Equine Anatomy Charlotte Flashcards
Rhomboids
Extends, elevates or bends the neck and head laterally.
Supraspinatus; extends and stabilizes the shoulder joint.
Infraspinatus
Extend and flex the shoulder joint.
Functions as a contractile collateral ligament.
Deltoideus; closely tied to the infraspinatus
Helps flexion of the shouler joint. The fascia parts starts from the scapula spine.
Latissimus dorsi
Helps with shoulder flexion and retracts the limb.
Also when the forelimb is extendedand planted on the ground, the latissimus dorsi pulls the body forward.
External intercostals
They assist in inspiration; the bring the ribs forward and outward which increases space between the thoracic cavity, creating a vacuum for air to fill.
Serratus dorsalis costalis
Expirartory muscle - pulls the ribs caudally.
Transverse abdominis
Compresses the abdominal viscera
Serratus ventralis thoracis
If the foreleg is stationary the muscle supports the trunk. During motion the muscle pulls the upper part of the scapula downa and back; This rotates the shoulder joint up and forward when the horse is taking a step. ( the cervicus does the opposite)
Internal abdominal Oblique
The muscle compresses the viscera during defecation, mocturation and paturition and expiration.
It also flexes the trunk
External Abdominal oblique
Compresses the abdominal viscera and assists in micturation, parturation and defecation expiration
Superficial Gluteal
Flexes the hip, protracts and abducts the hindlimb
Accessory Gluteal (Gluteal Minimus)
Flexes the hip and protracts and abducts the hindlimb
Tensor Fascia Latae
Flexes the hip joint, protracts the hindlinb, extends the stifle and tenses the fascia latae
Biceps femoris
Extends the hip and stifle joint.
The caudal division flexes the stifle, abducts the hindlimb and extends the hock joint.
Semimembranosus
If the limb is planted, this muscle extends the hip and stifle joint. If the limb is not planted this muscle retracts, adducts and rotates the limb inward.
Semitendinsus
If the limb is planted the muscle extends the hip, stifle and hock joints.
if the limb is not planted, this muscle flexes the stifle, retracts and adducts the limb
Deep digital flexor
A group of muscles that include the lateral digital flexor, the tibialis caudalis and the medial digital flexor. They all attach to the caudal surface of the tibia and the tibial condyle and joint into a common tendon that inserts into the plantar surface of the distal phalanx. They extend the hock and flex the digits.
Lateral digital Extensor
Extends the digits and flexes the hock
Long digital Extensor Muscle
This muscle extends the digits and flexes the hock
Serratus Ventralis Thoracis
If the foreleg is stationary, this muscle supports the trunk. During motion this muscles pulls the upper part of the scapula down and back. This rotates the shoulder joint up and forward when the horse is taking a step. The cervical part of the muscle does the opposite
Triceps (long head)
All triceps are elbow extensors.
Because the muscle crosses the shoulder joint it can help with shoulder flexion. It is also an important part of the stay apparatus to keep the elbow fixed,
Triceps lateral head
All triceps are elbow extensors
Extensor carpi radialis
Part of the stay apparatus and prevents flecion of the carpla joint when the weight is on the limb, This muscle has two heads, one attaching to the lateral epicondyloid crest of the humerus and the other head attaches just proximal to the humeral captulum.
Biceps Brachii
Extends the shouler joint and flexes the elbow joint
Pectoral Transversus
Connects the forelimb with the trunk. It adducts and retracts the forelimb
Pectoralis Descendens
Connects the forelimb with the trunk - it adducts and retracts the forelimb
Brachiocephalicus
It advances the limb and extends the shoulder. If the leg is planted, the muscle will draw the neck and head to the side (it has two parts the cleidobrachialis etc)
Omotransversarius
This muscle raises the scapula and helps to move the limn forward. If the forelimb is planted, it will move the neck laterally.
