Anatomy Lecture 2 Flashcards
What are the extrinsic muscles (Synsarcosis) of the Thoracic limb? (8)
Deep pectoral m., Superficial pectoral m., Brachiocephalicus m., Serratus ventralis m., Trapezius m., Rhomboideus m., Omotransversarius m. Latissimus dorsi m.
What are the two phases of Gait Analysis/Locomotion?
- Stance Phase
- Swing Phase
What is the stance phase?
the time the foot contacts the ground
- braking
- propulsion
- weight-bearing
What is the swing phase?
time the limb is propelled through the air
What are the muscles that stabilize the limb to the body wall during the stance phase? (5)
- Serratus ventralis m.
- Superficial and deep pectoral m.
- Trapezius m.
- Rhomboideus m.
What are the muscles that stabilize the shoulder during the stance phase? (8)
Supraspinatus m., Infraspinatus m., Subscapularis m., Teres major m., Teres minor m., Coracobrachialis m., Biceps brachii m., Triceps brachii m. (long head)
What are the muscles that extend the elbow during the stance phase? (3)
- Tensor fasciae antebrachii m.
- Triceps brachi m. (all heads)
- Anconeus m.
What are the muscles that flex the carpus and digits during the stance phase? (5)
- Ulnaris lateralis m.
- Flexor carpi ulnaris m.
- Flexor carpi radialis m.
- Superficial digital flexor m.
- Deep digital flexor m.
What happens during phase 1 of the swing phase?
the limb is advanced; shoulder and carpus are extended; elbow angle varies but extended in full stretch
What happens during phase 2 of the swing phase?
Limb is pulled caudally; shoulder and carpus are flexed; elbow angle varies, but flexed during full gallop
What are the muscles involved in phase 1 of the swing phase? (10)
Brachiocephalicus m., Serratus ventralis m., Trapezius m., Rhomboideus m., Omotransversarius m. Triceps brachii m., Biceps brachii m., Extensor carpi radialis m., Common digital extensor m., Lateral digital extensor m.
What are the muscles involved in phase 2 of the swing phase?(10)
Deep pectoral m., Latissimus dorsi m., Deltoideus m., Teres major m., Triceps brachii m., Biceps brachii m., Flexor carpi radialis m., Ulnaris lateralis m., Superficial digital flexor m., Deep digital flexor m.
How much weight of the animal is transferred to the thoracic limb during the stance phase? (%)
60%
What muscles transfer the weight of the head, neck, and cranial aspect of the trunk to the thoracic limb?
the serratus ventralis and pectoral mm.
What is the “sling muscle?”
The serratus ventralis
What is a first class lever?
(EFR) The fulcrum is between the effort and resistance “seesaw”
v————–v
^
What is a second class lever?
(FRE) The fulcrum is on one end, the effort at the opposite end, and the resistance between them
—-v—-^
What is a third class lever?
(FER) the fulcrum is on one end, the resistance at the opposite end, and the effort between them
v—–^—
^
If the foot is planted on the ground, what does it mean for the force required to flex the shoulder joint? Why?
a great deal of force will be needed to flex the shoulder joint because the limb would need to be lifted from the ground
A muscle attachment further from a joint will produce what? What does this mean?
A more powerful movement, therefore strength of movement increases with distance from the joint
What does a more proximal attachment to the joint do and what would its main function be?
a more proximal attachment increases the range of movement and would therefore function more as a joint stabilizer
Which muscles stabilize the shoulder joint while the foot is planted and have proximal attachments on the humerus? (6)
Supraspinatus m., Infraspinatus m., Subscapularis m., Coracobrachialis m., Teres Major m., Teres Minor m.
What muscle crosses the cranial aspect of the shoulder and is a powerful extensor muscle of the shoulder?
the tendon of the biceps brachii m.
What are the extensor muscles of the elbow joint?
- Tensor fasciae antebrachii m.
