BIOL 121: Skeletal Anatomy

Axial Skeleton Bones (Post-Cranial)

Vertebral Column - cervical, thoracic, lumbar, sacral, caudal

Ribs - sternum, xyphoid process, *keel*

Appendicular Skeleton Bones

Pectoral Girdle - clavicle, scapula, *suprascapula*, glenoid fossa/cavity

Forelimbs - humerus, radius, ulna, *radioulna*, carpals, metacarpals, phalanges, *carpometacarpus*

Pelvic Girdle - pelvis, acetabulum, *urostyle*

Hindlimb’s - femur, patella, tibia, *tibiotarsus*, fibula, *tibiofibula*, tarsals, astragalus, calcaneus, metatarsals, *tarsometatarsal*, phalanges/digits

Vertebral Column:

Cervical =

Thoracic =

Lumbar =

Sacral =

Caudal =

1. neck

2. on which ribs articulate’

3. abdominal region

4. enclosed by pelvic girdle

5. tail

Ribs:

Sternum =

Xyphoid process =

1. breastbone

2. cartilaginous extension of lower sternum

Keel (part of ribs)

In birds only; extension of sternum + attachment site for flight muscles

Pectoral Girdle:

Clavicle =

Scapula =

Glenoid Fossa/Cavity =

1. collarbone

2. shoulder blade

3. rounded groove that forms articular surface of scapula w/ humerus at shoulder joint

Suprascapula (part of pectoral girdle)

In frogs only; together w scapula forms shoulder blade

Forelimbs:

Humerus =

Radius =

Ulna =

Carpals =

Metacarpals =

Phalanges =

1. long part of upper limb

2. long bone of lower limb that extends from lateral side of elbow toward thumb (top)

3. long bone of lower limb that extends from elbow towards pinky (bottom)

4. wrist

5. palm

6. fingers

Radioulna (part of forelimbs)

In frogs only (radius + ulna)

Carpometacarpus (part of forelimbs)

In birds only + attaches many of flight feathers

Pelvic Girdle:

Pelvis =

Acetabulum =

1. has 2 os coxa bones

2. bowl shaped articular surface of pelvis that accommodates head of femur

Urostyle (part of pelvic girdle)

In frogs only; fusion of caudal vertebrae + forms pelvic girdle of frog

Hindlimbs:

Femur =

Patella =

Tibia =

Fibula =

Tarsals =

Astragalus / Talus =

Calcaneus =

Metatarsals =

Phalanges/Digits =

1. long thigh bone

2. kneecap

3. larger of two long bones of lower limb

4. smaller of two long bones of lower limb

5. ankle

6. lower part of ankle + transmits body weight to foot

7. heel bone

8. mid-foot bones

9. toes

Tibiotarsus (part of hindlimbs)

In birds only; homologous to tibia bone

Tibiofibula (part of hindlimbs)

In frogs only; bigger

Tarsometatarsals (part of hindlimbs)

In birds only

What are the different bone structures of the frog? Label the image

Suprascapula, radioulna, urostyle, tibiofibula

What are the different bone structures of birds? Label the image.

Keel, carpometacarpus, tibiotarsus, tarsometatarsal

Label the cat diagram

What are the evolutionary adaptations for increased running speed in cats?

1. vertebral column bends freely up/down —> increased stride length

2. limbs elongated + digitigrades —> increased stride length

3. reduced vestigial (“floating”) clavicle —> scapula moves more freely —> good shock absorber —> agility

What are the evolutionary adaptations for improved jumping in frogs?

1. Urostyle resistant to bending/breaking

2. Backbone jointed above sacral vertebra —> frog can leap

3. Radioulna + tibiofibula —> to withstand stress from jumping/landing

What are the evolutionary adaptations for flight in birds?

1. Keel —> attachment area for flight muscles

2. Pectoral girdle —> modified to provide support for forces associated w/ flight

3. Pelvic girdle —> expanded to provide large area for attachment of hind limb muscles

4. Tail reduced to stump —> attachment area for large tail feathers