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Limb Muscles - Horse Anatomy (view source)
Revision as of 14:26, 11 October 2012
, 14:26, 11 October 2012Created page with "{{unfinished}} ==Thoracic Limb== ===Extrinsic Musculature=== These muscles are responsible for joining the forelimb to the trunk, forming a synsarcosis rather than a conventi..."
{{unfinished}}
==Thoracic Limb==
===Extrinsic Musculature===
These muscles 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 to stabilize the scapula.
'''''Trapezius''''':
:'''Innervatation''': 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 the scapula against the trunk and swings cranially to advance the limb
'''''Brachiocephalic m.''''':
:'''Innervation''': Accessory n.
:Two parts separated by the clavicle, where it exists
:'''Origin''': Mastoid process of temporal bone, nuchal crest, wing of atlas and the transverse processes of the 2nd-4th cervical vertebrae
:'''Insertion''': Deltoid tuberosity and crest of the humerus
:'''Action''': Advances the limb and extends the shoulder joint when limb is in motion. Draws the head and neck ventrally when the limb is fixed
'''''Latissimus dorsi''''':
:'''Innervation''': local branch of brachial plexus
:The broadest muscle of the back
:'''Origin''': Thoracolumbar fascia
:'''Insertion''': Teres tuberosity of the humerus
:'''Action''': Antagonist to the brachiocephalic m. It retracts the free limb and flexes shoulder joint. It also draws the trunk forward over the fixed limb.
'''''Pectoral mm.''''':
:'''Innervation''': brachial plexus
:Two superficial parts, cranial and caudal
:'''Origin''': Cranial sternum
:'''Insertion''':
::Cranial ('''descending''') - The crest of the humerus, distal to the deltoid tuberosity
::Caudal ('''transverse''') - Covers the elbow joint to insert on the medial fascia of the forearm
:'''Action''': Adducts the forelimb, assist in protraction and retraction
'''''Serratis ventralis''''':
:'''Innervation''': branch of brachial plexus
:'''Origin''': C4 to 10th rib
:'''Insertion''': Medial scapula and scapular cartilage
:'''Action''': Supports 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''''':
:'''Innervation''': brachial plexus, although in some species, dorsal spinal nerves can innervate
:'''Origin''': Median connective tissue from poll to withers, lying deep to the trapezius
:'''Insertion''': Dorsal border and adjacent scapula
:'''Action''': Retracts the limb, may also raise limb
==Pelvic Limb==
==Thoracic Limb==
===Extrinsic Musculature===
These muscles 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 to stabilize the scapula.
'''''Trapezius''''':
:'''Innervatation''': 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 the scapula against the trunk and swings cranially to advance the limb
'''''Brachiocephalic m.''''':
:'''Innervation''': Accessory n.
:Two parts separated by the clavicle, where it exists
:'''Origin''': Mastoid process of temporal bone, nuchal crest, wing of atlas and the transverse processes of the 2nd-4th cervical vertebrae
:'''Insertion''': Deltoid tuberosity and crest of the humerus
:'''Action''': Advances the limb and extends the shoulder joint when limb is in motion. Draws the head and neck ventrally when the limb is fixed
'''''Latissimus dorsi''''':
:'''Innervation''': local branch of brachial plexus
:The broadest muscle of the back
:'''Origin''': Thoracolumbar fascia
:'''Insertion''': Teres tuberosity of the humerus
:'''Action''': Antagonist to the brachiocephalic m. It retracts the free limb and flexes shoulder joint. It also draws the trunk forward over the fixed limb.
'''''Pectoral mm.''''':
:'''Innervation''': brachial plexus
:Two superficial parts, cranial and caudal
:'''Origin''': Cranial sternum
:'''Insertion''':
::Cranial ('''descending''') - The crest of the humerus, distal to the deltoid tuberosity
::Caudal ('''transverse''') - Covers the elbow joint to insert on the medial fascia of the forearm
:'''Action''': Adducts the forelimb, assist in protraction and retraction
'''''Serratis ventralis''''':
:'''Innervation''': branch of brachial plexus
:'''Origin''': C4 to 10th rib
:'''Insertion''': Medial scapula and scapular cartilage
:'''Action''': Supports 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''''':
:'''Innervation''': brachial plexus, although in some species, dorsal spinal nerves can innervate
:'''Origin''': Median connective tissue from poll to withers, lying deep to the trapezius
:'''Insertion''': Dorsal border and adjacent scapula
:'''Action''': Retracts the limb, may also raise limb
==Pelvic Limb==