Muscles & Joint Questions

  1. Intertransverse muscles function to draw the tail sideways and originate from the transverse processes of the caudal vertebrae then insert into the middle and last caudal vertebrae. They are especially well-developed in which animal species? Ruminants and Horses

  2. Digastric muscle functions to draw the mandible downwards and opens the mouth. This is a single-bellied muscle in domestic animals, except in the horse, where it has a caudal and rostral belly.

  3. Describe the brachiocephalicus muscle of domestic animals.

    Carnivores: additional cleidocervical muscle

    Ruminants and Pigs: additional cleido-occipital muscle

    All domestic species: cleidomastoid is present

  4. Which muscles are involved in joints? Identify muscles present in the joints of the different animal species.

  5. Ulnar flexor muscle functions as a flexor of the carpus and acts as a supinator of the limb in which animal species? Carnivores

  6. Muscle of the deep layer of the girdle which is absent in the dog.

    Subclavian Muscle

  7. Subclavian muscle functions to fix the scapula. It originates from the first costal cartilage and blends with the tendon of insertion of the brachiocephalic muscle. It is a narrow band in the ruminants.

  8. Describe the subclavian muscles of the different animal species.

    RUMINANTS- narrow band; takes origin from the first costal cartilage and blends with the tendon of insertion of the brachiocephalic muscle

    PIG AND HORSES - arises from the second to fourth costal cartilage, passes over the shoulder joint and unites with the aponeurosis of the supraspinatus muscle

    CARNIVORES - absent

  9. The deltoid muscle of this animal species originates from the spine of the scapula through an aponeurosis.

    Horse and Pig

  10. Describe the deltoid muscle of the different animal species.

    Animal Species

    Deltoid Muscle Description

    Horse

    One head of origin arising from the spine of the scapula by means of an aponeurosis. The aponeurosis is partly fused to the infraspinatus muscle. Inserts on the deltoid tuberosity of the humerus. Functions as a flexor of the shoulder joint and supports abduction and rotation.

    Pig

    One head of origin arising from the spine of the scapula by means of an aponeurosis. Inserts on the deltoid tuberosity of the humerus.

    Ruminants

    Two heads of origin: arising from the spine of the scapula with an aponeurosis and from the acromion. Inserts on the deltoid tuberosity of the humerus. Functions as a flexor of the shoulder joint and supports abduction and rotation.

    Carnivores

    Two heads of origin: arising from the spine of the scapula with an aponeurosis and from the acromion. Inserts on the deltoid tuberosity of the humerus. Functions as a flexor of the shoulder joint and supports abduction and rotation, especially.

    Dog

    Two heads of origin: arising from the spine of the scapula with an aponeurosis and from the acromion. Inserts on the deltoid tuberosity. Functions as a flexor of the shoulder joint; abductor of the upper arm.

    Cat

    Two heads of origin: arising from the spine of the scapula with an aponeurosis and from the acromion. Inserts on the deltoid tuberosity of the humerus. Functions as a flexor of the shoulder joint and supports abduction and rotation.

  11. Which muscle does not cover the femoral triangle in the carnivores?

    Sartorius Muscle

  12. What muscles are involved in the femoral triangle?

    Sartorius muscle, Gracilis muscle, and Pectineal muscle

  13. Describe the gluteal muscles in the different animal species.

  14. Popliteal muscle lies directly over the caudal aspect of the stifle joint. In the horse, it is a flat, triangular muscle covered by the gastrocnemius and the superficial digital flexor tendon.

  15. Pectoral muscle in the bird which arises from the keel of the sternum and the clavicle and passes directly to the ventral surface of the dorsal tubercle of the humerus. Its contraction produces the powerful downstroke of the wing. This is the largest in birds.

  16. Supracoracoid muscle in the bird which lies deep to and is covered entirely by the pectoralis muscle. This muscle is used mainly for upstroke. Is it employed in flight?

