Anatomy Forelimb

Question 1

Describe the biceps brachialis, location, origin, insertion and function ?

Answer 1

Location = front of humerus

Origin = Scapular supraglenoid tubercle

Insertion = dorso medial tuberosity

Function = flexion of the elbow

Question 2

Describe the knee joint?

Answer 2

Carpal joint or knee is a hinge joint acting in flexion and extension

May also act in abduction and adduction in carnivores.

Radiocarpal joint

Synovial 1 large

Recessus 1 above carpal bone

Mediocarpal bone

Synovial 1 very large which can communicate with the carpometacarpal joint.

recessus = no

Carpometacarpal joint

Synovial one large

Recessus = no

Intercarpal joints

No synovial fluid or recessus

The joint is strengthened by the collateral and intercarpal ligaments.

Question 3

Identify the muscles 2,3, 5,6 and 7?

Answer 3

2 = M. Sternocephalicus

3= M. Brachiocephalicus

5 = Superficial descending M. Pectoralis

6 = Superficial Transverse M. Pectoralis

7 = Deep Pectoral

Question 4

Define the bony surfaces in contact, type of joint, movement, ligaments, synovial, recessus and bursa of the below joint?

Answer 4

Scapulohumeral joint

This is a spheroid which is functionally a freely moveable joint. In domestic species this movement is restricted flexion and extension due to muscle connections between the joint and trunk of the animal.

Connection between

head of the humerus and glenoid cavity of the scapular.

synovial = 1

bursa = 1

recessus = 1

Glenohumeral ligament and transverse ligament.

Question 5

Ulnar. N function

Answer 5

Inervates the flexors of the carpus and digits.

Question 6

N. Medianus function ?

Answer 6

Innervates the flexors of the carpus and digits.

Question 7

Locate the Serratus ventralis muscle,

Provide the point of origin, insertion and the muscle’s function?

Answer 7

Location = 6

Origin = cervical transverse process and the lateral side of the ribs.

Insertion = The medial side of the scapular

Function = If the fixed point is the vertebrae it pulls the the dorsal part of the scapular cranially and pushes the shoulder joint back.

Flexes the neck laterally.

The main role is to support the trunk between the two forelimbs.

Question 8

Teres major location, origin, insertion and function.

Answer 8

Location = 2

Origin = Scapular caudoproximal border

Insertion = Humeral teres major tuberosity

Function = Flexion of the shoulder

Question 9

Identify the M. Splenius,

Provide its origin, insertion and function ?

Answer 9

Location = 9

Origin = on mastoid process and atlas wing

Insertion = nuchal ligament, thoracic spinous processes

Function = Extend head when bothe muscles act together, extends and rotates head if only one muscle acts.

Question 10

Describe the Humeroradioulnar joint

Answer 10

Elbow Humeroradioulnar joint

Compound hinge joint

Humeral condyle - head of radius

Anconeal process of ulna - olecranon fossa of the humerus

trochlear notch of ulnma - humeral condyle

1 = synovial (large enclosing three articular parts)

Recessus = 1 dorsal, 1 caudal, 1 medial and 1 lateral

Question 11

N. musculocutaneus function

Answer 11

Innervates the flexes of the elbow,

cutaneous innervation of the dorsolateral brachium.

Question 12

Function N. radialis

Answer 12

Innervates the extensors of the elbow, carpus and digits.

Question 13

Function Axillary nerve.

Answer 13

Innervates the flexors (Teres major muscle )

Question 14

Name the scapular bone land marks (horse)

Answer 14

Scapular cartilage

supraspinous fossa

Infraspinous fossa

spine of scapular

glenoid cavity

supraglenoid tubercle

serratus surface

subscapular fossa

Question 15

Identify the suprasspinatus muscle, its origin, insertion and function?

Answer 15

Location

Origin = supraspinous fossa of the scapular

Insertion = Top two tubercles of the humerus (greater, lesser)

except carnivores only the greater turbercle

Function = stabileses the joint laterally and extends the shoulder

Question 16

Describe the location, origin, insertion and function of the triceps?

Answer 16

Location = 6

long head, lateral head, and medial head.

Origin = caudal side of scapular

Insertion = olecranon of the ulna

Function = to extend the elbow.

Question 17

Identify the muscles A to F on the diagram below?

Answer 17

A = Descending M. Pectoralis

B = Deep Pectoralis

C = M. Brachiocephalicus

D = Omotranversarius

E = Trapezius M. (cervical and thoracic parts).

