a) JOINTS OF THE THORACIC LIMB
Name
Participating bones
Form/
Function
Comments
Composition
I. Shoulder (humeral) joint Glenoid cavity of the scapula, Spheroid joint/ Movement in all A capsular synovial sheath invests the
head of the humerus Simple joint directions, chiefly tendon of origin of the biceps brachii a hinge joint muscle, which is kept in position by the (ginglymus) transverse retinaculum that bridges the
intertubercular groove.
II. Elbow (cubital) joint
a) Humero-ulnar joint Humeral condyle, Compound joint/ Snapping hinge Craniolateral recess deep to the common trochlear notch Ginglymus joint digital extensor muscle; 2. Craniomedial of the ulna recess deep to the biceps brachii muscle; 3. Caudal recess between the lateral epi- b) Humero-radial joint Humeral condyle, head Ginglymus dondyle and the olecranon.
of the radius
c) Proximal radio-ulnar Articular circumference Trochoid joint Rotation of the
c) joint of the radius, radial notch radius on its long
of the ulna axis
III. Distal radioulnar joint Ulnar notch of the radius, Trochoid joint/ Rotation of the The joint cavity communicates with the radial circumference Simple joint radius on its carpal joint. For treatment of growth of the ulna long axis disturbances, the radioulnar ligament may
be cut.
Joints of the Manus IV. Carpal joint
a) Antebrachiocarpal joint Trochlea of the radius, ulna, Ellipsoid joint, Predominantly a The joint cavity consists of two parts that radial carpal bone, compound joint hinge joint with communicate with each other. Proximal ulnar carpal bone slight abduction/ part: a) and e), which communicate with
adduction the radioulnar joint. Distal part: b) and c). movement The carpal joint has dorsal fascial rein-
forcement, the extensor retinaculum, b) Middle carpal joint Proximal and distal rows Condylar joint/ which retains the extensor tendons in
of the carpal bones Compound joint position. On the palmar aspect, the flexor retinaculum bridges the carpal canal. The c) Carpometacarpal joint Carpal bones I – IV Plane joint/ lateral and medial collateral ligaments are and MC I – V Compound joint relatively short ligaments since they bridge
only the antebrachiocarpal joint. d) Intercarpal joints Joints between the carpal Plane joint/
bones of a row Compound joint (perpendicular joints)
e) Joints of the accessory Accessory carpal bone, Plane joint/ Amphiarthrosis
e) carpal bone ulnar carpal bone, ulna Compound joint (little movement)
V. Metacarpophalangeal Proximal phalanges; Compound joint Mainly a hinge Metacarpophalangeal and interphalangeal joints proximal sesamoid bones; joint with slight joints have each in their joint capsules a
dorsal sesamoid bones; abduction and dorsal and a palmar outpouching. The metacarpal bones adduction as well joint capsule attaches at the margin of the
as axial rotation articular surfaces of the participating sesamoids. At the metacarpophalangeal joint there are proximal sesamoids palmarly and a single dorsal sesamoid.
VI. Proximal interphalangeal Proximal and middle Saddle joint/ Dorsal sesamoid is present. joints of the manus phalanges Simple joint
VII. Distal interphalangeal Middle phalanges and Saddle joint/ Distal sesamoid is present. joints of the manus distal phalanges Simple joint
The shoulder joint lacks typical ligaments external to the joint capsule. Their function is taken over by contractile tension-bands, the tendons of the infraspinatus and subscapular muscles. The lateral and medial gleno- humeral ligaments are ‘internal’ capsular reinforcements.
At the elbow joint the collateral ligaments bifurcate, forming radial and ulnar attachments. The anular ligament of the radius grips around the head of the radius and extends from the medial coronoid process of the ulna to the lateral collateral ligament.
b) SYNOVIALBURSAE
The subtendinous bursa of the infraspinatus muscle is located between its terminal tendon and the cartilage-covered lateral surface of the greater tubercle.
The subtendinous bursa of the subscapularis muscle lies between the inser- tional tendon of its muscle and the shoulder joint capsule.
The subtendinous bursa of the triceps brachii muscle is expanded between the olecranon and the insertion of the triceps brachii muscle.
The subcutaneous olecranon bursa is an acquired synovial bursa.
The bicipitoradial bursa lies between the tendon of the biceps and the radius and is frequently fused with the subtendinous bursa of the brachialis muscle.
The subtendinous bursa of the brachialis muscle is located between the end-tendon of the brachialis and the radius.
c) SYNOVIAL SHEATHS
Synovial sheaths protect the tendon of origin of the coracobrachial muscle
(Vagina synovialis m. coracobrachialis), and of the biceps brachii muscle in
the intertubercular groove (Vagina synovialis intertubercularis). The latter is an extension of the shoulder joint capsule with which it communicates. The end-tendons of the carpal joint extensors are protected by a synovial sheath (long abductor of digit I) or by synovial sheaths and bursae (exten- sor carpi radialis). The ulnaris lateralis end-tendon and its caudal extension to the accessory carpal are protected by a synovial bursa. The radial carpal flexor end-tendon is protected by a synovial sheath; the ulnar carpal flex- or by a bursa. The digital extensors are protected by synovial sheaths at the carpus, the digital flexors on the digits. The deep flexor usually has a syn- ovial sheath at the carpus.
1 2 3 3 4 5
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5''' 4 6 5 5'' 5' 4 3 2 1 7 13 12 11 9 10 8 9 8 9 11 14 15 B A 10 17 16 13 13' 18 12 D C C 19 D E E 4 6 4 4 6 4 D C E F 8 14Joints, synovial bursae and sheaths
Legend : Legend :
Legend :
(lateral view)
(lateral view)
(medial view) (medial view)
(medial view)
(medial view) (palmar view)
(dorsal view)
Shoulder joint Shoulder joint
Elbow joint Elbow joint
Carpal joint Carpal joint 1 Infraspinatus m. 2 Subscapular m. 3 Coracobrachialis m. 4 Biceps brachii m. Triceps brachii m.: 5 Lateral head 5' Longhead 5'‘ Accessoryhead 5'‘' Medial head 6 Brachialis m. 7 Anconeus m. 8 Ext. carpi radialis m. Subtendinous bursa of infraspinatus m.
Articular capsule Synovial bursa
Intertubercular synovial sheath Transverse retinaculum Articular capsule subscapular m. Subtendinous bursa of Med. glenohumeral lig.
Articular capsule Subcutaneous bursa olecranon Subtendinous bursa of triceps brachii m. brachialis m. subtendinous bursa of Bicipito-radial bursa and elbow
collateral lig. of Lat. and med.
9 Extensor digitalis com. m. 10 Supinator m.
11 Extensor digitalis lat. m.
12 Ulnaris lateralis m. Flexor carpi ulnaris m.: 13 Ulnar head
13' Humeral head
14 Abductor pollicis longus m. 15 Extensor pollicis m.
16 Supf. digital flexor m. 17 Deep digital flexor m. 18 Flexor carpi radialis m. 19 Interflexor mm.
Synovial bursae Articular capsules Synovial sheaths
abductor pollicis longus m. Sesamoid bone of Flexor retinaculum
Collateral lig. of med. carpus Synovial sheath
Articular capsules
A Anular lig. of radius B Dorsal ligg.
C Accessoro-metacarpal ligg.
D Deep palmar carpal lig. E Palm. carpometacarpal ligg. F Dors. carpometacarpal lig.
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I. The m. splenius (1), previously transected in its middle, extends from the
spinous processes of the first three thoracic vertebrae to the nuchal crest of the skull. II. The m. iliocostalis arises from the wing of the ilium and inserts onto the lumbar transverse process (m. iliocostalis lumborum, —24), the angles of the ribs, and the transverse processes of the last two cervical ver- tebrae (m. iliocostalis thoracis, —17). III. Also extending caudally to the wing of the ilium, the m. longissimus is divided along its length into the mm.
longissimus lumborum (23), thoracis (16), cervicis (12) and capitis (2). Cor-
responding to their region, these muscles insert onto lumbar transverse processes, tubercles of the ribs, cervical transverse processes and the mas- toid process of the cranium respectively. IV. The m. semispinalis capitis lies in the neck region dorsal to the m. longissimus and consists of a dorsal m.