Sternomandibularis
(sternomandibular - or sternocephalicus)
It opens the mouth and flexes or inclines the head and neck to the same side as the muscle
serratus ventralis cervicus
This muscle pulls the upper portion of the scapula forward and up, which rotates the shoulder joint down. This happens during the stance phase of the gait. If the leg is weight bearing, however, a contraction of this muscle will extend the neck *bilateral) or side bend (unilatera)
Longissimus dorsi
5 parts to this muscle; the atlantis, capitis, cervicis, thoracis and lumborum. Extend the spine and unilateral results in side bend.
Subscapularis
Medial to the scapular, between the scapula and the ribcage. It extends the shoulder and helps to stabilize the joint against flexion.
Serratus Dorsalis costalis
Expiratory muscle. It pulls the ribcage caudally,
Gluteus Medius
Extends the hip and assists abduction of the hindlimb.
Iliacus
Flexes the hip and protracts the hindlimb and rotates it outward. When the hindlimb is fixed (as in standing) the muscle stabilizes the vertebral column.
Psoas
The Psoas and iliacus together are called the ilopsoas. The psaos are in two parts *minor.major*
. This is Psoas major. It flexes the hip, rotates outwards and and stabilizes the vertebral column when the hindlimb is fixed.
The psoas minor can only flex the lumbar spine and pelvis because it doesn’t cross the hip joint.
Quadriceps femoris (quads)
This grouping of 4 muscles, i,e, the vastus medius, vastus lateralis, vastus intermedius and rectus femoris. They extend the stifle joint.
Gastrocnemius
Extends the hock and flexes the stifle
Gracilis
The most superficial muscle on the inner thigh. It adducts the limb and extends the stifle.
Adductor
Located next the sartorius, and is deep to the gracilis. When it contracts it adducts the limbm ,rotates the femur toward the medial plane an flexes the hip.
Sartorius
Flexes the hip joint, protracts and adducts the limb at the stifle
Rectus Abdominis
Aids, inspiration, urination and defecatoin and parturition. Flexion of the vertebral column when fellow muscles contract (and assists with lateral bending of the vertebral bending) Helps keep in the adominal viscera.
Brachialis
Flexes the elbow joint.
Teres minor
Flexes the shoulder joint
Juxtavertebral muscle Of the trunk
Multifidus (transverse spinous)
External intercostals
Run caudal ventral between the ribs. Aid inspiration. Meaning ribs are brought forward and outward making a vacuum for air to fill..
Rectus capitis ventralis
O: ventral arch of atlas
Ins; base of the skull
Function: flexes Atlanto - occipital joint. Or unilateral contraction inclines the head that side.
Rectus capitis dorsalis mit minor
O: dorsal tubercle of atlas Ins: terminates beneath the rectus capitis dorsalis mit major immediately lateral to the attachment of the funicular part of the nuchal ligament. Function: extension of th head.
Rectus dorsalis mit major
O: dorsal edge of spinous process c2 (axis) Ins: terminates on the nuchal crest (poll) Function: extend the head
Multifidus cervicus
O: articular processes of last 4-5 cervical vertebra and first thoracic. A ‘two’ joint coverage with 3 bundles. Ins: terminates on the spinous and articular processes of the cranial vertebra Function: stabilisers of the spine. They extend the neck, with unilateral contraction they pull the spinous processes causally and to that contracted side, resulting in twisting of the neck. (Right contraction, twisting will be clockwise as seen by the rider)
Temporalis
Closes the jaw for mastication (elevates he mandible) attaches to the temporal fossa and medial surface of the zygomatic arch and insets Into the coronoid process of the mandible.
Serratus ventralis cervicus
Attaches to the cervical vertebra of 4-7 and inserts on scapula cartilage. It pulls the upper portion of scapula forward and up which the shoulder joint down - this happens during the stance phase of the gait. If the leg is weight bearing, however, a contraction of this muscle will extend the neck (bilateral) or side bend) with unilateral.
