranon process

Antagonist: biceps brachii

Action: extend the elbow

rhomboideus

Thick mass of muscle between vertebrae (cat, occipital) & scapula

• Origin: vertebrae

• Insertion: scapula

• Antagonist: serratus ventralis

• Action: adduct & move scapula dorsally

splenius

Origin: several vertebrae

Insertion: temporal bone

Antagonist: sternocleidomastoid

Action: rotate the head or to extend the neck

intercostals

There are external & internal sets of these muscles

Origin: ribs

Insertion: ribs

Antagonist: ——

Action: moving the anterior chest wall for inhalation & exhalation

internal oblique

Origin: pelvic girdle & lumbodorsal fascia

Insertion: aponeurosis to linea alba

Antagonist: ——

Action: constrict abdomen

transversus abdominis

Fibers run downward & slightly backward

Origin: pelvic girdle & lumbodorsal fascia

Insertion: aponeurosis to linea alba

Antagonist:——

Action: constrict abdomen

quadriceps group

consists of 4 muscles: vastus lateralis, rectus femoris, vastus medialis, vastus intermedius

Origin: ilium & femur

Insertion: tibia

Antagonist: hamstring group

Action: extend the knee

vastus lateralis

the largest & most lateral of the quadriceps

Origin: ilium & femur

Insertion: tibia

Antagonist: hamstring group

Action: extend the knee

rectus femoris

muscle is medial to & is somewhat covered by the vastus lateralis

Origin: ilium & femur

Insertion: tibia

Antagonist: hamstring group

Action: extend the knee

vastus medialis

this is the muscle immediately medial to the rectus femoris

Origin: ilium & femur

Insertion: tibia

Antagonist: hamstring group

Action: extend the knee

vastus intermedius

Origin: ilium & femur

Insertion: tibia

Antagonist: hamstring group

Action: extend the knee

hamstring group

group of 3 muscles, mass of muscle tissue posterior to femur: biceps femoris, semimembranosus, semitendinosus

Origin: ischium

Insertion: tibia & fibula

Antagonist: quadriceps group

Action: extend the hip & to flex the knee