FRONTAL

Question 1

Os Frontale

Parts of the Frontal bone

Answer 1

Two frontal bones
Meet at the sutura interfrontalis

1.SQUAMA FRONTALIS
A. PARS ORBITALIS- forms the bony orbit
B. PARS NASALIS
- the two parts unite to form the squama
- participates in formation of CRANIAL ROOF

2. FACIES TEMPORALIS- lateral surface

Question 2

Structures of the Frontal bone

Answer 2

1. Sinus frontalis
   - each frontal bone contains ONE sinus in EQ
   - each frontal bone contains MORE sinus in ca,bo
   - Septum sinuum frontalium
   - Aperturae sinuum frontalium
2. Protuberantia intercornuales
   - in ox during the postnatal development of the frontal sinus are displaced backwards- the frontal bone become continuous with the Nucheal surface
   - Lies btw the Cornual process

Question 3

Os Frontale

SQAMA Frontalis

Answer 3

1. Processus Zygomaticus
   - projects laterally
   - in Ru unites with the frontal process of the zygomatic bone
   - in Eq unites with the zygomatic process of the Temporal Bone
2. Fossa Glandularis
   - in eq, bo
   - on the orbital surface of the processus zygomaticus
   - houses the lacrimal gland

PROCESSUS ZYGOMATICUS Ossis frontalis
—> Participate into the formation of the MARGO SUPRAORBITALIS

MARGO SUPRAORBITALIS
- forms the upper margin of the orbit

3. Foramen Supraorbitale
   - in Eq
4. Canalis SUPRAORBITALIS
   - in Bo
   - Supraorbital foramen = entrance of the canal
   - Double in OX
   - Continues by sulcus SUPRAORBITALIS
5. Ligamentum Orbitale
   - in ca
   - forms the upper margin of the orbit
   - below the ligament lies FOSSA LACRIMALIS
6. Linea Temporalis
   - lies at the junction of the squamos part of the temporal surface
   - In eq, ca continues as the crista sagittalis ext
7. Processus cornualis
   - in horned animals
   - at the caudal end of the squama on either side
   - form the bony basis of the horns

Question 4

Os Frontale

Pars ORBITALIS

Answer 4

1. Fovea Trochlearis
   - medial to the origin of the Zygomatic Process
   - Accomodates the trochlear cartilage of the M. obligquus dorsalis
2. Foramina Ethmoidalia
   - in ca
3. Foramen ethmoidale
   - in other species
4. Crista Orbitotemporalis