Avian Skeletal system

Question 1

What is special about avian bones?

Answer 1

They are light but strong (for flying)

The medullary cavity is filled with air rather than marrow

Question 2

Which part of the avian bone is filled with air?

Answer 2

The medullary cavity

Question 3

Describe the avian skull (2)

Answer 3

Lightweight box

Contains two huge orbits (eye sockets)

Question 4

What are orbits?

Answer 4

Eye sockets in the skull

Question 5

What forms the upper skull?

Answer 5

The premaxilla and nasal bones

Question 6

What do larger parrots have between the beak and the skull?

Answer 6

synovial joint

Question 7

What comprises the lower jaw?

Answer 7

Two fused mandibles

Question 8

What are 2 differences between the jaw of a mammal and the jaw of a bird?

Answer 8

Birds have two fused mandibles, mammals do not

Birds can move the upper jaw relative to the rest of the skull, mammals cannot

Question 9

In what way can a beak move?

Answer 9

Mainly scissor motion but can move in other subtle way

Question 10

What is the extension of the sternum and what is it for?

Answer 10

The keel / carina

Provides anchor to which a bird’s wing muscles can attach

Also provides adequate leverage for flight

Question 11

Do all birds have a keel?

Answer 11

No

Question 12

What is a keel/ carina?

Answer 12

An extension of the sternum for the wing muscles to attach to and provide leverage for flight

Question 13

Where do the flight muscles originate from?

Answer 13

The sternum

Question 14

What is different about avian cervical vertebrae to mammals?

Answer 14

The avian cervical vertebrae are highly mobile

Question 15

Describe the avian vertebrae of the trunk

Answer 15

inflexible and mostly fused

Question 16

What are the vertebrae of the trunk?

Answer 16

Thoracic vertebrae

Question 17

Which structure is found over the lungs

Answer 17

the notarium

Question 18

What is the synsacrum?

Answer 18

a fusion of the thoracic, lumbar and sacral vertebrae

Question 19

What do the thoracic, lumbar and sacral vertebrae fuse to form?

Answer 19

The synsacrum

Question 20

Which bones form the pygostyle

Answer 20

A fusion of the coccygeal vertebrae

Question 21

Which 4 bones make up the wings?

Answer 21

Humerus
Radius
Ulna
Manus

Question 22

What do the humerus, radius, ulna and manus form?

Answer 22

The wings

Question 23

Which muscles are responsible for the wing strokes?

Answer 23

Pectoral muscles

Question 24

Which muscle forms 15-20% of the bird’s total bodyweight?

Answer 24

Pectoral muscles

Question 25

Which muscles help lift the wings?

Answer 25

Supracoracoideus muscle

Question 26

What is the function of the Supracoracoideus muscle?

Answer 26

To lift the wing up

Question 27

What is the function of the pectoralis

Answer 27

To lower the wing down

Question 28

Which bones fuse to form a '3-fingered hand'

Answer 28

Bones of manus

Question 29

What do the bones of manus form?

Answer 29

A three fingered hand at the end of the wing

Question 30

Which bones comprise the thoracic girdle?

Answer 30

Clavicles Coracoids Scapulae

Question 31

What do the clavicles generally fuse to form?

Answer 31

furcula

Question 32

what is the furcula

Answer 32

A fusion of the clavicles

Question 33

What is the function of the coracoids

Answer 33

Act as struts to hold the shoulders at a constant distance from the sternum

Question 34

Which bones hold the shoulders at a constant distance from the sternum?

Answer 34

The coracoids

Question 35

What is the function of the furcula

Answer 35

Acts as a spring and stores energy when compressed during the down-beat flight movement

Question 36

Which bone structure acts as a spring during flight

Answer 36

Furcula

Question 37

Which bones comprise the legs?

Answer 37

``` Femur Tibiotarsus Fibula Tarsometatarsus Phalanges (digit bones) ```

Question 38

What does it mean if bones become pneumotised

Answer 38

The cavities become air filled rather than marrow filled

Question 39

What is the word for when bones become air filled rather than marrow filled

Answer 39

pneumotised

Question 40

Which bones do the air sacs invade and occupy? (4)

Answer 40

The medullary cavities of many vertebrae Pelvis Sternum Humerus