Frog Skeletal System

Skull, Lower Jaw

Part Position FunctionCranium Encloses brain

Suture (see above) Protect brain from traumaOlfactory capsule Houses scent organs

Otic capsule Lodges inner ear

Orbit Houses eyeball

Premaxillary processes Adjoins maxillary arch

Foramen magnum(in occipital region)

Hole through which spinal cord passes

Occipital condyles Articulate with first vertebra

Maxillary arch Borders orbit, bears teeth

Vertebrae

Part Position FunctionAtlas Articulates with occipital

condyles; one cervical vertebra

Centrum Body of vertebra

Neural arch Inner lining of neural spine

Neural canal Passageway through which spinal cord passes to and from brain and body

Neural spine Dorsal side of spine

Transverse processes Extend laterally to support body

Zygapophyses Articulate successive vertebrae

Sacral Ninth vertebra

Urostyle Tenth vertebra

Pectoral Girdle, Sternum, Forelimb

Part Position FunctionSuprascapula Flat trapezoid, cartilaginous

Scapula Articulates with suprascapula

Glenoid fossa Where upper arm bone fits;Smooth concavity on proximal end of scapula

Fenestra Gap between clavicle, coracoid, and spatula

Clavicle Anterior to fenestra; thin;Articulates with scapula

Coracoid Posterior to fenestra;Articulates with scapula;Directly attached to epicoracoid cartilage

Epicoracoid cartilage Joins left and right coracoids

Sternum (see above) Lies on mid-ventral axis

Episternum Flat, rounded

Omosternum Inverted y-shaped bone;Two arms rest on clavicle

Mesosternum Anterior end wedged between coracoids; articulates with xiphisternum at posterior end

Xiphisternum Posterior to mesosternum

Humerus Most proximal to body;Attaches to glenoid fossa

Radio-ulna Comprises forearm region

Pelvic Girdle, Hindlimb

Part Position FunctionOs innominatum Half of pelvic girdle

Acetabulum Cup-shaped depression;Where femur fits

Ilium Articulates with sacral;U-shaped; forms anterior border of acetabulum

Ischium Fan-shaped; forms posterior border of acetabulum

Pubis Triangle bone beneath ischium;Apex contributes to acetabulum

Femur Most proximal bone in hindlimb;Attaches to acetabulum

Tibio-fibula/ shank More distal to main body

Frog Muscular System

Head

Part Position FunctionTemporalis Raises lower jaw

(yellow)

Depressor mandibulae (see green pin above) Lowers lower jawMylohyoid Raises floor of mouth

Trunk

Part Position FunctionLongissimus dorsi Elevates head; straightens back

Coccygeosacralis Keeps coccyx region in line with ilium

Coccygeoiliacus Keeps coccyx region in line with ilium

External oblique Compresses abdomen

Rectus abdominis Compresses abdomen

Linea alba Connective tissue acting as septum; divides rectus abdominis into two symmetrical parts

Inscriptiones tendinae Connective tissue acting as septum; run perpendicular

Forelimb

Part Position FunctionSterno-radialis Draws arm towards chest

Pectoralis Draws arm towards chest

Latissimus dorsi Draws arm away from body

Deltoid Draws arm towards chest

Triceps brachi Straightens forearm

Hindlimb

Part Position FunctionTriceps extensor femoris Straightens shank; bends thigh

Semimebranosus Draws thigh medially; bends shank

Biceps femoris Draws thigh medially; bends shank

Sartorius Bends the leg

Gracilis major Draws thigh medially

Adductor magnus Adducts leg and thigh;Draws thigh ventrally

Gastrocnemius Bends shank; extends foot

Peroneus Straightens shank; bends foot

Tibialis anticus Bends foot

Tibialis posticus Extends foot