Avian Anatomy

crown

Top of the head; flat or tuft

eyes

Same with human eye but no eyelids

lores

Area between where the beak

joins the face and where the eye

starts

beak 

Consist of upper and lower jaw

supercelium

Eyebrow region

eye line

Line that extends from

back of eye towards the

nape

ears

Placed on either sides of

the face

nape

Neck region

throat/chin

Area below the face that

joins the breast

malar stripe

runs

down from the beak

along the throat.

mustache stripe

Located along the lower cheek,

resembling a mustache.

skin

thin, loose, and tears easily

skin 

Due to the poor blood vessel

and nerve supply, skin

wounds in birds don't bleed

as much as in mammals.

comb, wattles, and earlobes

are

soft skin outgrowths on the head.

dermis ; epidermis

— is thick and vascular, but the

—  is thin, making them

prone to injury and infection.

wattles’ edges

are used for

intradermal injections.

3 discrete skin glands

1. Sebaceous uropygial gland (preen or oil gland)

2. Aural gland

3. Vent gland

uropygial gland

In waterfowl, the secretion

waterproofs feathers and

insulates the submerged

body parts.

bacteriostatic lipid

The — 

layer may help protect

birds from skin infections.

aural sebaceous gland

• Glands around the external ear

• Produce a waxy substance

vent gland

• Secrete mucus (function uncertain)

• Possibly related to fertilization

cortex ; thinner

to lighten the skeletonm, the — of the avian is much — than in mammals

pneumatic

many of the larger bones are pneumatic

acts as conditionng chambers for inspired air

thinner cortex

many trabeculae

thicker cortex

few to no trabeculae

pneumatic bone 

Filled with air contained

membranous air sacs that connect

with the respiratory system.

pneumatic bone

The number of pneumatic bones is

reduced in diving birds as they restrict the

ability to stay under water.

medullary bone

Specialized bone used as a

source of calcium for the egg

shell in laying hen and only

occurs in birds and some

reptiles.

medullary bone

First source when more

calcium is required.

beak

The beak resembles a

pyramid with base

directed towards the

eyes.

premaxillary bone

The rostral tip of the

face is formed by the

palatine

frontal

maxillary

premaxillary bone 3 process

palatine process

Forms the rostral border

of the hard palate

frontal process

Forms a flexible

attachment to the frontal

bone

maxillary process

Free border forms the

edge of the upper beak

jugal bone

Homologous to malar or

zygomatic of mammals

quadrate bone

It articulates with the mandible

to form the main joint of the

lower jaw.

quadrate bone

Acts as a pivot, enabling birds

to open their beaks wide and

close them precisely.

quadrate bone

This structure also makes

dislocation of the jaw

unlikely, ensuring the stability

of the beak during feeding

and other activities.

mandible

Its five pairs of fused bones form an

acutely angled, caudally open

structure.

1. Dental (Dentary) Bone

2. Splenial Bone

3. Angular Bone

4. Supra-angular Bone

5. Articular Bone

mandible 5 pairs of fused bones

They form a sling that extends to

the back of the cranium.

This structure allows for significant

movement, as seen in the highly

extendable tongue of the

woodpecker.

1. Paraglossum

2. Basihyale

3. Urohyale

4. Bilateral cornu branchiale

- ceratobranchiale

- epibranchiale

hyobranchial apparatus

cervical vertebrae

The typically S-shaped avian cervical vertebral

column is generally considerably more mobile,

and contains more vertebra, than that of

mammals.

14

chicken cv 

17

duck cv

12

pigeon cv

atlas

Ring-shaped bone with a dorsal arch

and ventrally located body.

atla

The dorsal surface of the body

bears an articular surface that

forms a joint with the dens of axis

~ allows for the rotation of the

head.

thoracic vertebrae

Functionally, in terms of

breathing, the boundary

between the cervical and

thoracic vertebrae marks where

the first free ribs appear.

thoracic vertebrae

• Only the first and sixth thoracic

vertebrae occur as separate bones.

thoracic vertebrae

2nd to 5th vertebrae are fused to

form the notarium while the last

vertebra is fused with the

synsacrum.

notarium 

• The notarium is a rigid bone structure found

only in chickens and pigeons among

domestic birds.

thoracic vertebral stabilization

In other species, like ducks and geese,

— is achieved

through the ossification of tendons and

ligaments.

synsacrum

is formed by the last

thoracic vertebra, the lumbar vertebrae,

sacral vertebrae and the first caudal

vertebrae.

chicken

total of 15–16 vertebrae contribute to the synsacrum

caudal vertebrae

The terminal caudal vertebrae are

fused to form the pygostyle.

caudal vertebrae

The appearance of this plate-like

bone varies with species from

almost triangular to parallelogram-

shaped.

ribs

The ribs are classified as sternal

(complete), or asternal (incomplete).

chicken, quail, turkey, and pigeon

7 pairs of ribs

ducks and geese

9 pairs of ribs

• Coracoid bone

• Scapula

• Clavicle

pectoral girdle consist of