Serratus ventralis
O: last 3-4 cervical vertebra First 8-9 ribs Ins; scapula cartilage Function: backward and forward movement of the scapular and thus limb
Trapezius
Apopneurosis along the dorsal midline. Supraspinatus ligament of the cervical vertebra Ins: scapula cartilage Function: elevation of the shoulder
Rhomboideus
Nuchal and supraspinatus ligament. Ins: medial scapular cartilage Function: elevation of the scapular
Latissimus dorsi
O: supraspinatus ligament and thoracolumbar fascia Ins; teres (medial) tuberosity of the humerus Function; retracts limb after extension
Brachiocephalicus
O: temporal bone, wing of atlas, 2nd, 3rd, and 4th cervical cerebral. Ins; deltoid tuberosity of the humerus Function; Moves limb forward when the head and neck is fixed. Bilateral flexion, unilateral side flexion.
Brachialis
O: caudoproximal surface of the humerus. Ins: cranial medial portion of the radius Function: flexion of the elbow.
Biceps brachii
O: supraglenoid tubercle of the scapula. Ins: radial tuberosity. Function; extension of the shoulder and elbow
Triceps brachii
O: posterior border of the scapular, deltoid tuberosity, shall of humerus. Ins: lateral olecranon, medial olecranon.
Function: extension of the elbow.
Superficial digital flexor
O: medial epicondyle of the humerus. Posterior surface of the radius Ins; 2nd phalanx
Function: flexion of the carpus - extension of the elbow.
Deep digital flexion tendor
O: Medial epicondyle of humerus Proxima radius, proximal ulna. Ins; 3rd phalanx Function: flexion of the carpus Extension of the elbow Flexion of the digits
Flexor Carpi radialis
O: medial condyle of humerus Ins: proximal end of 2nd phalanx Function: flexion of carpus
Flexi Carpi ulnaris
O: medial epicondyle of humerus Medial olecranon Ins: accessory carpal bone Function: flexion of the carpus
Common digital extensor
Lateral epicondyle of humerus Shaft of ulna Ins: merges with the suspensory ligament branches and inserts into p3 Function; extension of the carpus and digit
Lateral digital extensor
O: lateral tuberosity of the radius Shaft is ulna Ins: combines with common digital extensor and inserts into p3 Function: extension of the carpus and extension of the digits.
Extensor Carpi radialis
O: lateral condyle of humerus Ins: metacarpal tuberosity Function: extension of carpus flexion of elbow
Infraspinatus
O: Infraspinatus fossa Scapular cartilage and spine Ins: greater tubercle of humerus Function: extends and flexes shoulder
Supraspinatus
O: supraspinatus fossa scapula cartilage and spine Ins: greater and lesser tubercles of humerus Function: extends shoulder and stabilises joint
Biceps femoris
O: spinous processes of sacra vertebra 3-5 Sacrosiatic ligament Ischia tuber Ins: patella, cranial border of the tibia, tuberosity of the calcareous Function; extension of the hip
Semitendinosus
O: last 2 sacral and first two caudal vertebra Sacrosiatic ligament Ischial Tuber Ins: cranial border of tibia Tuberosity of calcaneus Function: extension of hip and hock
Semi membranosus
O: 1st caudal vertebra Sacrosiatic ligament Ventromedial aspect of the ischial tuber Ins: medial condyle of the femur Medial condyle of the tibia Function: extension
Medial gluteal
O: longissimus dorsi, ilium, sacrum and sacrosiatic ligament Ins: greater trochanter of the femur Function: extension of the hip and inward rotation of the hip
Psoas
O: lumbar transverse processes Ins: lesser trochanter of the femur (medial) Function: flexion of the hip
Iliacus
O: ventral wing of the ilium Ins: lesser trochanter of the femur Function: flexion of the hip
Sartorius
Iliac fascia Ins: medial shaft of the stifle Function: flexion of hip and extension of stifle
Tensor fascia latae
O: coxal tuber Ins: lateral femoral fascia Patella ligament Function: flexion of the hip / extension of the stifle
Rectus femoris (quad)
O; body of ilium
Ins: patella tuberosity of Ilium
Function: flexion of hip / extension of stifle
Vastus lateralis (quad)
O: lateral surface of femur Ins: patella tuberosity of femur Function: extension of stifle
Vastus intermedius (quad)
Medial surface of femur Ins: patella and tuberosity of tibia Function: extension of stifle
Vastus medialis (quad)
Medial surface of femur Ins: patella and tuberosity of femur Function; flexion of hip and extension of stifle
Superficial digital flexor
O: supra condyle fossa of femur Ins: distal end of proximal phalanx Proximal end of distal phalanx Function; flexion of stifle Extension of hock Flexion of digits
Deep digital flexor
O: caudal surface of tibia Lateral tibial condyle
Ins: planter surface of distal phalanx Function: extension of hock and Flexion of digits
Gastrocnemius
O: distal tuberosity of femur Ins: tuberosity of calcaneus Function: extension of the hock
Longissimus capitis
O: TRanserve process of T1 and T2 and the transerce process of the last 5 Cervical Vertebrae
In: Terminates on the mastoid process of the temporal bone.