  17. The medial and lateral heads of this muscle enclose the fabellae in cats.

    Gastrocnemius Muscle

  18. Familiarize yourself with the different nerves innervating the muscles.

    Muscle Name

    Innervating Nerve(s)

    Quadrate muscle of the thigh

    Femoral nerve

    Straight muscle of the thigh

    Femoral nerve

    Lateral vastus muscle

    Femoral nerve

    Medial vastus muscle

    Femoral nerve

    Intermediate vastus muscle

    Femoral nerve

    Popliteal muscle

    Tibial nerve

    Gastrocnemius muscle

    Tibial nerve

    Soleus muscle

    Tibial nerve

    Superficial digital flexor muscle

    Tibial nerve

    Deep digital flexor muscle (Caudal tibial muscle)

    Tibial nerve

    Deep digital flexor muscle (Medial digital flexor muscle)

    Tibial nerve

    Deep digital flexor muscle (Lateral digital flexor muscle)

    Tibial nerve

    Sternomandibular muscle

    Ventral branch of accessory nerve

    Sternomastoid muscle

    Ventral branch of accessory nerve

    Sterno-occipital muscle

    Ventral branch of accessory nerve

    Latissimus dorsi (Broadest muscle of the back)

    Thoracodorsal nerve

    Trapezius muscle

    Dorsal branch of accessory nerve

    Omotransverse muscle

    Accessory nerve

    Superficial pectoral muscle

    Cranial and caudal thoracic nerves

    Transverse superficial pectoral muscle

    Cranial and caudal thoracic nerves

    Descending superficial pectoral muscle

    Cranial and caudal thoracic nerves

    Brachial muscle

    Musculocutaneous nerve, Radial nerve

    Biceps muscle of the arm

    Musculocutaneous nerve

    Triceps muscle of the forearm (Long head)

    Radial nerve

    Triceps muscle of the forearm (Lateral head)

    Radial nerve

    Triceps muscle of the forearm (Medial head)

    Radial nerve

    Anconeus muscle

    Radial nerve

    Tensor muscle of the antebrachial fascia

    Radial nerve

    Common digital extensor muscle

    Radial nerve

    Lateral digital extensor muscle

    Radial nerve, Superficial fibular nerve

    Long digital extensor muscle of the first and second digits

    Radial nerve

    Long abductor muscle of the first digit

    Radial nerve

    Superficial digital flexor muscle of the forearm

    Ulnar nerve, Median nerve

    Deep digital flexor muscle of the forearm

    Ulnar nerve, Median nerve

    Proximal digital interflexor muscles

    Ulnar nerve, Median nerve

    Major dorsal straight muscle of the head

    Dorsal branch of 1st cervical nerve

    Minor dorsal straight muscle of the head

    Dorsal branch of 1st cervical nerve

    Lateral straight muscle of the head

    Ventral branch of 1st cervical nerve

    Thoracic and cervical parts of the spinal muscle (pig/horse)

    Dorsal branches of the cervical, thoracic and lumbar nerves

    Thoracic and cervical parts of the spinal and semispinal muscle (carnivores/ruminants)

    Dorsal branches of the cervical, thoracic and lumbar nerves

    Multifidus muscle

    Dorsal branches of the cervical, thoracic and lumbar nerves

    Rotator muscles

    Dorsal branches of the thoracic nerves

    Interspinal muscles

    Dorsal branches of the thoracic nerves, dorsal branches of the lumbar nerves

    Intertransverse muscles

    Dorsal branches of the cervical, thoracic and lumbar nerves

    Internal oblique abdominal muscle

    Ventral branches of the thoracic and lumbar nerves

    Transverse abdominal muscle

    Ventral branches of the thoracic and lumbar nerves

    Straight abdominal muscle

    Ventral branches of the thoracic and lumbar nerves

    Lateral dorsal sacrococcygeal muscle

    Sacral and caudal nerves

    Medial dorsal sacrococcygeal muscle

    Sacral and caudal nerves

    Lateral ventral sacrococcygeal muscle

    Sacral and caudal nerves

    Medial ventral sacrococcygeal muscle

    Sacral and caudal nerves

    Intertransverse muscles of the tail

    Sacral and caudal nerves

    Coccygeal muscle

    Sacral and caudal nerves

    Iliocaudal muscle (only carnivores)

