FORELIMB AND HINDLIMB- MYOLOGY (origin and insertion and function) Flashcards

Question

Abductors of Shoulder

Answer 1

Trapezius and deltoid

Answer 2

origin: sternum insertion: lesser tubercle of humerus **function:** if fixed point is at thorax, adducts and internally rotates forelimb pulling it backwards as well as acting as an antagonist to the brchiocephalicus; if fixed point is forelimb, pulls thorax up and participates in impulsion; overall acts to support thorax

Answer 3

**Quadriceps femoris** - origin: ilium and medial, lateral and cranial sides of femur - insertion – tibial tuberosity - function: extends stifle and +/- flexes hip **® Tensor fascia latae** - function: flexes hip **® Sartorius** - function: flexes hip and rotates thigh outwards

Answer 4

- origin: spine and acromion process of scapula - insertion: deltoid tuberosity - function: flex shoulder and abduct limb

Answer 5

- origin: ischiatic tuberosity and adjacent parts of sacro-tuberous ligaments - insertion: tibial crest and calcaneus - function: extends hip and tarsus, and flexes stifle

Answer 6

- origin: lateral epicondyle of humerus - insertion: extensor process of distal phalanges of principle digits - function: extend carpus and digits

Answer 7

® generalized metacarpus has five bones, numbered from medial to lateral ® species differ due to absence or fusion of bones ® each bone is composed of a base that articulates with the carpus, a head which articulates with the proximal phalanx and a shaft that connects the two extremities ® two sesamoid bones are associated with each weight bearing metacarpal bone FUNCTION • Together, the metacarpals and phalanges allow for movement of the manus during locomotion • All joints have a caudal flexion angle and therefore, when in extension the animal is placing its foot forwards and when in flexion it is picking up its foot between strides ® Horses have three metacarpals, with the 1st and 5th missing • The 2nd and 4th are greatly reduced and form the splint bones with the distal ends called splint buttons • The 3rd metacarpal is called the cannon bone and is the only metacarpal to articulate with a digit ® Ruminants have two metacarpals, the 3rd and 4th which are fused at the shaft * they also have a greatly reduced 5th metacarpal * 1st and 2nd metacarpals are missing ® Carnivores have all five metacarpals with the 1st greatly reduced and bearing no weight • 1st called dew claw and has one associated sesamoid bone

Answer 8

- origin: supracondylar fossa on femur - insertion: plantoproximal edge of middle phalanx - function: extends tarsus and flexes digits

Answer 9

**® Long digital extensor** - origin: extensor fossa of femur - insertion: extensor process of distal phalanx - function: flexes tarsus and extends digits **® Lateral digital extensor** - origin: head of fibula - insertion: proximal (H), middle (R), and distal (C) - function: flexes tarsus and extends digits

Answer 10

- Pivot type synovial articulating between the dens of the axis and the cranial articular surface of the axis. * Joint is united by a loose capsule reinforced by peripheral ligaments: - Dorsal atlantoaxial ligament – corresponds to the interspinous ligament - Ventral atlantoaxial ligament – corresponds to ventral longitudinal ligament * Joint is also reinforced by deep ligaments: - Transverse atlantoaxial ligament – connects the 2 arches of the atlas and crosses over the dens, holding it against the ventral arch of the atlas (carnivores) - Longitudinal ligament of the dens – connects the apex of the dens to the atlas roof - Tectoria membrane – fibrous sheet covering the longitudinal ligament of the dens; attached from the dorsal side of the axis to the roof of the occipital foramen with two extensions that insert on the atlas ® **Movement**: ‘no’ movement (rotation) ® **synovial**: 1

Answer 11

* Characterized by their large size and long plate-like transverse processes * Distinguished from the last thoracic vertebrae by the lack of costal facets * Spinous processes are shorter and directed craniodorsally * Lateral movements are nearly impossible due to the sagittal orientation of the articular processes * Accessory processes can be seen on mid lumbar vertebrae

Answer 12

**• Sacrum –** - attaches to the pelvis helping to hold up the axial column; provides attachment for the hindlimb through attaching to the pelvis; stabilised through fusion of sacral bones **• Coxal bones –** **-** provides stability in the hind limb; helps hold up the axial column; provides substrate for muscle attachement (Gluteals; quadriceps; adductor); provides passage for birth; helps to hold in internal organs ® Acetabulum – articulates with the head of the femur forming the hip joint ® Greater ischiatic notch – where the sciatic nerve runs over the ilium in large animals ® Lesser ischiatic notch – where sciatic nerve runs over ilium in small animals ® Obturator foramen – opening in pelvic floor allowing the passage of the obturator nerve