Function: When both sides work together they extend the neck, unilaterally they flex the neck
Longissimus Captits
Bi laterally they extend the neck, unilaterally they flex the neck to the side that contracts.
Difficult to palpate as sandwiched between splenius and semi-spinalis
longissimus thoracis et lumborum Muscle
When both sides are activated they extend the back, when one side is activated they bend the spine laterally (to the side of contraction)
Masster
Origion: Begins at the facial crest and zygomatic Arch
Insertion: Terminates on the lateral surface of the mandible
Function: When active closes the jaw. Assists in mastication.
Temporalis
Origion: Temporal fossa and and medial surface of the zygomatic arch
Insertion: As it crosses medially and ventrally to the zygomatic arch it inserts on the coronoid process of the mandible.
Function: when the muscle is active it closes the jaw
The nuchal ligament that turns into the supraspinous ligament as it enters the thoracic vertebra.
The laminar portion provides further passive support of the head and neck. It roughly spans c2 - c5 (as opposed to c2-c7) There are two cords side by side and two sheets side by side (separated by loose connective tissue)
e
External Intercostals
Origin: Arise from the craial border of the ribs and their cartilages.
Insertion: Terminates on the caudal border of the ribs and cartilage.
Function: Support the ribcage and aid inspiration. (exhale)
External intercostals
Origin: Originates from the caudal border of the ribs
Insertion: Cranial border and lateral surface of the succeeding ribs.
Rectus capitis ventralis (ventral straight muscle of the head)
Origin: Begins at the ventral arch of the atlas
Insertion: Terminates on the two roughbasilar tubercles on the base of the skill at the junction of the basioccipital and the spenoid body
Function: Flexes the atlanto-occipital joint. Or when used unilaterally inclines the head to the contracted side.
Rectus capitis lateralis
Origin: Begins on the ventral arch of the atlas
Insertion: Terminates on the paracondylar oricess if the occipital bone
Function: Flexes atlanto-occipital joint and unilateral inclines the head to the contracted side.
Rectus capitis dorsalis minor
Origin: Muscle begins on the dorsal tubercle of the atlas
Insertion: Terminates beneath the rectus capitis dorsalis major immediately lateral to the attachment of the funicular part of the nuchal ligament on the occipital bone.
Function: Although a small weak muscle, it most likely assists the rectus capitis dorsalis major in the extension of the head.
Rectus capitis dorsalis major
Origin: Starts at the dorsal edge of the spinous process of the axis (c2)
Insertion: Terminates on the nuchal crest (Poll)
Function: Will extend the head
Multifidus (Cervicus)
Origin: Found on the articlar processes of the last 4-5 cervical vertebrae and the first thoracic vertebra. Has a two joint coverage.
Insertion: Terminates on the Spinous process and articuar process inserting in to the more cranial vertebra
Function: Stabilizers of the spine.Extend the neck. When contracting one side they pull the spinous processes caudally and towards the contracting muscle (twisting of the neck) (if the right hand side is contracted then twisting will be clockwise as seen by the rider)
Multifidus thorasic et lumborum
Origin: Originate on the articular processes of the thoracic, lumbar and sacral vertebrae. The multifidi begin at the mid-sacrum and extend to the cranial thorax where they continued by the multifidi of the neck.
