Lab 6: Muscular System of the Frog

The system of muscles in the body that allow movement and locomotion.

Muscular System

Muscles attached to bones through tendons, responsible for voluntary movements.

Skeletal Muscles

Connective tissue that connects muscles to bones.

Tendon

Broad, flat sheet-like tendon.

Aponeurosis

The fixed point of muscle attachment to bone.

Anatomical Origin

The movable point of muscle attachment to bone.

Insertion

The central, fleshy part of a muscle between its origins and insertions.

Belly Muscle

The points of origin of a muscle that have separate attachment sites.

Heads (muscle)

The multiple insertions of a muscle.

Slips (muscle)

The specific position of a muscle in the body.

Anatomical Location

Muscle that moves a body part towards the main axis of the body.

Adductor

Muscle that moves a body part away from the main axis of the body.

Abductor

Muscle that moves jointed parts away from each other.

Extensor

Muscle that moves jointed parts towards each other.

Flexor

Muscle that raises a body part.

Levator

Muscle that lowers a body part.

Depressor

The process of cutting apart or separating tissues for scientific study.

Dissection

Muscles located on the underside of the body.

Ventral Muscles

A small transverse muscle located at the anterior tip of the jaw that raises the lower jaw.

Submentalis

A muscle that raises the floor of the mouth during breathing and swallowing.

Mylohyoid

Connective tissue that attaches muscles to bones.

Tendon

Broad, flat, sheet-like tendon.

Aponeurosis

Fixed point of attachment of a muscle.

Anatomical origin

Movable point of attachment of a muscle.

Insertion

Part between the origin and insertion of a muscle.

Belly of the muscle

Multiple origins of a muscle.

Heads

Several insertions of a muscle.

Slips

Moves a part towards the main axis of the body.

Adductor

Moves a part away from the main axis of the body.

Abductor

Moves jointed parts away from each other.

Extensor

Moves jointed parts towards each other.

Flexor

Raises a part.

Levator

Lowers a part.

Depressor

Sartorius

A flat strap-like muscle running obliquely along the ventral side of the thigh; Origin:Pubis; Insertion:Tibiofibula; Action:Flexes the shank; adducts the thigh

Adductor longus

Muscle seen by cutting the belly of the sartorius; Origin:Ilium; Insertion:Femur; Action:Adducts the thigh

Adductor magnus

Thick muscle near the groin area, triangle shape when sartorius is in place; Origin:Pubic symphysis; ischial symphysis; Insertion:Distal end of the femur; Action:Adducts the thigh; flexes or extends the shank

Gracilis major

Large muscle with oblique fibers posterior to adductor magnus; Origin:Ischium; Insertion:Tibiofibula; Action:Adducts the thigh; flexes the shank

Gracilis minor

Long strip, narrow muscle at the posterior margin of gracilis major; Origin:Ischium; Insertion:Tibiofibula; Action:Adducts the thigh; flexes the shank

Semitendinosus

Deep muscle between gracilis major and adductor magnus; Origin:Ischium; Insertion:Tibiofibula; Action:Adducts the thigh; flexes the leg

Gastrocnemius

Large muscle at the back of the shank; Origin:Distal end of the femur; anterior portion of the knee; Insertion:Ankle of the foot; Action:Extensor of the foot

Tibialis posticus

Long, narrow but thick muscle anterior to gastrocnemius; Origin:Posterior surface of the tibiofibula; Insertion:Proximal end of the astragalus; Action:Extensor or flexor of the foot depending on foot position

Extensor cruris

Short, slender muscle at the anterior proximal half of the tibiofibula; Origin:Distal end of the femur; Insertion:Anterior surface of the proximal half of the tibiofibula; Action:Extensor of the foot

Flexor tarsi anterior

Narrow muscle distal to extensor cruris; Origin:Anterior surface of the middle and distal half of tibiofibula; Insertion:Proximal end of astragalus; fascia of the foot; Action:Flexor of the foot

Tibialis anticus

Most anterior muscle of the shank; Origin:Femur; Insertion:Distal end of the astragalus and calcaneus; Action:Flexor of the foot