The aim of our work was to study normal retinal blood supply in rats taking into account sections of vascular lesions, their branching and identifying parts of their vascularization. We used the following methods: postmortem dissection; postmortem injection of radiopaque mixture into arteries with the purpose of visualization of the investigated area of the vascular bed and subsequent post-mortem vasographic studies of the injected area. As a result of the studies we revealed that the vascularization of rat’s eye and retina at the macro level is supplied by the branches ramifying from the internal carotid artery (a. carotis interna), which branches off from the common carotid artery (a. carotis communis). The internal carotid artery (a. carotis interna) ramifies from the common carotid artery near the caudal end of the thyroid gland. The main direction of the internal carotid artery coincides with the direction of the external carotid artery course. After branching it goes deep and runs along the base of the skull. On its course the internal carotid artery is divided into two parts: cervical part (pars cervicalis), from which the sphenopalatine artery originates and cerebral part (pars cerebralis), from which the caudal connective artery, median, choroidal and rostral arteries originate. Sphenopalatine artery (a. sphenopalatina) is a vessel that in rats branches off in the area of the cervical internal carotid artery, enters the cranial cavity through the caudal foramen lacerum and comes out through petrotympanic fissure subdividing into pterygoid and palatine parts. Branches of sphenopalatine artery include: infraorbital artery, pharyngeal artery, artery of pterygoid canal, ophthalmic artery, descending palatine artery, cranial upper alveolar artery and sphenopalatine branch. Ophthalmic artery (a. ophtalmica) is a branch of the palatine part of sphenopalatine artery and originates in the cavity of pterygoid canal. Subsequently it enters the orbital cavity through the rostral foramen lacerum. In the orbital cavity it subdivides into the following branches: 1) branches of the eyeball; 2) the central retinal artery (a. centralis retinae); 3) muscular branches (rami musculares); 4) lacrimal artery (a. lacrimalis); 5) supraorbital artery (a.supraorbitalis); 6) ethmoid artery (a. ethmoidalis); 7) short and long ciliary arteries (a.a. ciliares posteriores longi et breve). The blood vessels of the retina together form vascular circle of optic nerve – circulus vasculosus n. optici, which is a set of interconnected anastomosing branches of short posterior ciliary arteries and the central retinal artery. The following retinal arterioles (venules) are also involved in the formation of such anastomosing: dorsomedial, ventromedial, posterolateral, ventrolateral and also dorsal and ventral arterioles (venules) areas of the macula. Ophthalmic artery – (1,9–2,0 mm) that branches directly from the internal carotid artery goes to the posterior pole of the eyeball locating on either side of the optic nerve. Approaching the eyeball division of branches takes place to form two trunks: nasal branch of ciliary trunk (truncus ciliaris nasalis) and temporal branch of ciliary trunks (truncus ciliaris temporalis). Farther, each of the trunks is divided into long nasal posterior ciliary artery (a. ciliaris nasalis posterioris longa) and short nasal posterior ciliary artery (a. ciliaris nasalis posterioris breve) and also long temporal posterior ciliary artery (a. ciliaris temporalis posterioris longa) and short temporal posterior ciliary artery (a. ciliaris temporalis posterioris breve). Short ciliary arteries are direct sources of choroidal vascularization of the uvea, which then participate in retinal vascularization on the part of pigment epithelium, forming a choroidal system of retinal vascularization. Central retinal artery (a. centralis retinae) (0,2–0,3 mm) goes into the thickness of the optic nerve and into the orbital cavity in the region of the optic disk and branches into the superior temporal retinal arteriole (a. temporalis retinae superior), superior nasal retinal arteriole (a. nasalis retinae superior), median retinal arteriole (a. medialis retinae), inferior retinal arteriole (a. nasalis retinae inferioror), and inferior temporal retinal arteriole (a. nasalis retinae inferioror), which directly participate in retinal vascularization on the part of internal limiting membrane forming retinal vascularization system. Muscular branches (rami musculares) ramify in the muscles of the eyeball and participate in the formation of dorsal and ventral anterior ciliary arteries and the artery of the third eyelid. Lacrimal artery (a. lacrimalis) is directed toward the lacrimal gland with its main trunk. It branches toward both of the eyelids. The second branch moving away from the lacrimal artery runs along the cutaneous nerve of the lower eyelid. Supraorbital artery (a. supraorbitalis) goes toward the muscles and skin of the forehead participating in their blood supply. Ethmoid artery (a. ethmoidalis) entering the nasal cavity is involved in the vascularization of mucosa of the nasal septum and ethmoid bone labyrinth.
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