Answer 13

• Overall, the tarsus is a compound hinge synovial joint that is composed of three main joints and two intrinsic joints ® **Tarsocrural joint** * Articulation between the proximal row of tarsal bones and the tibia and fibula (calcaneous not involved in horses) * Movement: flexion and extension (most moveable of all tarsal joints) * Synovials: 1 very large that communicates directly (horses and carnivores) and indirectly (ruminants) with the mediotarsal joint * Recessus: 1 dorsal and 1 caudal that is subdivided into 1 lateral and 1 medial by the lateral digital flexor tendon **® Mediotarsal joint** * Articulation between the proximal row of tarsal bones and the distal row of tarsal bones * Movement: none in horses, little flexion and extension in carnivores and high flexion and extension in ruminants * Synovials: 1 that communicates either directly (horses and carnivores) or indirectly (ruminants) with the tarsocrural joint * Recessus: none * Distal trochlea of the talus is present in ruminants and gives the mediotarsal joint more mobility **® Tarsometatarsal joint** * Articulation between the distal row of tarsal bones and the metatarsal bones * Movement: none * Synovials: 1 * Recessus: none **® Proximal intertarsal joint** * Articulation between the talus and calcaneus * Movement: none * Synovials: 3; proximolateral and medial synovials communicate with the tarsocrural synovial and the distal synovial communicates with the mediotarsal synovial * Recessus: none **® Distal intertarsal joint** * Articulation between the distal tarsal row * Movement: none * Synovials: 1 * Recessus: none

Answer 14

- Articulates proximally with the hip bone forming the hip joint and distally with the tibia forming the stifle joint - Head of the femur articulates with the acetabulum - Greater trochanter provides insertion for the middle gluteal - Third trochanter is only present in the horse - Medial and lateral condyle provide insertion for the semimembranosus - Extensor fossa provides attachment for the long digital extensor musle - Femoral trochlea articulates with the patella, with the medial larger than the lateral to allow rotation of stifle joint during patella locking in horses to hook over during patella locking

Answer 15

origin: brachial groove of humerus insertion: bicipital tuberosity

Answer 16

- origin: medial epicondyle - insertion: proximal metacarpus - function: flexes carpus

Answer 17

- origin: ischiatic tuberosity and adjacent parts of sacro-tuberous ligaments - insertion: medial condyle of femur and medial condyle of tibia - function: extends hip and extends and flexes stifle

Answer 18

- origin: lateral collateral ligament of elbow - insertion: proximal end of proximal (H), middle (R) or distal (C) phalanx of lateral digit - function: extend carpus and digits

Answer 19

**Extensor carpi radialis** - origin: humeral coronoid fossa - insertion: metacarpal tuberosity - function: extend carpus **Oblique carpal extensor (carnivores)** - function: extends carpus **Extensor carpi ulnaris (carnivores)** - origin: lateral epicondyle of humerus - insertion: accessory carpal bone and most lateral metacarpal - function: extend carpus

Answer 20

**origin:** supraspinous ligament and spinous process of thoracic and lumbar vertebrae - insertion: teres major tuberosity on humerus - function: if fixed point at axial column, pulls back brachium and acts as an antagonist of the pectoralis ascendens

Answer 21

FEMOROPATELLAR JOINT Movement: flexion and extension ® Synovials: 1 large ® Recessus: 1 cranial between the femur and the patellar insertion of the quadriceps FEMOROTIBIAL JOINT Movement: flexion which also results in internal rotation and extension which also results in external rotation • Rotation is due to medial trochlea being larger than lateral ® Synovials: 1 lateral and 1 medial ® Recessus: 1 subpopliteus that follows the popliteus tendon between the lateral meniscus and the popliteus groove and 1 subextensorius that follows the long digital extensor tendon at origin

Answer 22

- origin: ischiatic tuberosity and adjacent parts of sacro-tuberous ligament - insertion: patella and stifle ligaments - function: extends hip, stifle and tarsus; caudal part flexes stifle

