Thoracic Limb Locomotion Flashcards
Joints of the Forelimb
sysnsarcosis
Shoulder
Elbow (cubital)
Carpus
Fetlock
Digital
Manus
Forepaw
Pes
Hindpaw
Pollex
Dewclaw
Digit
a metacarpal + 3 phalanges
Phalanx (phalanges)
Proximal (P1)
Middle (P2)
Distal (P3)
Palpable Features of the forelimb thats easily recognized
a) Acromion; “hammate & suprahammate in cat”;
b) greater tubercle;
c)elbow
Palpable Features of the forelimb that requires deeper palpation
a) Spine of scapula;
b) tendon of origin of biceps;
c) deltoid tuberosity
d)lymph nodes
Superficial cervical lymph node
Can be palpated and is enlarged when the limb is retracted (bring back)
MEDIAL to the omotransversarus muscle. NOT under, NOT beside, NOT close to!
Axillary lymph node
Can be palpated and is enlarged when the limb is protracted ( bring forward)
Mammae
Vary from 8 - 12
Thoracic (2 pairs)
Abdominal (2 pairs)
Inguinal (one pair)
Pups nurse the caudal six mammae (best secretion)
Caudal 3 pairs, frequently involved in tumors, and mastitis.
Mammary Neoplasia
Uncontrolled growth of mammary cells can be remedied with :
Lumpectomy
Simple mastectomy
Regional mastectomy
Lumpectomy
Removal of a mass or part of a mamma
Simple Mastectomy
Is an incision of the entire gland
Regional mastectomy
Is excision of the involved and adjacent glands
Venipuncture
For purpose of withdrawing blood or injection
Cephalic vein and External Jugular veins
are important sites
You draw blood from Veins
You do NOT draw blood from ARTERIES!!!
Extrinsic Muscles
(Pectoral Girdle)
At least one attachment (~origin) is external, i.e., to axial skeleton
Intrinsic Muscles
Both attachments are internal to limb bones
The functions of Extrinsic Muscles
Sling the body between the forelimbs (serratus ventralis & deep pectoral)
-Deep pectoral: sternum to humerus ( weight bearing)
-Serratus Ventalis: sternum to scapula ( weight bearing)
Weight bearing (thoracic limb carries more weight about 60-70%, carry head, neck, thorax)
Stabilize the scapula
-If pectorals and serratus ventalis are cut (traffic accident) the scapula will be pulled up. abducted
DORSAK Median raphe: supraspinus ligaments
Rhomboids: Medial raphe to scapula
Trapezius thoracis: ???
Extrinsic Muscles Function: Movement
During progression, the muscles resolve into antagonist groups that control the swing - Stride gate progression
Protraction
Retraction
Protraction
Bring forward (cranially)
In the forelimb
- Advance
- All joints are extended
- End of stride
Retraction
Bring back (caudally)
In the forelimb
-Recovery
-Beginning of stride
-All joints are flexed
Extrinsic Muscles: Girdle Muscles Groups
- Superficial layer
- Deep layer
Superficial layer group of the Extrinsic Muscles Girdle Muscle group
Trapezius
Omotransversarius (superficial c.l.n.)
Brachiocephalicus
Latissimus dorsi
Superficial pectoral
Deep layer group of the Extrinsic Muscles Girdle Muscle group
Rhomboideus
Serratus ventralis
Deep pectoral
Clinical Consideration of the Extrinsic Muscles
Occasionally termination of Serratus ventralis on the scapula is torn by injury
Abnormal elevation of limb (dorsal border of scapula protrudes above level of thoracic spines
Muscles that are not apart of the synsarcosis nor intrinsic or extrinsic
Sternocephalicus:
Sternohyoideus:
Sternothyroideus:
Intrinsic Muscles acting on Shoulder Joint
Groups:
Lateral
those on the lateral surface of the shoulder
Medial
Caudal
Lateral Group of Intrinsic Muscles acting on the Shoulder Joint
Supraspinatus
Infraspinatus
They stabilize the joint by offering support
Infraspinatus
Tendon, and bursa is a “seat of painful inflammation”; &
The belly is suitable for I/M injection.
Medial Group of Intrinsic Muscles Acting on Shoulder Joint
Subscapularis
Coracobrachialis
Both stabilize the joint; support!!
Subscapularis
- arises from the distal end of the scapula
- a bursa cannot protect it because it is long so it uses a tendon sheath for protection
Caudal Group (Flexors) of Intrinsic Muscles acting on the Shoulder Joint
Deltoideus
Arthrocentesis
- Teres major
Teres minor
Extensors of Shoulder??
