Muscular system:

• Mimetic muscles = facial expression, control - eyelids, mouth, muzzle, cheeks and ears.
• Masticatory muscles = mastication - chewing, active most of the day.
• Orbicular eye muscles = close eyes.
• Orbicular mouth muscles = close lips.
• Levator upper lip muscles = raise lips.
• Auricular muscles = move ears.
• Digastric muscle = open the mouth.
• Sternocephalic muscle = head of the breast bone, aids in head lowering.
• Brachiocephalic muscle = upper arm/head of the brachium, aids in head lowering and when in motion the muscle aids protraction through shoulder joint extension.
• Jugular groove = jugular vein sits here - between the sternocephalic and brachiocephalic muscles. (Where intravenous injections happen).
• Splenius muscle = head of the withers/anterior neck, raises the head and exerts a cranial pull on the spinous processes of the withers.
• Semispinalis capitis muscle = upper thoracic vertebrae/occipital process on the skull, raises the head and moves it from side to side.
• Serratus ventralis muscle = posterior neck/inner scapula side of the anterior ribs, attaches forelimb to the trunk and enables it to move forwards + backwards.
• Trapezius muscle = raises and advances the scapula.
• Latissimus dorsi = retracts the forelimb.
• Longissimus dorsi = stabilises the spine and is responsible or lateral spine flexion when 1 side is contracted.
• Superficial pectorals = (descending + transverse) connect the cranial sternum, humerus and forearm fascia - protraction and adduction of the forelimb.
• Superficial pectorals = (ascending + deep) connect the caudal breastbone, humerus and forearm fascia - limb retraction.
• Abdominals meet on the white line/Linea alba.
• Abdominal wall = external oblique - fibres run backwards + downwards, internal oblique - fibres run forwards + downwards and transverse muscle.
• Straight abdominal muscle = (rectus abdominus muscle) ribs to the pubic bone, holds the abdominal wall and stops the pelvis tilting down.
• Supraspinatus shoulder muscle = above the spine on the scapula - shoulder extension.
• Infraspinatus shoulder muscle = below spine on the scapula - shoulder extension.
• Subscapularis shoulder muscle = inner/medial scapular - shoulder extension.
• Deltoideus muscle = spine/caudal scapula to the front of the humerus (deltoid tuberosity) - shoulder flexion.
• Triceps brachii = caudal scapula to olecranon - elbow extension.
• Tensor fascia antebrachii = deeper caudal spine to the humerus - elbow extension.
• Bicep brachii muscle = front of scapula to the radius - elbow flexion.
• Brachialis muscle = back of the humerus to the radius - elbow flexion.
• Psoas major/iliopsoas muscle = hindlimb protraction through flexing the hip joint.
• Middle gluteal muscle = hip extensor for thrust.
• Quadricep muscle = inserts on the patella via 3x ligaments, stifle extension, hip flexion and limb protraction.
• Adductors = muscles and tendons around the gaskin.
• Hamstring muscles = behind the femur, originate from the ischial tuberosity of the pelvis and sacrum. Inserts on the stifle/tibia and extends the hip, stifle and hock.
• Bicep femoris muscle = outside of the thigh.
• Semitendinosus and semimembranosus muscles = inside of the thigh.
• Cranial antebrachial = craniolaterally on the carpal joint and digit - extensors.
• Caudal antebrachial = caudolaterally on the carpal joint and digit - flexors.
• Tendon sheath = sits over the carpal/digit extensors, extend just below the carpus and have a radial nerve supply.
• Radial nerve paralysis = swinging limb lameness.