Answer 23

* Compound hinge synovial joint between the humerus, radius and ulna * Movement: flexion and extension * Synovials: 1 very wide * Recessus: 1 dorsal in coronoid process and radial fossa, 1 caudal in olecranon fossa, 1 medial under medial epicondyle, and 1 lateral under lateral epicondyle (expect in carnivores) * Joint capsule encloses all three articular parts * Collateral ligaments are located either side of the joint, restricting movement to only flexion and extension * Annular ligament is present in dogs and is a thin band of connective tissue that passes transversely around the head of the radius and attaches at both ends to the ulna and forms a ring in which the radius can turn in when the forearm us supinated and pronated * In horses the elbow joint is automatic, meaning that one it reaches a certain point of either flexion or extension, the joint requires no energy to be exerted and pops into place

Answer 24

function: extend elbow and flex shoulder **long head:** origin: caudal border of scapula and tricipital border of humerus insertion: olecranon **lateral + medial + accessory (absent in horses)** origin: caudal edge of humerus insertion: olecranon

Answer 25

Gastrocnemius - origin: lateral and medial supracondylar crests of femur - insertion: calcaneus - function: extends tarsus and +/- flexes stifle

Answer 26

**origin:** cranial part of sternal manubrium **insertion:** mastoid process and curve line of occipital (C), basilar process of occipital and molar part of mandible (R), molar part of mandible (H) **function:** flexes head and neck; if only one muscle acts, flexion is followed by rotation

Answer 27

Origin: - vertebrae C3-7 - ribs 1-7/8 Insertion: serrated surface of scapula **function:** if fixed point at thorax, pushes shoulder joint forwards and participates in impulsion; if fixed point at scapula, pulls up thorax and pulls ribs outwards, acting as an inspiratory; overall acts to support thorax and attach forelimb to thorax

Answer 28

- Shaft - Greater tubercle – divided into cranial and caudal parts in the horse and ox; insertion for the supraspinatus muscle - Lesser tubercle – along with greater tubercle, provides insertion for the supraspinatus muscle - Lateral epicondyle – provides attachment for the extensors of the forearm - Medial epicondyle – provides attachment for the flexor muscles of the forearm - Deltoid tuberosity – insertion for the deltoid muscle FUNCTION: - articulates proximally with the scapula, forming the shoulder joint and distally with the radius and ulna forming the elbow joint - provides muscle attachment for many muscles that act on the shoulder and elbow

Answer 29

(horse and ox) - origin: lateral epicondyle of humerus - insertion: accessory carpal bone and most lateral metacarpal - function: flex and extend carpus

Answer 30

**Subscapularis** function: adduct, extend and stabilize shoulder; rotate limb medially **Coracobrachialis** - function: adduct, extend and stabilize shoulder

Answer 31

® Gracillis ® Pectineus ® Adductor ® External obturator

Answer 32

- origin: olecranon and medial epicondyle of humerus - insertion: accessory carpal bone - function: flex carpus

Answer 33

**origin:** cervical part on nuchal ligament and thoracic part of supraspinous ligament **insertion:** scapula spine **function:** abducts and lifts the scapula

Answer 34

® _Spheroid_ synovial joint between head of femur and acetabulum of pelvis ® **Movement:** flexion and extension in horses as well as abduction and adduction in ruminants as well as lateral rotation and circumduction in carnivores ® **Synovials:** 1 large ® **Recessus:** none ® Ligament of the femoral head is a short intracaptular ligament that extends from the cavity to the notch on the head of the femur ® Acetabular lip is the band of fibrocartilage around the rim of the acetabulum that increases the depth of the acetabulum and decreases the pressure of contact ® Transverse acetabular ligament crosses the acetabular notch and completes the acetabular cavity ® In horses, there is an accessory ligament of the femoral head which extends from the prepubic ligament through the acetabular notch under the transverse ligament and attaches with the ligament of the femoral head; it stabilizes the hip and prevents the horse from abduction and adduction

Answer 35

Modified condylar synovial between the metacarpal bone and the proximal phalanx, including the proximal sesamoid bones **Movement:** flexion and extension **Synovials:** 1 that communicates with its homologue on the palmar side in ruminants **Recessus:** 1 dorsal located under the digital extensor tendon (less developed) and 1 palmar located above the proximal sesamoid bones (very developed) **Ligaments:** _Proximal scutum_ is a ligament between the proximal sesamoids _Interdigital intersesamoid ligaments_ are located between the proximal sesamoid couples in ruminants and carnivores _Collateral ligaments_ are present either side of the joint restricting movement