Deltoideus
- Shoulder joint puncture: pass needle midway between acromion & greater tubercle through deltoideus
- needed to figure out what type of infection or for inducing medication
Latissimus Dorsi
Not a primary flexor but it is the most powerful flexor
Shoulder Joint
Joint capsule envelops the tendon of the biceps brachii (intertubercular bursa)
Tendon of biceps brachii is covered by transverse humeral retinaculum.
Transverse Humeral retinaculum
Luxation of the joint is rare. Why?
No clavicle connection with the trunk
Entire joint “rides” with the blow
Supporting tendons
Clinical Consideration of the Shoulder Joint
Osteochondritis Dissecans (OCD)
Fractures
Supracondylar Foramen
Osteochondritis Dissecans (OCD)
Erosion of the articular cartilage of head of humerus
Common in giant, rapidly growing breeds of dogs.
Elicits a pain response when the shoulder is hyperextended (stabilizing the scapula)
Clinical Consideration of OCD
Diagnosis:
Lateral radiograph of shoulder region
# 13 slough off cartilage
Extend the shoulder – shows pain!
because it is swimming in the synovial fluid
Clinical Consideration of Fractures of the Humerus
are very common
Note the humerus S-shape contour
‘Intramedullary pin’ to repair fractures of shaft
The groove medial to greater tubercle
Intramedullary pin is driven to immobilize fracture of body
Clinical Consideration of Supracondylar Foramen (cat)
The brachial artery and median nerve pass through
-Fracture at this point can have serious repercussions
Intrinsic Muscles acting on Elbow joint
Extensors
Flexors
Extensor Group of Intrinsic Muscles acting on the Elbow Joint
Triceps Brachii ( the main actor)
- long
-lateral
-medial
-Accessory heads
- Tricipital bursa
- Subcutaneous bursa
-The painful one
Aconeus
- mainly to protect the joint capsul rather than an extensor
Tensor Fascia antebrachii
Tricipital Bursa Olecranon
Elbow joint is punctured cranial to the lateral collateral ligament
Needle is directed distally,& caudomedial
- this is in order to draw synovial fluid from the elbow joint
Flexor Group of Intrinsic Muscles acting on the Elbow Joint
Biceps brachii
- Transverse humeral retinaculum & intertubercular bursa
Brachialis
Clinical Consideration of the Elbow Joint
Degenerative Joint Disease (DJD)
Ununited Anconeal Process
Panosteitis
Clinical Consideration of Degenerative Joint Disease (DJD)
Generalized swelling of elbow joint
Diagnosis!!
Decreased range of (flexion) motion
Measured with a Goniometer.
Clinical Consideration Ununited Anconeal Process
If the anconeal process fails to ossify, or if it becomes detached, the loose piece causes severe lameness
Mainly encountered in larger breeds
Clinical Consideration of Panosteitis
(juvenile osteomylitis):
Lesions are found in proximal radius
Self-limiting disease of young, large breeds of dogs (eosinophilia) ( numbers of the eoisinophil go up)
A disease of Unknown origin. Endosteal bone formation as the marrow is invaded by bone trabeculae. Predominantly affects male (80%).
Surgical Approach to Elbow Joint
Incision through skin, s/c tissue over caudal Proximal ulna.
Elevate flexor Carpi ulnaris, & DDF medially, & ulnaris lateralis laterally to expose the bone
Intrinsic Muscles acting on the Carpal & Digital Joints
Extensors
Flexors
Extensor Group of Intrinsic Muscles acting on the Carpal & Digital Joints
Extensor Carpi radialis
Ulnaris lateralis
-(Extensor Carpi ulnaris)
Abductor pollicis longus
Common digital extensor
Lateral digital extensor
-These muscles have the following features in common:
-Extensor action on the carpus joint -Craniolateral position on forearm -Origin from lateral epicondyle of humerus -Supplied by the same nerve
Intrinsic Group of Intrinsic Muscles acting on the Carpal & Digital Joints
Flexor carpi radialis
Flexor carpi ulnaris
Superficial digital flexor
Deep digital flexor
These muscle have the following features in common:
-Flexor action on the carpus joint
-Caudal position on forearm
-Origin from medial epicondyle of humerus
-Supplied by the same nerve
Clinical Consideration of the radius
Fractures of the radius are among the most common in the dog
Surgical exposure of the the radial diaphysis (shaft) is by retracting the Extensor carpi radialis laterally.
Surgical Approach to declawing
Dorsal Elastic Ligament:
(Onychectomy) = removal of the 3rd ‘distal’ phalanx
Intrinsic Muscles acting on Shoulder Joint
Groups:
Lateral
those on the lateral surface of the shoulder
Medial
Caudal