    Sacral and caudal nerves

    Internal obturator muscle

    Sciatic nerve

    External obturator muscle

    Obturator nerve

    Gemellus muscles

    Sciatic nerve

    Quadrate muscle of thigh

    Sciatic nerve

    Articular muscle of the hip joint

    Sciatic nerve

    Orbicular muscle of the eye

    Facial nerve, zygomatic branch

    Levator muscle of the medial angle of the eye

    Facial nerve, zygomatic branch

    Retractor muscle of the lateral angle of the eye

    Facial nerve, zygomatic branch

    Brachiocephalic muscle

    Accessory nerve

    Rhomboid muscle

    Dorsal and ventral branches of cervical and thoracic spinal nerves

    Ventral serrate muscle (thoracic part)

    Long thoracic nerve

    Major teres muscle

    Axillary nerve

    Subscapular muscle (caudal third)

    Axillary nerve

    Capsular muscle

    Axillary nerve

    Teres minor muscle

    Axillary nerve

    Deltoid muscle

    Axillary nerve

    Cleidobrachial muscle

    Axillary nerve

    Extensor muscles of the thoracic limb (except shoulder joint)

    Radial nerve

    Pronator teres muscle

    Median nerve

    Flexor muscles of the forearm and carpus (most)

    Ulnar nerve, Median nerve

    Interosseous muscles (palmar)

    Ulnar nerve

    Superficial pectoral muscle

    Cranial pectoral nerve

    Subclavian muscle (ungulates)

    Cranial pectoral nerve

    Deep pectoral muscle

    Caudal pectoral nerves

    Subscapular muscle (cranial and middle part)

    Subscapular nerves

    Supraspinatus muscle

    Suprascapular nerve

    Infraspinatus muscle

    Suprascapular nerve

    Coracobrachial muscle

    Musculocutaneous nerve

    Semitendinosus muscle (partly)

    Caudal femoral cutaneous nerve

    Biceps femoris muscle

    Caudal gluteal nerve

    Gluteobiceps muscle

    Caudal gluteal nerve

    Superficial gluteal muscles (depending on species)

    Caudal gluteal nerve

    Vertebral heads of the hamstring muscles (depending on species)

    Caudal gluteal nerve

    Middle gluteal muscle

    Cranial gluteal nerve

    Piriform muscle

    Cranial gluteal nerve

    Deep gluteal muscle

    Cranial gluteal nerve, Sciatic nerve

    Tensor of fascia lata

    Cranial gluteal nerve

    Semitendinosus muscle

    Tibial nerve

    Semimembranous muscle

    Tibial nerve

    Gastrocnemius muscle

    Tibial nerve

    Soleus muscle

    Tibial nerve

    Popliteal muscle

    Tibial nerve

    Superficial digital flexor muscle (hindlimb)

    Tibial nerve

    Deep digital flexor muscle (hindlimb)

    Tibial nerve

    Cranial tibial muscle

    Deep fibular nerve

    Long digital extensor muscle (hindlimb)

    Deep fibular nerve

    Lateral digital extensor muscle (hindlimb)

    Deep fibular nerve, Superficial fibular nerve

    Long fibular muscle

    Deep fibular nerve

    Short fibular muscle

    Deep fibular nerve

    Third fibular muscle

    Deep fibular nerve

    Short digital extensor muscle (hindlimb)

    Deep fibular nerve

    Gemelli muscles

    Sciatic nerve

    Internal obturator muscle

    Sciatic nerve

    Quadriceps muscle of the thigh

    Sciatic nerve, Femoral nerve

    Pectineal muscle (part in)

    Obturator nerve

    Gracilis muscle (part in)

    Obturator nerve

    Adductor muscles

    Obturator nerve

    Sartorius muscle (in part)

    Saphenous nerve (branch of femoral nerve)