Answer 36

CRANIUM: bones surrounding brain * occipital region * temporal region * floor of cranium * rostral wall of cranium * roof of cranium ruminant: frontal bone forms entire roof horse: interparietal bone b/t the 2 parietal bones rostral to occipital bone. * mastoid process: attachment site for muscles --\> 3 types of skulls in **dogs** relative to facial bone proportions: 1. mesaticephalic- average 2. dolicephalic: larger facial components 3. brachiocephalic: shorter facial components FUNCTION: * Muscle attachment – facial muscles and muscles of the neck on occipital * Contain the brain – main nervous system centre * Contains nasal cavities – breathing * Oral cavities and mouth – eating * Has holes for the eyes – sight * Occipital bone – has a hole for the exit of the brain stem and spinal cord

Answer 37

® Anconeal process – articulates with the olecranon fossa on the humerus when the elbow is extended ® Coranoid process – articulates with the humerus ® Olecranon – provides a lever arm for the extensor muscles of the elbow and forms the point of the elbow; upon extension of the elbow it fits into the olecranon fossa of the humerus; provides insertion for tripceps brachii muscle FUNCTION ® the radius is the main weight bearing bone of the forearm and articulates with the humerus and ulna forming the elbow and with the carpal bones forming the carpus ® three distal grooves on cranial surface of radius accommodate tendons ® the ulna serves mainly for muscle attachment and formation of the elbow joint and articulates proximally with the humerus and radius and distally with the carpal bones ® In horses and ruminants the ulna is fused to the radius, preventing the animal from supinating their forearm, resulting in them being in permanent pronation • Large animals are locked in permanent pronation so as they are able to bear larger weight loads whilst moving, compared to a carnivore, which needs the ability to supinate so as to leap and catch prey, or climb a tree etc. ® In horses only, the distal epiphysis of the ulna is fused with the radius, and in essence becomes part of the radius

Answer 38

**_metatarsal bones -_** numbered from medial -\> lateral - has two sesamoid bones - associated to weight bearing the metatarsal bones **horses:** * metatarsus 2+4 = splint bones * metatarsus 3 = only metatarsal to articulate with a digit = cannon bone **ruminants:** * two metatarsal bones: 3rd + 4th --\> fused at shaft * greatly reduced 5th metatarsal bone **carnivores:** * have all 5 metatarsals * 1st greatly reduced - not weight bearing = dew claw **_Phalanges_** **horses:** * 1 digit: 3 metatarsals * ex. process - for DDF * prox ses. bones= 2 small bones = part of suspensory apparatus of fetlock joint * dis. ses. bone= not embedded in a tendon but located b/t DDF and middle and distal phalanges **ruminants:** * 4 digits - 2 weight- bearing * 1st digit = missing * 2nd + 5th = vestiges (horny dew claws) * 3rd + 4th = 3 phalanges and 3 sesamoid bones * 2 prox sesamoid bones = at metatarsophalangeal joint + 1 distal at distal interphanangeal joint for EACH DIGIT **carnivores** * 2nd - 5th = weight bearing * 1st = dew claw (1st digit and 1st metatarsal)- 1 sesamoid * prox phalanx- has head, body and base * middle- same structure but smaller in length * distal phalanx- has distal flexor process for DDF to insert + extensor process for CDE * 2 palmer sesamoid bones per digit, except 1 for 1st digit * distal sesamoid bone- cartilage **_Function:_** * Together, the metatarsals and phalanges allow for movement of the foot during locomotion * All joints have a caudal flexion angle and therefore, when in extension the animal is placing its foot forwards and when in flexion it is picking up its foot between strides

Answer 39

origin: fascia covering the lateral side of latissimus dorsi inserts: olecranon function: extend elbow

Answer 40

- origin: humeral coronoid fossa - insertion: metacarpal tuberosity - function: extend carpus

Answer 41

(carnivores) - origin: lateral epicondyle of humerus - insertion: accessory carpal bone and most lateral metacarpal - function: extend carpus

Answer 42

**® Cranial tibial** - function: flexes hock and supinates **® Peroneus tertius** - origin: extensor fossa of femur - insertion: calcaneus and tarsal 4, and tarsal 3 and proximal metatarsal 2 - function: flexes tarsus **® Peroneus longus** - function: pronates and flexes tarsus **® Peroneus brevis** - function: flexes tarsus

