Clinical Anatomy
The orbit is conical and has a volume of about 30 cm3. The anterior orbital rim has horizontal and vertical diameters of 4.0 cm and 3.5 cm, respectively; however, the orbital dimension widens posteriorly, with a maximum diameter 1 cm posterior to the rim. The distance from the anterior orbital rim to the apex is approximately 4.5 to 5 cm along the medial orbital wall, whereas the distance from the lateral orbital rim to the superior orbital ssure is about 4 cm.
The medial orbital walls are parallel to each other and approximately 2.5 cm apart. The lateral wall forms a 45-degree angle with the ipsilateral medial wall. The two lateral walls form a 90-degree angle (Fig. 13.1).
临床解剖
眶部为体积约30cm3的圆锥体。位于前方的眶缘范围的橫径为4.0cm,垂直径为3.5cm;眶缘的范围向后仍会较前继续增宽,最大不超过1cm。沿眶内侧壁测量,眶缘至眶尖的距离约4.5~5cm。而眶外侧缘至眶上裂的距离约4cm。
两侧眶内侧壁彼此平行,间距约2.5cm。眶外侧壁与同侧内侧壁的夹角为45度。两侧眶外侧壁的夹角为90度(图13.1)。
图13.1 眶的径线长度和体积。
Orbital Bones
Orbital Rim
The orbital rim is composed of the frontal, zygomat ic, and maxillary bones that adjoin at suture lines (frontozygomatic, zygomaticomaxillary, and frontomaxillary, respect ively). The lateral and superior rims are the strongest. The orbital rim creates the anterior lacrimal crest and then spirals posteriorly to end at the posterior lacrimal crest. The lacrimal sac fossa is found between
the two crests (Fig. 13.2a).
眶骨
眶缘
眶缘由额骨、颧骨和上颌骨围成,三块骨的骨缝分别为额颧缝、颧上颌缝和额上颌缝。骨性眶外侧缘和上缘最为粗厚。眶缘包含泪前嵴,该嵴向后螺旋状延伸形成泪后嵴。泪前嵴和泪后嵴之间形成泪囊窝(图13.2a)。
Orbital Walls
Seven orbit al bones compose the four walls of the orbit (Fig.13.2a).
眶壁
眶的四个壁由7块骨构成(图13.2a)。
Orbital Roof
The orbital roof, which is the oor of the anterior cranial fossa,consists of the frontal and lesser wing of sphenoid bones. The supraorbital notch or foramen, through which the supraorbital nerve (CN V1) and vessels travel, divides the medial one-third and lateral two-thirds of the superior orbital rim. The lacrimal gland is found laterally in the lacrimal gland fossa.
眶顶
眶顶即颅前窝底部,由额骨和蝶骨小翼构成。在眶顶,眶上切迹或眶上孔是眶上缘内三分之一和外三分之二的分界点,眶上神经(三叉神经眼支分出)和血管经过该处。在眶顶的外侧,泪腺位于泪腺窝。
Lateral Orbital Wall
The lateral orbital wall, separated from the roof by the superior orbital ssure, consists of the zygomatic and greater wing of the sphenoid bones (Fig. 13.2b). The zygomaticofacial and zygomaticotemporal canals transmit vessels and zygomatic nerve branches. Occasionally, a meningo-orbital foramen is identified lateral to the superior orbital ssure and transmits a branch of the middle meningeal artery.3,4 Whitnall’s tubercle is a protuberance on the inner aspect of the lateral orbital rim approximately 4 mm posterior to the rim and 10 mm inferior to the frontozygomatic suture. The lateral canthal tendon, lateral horn of the levator aponeurosis, Lockwood’s ligament, and check ligament of the lateral rectus muscle at tach to the tubercle.
眶外侧壁
眶外侧壁在眶上裂与眶顶分离,该壁由颧骨和蝶骨大翼构成(图13.2b)。在眶外侧壁,颧神经的分支和伴行血管经过颧面管和颧颞管。有时,在眶上裂的外侧可见眶-脑膜孔,脑膜中动脉的一支经过该孔。Whitnall’s结节是眶外侧缘内壁上的一个凸起,该凸起约在眶缘后方4mm以及额颧缝下方10mm。外眦韧带附着于该结节,另一端连接提上睑肌腱膜的侧角、Lockwood’s韧带和外直肌翼状韧带的外侧。
Orbital Floor
The orbital floor, separated from the lateral wall by the inferior orbital ssure, consists of the zygomatic, maxillary, and palatine bones. The floor forms the roof of the maxillary sinus. The infraorbital groove or canal, through which the infraorbital nerve (CN V2 branch) and artery travel, divides the floor. The infraorbital nerve and artery then exit through the infraorbital foramen,
which is approximately 1 cm inferior to the orbital rim on the anterior maxillary bone face (Fig. 13.2c).
眶底
眶底在眶下裂与眶外侧壁分离。该部分由颧骨、上颌骨和腭骨构成。眶底即上颌窦的顶壁。眶下沟或者眶下孔将眶底分为内外两部分,该处由眶下神经(三叉神经上颌支分出)和伴行动脉穿过。约在眶缘下方1cm的上颌骨前面,眶下神经和动脉穿出眶下孔(图13.2c)。
Medial Orbital Wall
The medial orbital wall consists of the maxillary, lacrimal, ethmoid, and sphenoid bones. The anterior and posterior ethmoidal foramina, with ethmoidal vessels passing through, are found on the medial wall along the frontoethmoidal suture. Along the medial wall, the distance between the anterior lacrimal crest, anterior ethmoidal foramen, posterior ethmoidal foramen, and orbital apex is approximately 24 mm, 12 mm, 6 mm, respectively (Fig. 13.2d).
眶内侧壁
眶内侧壁由上颌骨、泪骨、筛骨和蝶骨构成。在该壁上,沿着额筛缝,筛前、后孔由对应的筛部血管经过。泪前嵴与筛前孔、筛后孔和眶尖之间的距离分别约24mm、12mm、6mm(图13.2d)。
图13.2 (a) 眶骨、缝、孔和裂。前视图。眶缘由额骨、颧骨和上颌骨组成,三块骨分别在额颧缝、颧上颌缝和额上颌缝处连接。(b)外侧壁,右眶。外侧眶壁在眶上裂与眶顶分离,该壁由颧骨和蝶骨大翼构成。(c)眶底,右眶。眶底在眶下裂与眶外侧壁分离,有颧骨、上颌骨和腭骨构成。(d)内侧壁,右眶。眶内侧壁由上颌骨、泪骨、筛骨和蝶骨组成。(源自THIEME Atlas of Anatomy, Head and Neuroanatomy. © Thieme 2010, 由Karl Wesker插图.)
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