Insertion: Normally these bundles terminates on the summits of the spinous processes of the preceding vertebrae. However on the first eight thoracic vertebrae which have exceptionally long spinous processes, the muscles of the end of the sides.
Obliquus capitis cranialis (cranial head oblique muscle)
Origin: arises from the entire cranial edge and adjacent ventral surface of the wing of the atlas (c1)
Insertion: It terminates primarily on the nuchal crest of the occipital bone with minimal fibers terminating on the dorsal end of the paracondylar process.
Function: The main action of the muscle is to extend the the atlanto-occipital joint, thus straightening the horses head. There may be minimal lateral movement of the joint when contracting on one side.
Obliquus capitis caudalis (caudal head oblique muscle)
Origin: It arises from the lateral surface of the spinous process and articular process of the axis (c2)
Insertion: Inserts into the dorsal surface of th e atlas’s wing
Function: It rotates the atlas and head to the same side as the muscle. It also assists in extending and fixing the atlanto xial joint (c1-c2)
Longus capitis (long muscle of the head)
Origin: It begins on the transverse processes of c3-c5
Insertion: same termination as the rectus capitis ventralis on the same two rough tubercles (basilar tubercles) at the junction of the basioccipital and the spenoid body. The tendons of this muscle and the rectus capitis ventralis re fused near the insertion.
Function: When this muscle contracts both sides the neck is flexed at the nuchal curve. When only one side is engaged, it bends the neck sideways (laterally) to the side of contraction.
Semispinalis capitis
Origin: Transerve process of thoracic vertebra 1-7. Articular processes of cervical verebra 3-7
Insertion: occipital bone
Function: Elevation of the neck, lateral movements of the head and neck
Longissimus thoracis et lumborum
OR: Begins at the ilium and thge frist to theird SP of the sacrum, the thoracic and lumbar SP and the supraspinatus ligament
INS: On the thoracic and lumbar transverse processes
Retractor Costae
When active, retracts the last rib moving it caudally and medially. It therefore aids expiration
Retractor Costae
OR: Arises from the transverse process of the L1 to L3 or L4 via the thoracolumbar fascia
INS: Ends on the last rib.
Infraspinatus
Makes fine adjustments to the angle of the shoulder joint and to facilitate balance and limb direction,
It abducts the arm and rotates it laterally (external rotation) Also acts as a lateral collateral ligament to the shoulder joint
Infraspinatus
OR: Infraspinatus fossa of the scapula
INS: Ends on the greater tubercle of the humerus and distal to the supraspinatus
Longissimus capitis
O: TRanserve process of T1 and T2 and the transerce process of the last 5 Cervical Vertebrae
In: Terminates on the mastoid process of the temporal bone.
Function: When both sides work together they extend the neck, unilaterally they flex the neck
Longissimus Captits
Bi laterally they extend the neck, unilaterally they flex the neck to the side that contracts.
Difficult to palpate as sandwiched between splenius and semi-spinalis
longissimus thoracis et lumborum Muscle
When both sides are activated they extend the back, when one side is activated they bend the spine laterally (to the side of contraction)
Masster
Origion: Begins at the facial crest and zygomatic Arch
Insertion: Terminates on the lateral surface of the mandible
Function: When active closes the jaw. Assists in mastication.
Temporalis
Origion: Temporal fossa and and medial surface of the zygomatic arch
Insertion: As it crosses medially and ventrally to the zygomatic arch it inserts on the coronoid process of the mandible.
Function: when the muscle is active it closes the jaw
The nuchal ligament that turns into the supraspinous ligament as it enters the thoracic vertebra.
The laminar portion provides further passive support of the head and neck. It roughly spans c2 - c5 (as opposed to c2-c7) There are two cords side by side and two sheets side by side (separated by loose connective tissue)
e
External Intercostals
Origin: Arise from the craial border of the ribs and their cartilages.
Insertion: Terminates on the caudal border of the ribs and cartilage.