Answer 43

**Superficial digital flexor** - origin: medial epicondyle of humerus - insertion: middle phalanx - function: flex carpus and digits **Deep digital flexor** - origin: humerus, radius and ulna - insertion: semilunar line of distal phalanx - function: flex carpus and digits

Answer 44

- origin: medial epicondyle of humerus - insertion: middle phalanx - function: flex carpus and digits

Answer 45

**Vertebral body joints –** _symphysis_ formed by intervertebral discs joining adjacent vertebrae. * cranial head of vertebral body articulates with caudal fossa on adjacent vertebral body. * Between adjacent vertebral bodies, there is an intervertebral disc and a fibrocartilaginous element consisting of an outer fibrous ring and an inner pulpy nucleus. * Ventral and dorsal longitudinal ligaments reinforce the joints, preventing hyperflexion and hyperextension. **Vertebral arc joints** – synovial joints between cranial and caudal articular processes. * The articular surfaces consist of cranial articular processes facing upwards and the caudal articular processes which face downwards. Joints are united by articular capsules and reinforced by interlamellar, interspinous and supraspinous ligaments, preventing abnormal separation of the vertebral spines during flexion of vertebral column.

Answer 46

- origin: extensor fossa of femur - insertion: calcaneus and tarsal 4, and tarsal 3 and proximal metatarsal 2 - function: flexes tarsus

Answer 47

Structure: • Talus – largest bone of tarsus located on the dorsomedial side; horses + ruminants: articulates by its trochlea with the tibia carnivores: tibia and fibula 2 talus ruminants : 1 talus carnivores * Calcaneous – second bone of the proximal row, lateral to the talus that serves as muscle attachment for gastrocnemius muscle and serves as a lever arm for the superficial digital flexor tendon * Central tarsal – fused with 4th tarsal in ruminants * 1st – fused with 2nd tarsal in horses * 2nd – fused with 3rd tarsal in ruminants; fused with 1st tarsal in horses * 3rd – fused with 2nd tarsal in ruminants * 4th – fused with central tarsal in ruminants Function: • Tarsal bones - Number of bones varies between species due to fusion of one or more bones - Together form a compound joint consisting of multiple communicating synovial joints - As a whole, the tarsus serves to provide shock absorption during locomotion - Allow for easy and free movement of the tarsus: flexion and extension --\> **Reciprocal mechanism** in horses links the tarsus to the stifle

Answer 48

® Condylar synovial between the middle phalanx and the distal phaland and the distal sesamoid bone ® Movement: flexion and extension ® Synovials: 1 ® Recessus: 1 dorsal under the extensor tendon and 1 palmar (more developed) at the middle phalanx palmar side just above the distal sesamoid bone ® Distal scutum is a fibrocartilaginous surface on the flexor surface of the distal sesamoid that provides a sliding surface and pulley for the DDF tendon ® In carnivores the distal sesamoid is absent and is replaced by a fibrocartilaginous buldge ® Collateral ligaments are present either side of the joint restricting movement ® Collateral sesamoid ligaments are present in horses and ruminants and prevent the sesamoid bones from moving ® Dorsal ligaments are present in carnivores and are responsible for keeping the claw retracted

Answer 49

7 vertebrae ## Footnote - transverse foramen --\> forms a transverse canal - **atlas:** supports head (_yes_ movement), flex and extension, lacks body and spinous process - **axis:** has dens--\> forms pivot joint allows _no_ movement C7= no transverse foramen + articulates with head of 1st rib

Answer 50

* A **condylar synovial joint** between the condyles of the mandible and the mandibular fossa of the temporal bones * It has a loose joint capsule with the lateral side strengthened to form a lateral ligament * Articular discs are present in the form of a thin meniscus lying between the two articular surfaces of the joint * A small amount of lateral movement occurs during mastication or during grinding in herbivores

Answer 51

- origin: gluteal fossa of ilium - insertion: greater trochanter of femur - function: extends hip and +/- abducts thigh

Answer 52

origin: sterum insertion: cranial surface of humerus **function:** pulls forelimb forwards and adducts

Answer 53

- origin: ischiatic tuberosity and adjacent parts of sacro-tuberous ligament - insertion: medial condyle of femur and medial condyle of tibia - function: extends hip and extends and flexes stifle

