Muscles & Biomechanics & joints

Question 1

What forelimb joint allows abduction and adduction

Answer 1

The shoulder joint (scapulohumerus)

Question 2

What are extrinsic muscles?

Answer 2

They have insertions outside of the area. Ie. The forelimb, in the trunk, neck and head.

Question 3

What supports the thorax and forehand.

Answer 3

The serratus corset and pectoral corset. (Cervical and thoracic) (Ascending and subclavius)

Question 4

Movement of the forelimb during locomotion: Protraction (extension)

Answer 4

Thoracic ventral serratus pulls scapula down, Omotransvervse and Brachiocephalicus pull scapula (distal part) and humerus cranial and trapezius pulls scapula up and the ascending pectoral pulls the humerus up too. Which pulls the shoulder (scapula) back and humerus forward.

Question 5

Protraction of the forelimb. What muscles are used;

Answer 5

Trapezius (thoracic) Brachiocephalicus Omotransvervse Descending pectoral Thoracic serratus muscle

Question 6

Retraction (population - push off)

Answer 6

Rhomboid pulls scapula forward, trapezius cerci I pulls scapula forward (cranial) The Cervical serrate and subclavius pull the scapula (left had side) down (ventral). While the latissimus dorsi and pulls the humerus (up/dorsal) and the ascending pectoral pulls humerus (medial Attachment) causal.

Question 7

The muscles involved in retraction (population)

Answer 7

Trapezius (cervical) Rhomboid Cervical serrate Subclavius Latissimus dorsi Ascending pectoral

Question 8

Protraction of the limb. Two groups involved dorsal and ventral. Name them; (Horse extending the leg in front of itself)

Answer 8

Dorsal; thoracic trapezius And caudal bundles of serratus. It draws the dorsal extremity of the scapula back The ventral group; ascending pectorals Brachiocephalicus, Omotransvervse draws the humerus and ventral angle of the scapula forwards

Question 9

Retraction (draws the limb back) Producing propulsion. What are the dorsal and ventral group of muscles called?

Answer 9

Dorsal; rhomboid, trapezius, cervical serratus and subclavius muscles. The ventral group; ascending pectoral, latissimus dorsi muscle.

Question 10

Abduction What muscles are involved;

Answer 10

Muscles both intrinsic and extrinsic. Extrinsic: trapezius rhomboid draws the dorsal extremity of the scapula medially and effect the release of the shoulder joint. Intrinsic; infraspinstus & deltoid which are abductors of the shoulder joint.

Question 11

Adductors

Answer 11

Produced mainly by the descending transverse and ascending pectorals. Adduction of the scapula-numeral joint is produced by the subscapularis.

Question 12

Muscles of the shoulder that mobilise the scapular-humeral joint exclusively.

Answer 12

Extensor : supraspinatus Flexor: (deltoid & teres major) Adductors (subscapularis & brachialis) Abductors; infraspinstus & teres minor)

Question 13

Muscles of the arm Produce all the movements of the elbow joint:

Answer 13

Flexor (biceps, brachii and brachialis) Extensors (triceps brachii - long, lateral & medial heads) Tensor fascia antebrachii Anconeus

Question 14

What do the joints in the fore limb do (ie what type of joint)

Answer 14

Flexion and extension only. (Only the pelvic and pectoral girdle do lateral and rotation movements.