Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Anatomy > pectoral girdle > Flashcards

pectoral girdle Flashcards

1
Q

what does the pectoral girdle include? what are its signature characteristics and the function of these? where does it get support and stabilization?

A

clavicle and scapula in an incomplete ring (open posteriorly) to allow mobility +independent motion
-support and stabilization by axio-appendicular muscles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is the sternoclavicular joint?

A

single articulation between the pectoral girdle and the axial skeleton. (scapula has no articulation w/ axial- only attached via muscles)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what are the 3 chief characteristics of the clavicle? expand on each.

A
  1. Elongated S shape
    - -Convex medially (curve protudes anteriorly)
    - -Concave laterally
  2. Enlarged sternal (medial) end
    - -Articulates with manubrium
    - -Sternoclavicular joint (SC)
  3. Flattened acromial (lateral) end
    - -Articulates with acromion process
    - -Acromioclavicular joint (AC)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

when someone falls on an outstretched arm, where are they likely to have a fracture/break?

A

weak points: clavicle or wrist

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

when people fall on their shoulder, where will they have a fracture/break? why?

A

clavicle - it transmits force from the upper limb to the axial skeleton

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what are the movements of the clavicle?

A

swinging strut, suspends scapula at corcacoid process . Allows scapula to “glide” on the thoracic wall (scapulothoracic joint)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what movements can the scapula do at the scapulothoracic joint?

A

elevation/depression
protraction/retraction
upward rotation/downward rotation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

characteristics of scapula structure? Think medial/lateral, anterior/posterior, superior/inferior

A

Medial, lateral, superior borders
–Suprascapular notch
–Superior transverse scapular ligament
Superior, lateral, inferior angles

Posterior surface divided by spine
--Supraspinous fossa (above spine)
--Infraspinous fossa (below spine)
Acromion- lateral end of spine 
--Acromioclavicular (AC) joint

Anterior subscapular fossa: indented region
Coracoid process- looks like little thumb
–Coracoclavicular ligament
Lateral surface bears glenoid fossa
–“Socket” for much larger humeral head

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what two features create a foramen on the superior border of the scapula?

A

suprascapular notch and superior transverse scapular ligament

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

how does the acromion project?

A

anterior and laterally

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

where is the weight of the scapula and upper limb suspended?

A

center of balance: the strong coracoclavicular ligament- which is attached to the coracoid process on the anterior surface of scapula

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

how does the scapula and humerus counterbalance each other?

A

the balance of the coracoclavicular ligament but also the pull of the rhomboids against the weight of the limb.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

posterior axio-appendicular muscles…O,I,A? What do they include?

A

Originate on axial skeleton
Insert on appendicular skeleton
Move or stabilize pectoral girdle and/or humerus
includes: superficial and deep extrinsic shoulder muscles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

superficial extrinsic shoulder muscles

A

trapezius and lat. dorsi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

deep extrinsic shoulder muscles

A

rhomboids (major and minor) + levator scapulae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

scapulohumeral muscles: O,I,A. which muscles are included?

A

the intrinsic should muscles. O&I on appendicular skeleton. predominantly O on scapula and I on humerus

Act: on glenohumeral (shoulder) joint

  • Deltoid
  • teres major
  • rotator cuff group
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what muscles are in the rotator cuff group?

A 
"SITS"
supraspinatus
infraspinatus
teres minor
subscapularis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Deltoid features, O,I,A, Innerv.?

A

inverted triangle: anterior, middle, and posterior portions
O- lateral third clavicle, acromion, lateral scapular spine
I-deltoid tuberosity (prominence on humerus)
A-abducts arm after 15degrees
–anterior: flexes
–posterior:extends (when adducted)
innveration:axillary nerve C5, C6 - terminal branch of brachial plexus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what abducts arm the first 15degrees?

A

supraspinatus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Teres Major:general location, O,I,A, Innerv.

A

Forms posterior lateral boundary of axilla, runs very close to latissimus dorsi.
O-posterior surface of inferior scapular angle
I-intertubercular groove of humerus (posteromedial to latissimus dorsi)
Adducts & medially rotates arm
Innervated by lower subscapular nerve (C5, C6)
–(Collateral/preterminal branch of brachial plexus)
NOT THORACODORSAL NERVE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what does “teres” mean?

