頸闊肌
頸闊肌(Platysma)是頸部前側的淺層肌肉。它是一塊表面肌肉,主要覆蓋在胸鎖乳突肌表面。頸闊肌收縮時,會使頸部皮膚稍微起皺,產生「弓弦」(Bowstring)的效果。
頸闊肌 | |
---|---|
基本資訊 | |
起點 | 鎖骨上下方的皮下組織 |
終點 | 下頷骨底部、臉頰皮膚、下脣皮膚、嘴角、口輪匝肌 |
動脈 | 頦下動脈與肩胛上動脈兩者的分支 |
神經 | 顏面神經頸支 |
相關動作 | (悲傷或驚嚇時)使嘴往下往外,使頸部皮膚往上緊貼牙齒 |
拮抗肌 | 嚼肌、顳肌 |
標識字符 | |
拉丁文 | Platysma |
TA98 | A04.2.01.001 |
TA2 | 2147 |
FMA | FMA:45738 |
格雷氏 | p.387 |
《肌肉解剖學術語》 [在維基數據上編輯] |
結構
頸闊肌是一塊大片的扇形肌肉,肌肉纖維從蓋住胸大肌(Pectoralis major)與三角肌(Deltoid)上段的筋膜出發,構成扇形的寬端,接着肌肉向上越過鎖骨,沿着頸部邊緣向上向內側走,留下頸部中線下半段沒有被覆蓋。一些肌肉纖維在下頷聯合後下方會合,往後沿斜線(Oblique line)穿過下頷骨,其他肌肉纖維則附着在臉下方的皮膚與皮下組織上,或者與顴大肌、口輪匝肌等肌肉融合[1]。如果將嘴的外緣盡量向下拉,就會感受到頸部的頸闊肌拉緊。
神經
血管
相對位置
頸闊肌淺層有皮下筋膜與組織[1][3],深層有許多頸部構造,包含由下頷角下至鎖骨的頸外靜脈[4],以及更深的頸外動脈、腮腺、小枕神經、大耳神經[5]及顏面神經下頷支[6]
變異
頸闊肌變異發生於延展程度,伸展入面部的高度、穿過鎖骨或肩部的程度都因人而異。頸闊肌可能會在單側消失或交叉到對側,可能附着在鎖骨、乳突(Mastoid process)或枕骨上。一小部分的肌束可能會形成枕小肌(Occipitalis minor),從斜方肌(Trapezius)通到胸鎖乳突肌(Sternocleidomastoid, SCM)終點。
功能
起皺
頸闊肌整片運動時,頸部表麵皮膚會產生斜向的皺紋,有如弓弦(bowstring)一般。[3]
下顎及下脣
頸闊肌前部(整塊肌肉最厚的部分)能夠使下顎向下降,並在蹙額撇嘴(frown)時把下脣與嘴角往下拉。平時頸闊肌的降下脣作用很小,該動作主要由降口角肌與降下脣肌負責。只有很少人能夠有意識地操縱頸闊肌。皮膚鬆弛的老年人的頸部前部兩側可以看到兩根溝,就是頸闊肌形成的。
臨床重要性
傷害
由於頸闊肌既淺且薄,因此容易發生穿刺傷,它的破壞是頸部穿刺傷的標誌,於槍擊時搭配CTA,能夠有效診斷血管損傷[7],有效減少需要手術的個案數。[8]
頸部手術
頸闊肌在頸部手術中一定會被切開,以便醫療團隊處理深層結構[1][6]。若要避免疤痕產生,就必須精準縫合頸闊肌肌肉纖維。[1]
整形手術
頸闊肌張力下降產生皺紋,可能導致肌肉變薄縮短,可能與正常衰老有關,也可能是顏面神經麻痺(Facial nerve palsy)的續發性併發症[3]。舉重或拉皮手術可能會使頸闊肌張力進一步下降,造成頸闊肌運動障礙(Platysma dyskinesia),英語俗稱Turkey neck「火雞頸」。保守治療是可行選項之一,也可以注射肉毒桿菌毒素並執行頸闊肌成形術[9]。症狀減緩約需兩周。[10]
動物
在寵物中只有食肉目和豬有頸闊肌。這些動物的頸闊肌終點不在喉部,肌肉會向後一直延伸到肩膀。
食肉目還有兩塊下頜和胸之間的表皮肌肉。它們可以使得頸部下部的皮膚拉緊。
有蹄類沒有頸闊肌。它們只有在頸部的背部有兩塊表皮肌肉。
參考資料
- ^ 1.0 1.1 1.2 1.3 1.4 Eibling, David E. 78 - Neck Dissection. Operative Otolaryngology: Head and Neck Surgery 1 2nd. Philadelphia: Saunders. 2008: 679 – 708. ISBN 978-1-4377-2083-9. OCLC 825780332. doi:10.1016/B978-1-4160-2445-3.50082-0 (英語).