Function: Support the ribcage and aid inspiration. (exhale)
External intercostals
Origin: Originates from the caudal border of the ribs
Insertion: Cranial border and lateral surface of the succeeding ribs.
Rectus capitis ventralis (ventral straight muscle of the head)
Origin: Begins at the ventral arch of the atlas
Insertion: Terminates on the two roughbasilar tubercles on the base of the skill at the junction of the basioccipital and the spenoid body
Function: Flexes the atlanto-occipital joint. Or when used unilaterally inclines the head to the contracted side.
Rectus capitis lateralis
Origin: Begins on the ventral arch of the atlas
Insertion: Terminates on the paracondylar oricess if the occipital bone
Function: Flexes atlanto-occipital joint and unilateral inclines the head to the contracted side.
Rectus capitis dorsalis minor
Origin: Muscle begins on the dorsal tubercle of the atlas
Insertion: Terminates beneath the rectus capitis dorsalis major immediately lateral to the attachment of the funicular part of the nuchal ligament on the occipital bone.
Function: Although a small weak muscle, it most likely assists the rectus capitis dorsalis major in the extension of the head.
Rectus capitis dorsalis major
Origin: Starts at the dorsal edge of the spinous process of the axis (c2)
Insertion: Terminates on the nuchal crest (Poll)
Function: Will extend the head
Multifidus (Cervicus)
Origin: Found on the articlar processes of the last 4-5 cervical vertebrae and the first thoracic vertebra. Has a two joint coverage.
Insertion: Terminates on the Spinous process and articuar process inserting in to the more cranial vertebra
Function: Stabilizers of the spine.Extend the neck. When contracting one side they pull the spinous processes caudally and towards the contracting muscle (twisting of the neck) (if the right hand side is contracted then twisting will be clockwise as seen by the rider)
Multifidus thorasic et lumborum
Origin: Originate on the articular processes of the thoracic, lumbar and sacral vertebrae. The multifidi begin at the mid-sacrum and extend to the cranial thorax where they continued by the multifidi of the neck.
Insertion: Normally these bundles terminates on the summits of the spinous processes of the preceding vertebrae. However on the first eight thoracic vertebrae which have exceptionally long spinous processes, the muscles of the end of the sides.
Obliquus capitis cranialis (cranial head oblique muscle)
Origin: arises from the entire cranial edge and adjacent ventral surface of the wing of the atlas (c1)
Insertion: It terminates primarily on the nuchal crest of the occipital bone with minimal fibers terminating on the dorsal end of the paracondylar process.
Function: The main action of the muscle is to extend the the atlanto-occipital joint, thus straightening the horses head. There may be minimal lateral movement of the joint when contracting on one side.
Obliquus capitis caudalis (caudal head oblique muscle)
Origin: It arises from the lateral surface of the spinous process and articular process of the axis (c2)
Insertion: Inserts into the dorsal surface of th e atlas’s wing
Function: It rotates the atlas and head to the same side as the muscle. It also assists in extending and fixing the atlanto xial joint (c1-c2)
Longus capitis (long muscle of the head)
Origin: It begins on the transverse processes of c3-c5
Insertion: same termination as the rectus capitis ventralis on the same two rough tubercles (basilar tubercles) at the junction of the basioccipital and the spenoid body. The tendons of this muscle and the rectus capitis ventralis re fused near the insertion.
Function: When this muscle contracts both sides the neck is flexed at the nuchal curve. When only one side is engaged, it bends the neck sideways (laterally) to the side of contraction.
Semispinalis capitis
Origin: Transerve process of thoracic vertebra 1-7. Articular processes of cervical verebra 3-7
Insertion: occipital bone
Function: Elevation of the neck, lateral movements of the head and neck
Longissimus thoracis et lumborum
OR: Begins at the ilium and thge frist to theird SP of the sacrum, the thoracic and lumbar SP and the supraspinatus ligament
INS: On the thoracic and lumbar transverse processes
Retractor Costae
OR: Arises from the transverse process of the L1 to L3 or L4 via the thoracolumbar fascia
INS: Ends on the last rib.