    Inner lumbar muscles

    Femoral nerve

    Abdominal muscles

    Iliohypogastric nerve, Ilioinguinal nerve

    Internal oblique abdominal muscle

    Genitofemoral nerve

    Cremaster muscle

    Genitofemoral nerve

    Brachiocephalic muscle

    Dorsal branch of accessory nerve

    Trapezius muscle

    Dorsal branch of accessory nerve

    Omotransverse muscle

    Dorsal branch of accessory nerve

    Sternocephalic muscle

    Ventral branch of accessory nerve

    Cleidomastoid muscle

    Ventral branch of accessory nerve

    Cleido-occipital muscle

    Ventral branch of accessory nerve

    Lingual musculature

    Hypoglossal nerve (XII)

    Superficial levator muscle of eyelid

    Oculomotor nerve (III)

    Muscles of the eyeball (apart from dorsal oblique and lateral straight)

    Oculomotor nerve (III)

    Dorsal oblique muscle of the eyeball

    Trochlear nerve (IV)

    Masticator nerve muscles (Masseter, Temporal, Pterygoideus)

    Mandibular nerve (V3)

    Mylohyoid muscle

    Inferior alveolar nerve (branch of Mandibular nerve V3)

    Rostral part of digastric muscle

    Inferior alveolar nerve (branch of Mandibular nerve V3)

    Lateral straight muscle of eyeball

    Abducent nerve (VI)

    Lateral quarter of retractor muscle of eyeball

    Abducent nerve (VI)

    Stapedius muscle

    Stapedius nerve (branch of Facial nerve VII)

    Muscles for the pinna of the ear

    Caudal auricular nerve (branch of Facial nerve VII)

    Muscles for the eyelids

    Auriculopalpebral nerve (branch of Facial nerve VII)

    Muscles for the skin on the neck

    Cervical branch (branch of Facial nerve VII)

    Caudal part of the digastric muscle

    Digastric branch (branch of Facial nerve VII)

    Facial muscles (mimic)

    Buccal branches (branch of Facial nerve VII)

    Caudal stylopharyngeal muscle

    Pharyngeal branch (branch of Glossopharyngeal nerve IX)

    Pharynx muscles

    Pharyngeal branch (branch of Glossopharyngeal nerve IX), Vagus nerve (X)

    Levator muscle of soft palate

    Lingual branch (branch of Glossopharyngeal nerve IX)

    Tensor muscle of soft palate

    Lingual branch (branch of Glossopharyngeal nerve IX)

    Muscles of larynx

    Vagus nerve (X)

    Muscles of pharynx

    Vagus nerve (X)

    Brachiocephalic muscle

    Dorsal branch of Accessory nerve (XI)

    Trapezius muscle

    Dorsal branch of Accessory nerve (XI)

    Omotransverse muscle

    Dorsal branch of Accessory nerve (XI)

    Sternocephalic muscle

    Ventral branch of Accessory nerve (XI)

    Cleidomastoid muscle

    Ventral branch of Accessory nerve (XI)

    Cleido-occipital muscle

    Ventral branch of Accessory nerve (XI)

  19. Lumbar and iliac parts of the iliopsoas muscle are fused in which animal species?

    Carnivores

  20. Which muscle of the rump is only present in the cat?

    Gluteofemoral Muscle

  21. During surgery, this muscle is commonly dissected in dogs suffering from hip dysplasia. What’s the function of this muscle?

    Pectineal Muscle - adduction

  22. Describe the articulation of the hyoid apparatus in the different animal species.

    Species

    Articulation Point with Skull

    Components Involved in Articulation (Suspensory Apparatus)

    Joint Type

    Carnivores

    Mastoid process of the petrous temporal bone

    Tympanohyoid

    Syndesmosis or Synchondrosis

    Ruminants

    Styloid process of the tympanic part of the temporal bone

    Tympanohyoid

    Syndesmosis or Synchondrosis

    Horse

    Styloid process of the tympanic part of the temporal bone

    Tympanohyoid

    Syndesmosis or Synchondrosis

    Pig

    Nuchal process of the squamous temporal bone

    Tympanohyoid

    Synchondrosis

  23. Differentiate the atlantoaxial joint of the different animal species.

    Feature

    Carnivores

    Ruminants

    Horse

    Pig

    Joint Cavity

    Shares a common joint cavity with the atlanto-occipital joint.