F - Latissimus Dorsi

Question 18

What is an intrinsic muscle of the forelimb?

Answer 18

Amuscle originating from a bone in the forelimb and inserting on a bone in the forelimb.

Question 19

Identify the Trapezius muscle,

explain its function provide its point of origin and insertion ?

Answer 19

Location E = Cervical and Thoracic parts

Origin = nuchal ligament ( cervical part), and supraspinous ligament (thoracic part).

Insertion = On the scapular spine.

Function = Abducts the scapula, and pulls it up.

Question 20

Infraspinatus muscle, location, orgin, insertion and function?

Answer 20

Location = under the deltoid

Origin = Infraspinous fossa

Insertion = Humeral greater turbercle and humeral convex surface

Function joint stabilisation laterally, and abducts + externally rotates the arm

Question 21

Deltoid location, origin, insertion and function?

Answer 21

Location = above the infraspinatus muscle

split into pars scapularis and pars acromialis

Origin = distal scapular spine or acromion

Insertion = humeral deltoid tuberosity

Function = Felexes the should and abducts and externally rotates the arm.

Question 22

Identify the Omotransversarius

Define it function, origin and insertion?

Answer 22

Location = D

Origin = Atlas (dogs), axis (horses and ruminants)

Insertion = To the scapular spine

Function = If the fixed point is the neck, it pulls the scapular cranially and extends the forelimb. If the fixed point is the scapular it pulls the neck dorsoventrally. If the two muscles act together the neck is pulled back between the scapula.

Question 23

Identify the Rhomboideus muscle,

Privide its point of origin, insertion and describe the function?

Answer 23

Location = 7

Origin = nuchial crest

Insertion = dorsal side of the scapular

Function Pulls the scapular up and forward, or if the fixed point is the scapular it pulls the nuchial ligament.

Question 25

Describe the location, origin, insertion and function of the Coracobrachialis ?

Answer 25

Location = 10

Origin = coracoid process of the scapular

Insertion = medial side of the humerus

Function = acts to stabilise the shoulder, adducts and internally rotates the arm.

Question 27

Identify the Latissimus Dorsi,

Describe its function, origin and insertion?

Answer 27

Location = F

Origin = Supraspinous ligament and spinous process of the thoracic and lumbar vertebrae.

Insertion = Teres major tuberosity

Function = Antagonistic of the brachiocephalicus, pulls the brachium back.

Question 28

Describe the subscapularis location, origin, insertion and function?

Answer 28

Location = 9

Origin = Subscapular fossa

Insertion = Humeral lesser tubercle

Function = Stabilises the joint and adducts and internally rotates the arm.

Question 29

Describe the location of the three different pectorial muscles, and name them?

Then describe their function, origin and insertion?

Answer 29

Location as seen in image.

Superficial Pectorals

Descending M. Pectorals

Origin = Sternal manubrium

Insertion = deltoid tuberosity and humeral crest.

Function = Pulls the forelimb cranually, and adducts the brachium.

Transverse M. Pectorals

Origin = Sternal carina

Insertion = humeral crest

Function = Pulls the forelimb cranially and adducts the brachium.

Deep M. Pectoral

Origin = caudal half of sternum

Insertion = dog (minor humeral tubercle), medial lip of the interbubercular groove.

Function Adducts and internally rotates the limb.

Question 30

What is an extrinsic muscle of the forelimb?

Answer 30

The extrinsic muscles of the forelimb,

which have an attachment to the bones of the limb and an attachment to the trunk,

are responsible for suspending the trunk between the forelimbs and for moving the forelimbs relative to the trunk.

Question 31

Identify the Brachiocephalicus muscle,

and its function, origin and insertion?

Answer 31

Location = C

Origin = Mastoid process

Insertion = Humeral crest

Function =

If the fixed point is the forelimb it acts to flex the head and neck. If only one of the muscles function the neck also rotates to the side of the functioning muscle.

If the fixed point is the head it acts to move the forelimb (humerus) forwards.

Question 32

Note how bones interconnect, and land marks of humerus and scapular ?

Question 33

Describe the three different types of bone marrow ?

Answer 33

Red bone marrow = hematogenic and osteogenic persisting within the adult axial skeleton.

Yellow bone marrow = not hematogenic, rich in fat cells

Grey bone marrow = not hematogenic, litle fat often in older skinnier subjects.