A

“round” - cylindrical shape of muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what type of baseball pitch would the teres major help in?

A

screwball, medial/internal rotation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

which muscle is not part of the rotator cuff group but does serve to rotate the humerus?

A

teres major

24
Q

what do the rotator cuff muscles do?

A

all 4 form a tendinous cuff around glenohumeral joint that stabilizes the oversized humeral head into undersized glenoid fossa - think of thumb and first three finger grabbing onto humeral- they form “ the cuff “

  • -3 of the 4 serve to rotate the humerus. (supra only ABducts)
  • -4 muscles provide tendinous support- support on all sides except inferiorly - plays a role in shoulder dislocation
25
Q

what are the placement of the rotator cuff muscles in the finger model?

A

holding the head of the humerus with the palm as the glenoid fossa

thumb: subascapularis
pointer: supraspinatus
middle: infraspinatus
ring: teres minor

26
Q

supraspinatus: O,I,A, Inner,Blood?

A 
O-supraspinous fossa
I-greater tubercle (superior portion)
A: First 15° abduction of arm
Innervated: suprascapular nerve (C4-6)
---Collateral/preterminal branch of brachial plexus
-blood: suprascapular artery
27
Q

what is the general location of the supraspinatus?

A

passes under the acromion and under the acromion ligament “bridge”

28
Q

infraspinatus: O,I,A, blood?

A

O-infraspinous fossa of scapula
I-greater tubercle of humerus (posterior portion)
A: Laterally rotates arm
Innervated: suprascapular nerve (C5-6)
—-Collateral/preterminal branch of brachial plexus
blood: suprascapular artery

29
Q

what muscle aids in the curveball pitch?

A

infraspinatus (lateral rotation)

30
Q

suprascapular nerve and artery: general location

A

both originate in neck go into the pectorogirdle region

31
Q

suprascapular artery: originates where? goes where? supplies what?

A

-O: thyrocervical trunk
“army”: Passes OVER superior transverse scapular ligament
Passes deep to acromion
-Forms scapular anastomoses with intercostal arteries (backup if occlusion of vessel occurs)
-supplies both spinatus muscles

32
Q

suprascapular nerve:

A

O:superior trunk of brachial plexus
“navy”:Passes UNDER superior transverse scapular ligament
-Passes deep to acromion- through the suprascapular notch/ “foramen”
-Innervates supraspinatus & infraspinatus

33
Q

Teres minor: O,I,A, Inner.?

A

O-lateral border of scapula (mid-portion)
I-greater tubercle of humerus (posterior portion)
Laterally rotates arm
Innervated by axillary nerve (C5-6)
–Terminal branch of brachial plexus

34
Q

what muscle does the teres minor often blend with?

A

infraspinatus

35
Q

what nerve serves both the teres minor and deltoid?

A

axillary C5,C6

36
Q

subscapularis: O,I,A, Innerv?

A

O-anterior surface of scapula
I-lesser tubercle of humerus
Forms portion of posterior wall of axilla
A: Medially rotates arm (screwball), anterior support
Innervated: upper & lower subscapular nerves (C5-7)
–Collateral branches of brachial plexus

37
Q

which muscle of pectoral girdle will we not see in lab b/c it is located on the anterior surface of the scapula?

A

subscapularis - occupies subscapular foss

- we will see serratus anterior

38
Q

what makes up the quadriangular space?

A 
-Communicate with axilla
S-inferior border of teres minor
L-surgical neck of humerus
I-superior border of teres major
M-lateral border of long head of triceps brachii
39
Q

what muscle bisects the teres major from minor?

A

longhead of the triceps brachii

major is anterior to it, minor is posterior

40
Q

what nerve and artery pass through the quadriangular space?

A

Axillary nerve & posterior circumflex humeral artery (brachial plexus) pass through here

41
Q

what makes up the triangular space ?

A

communicate w/ axilla
S-inferior border of teres minor
L-medial border of long head of triceps brachii
I-superior border of teres major

42
Q

what artery goes through the triangular space?

A

Circumflex scapular artery (branch of subscapular)

43
Q

longhead of the triceps: anterior and posterior to what? originates where? what does it separate?