Answer 54

- origin: caudal face of tibia and fibula - insertion: semilunar line of distal phalanx - function: extends tarsus and flexes digits

Answer 55

**® Biceps femoris** - origin: ischiatic tuberosity and adjacent parts of sacro-tuberous ligament - insertion: patella and stifle ligaments - function: extends hip, stifle and tarsus; **caudal part flexes stifle** **® Semitendinosus** - origin: ischiatic tuberosity and adjacent parts of sacro-tuberous ligament - insertion: tibial crest and calcaneous - function: extends hip and tarsus and flexes stifle **Semimembranosus:** - origin: ischiatic tuberosity and adjacent parts of sacro-tuberous ligament - insertion: medial condyle of femur and medial condyle of tibia - function: extends hip and extends and flexes stifle

Answer 56

**Supraspinatus** **- origin:** supraspinous fossa **- insertion:** greater and lesser tubercles of humerus **- function:** extend and stabilize shoulder **Infraspinatus** origin: infraspinous fossa inserts: greater tubercle of humerus **- function:** extend, flex and stabilize shoulder **Biceps brachii** **origin:** supraglenoid tubercle of scapula **- insertion:** bicipital tuberosity of humerus **- function:** flex elbow and extend shoulder

Answer 57

- origin: caudal border of scapula and tricipital line of humerus - insertion: olecranon - function: extend elbow and flex shoulder

Answer 58

**origin:** humeral crest **insertion:** mastoid process and mastoid crest (H), and nuchal ligament (C), and pars basilar of occipital (R) **function:** if fixed point is at head, pulls forelimb forwards with omotransversarius; if fixed point is at limb, flexes head and neck; if only one muscle acts, flexion is followed by rotation

Answer 59

• Flexors **® Deep digital flexor** - origin: caudal face of tibia and fibula - insertion: semilunar line of distal phalanx - function: extends tarsus and flexes digits **® Superficial digital flexor** - origin: supracondylar fossa on femur - insertion: plantoproximal edge of middle phalanx - function: extends tarsus and flexes digits

Answer 60

**_Pastern joint (proximal phalangeal)_** ® Condylar synovial between the proximal phalanx and the middle phalanx ® Movement: flexion and extension **® Synovials: 1** **® Recessus:** 1 dorsal under the extensor tendon and 1 palmar (more developed) at the middle scutum under the SDF insertion ® Collateral ligaments are present either side of the joint restricting movement ® Palmar ligaments are present in horses and ruminants and prevent the hyperextension of the joint **_• Coffin joint (distal phalangeal)_** ® Condylar synovial between the middle phalanx and the distal phaland and the distal sesamoid bone ® Movement: flexion and extension ® Synovials: 1 ® Recessus: 1 dorsal under the extensor tendon and 1 palmar (more developed) at the middle phalanx palmar side just above the distal sesamoid bone ® Distal scutum is a fibrocartilaginous surface on the flexor surface of the distal sesamoid that provides a sliding surface and pulley for the DDF tendon ® In carnivores the distal sesamoid is absent and is replaced by a fibrocartilaginous buldge ® Collateral ligaments are present either side of the joint restricting movement ® Collateral sesamoid ligaments are present in horses and ruminants and prevent the sesamoid bones from moving ® Dorsal ligaments are present in carnivores and are responsible for keeping the claw retracted

Answer 61

origin: gluteal fascia inserts: 3rd trochanter - function: abducts thigh

Answer 62

- have articular facets - articulate with ribs - shape- dorso-convex = limited flexibility - anticlinal vertebra - costal fovea: 2 facets - transverse costal fovea: facet on transverse process FUNCTION: * Articulate with ribs which surround and protect thoracic cavity * Provide muscle attachment – e.g. latissimus dorsi; erector spinae; longissimus thoracics * Provide part of spinal column – passage of spinal cord – posture etc. * Anticlinal vertebra – often used to read a radiograph * Costal fovea – articulates with head of rib * Transverse costal fovea – articulates with tubercle on rib

Answer 63

- origin: ischiatic tuberosity and adjacent parts of sacro-tuberous ligament - insertion: tibial crest and calcaneous - function: extends hip and tarsus and flexes stifle

Answer 64

- origin: ischiatic tuberosity and adjacent parts of sacro-tuberous ligament - insertion: tibial crest and calcaneous - function: extends hip and tarsus and flexes stifle

Answer 65

origin: iliac crest insertion: medial side of stifle - function: flexes hip and rotates thigh outwards (in dogs- consist of two bellies)

Answer 66

® Superficial gluteal (dog) origin: gluteal fascia inserts: 3rd trochanter - function: abducts thigh ® Gluteal femoris (ruminant) - function: abducts thigh

Answer 67

Pastern joint (proximal phalangeal) ® Condylar synovial between the proximal phalanx and the middle phalanx ® Movement: flexion and extension ® Synovials: 1 ® Recessus: 1 dorsal under the extensor tendon and 1 palmar (more developed) at the middle scutum under the SDF insertion ® Middle scutum is a fibrocartilaginous ridge that completes the palmoproximal border of the middle phalanx on the flexor tuberosity extending the joint contact surface between the proximal and middle phalanges and providing insertion points for the SDF tendon and a sliding surface and pulley for the DDF tendon ® Collateral ligaments are present either side of the joint restricting movement ® Palmar ligaments are present in horses and ruminants and prevent the hyperextension of the joint

Answer 68

Spine – origin of deltoid muscle Supraglenoid tubercle – origin of biceps muscle Acromion – absent in horses; origin for acromial part of deltoid muscle Supraspinous fossa – origin of supraspinatus muscle Infraspinous fossa – origin of infraspinous muscle FUNCTION: - attaches forelimb to thorax, stabilising limb - make up the thoracic girdle - articulates with the humerus, forming the shoulder joint

Answer 69

**Deltoid** - origin: spine and acromion process of scapula - insertion: deltoid tuberosity - function: flex shoulder and abduct limb **Teres major** - origin: caudal border of scapula - insertion: teres major tuberosity - function: flex shoulder and rotate limb medially **Triceps brachii** - origin: caudal border of scapula and tricipital line of humerus - insertion: olecranon - function: extend elbow and flex shoulder

Answer 70

**Femur** - Articulates proximally with the hip bone forming the hip joint and distally with the tibia forming the stifle joint - Head of the femur articulates with the acetabulum - Greater trochanter provides insertion for the middle gluteal - Third trochanter is only present in the horse - Medial and lateral condyle provide insertion for the semimembranosus - Extensor fossa provides attachment for the long digital extensor musle - Femoral trochlea articulates with the patella, with the medial larger than the lateral to allow rotation of stifle joint during patella locking in horses - Supracondylar crest provides origin for the gastrocnemius muscle - Supracondylar fossa provides origin for the superficial digital flexor muscle **Tibia & Fibula** - Articulate proximally with the condyles of the femur and distally with the tarsal bones - Separated by an interosseous space - Tibia is medially located and is the main weight bearing bone - Fibula serves mainly for muscle attachment and is most lateral - In carnivores: not fused - In ruminants the head of the fibula fuses to the tibia and most of the body of the fibula fails to develop and the lateral malleolus remains separate from the tibia - In horses the fibula is reduced to a bone that reaches only halfway down the tibia and the true distal end of the fibula is fused with the tibia FUNCTION: - Tibia provides main muscle origins for many of the distal hind limb muscles and insertions for muscles which act on the stifle such as the semimembranosus, semitendinosus and quadriceps femoris

Answer 71

origin: infraspinous fossa inserts: greater tubercle of humerus - function: extend, flex and stabilize shoulder

Answer 72

origin: olecranon fossa inserts: lateral surface of the olecranon function: extend elbow

Answer 73

® Bone formed by the fusion of sacral vertebrae ® The wings articulate with the hip bones forming the sacroiliac joint ® Portion of vertebral canal through sacrum is called the sacral canal ® In horses and carnivores the spinous processes are unfused whereas ® In ruminants the spinous processes are fused and are called the median sacral crest

Answer 74

yellow-elastic CT connecting the upper cervical vertebrae or occipital with the spinous process of the thoracic vertebrae. Helps to support the head and has a role in locomotion in large animals by rigidification of the axial column. In large animals (horse and ox) it consists of two paired parts: ® **Funicular (cord)** – which is paired and arises from the occipital and inserts on spines of thoracic vertebrae of the withers ® **Lamellar (sheet**) – consists of two sheets of CT arising from the second and third thoracic spines and the funicular part and inserts on cervical spines C2 – C6.

