Lacrimal bone: contains the nasolacrimal duct, which carries fluid from the surface of the eye, to the nose

The bones of the horse are the same as those of other domestic species, but the third metacarpal and metatarsal are much more developed and the second and fourth are undeveloped, having the first and fifth metacarpal and metatarsal. [22] Horse skeleton bones The orbit is a complete bony circle in the HORSE, PIG, and RUMINANTS (whereas in the DOG it is completed laterally by the orbital ligament). The small frontal sinus of EQUINE is continuous with the dorsal conchal sinus rostrally and is called the conchofrontal sinus. In EQUINE, ventrally the frontal sinus opens into the maxillary sinus via a large frontomaxillary opening. (Fig. 14B-7/4) Basically, all sinuses drain to the maxillary sinus in EQUINE. Throatlatch [5] [6] [7] [8] [9] [10] (also, throttle, throatlash [ citation needed], throat [11]): the point at which the windpipe meets the head at the underside of the jaw, [3] corresponding to where the eponymous part of a bridle goes. [12] The mare's reproductive system is responsible for controlling gestation, birth, and lactation, as well as her estrous cycle and mating behavior. It lies ventral to the 4th or 5th lumbar vertebrae, although its position within the mare can vary depending on the movement of the intestines and distention of the bladder.The superior and inferior palpebrae are the upper and lower eyelids, respectively. The separation between the eyelids is the palpebral fissure. The medial and lateral corners, where the eyelids meet, are called medial and lateral palpebral commissures, respectively. Joints and Ligaments [ edit | edit source ] Joints and Ligaments of the Skull [ edit | edit source ] The muscles of mastication are well developed in ungulates and are bilateral, and (mostly) innervated by CN V Trigeminal. As a result of wear, the edges of the infundibula become razor sharp, making the occlusal surface of the molar teeth an efficient grinding surface. Although the greater width of the maxillary cheek teeth and their outer ridges, or cingula (cingulum is singular), are often sharp and need to be filed down or “ floated” to prevent injury to the buccal (cheek) mucosa. The auriculopalpebral branch (CN VII Facial) carries motor to the superior palpebrae and muscles around the eye.

The medial pterygoid m. (deep ) runs from the pterygoid process to the ramus and condylar process of the mandible and causes side to side movements of the jaw. The masseter (unilaterally) and medial pterygoid mm. act to cause lateral movements in the jaw. Figure above – Lateral view of equine head, blue indicates left guttural pouch. Labeled structures: common carotid, internal carotid, occipital, external carotid, and linguofacial aa. Note stylohyoid bone running into the ventral boundary of the guttaral pouch, forming medial and lateral compartments of the pouch. Joints: where bones come together. Joints help a horse to have motion and can allow for rotation, bending, straightening or may not move at all. The equine tongue is made up of twelve different muscles [14] including styloglossus, genioglossus and hyoglossus. These muscles are covered by mucosa on the sides and underneath. [1]Elbow: The joint of the front leg at the point where the belly of the horse meets the leg. Homologous to the elbow in humans There are several cranial nerves that run along the guttural pouch. They include: CN IX Glossopharyngeal, X Vagus, XI Accessory, and XII Hypoglossal. CN VII Facial and CN V Trigeminal branches are also found near the dorsal and lateral edge of the pouch. A poll is a protuberance between the ears or just caudal to the ears. Typically, animals are now bred and selected to have no horns. The genioglossus m. is found at the ventral floor of the tongue and originates on the inside of the chin (near the mandibular symphysis) or the genial tubercle, hence the name genio-glossus, from chin to tongue. The mandibular salivary glands are also very prominent (especially in BOVINE, Fig. 25.2), and are near the mandibular lymph nodes.