biventer cervicis (4), characterized by tendinous intersections directed trans-
versely, and a ventral m. complexus (3). Both muscles extend from the cer- vico-thoracic boundary to the cranium. V. The m. spinalis et semispinalis
thoracis et cervicis (15) lies medial and adjacent to the m. longissimus and
courses between the second cervical and eleventh thoracic vertebrae. VI. The multipennate mm. multifidi extend from the axis to the sacrum. In the caudal half of the neck, the m. multifidus cervicis (10) lies deep to the m. complexus and is traversed by dorsal branches of cervical nerves on its ven- trolateral aspect. The m. multifidus thoracis is situated deeply, and the m.
multifidus lumborum (26) lies deep to the thoracolumbar fascia, adjacent to
lumbar vertebrae and their spinous processes. VII. At the level of the seventh lumbar vertebra the m. sacrococcygeus (-caud.) dorsalis medialis (27) con- tinues the oblique pennate m. multifidus by means of an approximating fiber-flow directed caudally. VIII. The m. sacrococcygeus (-caud.) dorsalis
lateralis (25) begins acutely at the fourth lumbar vertebra and, as the cau-
domedial continuation of the m. longissimus, proceeds to the tail by a strong terminal tendon. IX. The mm. interspinales lie deeply between the spinous processes. X. The mm. intertransversarii (8) are superficial in the neck; whereas, in the thoracolumbar region they are situated deeply along the ver- tebral column. The mm. intertransversarii cervicis are located ventral to the line of insertion of the m. longissimus cervicis. XI. The mm. scaleni extend from the fourth or fifth cervical vertebra to the eighth rib (m. scalenus dor-
salis, —14) and the first rib (m. scalenus ventralis, m. scalenus medius, —13). XII. The m. longus capitis (9) lying adjacent and ventromedial to the mm.
scaleni is situated ventrolateral to the cervical vertebrae. Arising from the sixth cervical vertebra it inserts on the muscular tubercle of the occipital bone. XIII. The m. longus colli (see text-illustration), which appears plait- ed, is situated ventromedially on the cervical and thoracic parts of the ver- tebral column. Arising on the first cervical vertebra it extends to the sixth thoracic. XIV. The m. rectus capitis dorsalis major (6) continues cranially from the spinous process of the axis. Between the spinous process of the axis and the occipital bone it overlies the deeper m. rectus capitis dorsalis minor
(XV.). XVI. The m. obliquus capitis caudalis (7) extends from the lateral sur-
face of the spinous process of the axis to the dorsal surface of the wing of the atlas. XVII. The m. obliquus capitis cranialis (5) runs from the wing of the atlas to the occipital bone.
b) The NUCHAL LIGAMENT (11), which is paired, lies dorsomedian above the
spinous processes of the cervical vertebrae and connects the spinous
processes of the second cervical and first thoracic vertebrae. Caudally it passes over into the supraspinous ligament. The yellow color of the nuchal ligament indicates a predominance of elastic fibers.
c) The LUMBAR CUTANEOUS NERVES form a dorsal, a lateral and a ventral
series of cutaneous nerves by means of their serial passage through the stra- ta of skeletal muscles.
I. The series of dorsal lumbar cutaneous nerves is formed from nL1 to 4 dl
(dorsal clunial nn.) and becomes subcutaneous approximately 8 cm from the dorsal midline. As a rule the nL5 to 7 dl do not reach the cutaneous field of innervation.
II. The series of lateral lumbar cutaneous nerves arises from branches of the
cranial iliohypogastric (nL1 vl), caudal iliohypogastric (nL2 vl), ilioinguinal (nL2 and 3 vl) and lateral cutaneous femoral (nL3 and 4 vl) nn. These nerves pass through the abdominal muscles on a line directed caudodorsally from the ventral end of the last rib to the tuber coxae. The cranial iliohypogastric
n. (18, –with accompanying blood vessels), and the caudal iliohypogastric n. (19) pierce the m. obliquus externus abdominis. The ilioinguinal n. (20,
–sometimes absent) and the lateral cutaneous femoral n. (21, –with accom- panying blood vessels) become subcutaneous over the dorsal border of the m. obliquus externus abdominis.