Muscular System - Extrinsic Muscles Overview

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Questions and Answers

Which muscle is primarily responsible for extension in the hip joint?

M.adductor

M.gluteus medius (correct)

M.gracilis

M.piriformis

Which of the following muscles is not involved in the flexion of the hip joint?

M.adductor

M.gluteus maximus (correct)

M.sartorius

M.pectineus

What role does the M.popliteus primarily serve in the stifle joint?

Extensor

Adductor

Rotator

Flexor (correct)

Which muscle group does M.gluteus profundus belong to?

Abductors Signup and view all the answers

In horses, which muscle is primarily responsible for abduction at the hip joint?

M.tensor fasciae latae Signup and view all the answers

Which muscle assists the M.popliteus in flexing the stifle joint?

M.semitendinosus Signup and view all the answers

Which of the following muscles is categorized as a rotator of the hip joint?

M.piriformis Signup and view all the answers

Which of the following muscles is mainly responsible for flexing the digits?

M.interosseus Signup and view all the answers

Which muscle is primarily responsible for extension at the elbow joint?

M.triceps brachii Signup and view all the answers

Which of the following muscles is categorized as a flexor of the carpus?

M.Flexor carpi radialis Signup and view all the answers

What is the primary action of the M.supraspinatus muscle?

Abduction of the shoulder Signup and view all the answers

Which of the following muscles is classified as a rotator of the forearm?

M.Supinator Signup and view all the answers

Which muscle serves as both an abductor and a flexor?

M.Teres major Signup and view all the answers

Which of the following muscles aids in flexing the digits?

M.Flexor digitalis profundus Signup and view all the answers

Which muscle is described as a flexor of the carpus and contributes to the digital flexors?

M.Flexor carpi ulnaris Signup and view all the answers

Which muscle functions as an abductor and partly flexes the shoulder?

M.Coracobrachialis Signup and view all the answers

Which muscle is primarily responsible for the powerful downstroke in birds during flight?

Pectoralis Signup and view all the answers

What is the primary function of the supracoracoid muscle in birds?

Facilitates the upstroke of the wing Signup and view all the answers

Why do birds have a sparse dorsal musculature?

To reduce weight for sustained flight Signup and view all the answers

How does the arrangement of pectoral muscles contribute to a bird's flight stability?

They concentrate mass ventrally near the center of gravity Signup and view all the answers

Which statement best describes the role of tendons in birds?

They reduce the need for bulky muscles in limbs and wings Signup and view all the answers

Which muscle is NOT a part of the quadriceps femoris group?

M.gluteus medius Signup and view all the answers

Which of the following muscles assists the quadriceps femoris?

M.tensor fasciae latae Signup and view all the answers

What is the primary function of the quadriceps femoris?

Extension of the knee Signup and view all the answers

Which of the following is NOT a flexor muscle listed?

M.triceps surae Signup and view all the answers

Which muscle is a part of the triceps surae?

M.soleus Signup and view all the answers

Which extensor muscle is responsible for extending the digits?

M.extensor digitalis longus Signup and view all the answers

Which muscle could you classify as a medial muscle?

M.vastus medialis Signup and view all the answers

Which muscle is typically categorized as a flexor of the digital structures?

M.flexor digitalis profundus Signup and view all the answers

What is the primary function of the M.trapezius?

Elevates and rotates the scapula Signup and view all the answers

Which muscle originates from the neck and extends to the scapula as part of the extrinsic muscles of the thoracic limb?

M.serratus ventralis Signup and view all the answers

What muscle is considered the primary flexor of the elbow joint?

M.biceps brachii Signup and view all the answers

Which of the following muscles is not part of the extrinsic muscles of the thoracic limb?

M.biceps brachii Signup and view all the answers

What is the innervation of the M.latissimus dorsi?

Thoracodorsal nerve Signup and view all the answers

Which of these species has a M.cleidobrachialis as part of the brachiocephalicus muscle?

Dog Signup and view all the answers

What is the role of the M.pectoralis profundus?

Adducting the forelimb Signup and view all the answers

Which muscle is a flexor of the shoulder joint?

M.deltoideus Signup and view all the answers

Study Notes

Muscular System - 2

Extrinsic muscles of the thoracic limb originate on the neck and thorax, extending to the scapula or humerus, reaching as far distally as the elbow joint.
Muscles include: Trapezius (cervical and thoracic parts), Rhomboideus (cervical and thoracic/capitis), Latissimus dorsi, Omotransversarius, Serratus ventralis (cervical and thoracic), Pectorales superficiales (descending and transverse), Pectoralis profundus (including subclavius in Equidae), and Brachiocephalicus (including cleidomastoideus, cleidobrachialis, and cleidooccipitalis).
Different species (horse, ox, sheep, goat, pig, dog, cat) have variations in muscle names and attachments within the Brachiocephalicus group.

Muscles of the Thoracic Limb

Muscles of the shoulder, elbow, radioulnar joints, carpal joints, and digits are detailed.
Flexors and extensors are categorized for each joint, providing a comprehensive overview.

Muscles of the Shoulder Joint

Flexors include the deltoideus (acromial and scapular parts), teres major, and teres minor.
Extensors include supraspinatus, coracobrachialis, biceps brachii, and infraspinatus (partly flexor/abductor).
Subscapularis is also categorized as an adductor/ (partly extensor) muscle.

Other Limb Muscles

Muscles of the elbow joint, including biceps brachii, brachialis, triceps brachii (with three heads), anconeus, and tensor fasciae antebrachii, are detailed.
Muscles of the radioulnar joints for carnivores are listed (supinator and pronator groups).
Relevant descriptions of the muscles of the carpus and digits (flexors and extensors) are included, and specific muscles like flexor carpi radialis, flexor carpi ulnaris, extensor carpi ulnaris, extensor carpi radialis, abductor digiti I (pollicis) longus, and relevant superficial and deep digital flexors and extensors are mentioned.

Stay Apparatus in the Thoracic Limb of a Horse

The stay apparatus comprises muscles, ligaments, and tendons that lock the limb joints in the horse, enabling it to stand or sleep, reducing fatigue.
Key muscles and ligaments supporting this function are mentioned, including the common digital extensor muscle, dorsal branches of the suspensory ligaments, and others.

Muscles of the Pelvic Limb

Muscles related to hip, stifle, tarsal, and digital joints (flexors and extensors) are highlighted.
Specific muscles (gluteal, adductor, biceps femoris, sartorius, pectineus, quadriceps femoris, and rotator groups) are mentioned in detail.

Muscles of the Stifle Joint

Flexor muscles are mentioned, along with the crucial quadriceps femoris group as extensors.
Supporting muscles that aid the stifle joint are also included, such as tensor fasciae latae and biceps femoris.

Muscles of the Tarsus and Digits

Flexor and extensor muscles for the tarsal and digital joints are covered, including tibialis cranialis, peroneus (fibularis) tertius and longus; triceps surae (with gastrocnemius and soleus components); tendon groups such as calcaneus communis and important flexor and extensor muscles relevant to the digits are detailed.

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Description

This quiz covers the extrinsic muscles of the thoracic limb, detailing their origins, variations across species, and specific muscle names. Additionally, it includes categories of muscles relating to shoulder and elbow joints, as well as flexors and extensors for a complete understanding of the musculoskeletal system in various animals.