Muscles of the Forelimb Flashcards
(17 cards)
Identify the brachiocephalicus muscle :
The m. brachiocephalicus is divided by an indistinct clavicular intersection, the tendinous remnant of the clavicle, into the m. cleidocephalicus (extending from the tendon to the head) and the m. cleidobrachialis (extending from the tendon to the arm). In dogs, the m. cleidocephalicus has two distinct muscle bellies, one inserting on the neck (pars cervicalis), visible here, and one on the skull (pars mastoideus).
Attachments: dorsal median raphe of neck & mastoid process of skull (m. cleidocephalicus); cranial aspect of distal humerus (m. cleidobrachialis)
A: Advance limb, extend shoulder, laterally flex neck
N: Cervical spinal nn., accessory n.
Identify the clavicular intersection :
m. brachiocephalicus
The m. brachiocephalicus is a long muscle bridging between the brachium and the head. It is divided by a more-or-less distinct clavicular intersection (tendon), the connective tissue remnant of the clavicle, into the m. cleidocephalicus (extending from the intersection to the head and the m. cleidobrachialis (extending from the intersection to the arm).
m. cleidocephalicus
In dogs, the m. cleidocephalicus has two distinct muscle bellies, one inserting on the neck (pars cervicalis) and one on the skull (pars mastoideus). Pars cervicalis is a fan-shaped strap muscle; pars mastoideus takes origin at the clavicular intersection with it, but becomes identifiable as a thicker, separate portion at midneck, running deep to the cranial edge of the cervical portion.
O: clavicular intersection
I: dorsal median raphe of neck (pars cervicalis) and mastoid process of skull (pars mastoideus)
A: advance limb, extend shoulder, lateral flexion of neck (unilateral action) or fixation of neck (bilateral action)
N: ventral brr. of cervical spinal nn., accessory n.
m. cleidobrachialis
The m. cleidobrachialis is a rope-like muscle that runs from its origin at the clavicular intersection across the cranial aspect of the shoulder, distad between the m. brachialis and m. biceps brachii to its insertion on the humerus.
O: clavicular intersection
I: cranial aspect of distal humerus
A: advance limb, extend shoulder, lateral flexion of neck (unilateral action) or fixation of neck (bilateral action)
Identify the cleidobrachialis muscle:
m. cleidobrachialis
The m. brachiocephalicus is a long muscle bridging between the brachium and the head. It is divided by a more-or-less distinct clavicular intersection (tendon), the connective tissue remnant of the clavicle, into the m. cleidocephalicus (extending from the intersection to the head and the m. cleidobrachialis (extending from the intersection to the arm).
m. cleidocephalicus
In dogs, the m. cleidocephalicus has two distinct muscle bellies, one inserting on the neck (pars cervicalis) and one on the skull (pars mastoideus). Pars cervicalis is a fan-shaped strap muscle; pars mastoideus takes origin at the clavicular intersection with it, but becomes identifiable as a thicker, separate portion at midneck, running deep to the cranial edge of the cervical portion.
O: clavicular intersection
I: dorsal median raphe of neck (pars cervicalis) and mastoid process of skull (pars mastoideus)
A: advance limb, extend shoulder, lateral flexion of neck (unilateral action) or fixation of neck (bilateral action)
N: ventral brr. of cervical spinal nn., accessory n.
m. cleidobrachialis
The m. cleidobrachialis is a rope-like muscle that runs from its origin at the clavicular intersection across the cranial aspect of the shoulder, distad between the m. brachialis and m. biceps brachii to its insertion on the humerus.
O: clavicular intersection
I: cranial aspect of distal humerus
A: advance limb, extend shoulder, lateral flexion of neck (unilateral action) or fixation of neck (bilateral action)
Identify the cleidocephalicus muscle:
m. cleidocephalicus
In dogs, the m. cleidocephalicus has two distinct muscle bellies, one inserting on the neck (pars cervicalis) and one on the skull (pars mastoideus). Pars cervicalis is a fan-shaped strap muscle; pars mastoideus takes origin at the clavicular intersection with it, but becomes identifiable as a thicker, separate portion at midneck, running deep to the cranial edge of the cervical portion.
