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Bovine Forelimb - Anatomy & Physiology (view source)
Revision as of 16:37, 6 January 2011
, 16:37, 6 January 2011→Muscles of the Forelimb
===Extrinsic Musculature===
===Extrinsic Musculature===
These muscle are responsible for joining the forelimb to the trunk, forming a synsarcosis rather than a conventional joint. Collectively, they act to transfer the weight of the body to the forelimbs as well as stabilize the scapula.
These muscle are responsible for joining the forelimb to the trunk, forming a synsarcosis rather than a conventional joint. Collectively, they act to transfer the weight of the body to the forelimbs as well as stabilize the scapula.
'''Trapezius''': Accessory n.
Origin: mid-dorsal raphe and supraspinous ligament.
Insertion: spine of the scapula.
Body: two parts, cervical and thoracic separated by aponeurosis.
Action: raises scapula against the trunk and swings cranially to advance the limb.
'''''Serratis ventralis''''': branch of brachial plexus
'''Brachiocephalic m.''': Accessory n.
'''''Rhomboids''''': brachial plexus,
The two parts are separated by the clavicle, where it exists.
Origin: occipital bone, nuchal ligament and the mastoid process.
Insertion: deltoid tuberosity and fascia of the limb.
Actions: advances the limb and extends the shoulder joint when limb is in motion. Draws the head and neck ventrally when the limb is fixed.
'''Omotransversarius''': Accessory n.
Origin: transverse processes of the atlas.
Insertion: acromion and spine of scapula.
Action: advancing the limb.
'''Latissimus dorsi''': local branch of brachial plexus
The '''broadest muscle of the back'''.
Origin: thoracolumbar fascia.
Insertion: teres tuberosity of the humerus.
Actions: antagonist to the brachiocephalic m. The cranial fibers strap the scapula to the chest. It retracts the free limb and flexes shoulder joint. It draws the trunk forward over the fixed limb.
'''Pectoral mm.''': brachial plexus
Two superficial parts, cranial and caudal, these aren't very distinct in the ox.
Origin: cranial sternum.
Insertion: 1. cranial ('''descending'''), crest of the humerus distal to the deltoid tuberosity.
2. caudal ('''transverse'''): covers elbow joint to insert on the medial fascia of the forearm.
Action: adduct the forelimb and assist in protraction and retraction.
'''Serratis ventralis''': branch of the brachial plexus.
Origin: C4 to 10th rib.
Insertion: medial scapula and scapular cartilage.
Action: supporting the weight of the trunk. It is reinforced by strong fascia. The cervical portion can retract the limb and the caudal portion can advance the limb.
'''Rhomboids''': brachial plexus,
Origin: nuchal ligament.
Insertion: dorsal border and adjacent scapula.
Action: retracting the limb, may also raise the limb.
===Intrinsic Musculature===
===Intrinsic Musculature===
====Muscles of the Shoulder====
====Muscles of the Shoulder====
These muscles are grouped:
These muscles are grouped:
*Lateral:'''Supraspinatus ''' and '''Infraspinatus''', Suprascapular n. of the brachial plexus
*Lateral:'''Supraspinatus ''' and '''Infraspinatus''', Suprascapular n. of the brachial plexus