Encyclopedia entry
Serratus Posterior Inferior and Serratus Posterior Superior
Abstract
There is considerable variation in the number of digitations of these muscles. The number of slips of the serratus superior may be reduced to five or six slips. Mori (1964) describes the vertebral origin of serratus posterior superior, in his cases, as follows: Cervical Thoracic Right side Left side Total % IV - VII 2 2 4 4 V - VII 5 7 12 12 VI I 18 15 33 33 V I 20 21 41 41 VI I 2 1 3 3 IV II 1 2 2 2 V II 2 2 4 4 Upper Limit Cervical Right side Left side Total % IV 24 18 42 42 V 27 30 57 57 VI 2 1 3 3 Lower Limit Cervical/ Thoracic Right side Left side Total % VII 7 9 16 16 I 40 37 77 77 II 3…
There is considerable variation in the number of digitations of these muscles. The number of slips of the serratus superior may be reduced to five or six slips. Mori (1964) describes the vertebral origin of serratus posterior superior, in his cases, as follows:
Cervical
Thoracic
Right side
Left side
Total
%
IV - VII
2
2
4
4
V - VII
5
7
12
12
VI
I
18
15
33
33
V
I
20
21
41
41
VI
I
2
1
3
3
IV
II
1
2
2
2
V
II
2
2
4
4
Upper Limit
Cervical
Right side
Left side
Total
%
IV
24
18
42
42
V
27
30
57
57
VI
2
1
3
3
Lower Limit
Cervical/ Thoracic
Right side
Left side
Total
%
VII
7
9
16
16
I
40
37
77
77
II
3
3
6
6
Insertion
(From Mori, 1964) The ribs of insertion are as follows:
Ribs
Right side
Left side
Total
%
II, III, IV
44
40
84
26
II, III, IV, V
72
76
148
46
II, III, IV, V, Vi
10
6
16
5
III, IV
4
0
4
1
III, IV, V
34
38
72
23
The serratus inferior may be reduced to two digitations, the first and last being absent.
Upper Limit of Vertebral Origin of Serratus Posterior Inferior
(From Mori, 1964)
Upper Limit
Right side
Left side
Total
%
T X
15
16
31
31
XI
31
29
60
60
XII
4
3
7
7
L I
0
1
1
1
II
0
1
1
1
Insertion
Ribs
Right side
Left side
Total
%
VIII, IX, X,XI, XII
3
2
5
2.1
IX, X, XI
22
22
44
11.5
X, XI
3
4
7
2.0
X, XI, XII
3
3
6
1.5
Xi, XII
2
1
3
1.0
The 11th rib is the lowest limit of insertion in 61 sides, 26% and the 12th rib is the lowest limit of insertion in 145 sides, 93% of Mori's cases.
Absence of the superior and inferior muscles have been recorded but this is extremely rare; when absent they are replaced by fibrous tissue. Cases have been described, in which the serratus inferior showed irregular arrangements of its digitations as a result of associated accessory muscles.
Syn.: mm. (serrati posterior) Hintere Sägemuskeln, Petits dentelés postérieurs.
Riferimenti dell’opera originale
Elenco riportato come compare nella fonte, senza normalizzazione dei formati bibliografici.
- Anson, B.J., Ed. (1966) Morris' Human Anatomy, 12th ed. The Blakiston Division, McGraw -Hill Book Company, New York.
- Macalister, A. (1875) Additional observations on muscular anomalies in human anatomy (third series), with a catalogue of the principal muscular variations hitherto published. Trans. Roy. Irish Acad. Sci. 25:1-134.
- Mori, M. (1964) Statistics on the musculature of the Japanese. Okajimas Fol. Anat. Jap. 40:195-300.
Anatomical classification
- Systems:
- Muscular system
Content provenance
Adaptation
Adaptation of «Serratus Posterior Inferior and Serratus Posterior Superior — Illustrated Encyclopedia of Human Anatomic Variation: Opus I: Muscular System» by Ronald A. Bergman, Adel K. Afifi, Ryosuke Miyauchi. Source: https://www.anatomyatlases.org/AnatomicVariants/MuscularSystem/Text/S/16Serratus.shtml Original work distributed under the CC BY-NC-SA 4.0 licence (https://creativecommons.org/licenses/by-nc-sa/4.0/deed.it). Adaptation by Redazione AIVA. Changes from the original: Testo originale inglese riprodotto integralmente e riorganizzato nel formato scheda del portale (sintesi, testo, riferimenti), senza modificarne le affermazioni. La traduzione italiana non è ancora stata eseguita, e la pagina lo dichiara. Le figure non sono state copiate: sono collegate alla pagina d’origine. This publication is not approved or endorsed by the authors of the original work.
Licence
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