IVRI Anatomy
A free veterinary anatomy learning platform for B.V.Sc., M.V.Sc., DVM and veterinary medicine students worldwide, developed at the Veterinary Anatomy Section, ICAR-Indian Veterinary Research Institute, Bareilly—covering VCI/MSVE and international university curricula through regional anatomy, histology, embryology, comparative biomechanics, clinical notes, quizzes and revision.
Forms the caudal portion of the hard palate and the lateral wall of the choanae (posterior nares).
Horizontal Plate: Forms the posterior 1/4 of the hard palate. In the ox, this plate is extensive and hollowed by the Palatine Sinus, which communicates with the maxillary sinus.
Perpendicular Plate: Forms the lateral wall of the nasal cavity caudal to the maxilla. It helps bound the Pterygopalatine fossa.
Foramina: The Greater and Lesser Palatine foramina are located here, transmitting the palatine nerves and vessels to the hard palate.
A thin, strap-like bone lying on the lateral side of the choanae.
Hamulus (Hamulus pterygoideus): A thin, hook-like process at the ventral end. It acts as a pulley for the tendon of the tensor veli palatini muscle. In the ox, the hamulus is sharp and distinct.
Structure: In the ox, it is a distinct, thin plate overlapping the pterygoid process of the sphenoid.
An unpaired bone forming the ventral part of the nasal septum.
Sulcus Septi Nasi: A deep groove on the dorsal border that receives the cartilaginous nasal septum.
Posterior Border: Free, sharp, and concave, separating the two choanae (posterior nostrils). In the ox, the vomer is deeply grooved and extends far caudally. It sits on the floor of the nasal cavity but does not fuse with the maxilla along its entire length, leaving a gap.
| OX (BOS TAURUS) | Palatine: Large, pneumatized. Pterygoid: Large, distinct sharp hook. Late fusion. Vomer: Deeply grooved; free caudal border sharp. |
| HORSE (EQUUS CABALLUS) | Palatine: Narrow; pneumatized. Pterygoid: Distinct grooved hook. Late fusion. Vomer: Fuses with palatine process. |
| DOG (CANIS LUPUS) | Palatine: Wide; not pneumatized. Pterygoid: Short, quadrate; blunt. Early fusion. Vomer: High vertical plate. |
| PIG (SUS SCROFA) | Palatine: Extensive. Pterygoid: Broad plate. Late fusion. Vomer: Long and broad. |
| FOWL (GALLUS DOMESTICUS) | Palatine: Long thin rods; crucial for cranial kinesis. Pterygoid: Rod-like; articulates with Quadrate. Mobile joint. Vomer: Vestigial or absent; thin vertical plate when present. |
Explore the hidden mechanics of why structures are present, absent or modified across domestic and wildlife species—and how each anatomical design supports movement, function and clinical practice.
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