- ^ Anatomy & Physiology, 8th Edition, McGraw-Hill Co., 2008.
- ^ 3.0 3.1 3.2 Posnick, Jeffrey C. 40 - Aesthetic Alteration of the Soft Tissues of the Neck and Lower Face: Evaluation and Surgery. Orthognathic Surgery: Principles & Practice. St. Louis: Saunders. 2014: 1746 – 1783. ISBN 978-1-4557-5027-6. OCLC 860861780. doi:10.1016/B978-1-4557-2698-1.00040-X (英語).
- ^ Kim, Se-Hoon; Chang, Ung-Kyu; Kim, Daniel H.; Bilsky, Mark H., Kim, Daniel H.; Chang, Ung-Kyu; Kim, Se-Hoon; Bilsky, Mark H. , 編, Chapter 19 - Management of Upper Cervical Spine Tumors, Tumors of the Spine (Philadelphia: W.B. Saunders), 2006-01-01: 378–394 [2021-01-06], ISBN 978-1-4160-3367-7, (原始內容存檔於2022-02-06) (英語)
- ^ Kim, Se-Hoon; Chang, Ung-Kyu; Kim, Daniel H.; Bilsky, Mark H. 19 - Management of Upper Cervical Spine Tumors. Tumors of the Spine. Philadelphia: Saunders. 2008: 378 – 394. ISBN 978-1-4377-2164-5. OCLC 489078564. doi:10.1016/B978-1-4160-3367-7.10019-7 (英語).
- ^ 6.0 6.1 Wolfe, Michael J.; Wilson, Keith. 21 - Head and Neck Cancer. Essentials of Surgical Oncology: Surgical Foundations. Philadelphia: Mosby. 2007: 329 – 357. ISBN 0-8151-4385-0. OCLC 608607674. doi:10.1016/B978-0-8151-4385-7.50027-8 (英語).
- ^ Cothren, C. Clay; Moore, Ernest E. 19 - Penetrating Neck Trauma. Abernathy's Surgical Secrets 6th. Philadelphia: Mosby. 2009: 110 – 113. ISBN 0-323-07475-8. OCLC 460933202. doi:10.1016/B978-0-323-05711-0.00019-7 (英語).
- ^ Bell, RB; Osborn, T; Dierks, EJ; Potter, BE; Long, WB. Management of penetrating neck injuries: a new paradigm for civilian trauma. J. Oral Maxillofac. Surg. 2007, 65 (4): 691–705. PMID 17368366. doi:10.1016/j.joms.2006.04.044.
- ^ Labb??n a similar fashion to other muscles, the platysma is vulnerable to tears, strains and muscle atrophy among many other possible conditions. The platysma is vulnerable to neck injuries that may penetrate it. A type of medical imaging called CTA (computed tomography angiography), used to visualise arterial and venous vessels, is useful to minimise the number of neck explorations, thus improving the handling of the condition.[3] Another area of importance of the platysma lies in plastic surgery. Neck bands in the area become most noticeable with age, aggravated by weightlifting or facelift. If it doesn't heal with time, there are many options to correct this: Botox/Dysport/Xeomin and platysmaplasty. Platysmaplasty is a surgery in this area, that can be open or closed, in the latter a specialised instrument called plastymotome that allow the surgery to be done without incisions. It takes approximately 2 weeks for the symptoms to be reduced.[4], Daniel; Franco, R G.; Nicolas, J. Platysma Suspension and Platysmaplasty during Neck Lift: Anatomical Study and Analysis of 30 Cases. Plastic and Reconstructive Surgery. May 2006, 117 (6): 2001–2007. ISSN 0032-1052. doi:10.1097/01.prs.0000218972.75144.9c.
- ^ Daher, JC. Closed platysmotomy: a new procedure for the treatment of platysma bands without skin dissection. Aesthetic Plast Surg. 2011, 35 (5): 866–77. PMC 3192284 . PMID 21847680. doi:10.1007/s00266-011-9782-0.
- ^ Alam, Murad; White, Lucile E. 1 - Anatomy in Dermatologic Surgery. Complications in Dermatologic Surgery. Philadelphia: Mosby. 2008: 1 – 18. ISBN 0-323-04546-4. OCLC 811786617. doi:10.1016/B978-0-323-04546-9.10001-9 (英語).
延伸閱讀
- David Burnie. 新世紀人體學習百科. 台灣: 貓頭鷹出版社. 1997-06-30. ISBN 957-9684-11-1 (中文).