    Atlanto-occipital joint cavities communicate ventrally.

    Atlanto-occipital joint cavities communicate ventrally.

    Ligaments

    Transverse ligament of the atlas present. Alar ligaments attach to medial surface of the condyles.

    Ventral atlantoaxial ligament present. Longitudinal ligaments present. Alar ligaments attach to inner surface of the ventral arch of the atlas.

    Ventral atlantoaxial ligament present. Longitudinal ligaments present. Alar ligaments attach to inner surface of the ventral arch of the atlas.

    Transverse ligament of the atlas present. Alar ligaments attach to the rim of the foramen magnum.

    Additional Structures

    Movement

    Rotation around the longitudinal axis of the dens.

    Rotation around the longitudinal axis of the dens.

    Rotation around the longitudinal axis of the dens.

    Rotation around the longitudinal axis of the dens.

    Dorsal Atlantoaxial Membrane

    Strengthens the joint capsule externally.

    Strengthens the joint capsule externally.

    Strengthens the joint capsule externally.

    Strengthens the joint capsule externally.

    Elastic Dorsal Axial Ligament

    Extends between dorsal tubercle of atlas and spinous process of axis.

    Extends between dorsal tubercle of atlas and spinous process of axis.

    Extends between dorsal tubercle of atlas and spinous process of axis.

    Extends between dorsal tubercle of atlas and spinous process of axis.

  24. What’s the function of transverse ligaments?

    Provide stability and connection across anatomical structures.

  25. What’s the function of the following ligaments? How are they unique among the different animal species?

    Ligament Name

    Function

    Species-Specific Differences

    Longitudinal ligaments

    Dorsal longitudinal ligament

    Passes along the floor of the vertebral canal, attached to each intervertebral disc.

    Extends from the dens of the axis to the sacrum.

    Ventral longitudinal ligament

    Follows the ventral aspect of the vertebrae, attached to each intervertebral disc.

    Extends from the eighth thoracic vertebra to the sacrum.

    Transverse ligaments

    Transverse ligament of the atlas

    Straps the dens to the atlas, prevents undue movement, protects the medulla oblongata.

    Present in pigs and carnivores.

    Transverse ligament of the stifle

    Connects the cranial angles of the two menisci.

    Present in carnivores and some bovine individuals.

    Intertransverse ligaments

    Extend between the transverse processes of the lumbar vertebrae, tensed during lateral flexion and rotation.

    Located in the lumbar vertebrae.

    Transverse humeral ligament

    Bridges the bicipital groove and holds the like-named tendon in place.

    Present in carnivores.

    Transverse acetabular ligament

    Bridges the acetabular notch and keeps the ligament of the head of the femur and the joint capsule in place.

    (No specific species differences mentioned for its presence, but hip joint anatomy varies).

    Short transverse ligament (carpal)

    Joins the neighbouring bones of the same row.

    Located in the carpus. Anatomy of carpal bones varies.

    Transverse bands (dewclaws)

    Join the second and fifth digits to the cannon bone proximally and to the main digits distally.

    Formed by fasciae in animals with dewclaws.

    Atlantoaxial ligaments

    Ventral atlantoaxial ligament

    Reinforces the joint capsule ventrally.

    Extends between the ventral tubercle of the atlas and the ventral spine of the axis in ruminants and horses.

    Dorsal axial ligament

    Extends between the dorsal tubercle of the atlas and the spinous processes of the axis.

    Elastic.

    Elastic dorsal axial ligament

    Extends between the dorsal tubercle of the atlas and the spinous processes of the axis. (Likely the same as Dorsal axial ligament)

    Elastic.