- Triceps brachii m.
- Anconeus m.
What muscle is an extensor of the shoulder and a flexor of the elbow?
the Biceps brachii m.
What are the flexor muscles of the carpus and digits?
- Flexor carpi radialis m.
- Flexor carpi ulnaris m.
- Ulnaris Lateralis m.
- Superficial digital flexor m.
- Deep digital flexor m.
What is the origin?
the more stable point of attachment
What is the insertion?
the more mobile point of attachment
Which muscles are on the lateral face of the scapula and shoulder?
- Deltoideus
- Infraspinatus
- Teres minor
- Supraspinatus
What muscles are on the medial face of the scapula and shoulder?
- Subscapularis
- Teres major
- Coracobrachialis
What are the muscles on the caudal part of the arm?
- Tensor fasciae antebrachii
- Triceps brachii
- Anconeus
What are the muscles on the Cranial part of the arm?
- Biceps brachii
- Brachialis
What are the muscles on the cranial and lateral part of the forearm?
- Extensor carpi radialis
- Common digital extensor
- Lateral digital extensor
- Ulnaris lateralis
- Supinator
- Abductor digiti I longus
What muscles are on the Caudal and medial part of the forearm?
- Pronator teres
- Flexor carpi ulnaris
- Flexor carpi radialis
- Superficial digital flexor
- Deep digital flexor
- Pronator quadratus
What are the extensor muscles of the shoulder?
Infraspinatus, Supraspinatus, Subscapularis, Coracobrachialis
What are the flexors of the shoulder?
Deltoideus, Teres minor, Teres major
What are the extensors of the elbow?
tensor fasciae antebrachii, triceps brachii, Anconeus
What are the flexors of the elbow?
biceps brachii, brachialis, supinator, pronator teres
What are the extensors of the carpus and digits?
Extensor carpi radialis, Common digital extensor, Lateral digital extensor, Abductor digiti I longus
What are the flexors of the carpals and digits?
Ulnaris lateralis, flexor carpi radialis, flexor carpi ulnaris, superficial digital flexor, deep digital flexor
What are the pronators of the antebrachium?
pronator teres, pronator quadratus
What is the synsarcosis?
the “joint” that attaches the scapula to the body wall
- it is muscular rather than bony
What are the two parts of the Trapezius?
Cervical and Thoracic
What is the name of the lymph node that attaches to the omotransversarius?
the superficial cervical lymph node or prescapular lymph node
What are the three parts of the rhomboideus?
pars capitis, pars cervicis, pars thoracis
What are the two parts of the serratus ventralis?
pars cervicis, pars thoracis
Is the sternocephalicus an extrinsic muscle of the thoracic limb?
NO
What covers the origin of the biceps brachii on the humerus?
The transverse humeral retinaculum
What is the Brachioradialis?
a very thin muscle that is usually removed with the skin during dissection. May be adjacent to or may cover the cephalic vein
What are the annular ligaments of the palmar surface of the Digits?
the Palmar, Proximal digital, and Distal digital
What are the boundaries of the carpal canal?
Dorsal Border: Palmar carpal ligament
Lateral Border: Accessory carpal bone
Palmar Border: Flexor retinaculum
Where are the Interossei muscles located?
on the palmar aspect of the metacarpal bone of each digit
the tendon of each interosseus muscle contains what?
Two proximal sesamoid bones
What is the name of the structure where the deep digital flexor switches with the superficial digital flexor?
The manica flexoria
What does the Dorsal ligament extend between (origin + Insertion)?
Proximal Dorsal end of the Middle phalanx and Dorsal surface of the Distal Phalanx
What muscles must be affected if an animal is “knuckling over”?
Extensors of the carpus which are supplied by the radial nerve
If an animal is maintaining extension of the shoulder and elbow, which muscle must be effected?
The biceps brachii (flexor of elbow) which is supplied by the musculocutaneous nerve