O: clavicular intersection
I: dorsal median raphe of neck (pars cervicalis) and mastoid process of skull (pars mastoideus)
A: advance limb, extend shoulder, lateral flexion of neck (unilateral action) or fixation of neck (bilateral action)
N: ventral brr. of cervical spinal nn., accessory n.
Identify the cutaneous trunci muscle:
The m. cutaneus trunci is a sheet of skeletal muscle attached to the skin of the thorax and abdomen. It frequently is removed during skinning.
O: superficial fascia of trunk
I: caudal border of deep pectoral muscle & fascia of medial brachium
A: twitch of skin
N: lateral thoracic nerve
Identify the deltoid muscle:
The m. deltoideus has two heads, pars scapularis and pars acromialis.
O: spine and acromial process of scapula
I: deltoid tuberosity of humerus
A: flexion of shoulder joint
N: axillary n.
Identify the deltoid muscle, acromial part:
(deltoid m., acromial part)
The m. deltoideus has two heads, pars scapularis and pars acromialis.
O: spine and acromial process of scapula
I: deltoid tuberosity of humerus
A: flexion of shoulder joint
N: axillary n.
Identify the triceps brachii muscle, lateral head (catput laterale)
(triceps brachii m., lateral head)
In the dog, the m. triceps brachii possesses four heads. These insert in common via a stout tendon on the point of the elbow, formed by the olecranon of the ulna. There is a synovial bursa between the tendon of the long head and the cranial part of the olecranon.
O: long head: caudal border of scapula; lateral head: tricipital line of humerus; accessory head: neck of humerus; medial head: crest of lesser tubercle
I: olecranon
A: shoulder flexion (long head only) and extension of elbow
N: radial n.
Identify the triceps brachi muscle, long head (caput longum):
(triceps brachii m., long head)
In the dog, the m. triceps brachii possesses four heads. These insert in common via a stout tendon on the point of the elbow, formed by the olecranon of the ulna. There is a synovial bursa between the tendon of the long head and the cranial part of the olecranon.
O: long head: caudal border of scapula; lateral head: tricipital line of humerus; accessory head: neck of humerus; medial head: crest of lesser tubercle
I: olecranon
A: shoulder flexion (long head only) and extension of elbow
N: radial n.
Identify the trapezius muscle, thoracic part:
(trapezius m., thoracic part)
The m. trapezius has cervical (pars cervicalis) and thoracic (pars thoracis) parts.
O: dorsal median raphe of neck and trunk (ca. C3 to T9)
I: spine of scapula
A: elevation and abduction of thoracic limb
N: accessory n.
Identify the trapezius muscle, cervical part:
(trapezius m., cervical part)
The m. trapezius has cervical (pars cervicalis) and thoracic (pars thoracis) parts.
O: dorsal median raphe of neck and trunk (ca. C3 to T9)
I: spine of scapula
A: elevation and abduction of thoracic limb
N: accessory n.
Identify the trapezius muscle:
The m. trapezius has cervical (pars cervicalis) and thoracic (pars thoracis) parts.
O: dorsal median raphe of neck and trunk (ca. C3 to T9)
I: spine of scapula
A: elevation and abduction of thoracic limb
N: accessory n.
Identify the sternocephalicus muscle:
The m. sternocephalicus has two distinct muscle bellies. The occipital part is broad and flat, and the mastoid part is round in cross-section.
O: manubrium sterni
I: pars occipitalis: nuchal crest in the occipital region. pars mastoideus: mastoid process of the temporal bone.
A: draw head and neck to side.
N: branches from accessory nerve and ventral branches of cervical nerves.
Identify the platysma muscle:
The m. platysma is a sheet of skeletal muscle attached to the skin of the neck and head. It frequently is lost during skinning, although you should try to preserve it.
O: dorsal raphe of neck
I: cheek and commissure of labia
A: draws lips caudad
N: facial n.
Identify the omotransversarius muslce:
m. omotransversarius
O: distal scapular spine
I: wing of atlas
A: draw limb craniad
N: branches from accessory n.
Identify the deltoid muscle, pars scapularis:
(deltoid m., scapular part)
The m. deltoideus has two heads, pars scapularis and pars acromialis.
O: spine and acromial process of scapula
I: deltoid tuberosity of humerus
A: flexion of shoulder joint
N: axillary n.