A

Separates two spaces: quadrangular from triangular
O: at inferior glenoid tubercle
Anterior to teres minor
Posterior to teres major

44
Q

triangular interval

A

S-inferior border of teres major
M-lateral border of long head of triceps brachii
L-medial border of lateral head of triceps brachii
Radial nerve & profunda (deep as in “profoundly deep person” brachii artery
–Both course in radial (spiral) groove

45
Q

what is the largest branch of the brachial plexus?

A

radial nerve

46
Q

structures that cross triangular interval..pass in what way?

A

pass in radial/spiral groove of humerus - an oblique/diagonal groove - nerve passes in this
- groove spirals to lateral aspect of humerus and we see nerve there again. important landmark in understanding triceps muscle

47
Q

anterior and posterior compartments of the arm- muscles and nerves

A

Anterior

  • -Flexors of forearm & arm (biceps brachii, brachialis, coracobrachialis)
  • -Musculocutaneous nerve (term branch of brachial plexus)

Posterior

  • -Extensors of forearm- (triceps brachii)
  • -Radial nerve
48
Q

Triceps Brachii: O,I,A, Innerv?

A

Long, lateral, & medial heads
O-inferior lip of glenoid fossa (long head);
posterior humerus, above radial groove (lateral head); posterior humerus, below radial groove (medial head)
I-olecranon process (of ulna)
A:Extends forearm, long head also extends & adducts arm (b/c it crosses the shoulder joint)
Innervated by radial nerve (C6-C8)

49
Q

what are the variances in strength/activity of the different parts of triceps brachii?

A

Long head-least active
Medial head-most active
Lateral head-strongest, only used against resistance

50
Q

anconeus: O,I,A, Innerv.?

A

small “cone” on the ulna, just distal from elbow joint
O-lateral epicondyle of humerus
I-lateral olecranon process & proximal ulna
A: Assists in extension of forearm
Innervated by radial nerve (C7-T1)

51
Q

what are the three major clinical correlations we talk about with the rotator cuff/posterior arm?

A

axial nerve injury, rotator cuff injury, glenohumeral dislocations

52
Q

4 Causes of axial nerve injury? What will result from this injury?

A
  1. Surgical neck (of humerus) fractures: axillary nerve wraps around this part of the humerus
  2. Glenohumeral dislocations
  3. Improper crutch fitting/use: should be 2 inches below axillary floor
  4. Improper IM injections: IM should be 2 fingerbreadths below acromion

these can lead to: Deltoid atrophy & Lateral shoulder numbness

53
Q

where is the surgical neck of the humerus?

A

just below tubercles

54
Q

what causes Degenerative Tendonitis? what are the symptoms?

A

Repetitive/forceful use of upper limb above horizontal plane
Supraspinatus tendon & humeral head grate on coracoacromial arch/”bridge”/ligament (Supraspinatus tendon relatively avascular- doesnt heal well w/out blood supply)

symptoms: Shoulder stiffness & Pain on initiating abduction or reaching behind back

55
Q

what causes rotator cuff tear? what are the symptoms?

A

Usually supraspinatus tendon
Usually preceded by degenerative tendinitis
Fall on shoulder
Forceful lifting motion
symptoms: Unable to resist gravity from 90° abduction
& Can’t initiate/maintain abduction

56
Q

Glenohumeral Dislocation

A

joint: Highly mobile but unstable- head too big for socket and no inferior support
cause: Forceful extension & lateral rotation
MO: Nearly always inferior
head of humerus displaces into Quadrangular space
and pinches Axillary nerve

Clinically described by location of dislocated humeral head

  • -either Anterior (pulled by pectoralis) or posterior (pulled by latissimus and teres major) to glenoid fossa
  • -Anterior most common (pectoralis is stronger so it Wins)
57
Q

how are the radial and axillary nerves oriented in the arm?

A

posterior cord of brachial plexus comes under the lateral end of the clavicle, anteriorly into the glenohumeral( glenoid fossa/humerus) joint. just under the head of the humerus it branches laterally (axillary nerve) and wraps around humerus posterior then anteriorly. the larger part of the cord follows inferiorly (radial nerve) down the arm.

Anatomy (13 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions