Lecture 14 - Musculoskeletal 3 Flashcards

1
Q

what are the three parts of the deltoid?

A

anterior, posterior and middle fibres

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2
Q

what is the origin and insertion of the entire deltoid?

A

origin: the anatomical horseshoe
- clavicle and scapula
insertion: the deltoid tuberosity of the humerus

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3
Q

what is the primary movement of the deltoid’s anterior fibres?

A

flex the shoulder
internal rotator of the humerus

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4
Q

what is the primary movement of the deltoid’s posterior fibres?

A

extend the shoulder (pulls humerus backwards)
externally rotates arm

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5
Q

what is the primary movement of the deltoid’s middle fibres and entire deltoid?

A

abducts humerus/arm, but does depend of where arm is and which fibres are activated

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6
Q

how do the anterior and posterior fibres of the deltoid relate to each other?

A

they are antagonists in rotation and flexion/extension.
but flexing them at the same time can cause adduction of the humerus at anatomical position, and assist in further abduction when arms are lifted

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7
Q

how does the supraspinatus assist in abduction?

A

the middle fibres of the deltoid would try to pull up on the humerus. The corcoacromial arch prevents this, so the supraspinatus starts abduction to take the humerus far enough away from your body so the middle fibres can start to contract

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8
Q

what is the origin and insertion of the teres major?

A

origin: inferior angle of the posterior scapula just below the teres minor
insertion: medial lip of the intertubercular groove on the anterior humerus
- goes from posterior to anterior like lat dorsi

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9
Q

what is the primary movement of the teres major?

A

adductor of the shoulder
also an internal/medial rotator

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10
Q

what does a teres mean

A

the muscle is circular or round when cut in cross-section

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11
Q

what muscles form the anterior and posterior fold of the armpit?

A

anterior = pectoralis major
posterior = latissimus dorsi and teres major

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12
Q

what is the origin and insertion of the coracobrachialis?

A

origin: coracoid process
insertion: medial side of humerus (opposite the deltoid tuberosity)

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13
Q

what is the primary movement of the coracobrachialis?

A

adduction of shoulder

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14
Q

what is the insertion of the pectoralis major and what is its significance to the arm?

A

lateral lip of the intertubercular groove
- hold tendon of the biceps brachii in place

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15
Q

what do all components of a compartment share?

A

the same nerve supply, drained by the same vein and lymphatics

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16
Q

at what point in the arm can we begin to form compartments?

A

just under the insertion of the deltoid (deltoid tubercle) and the coracobrachialis, the lateral and medial intermuscular septa begin.

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17
Q

describe the comparment of the arm at the mid humerus

A

there is a flexor compartment with 3 muscles and an extensor compartment with 1 muscle. these two are separated by the humerus and the lateral and medial intermuscular septa

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18
Q

true or false, the origin of muscles can be an intermuscular septum

19
Q

what is the primary movement of the brachialis?

A

main elbow flexor

20
Q

what is the origin and insertion of the brachialis?

A

origin is the intermuscular septa of the flexor compartment of the arm

21
Q

why do the long muscles of the hands and fingers attach to the side of the elbow/humerus?

A
  • long muscles account for large range of motion and stronger movements (larger muscle bellies, muscles can only contract 1/3 of their length)
22
Q

how does muscle attachment on the elbow for hand movement change the structure of the upper arm/elbow compartment?

A

the lateral and medial intermuscular septa split to create another compartment on each side, where the muscles for hand movement can attach
- medial and lateral compartments created as well as flexor and extensor compartments for the common tendons

23
Q

where do the majority of the muscles of the forearm originate?

A

on the lateral and medial epicondyles of the humerus/elbow via a common tendon

24
Q

the lateral epicondyle shares a common __________ tendon of the forearm, and the medial epicondyle shares a common _________ tendon of the forearm

A

extensor, flexor

25
Q

where does the common extensor tendon go/occupy?

A

from the lateral side of the humerus around to the posterior side of the forearm.

26
Q

where does the common flexor tendon go/occupy?

A

from the medial side of the humerus around to the anterior side of the forearm.

27
Q

what are the three muscles of the flexor compartment of the upper arm?

A
  • biceps brachii
  • brachialis
  • coracobrachialis
28
Q

what originates from the medial and lateral compartments OTHER than the common tendons?

A

medial: pronator teres on the supracondylar ridge
lateral: Brachioradialis and ECRL (extensor carpi radialis longus)

29
Q

what muscle forms the extensor compartment of the upper arm?

A

the triceps brachii

30
Q

what is the primary movement of triceps brachii?

A

elbow extensor

31
Q

what are the two origins and two insertions of the biceps brachii?

A

long head origin: supraglenoid tubercle
short head origin: coracoid
insertion 1: bicipital aponeurosis (not a bony insertion)
insertion 2: radial tuberosity (bump on inside of radius)

32
Q

what is the primary movement of biceps brachii?

A

supinator (towards holding bowls of soup from spilt soup = supination)
and then elbow flexor
= pulls the radius back over the ulna to anatomical position

33
Q

what is the primary movement of brachialis?

A

main elbow flexor

34
Q

what is the origin and insertion of the brachialis?

A

origin: anterior surface of distal humerus
insertion: tuberosity of the ulna

35
Q

how does supernation happen in terms of forearm bones?

A

the distal end of the radius crosses over the top of the ulna as the proximal end rotates against the humerus, and this brings the hand with it

36
Q

random function of the tendon of the long head biceps tendon?

A

keeps the humerus against the glenoid as the humerus rotates

37
Q

what is a problem with the biceps long head as we get older?

A

osteophytes can cause rupturing of the long head biceps - worn down tendon

38
Q

which nerve innervates all three muscles of the anterior flexor compartment?

A

the musculocutaneous nerve

39
Q

what are the head of the triceps?

A

lateral, medial, long heads

40
Q

what is the insertion of the triceps heads?

A

olecranon of the ulna

41
Q

what is the forearm muscle that assists triceps in elbow extension?

A

anchoneus
lateral epicondyle -> back of the ulna

42
Q

what are shunt muscles?p

A

prevent unwanted inferior movement/dislocation of the humeral head at the shoulder joint during loading.
but they are not shortening

43
Q

what are the shunt muscles of the arm?

A

deltoid
short head biceps
coracobrachialis
long head triceps