Answer 75

- origin: ilium and medial, lateral and cranial sides of femur - insertion – tibial tuberosity - function: extends stifle and +/- flexes hip

Answer 76

- origin: head of fibula - insertion: proximal (H), middle (R), and distal (C) - function: flexes tarsus and extends digits

Answer 77

* A _condylar synovial joint_ between the condyles of the mandible and the mandibular fossa of the temporal bones * It has a loose joint capsule with the lateral side strengthened to form a lateral ligament * Articular discs are present in the form of a thin meniscus lying between the two articular surfaces of the joint * A small amount of lateral movement occurs during mastication or during grinding in herbivores

Answer 78

• Joint - relatively immoveable articulation between wings of the sacrum and the ilium. Combined _cartilaginous and synovial joint_. Fibrocartilage unites the surfaces of the wings to the ilium, forming a sacroiliac synchondrosis. There is a _tight joint capsule_ along the margin of the joint, reinforced by _dorsal and ventral sacroiliac ligaments_. There is _little to no movement._ ® **Synovials:** 1 small • Sacrosciatic ligament **Dogs** – reduced to a fibrous band from transverse process of sacrum to ischiatic tuberosity and called the sacrotuberal ligament **Horses & ox –** sacrotuberal and sacrospinal ligaments are fused. Expanded to a broad sheet that largely fills the space between the lateral border of the sacrum and the dorsal border of the ilium and ischium – leaves open two foramina adjacent to the greater and lesser sciatic notches. **Function:** • Joint – attach pelvic limb to the axial column and stabilise the axial column **• Sacrosciatic ligament** ® Greater sciatic foramen – where cranial gluteal and sciatic nerves leave pelvis ® Lesser sciatic foramen – where pudental nerve leaves pelvis

Answer 79

They are both flexor and extensor muscles: they work to extend and strengthen columns; if one muscle acts, flexes column laterally **Common erector spinae** - origin: iliac crest - insertion: last thoracic and lumbar vertebrae **Spinalis thoracis (spinous)** - origin: thoracic spinous process - insertion: other thoracic spinous process **Longissimus thoracis** - origin: lumbar/thoracic spinous proocess - insertion: lumbar/thoracic mamillar processes and costal tubules **Iliocostalis** - origin: lateral border of common erector spinae and iliac crest as well as lumbar transverse process and ribs - insertion: long oblique tendons and proximo-lateral sides of ribs

Answer 80

- origin: iliac crest - insertion: last thoracic and lumbar vertebrae - function: extends and strengthens, flexes column laterally if one muscle acts

Answer 81

- origin: thoracic spinous process - insertion: other thoracic spinous process - function: both muscles act, extends and strengthens colums; if one muscle acts, flexes column laterally

Answer 82

- origin: lumbar/thoracic spinous proocess - insertion: lumbar/thoracic mamillar processes and costal tubules - function: both muscles act, extends and strengthens colums; if one muscle acts, flexes column laterally

Answer 83

- origin: lateral border of common erector spinae and iliac crest as well as lumbar transverse process and ribs - insertion: long oblique tendons and proximo-lateral sides of ribs - function: both muscles act, extends and strengthens colums; if one muscle acts, flexes column laterally

Answer 84

**erector spinae** originates: iliac crest insert: last thoracic and lumbar vertebrae **spinalis** origin: thoracic spinous process insert: other thoracic spinous processes **iliocostalis** origin: lateral border of common erector spinae and iliac crest as well as lumbar transverse process and ribs insert: long oblique tendons and proximo-lateral sides of ribs **longissimus thoracicus** origin: lumbar/ thoracic spinous insert: lumbar/ thoracic mamillar processes and costal tubules

Answer 85

originates: iliac crest insert: last thoracic and lumbar vertebrae

Answer 86

origin: thoracic spinous process insert: other thoracic spinous processes

Answer 87

origin: lateral border of common erector spinae and iliac crest as well as lumbar transverse process and ribs insert: long oblique tendons and proximo-lateral sides of ribs

Answer 88

origin: lumbar/ thoracic spinous insert: lumbar/ thoracic mamillar processes and costal tubules

Answer 89

musculoaponeurotic partition that separates the thoracic cavity from the abdominal cavity. It acts as an inspiratory through increasing the transverse diameter of the thorax and displacing the sternum forwards and downwards.