  1. Give examples of long and short ligaments.

    Category

    Ligament Name

    Source(s)

    Short

    Short ligaments (bridge successive vertebrae)

    Short

    Interarcuate ligaments (ligamenta flava)

    Short

    Intertransverse ligaments (ligamenta intertransversaria)

    Short

    Interspinous ligaments (ligamenta interspinalia)

    Short

    Var. short ligaments (of the Tarsal joint or hock)

    Short

    Short ligaments, joining neighbouring bones of the same row or adjacent rows (of carpal joints)

    Short

    Vertical, horizonal, short lig. (of carpal joints)

    Short

    Short transverse ligament (carpal)

    Short

    Middle ligaments of the fetlock

    Short

    Distal sesamoid ligaments

    Short

    Oblique sesamoid ligaments

    Short

    Interdigital intersesamoid ligaments

    Short

    Collateral sesamoid ligaments

    Short

    Interdigital phalangeosesamoid ligaments

    Short

    Interdigital sesamoidean ligaments

    Short

    Straight sesamoid ligament (ligamentum sesamoideum rectum)

    Short

    Cruciate sesamoid ligaments (ligamenta sesamoidea cruciata)

    Short

    Short sesamoid ligaments (ligamenta sesamoidea brevia)

    Short

    Ligaments of the distal sesamoid bone (elastic axial and abaxial, collateral) (of coffin joint)

    Short

    Ligaments of the cartilages of the distal phalanx (of coffin joint)

    Short

    Impar distal sesamoid ligament (ligamentum sesamoideum distale impar)

    Short

    Short lateral collateral ligament (ligamentum collaterale tarsi laterale breve)

    Short

    Short medial collateral ligament (ligamentum collaterale tarsi mediale breve)

    Short

    Various short ligaments bridge the joint spaces (ligamenta tarsi interossea) (of tarsal joint)

    Short

    Proximal sesamoid ligaments (implied by the category of distal sesamoid ligaments in fetlock)

    Long

    Ventral atlantoaxial ligament (ruminants & horse)

    Long

    Longitudinal ligaments of the vertebral canal (horse & ruminants)

    Long

    Long ligaments (sev. Vert. forming fxnal units)

    Long

    Dorsal longitudinal ligament (ligamentum longitudinale dorsale)

    Long

    Ventral longitudinal ligament (ligamentum longitudinale ventrale)

    Long

    Nuchal ligament (nuchal funiculus; nuchal lamina)

    Long

    Supraspinous ligament (ligamentum supraspinale)

    Long

    Nuchal funiculus (funiculus nuchae)

    Long

    Nuchal lamina (lamina nuchae)

    Long

    Long lateral collateral lig. (of Tarsal joint or hock) (ligamentum collaterale tarsi laterale longum)

    Long

    Long medial collateral lig. (of Tarsal joint or hock) (ligamentum collaterale tarsi mediale longum)

    Long

    Dorsal tarsal ligaments (of Tarsal joint or hock)

    Long

    Long plantar ligament (of Tarsal joint or hock)

    Long

    Long lateral and medial carpal collateral lig. (of carpal joints) (ligamenta collateralia carpi)

    Long

    Axial and abaxial collateral ligaments (bridge each fetlock joint)

    Long

    Dorsal ligament of the coffin joints (ligamentum dorsale)

  2. Which ligaments of specific joints are only present in a specific group of animals or animal species?

    Animal Group/Species

    Joint

    Ligament(s) Present Only In This Group/Species

    Ruminants & Horse

    Atlanto-axial joint

    Ventral atlantoaxial ligament

    Horse & Ruminants

    Vertebral canal

    Longitudinal ligaments of the vertebral canal (fan out from the basilar part of the occiput)

    Carnivores & Pigs

    Atlas

    Transverse ligaments of the atlas (strap the dens)

    Dog

    Nuchal ligament

    Paired nuchae (as a subdivision of the nuchal ligament)

    Ruminants

    Nuchal ligament

    Paired funiculus, paired cranial lamellar part (as subdivisions)

    Horse

    Nuchal ligament

    Paired nuchal funiculus and a lamellar part (as subdivisions)

    Ruminant & Pig

    Sternum

    Sternal ligament (lies on the dorsal surface of the sternum)

    Horse

    Sternum

    Sternal ligament (divides into three branches)

    Some Carnivores

    Sternum

    Sternal ligament (absent)

    Ruminants

    Tibiofibular joints

    No proximal tibiofibular joint (head of fibula fused to tibia)

    Horse

    Tibiofibular joints

    Only the proximal tibiofibular joint exists (distal end of fibula fused to tibia)

    Dog

    Distal radioulnar joint

    Distinct radioulnar ligament

    Cat

    Distal radioulnar joint

    Radioulnar ligament consists of fibers embedded in joint capsule

    Carnivores

    Carpal joints

    Absence of long continuous collateral ligaments (only antebrachiocarpal joint bridged)

    Ruminants

    Fetlock joint (MCP joint)

    Proximal interdigital ligament (joins proximal phalanges to axial sesamoid bones)

    Dog

    Distal interphalangeal joints

    Two long elastic cord-like dorsal ligaments

    Cat

    Distal interphalangeal joints

    Short single dorsal ligament (in addition to two long dorsal ligaments)

    Ruminants

    Coffin joint (DIP joint)

    Dorsal ligament of the coffin joints (elastic band)

    Ruminants

    Coffin joint (DIP joint)

    Elastic axial and abaxial ligaments of the distal sesamoid bone

    Ruminants

    Coffin joint (DIP joint)

    Lateral and medial chondroungular collateral ligaments

  3. Familiarize yourself with the different common names of joints.

    Anatomical Joint Name

    Common Name(s)

    Pedal joints

    Tarsal joint or hock

    Metacarpophalangeal joints

    Fetlock

    Proximal interphalangeal joints

    Pastern joint

    Distal interphalangeal joints

    Coffin joint

  4. Which joint/s are absent in specific groups of animals or animal species?

    Animal Group/Species

    Absent Joint(s)

    Some Carnivores

    Sternal ligament

    Ruminants

    Proximal tibiofibular joint

    Intermetacarpal joints between the fused 3rd and 4th MC bones (functionally)

    Horses

    Distal tibiofibular joint

    Adult Ungulates

    Synovial proximal radioulnar joint (limited/absent due to synchondrosis)

  5. Which muscle/s are present only in specific groups of animals or animal species?

    Animal Group/Species

    Muscle(s) Present Only In This Group/Species

    Carnivores

    Superficial sphincter muscle of the neck

    Cervical superficial sphincter muscle

    Supramammary muscles (female)

    Extensor muscle of the first and second digits

    Quadrate pronator muscle

    Short digital flexor muscle (thoracic limb)

    Abductor muscle of the thigh

    Ruminants

    Depressor muscle of the upper lip

    Horse

    Digastric muscle (with caudal and rostral belly)

    Articular muscle of the shoulder joint

    Cat

    Gluteofemoral Muscle

  6. Describe the masseter muscles of the different animal species.

    Animal Species

    Description of Masseter Muscle

    Carnivores

    Separated into three layers by tendinous sheets.

    Pig

    Three layers are firmly fused and difficult to dissect.

    Ox

    Pronounced tendinous intersections forming five distinct parts.

    Horse

    Up to fifteen tendinous intermuscular strands, forming multiple layers.

  7. Familiarize yourself with the different bones or structures of bones which make up a joint.

  8. Identify which ligaments are absent/present in the animal species.

  • Example: this ligament is present among the different animal species except in ______

  1. Muscles & joints – Focus on the species-specific differences.

  2. Functions and innervations – Which muscles are present or absent in the different animal species?

  3. Groupings of muscles and ligaments

  • Ex. Long vs. short ligaments

  • Ex. Extensors vs. flexors

  1. Which structures are involved in the stay apparatus of the horse?

    The stay apparatus of the horse involves the following structures:

    Thoracic Limb:

    • Suspensory ligament

    • Collateral sesamoid ligaments

    • Palmar ligaments

    • Distal sesamoidean ligaments

    • Biceps brachii

    • Superficial digital flexor muscle

    • Superior check ligament

    • Deep digital flexor muscle

    • Inferior check ligament

    Pelvic Limb:

    • Patella

    • Patellar ligaments

    • Third fibular muscle

    • Superficial digital flexor muscle

    • Gastrocnemius muscle

    • Other ligaments/tendons in the pelvic distal limb