Shoulder/Arm Anatomy Flashcards
1
Q
What are the factors that affect the amount of force a muscle exerts at a joint axis?
A
Size/Bulk of a muscle (Cross-sectional area)
Shape of a muscle: straight or penate or something
angle of pull relative to the axis
Insertion site close to or far away from joint
2
Q
What is a straight muscle good for? What is a penate or bipenate muscle good for?
A
Straight Muscle: great ability to change in length
Bipenate or penate muscle: supplies more power, less ROM
3
Q
When a muscle is attached close to the joint…it is good for? When it is attached far away?
A
Close to the joint: speed
Far from the joint: power
4
Q
All muscles help to stabilize the joint they _____.
A
the joint they cross
5
Q
In general, the upper extremity is good for speed/power & the lower extremity is good for speed/power.
A
Upper Extremity: Speed
Lower Extremity: Power
6
Q
What are the 3 things you must ask yourself when you look at a new muscle?
A
What are the axes this muscle exhibits? What are its possible actions? Where does the muscle cross the joint relative to the axis?
7
Q
Describe how the upper limb is stabilized.
A
What is crazy about the upper limb is that the only bone attachment to the axial skeleton/stabilization is the sternoclavicular joint. The rest is just muscle stabilization. This is why it is so freely moveable.
8
Q
Why is it important that the inferior angle of the scapula can move laterally & medially?
A
b/c this allows for full abduction of the scapula.
9
Q
What is the shape of the clavicle? What is the superior side like? What is the inferior side like?
A
S-shaped clavicle
Superior side is smooth
Inferior side is rough so that ligaments can attach to it.
10
Q
T/F The clavicle is a common bone to fracture.
A
TRUE
11
Q
What is the origin of the clavicle?
A
membranous origin
12
Q
What are 2 fun bone facts of the clavicle?
A
- first long bone to ossify: weeks 5-6
2. last long bone to fuse @ epiphyseal plate around 25 years
13
Q
How does the clavicle ossify?
A
intramembranous ossification
a little endochondral ossification maybe
14
Q
What are the 2 joints that the clavicle is a part of?
A
sternoclavicular joint
acromioclavicular joint
15
Q
What are 2 possible actions of the shoulder girdle?
A
shoulder shrug: elevation/depression
Protraction/Retraction (along the vertical axis)
16
Q
During protraction/retraction of the scapula…what must happen to the scapula?
A
It must glides along the chest wall with 15 degrees worth of gliding movement
17
Q
Movements of the shoulder girdle require some mobility of the ____ joint.
A
AC joint
18
Q
Which ligaments stabilize the acromioclavicular joint (AC)?
A
Mainly: coracoclavicular ligaments
Maybe sorta: coracoacromial ligament
19
Q
What are the 2 ligaments that make up the coracoclavicular ligaments? Where are they located?
A
trapezoid ligament (more lateral) conoid ligament (more medial)
20
Q
What is the function of the coracoacromial ligament?
A
it forms the roof of the glenohumeral joint–>this is where the head of the humerus rests!!
21
Q
Where does the clavicle usu fracture?
A
usu in the middle & distal 3rd
**usu just proximal to the coracoclavicular ligaments
22
Q
What is the difference b/w shoulder separation & shoulder dislocation?
A
shoulder separation: occurs at the AC joint
shoulder dislocation: occurs @ the glenohumeral jt
23
Q
T/F You cannot separate the AC joint w/o tearing the coracoclavicular ligaments, as they are a strong stabilizing force.
A
FALSE. You can separate the AC jt w/o tearing the ligaments. It consists of just a broken clavicle, distal to the ligaments.
Often though, you break the clavicle & tear the ligaments.
24
Q
Describe shoulder dislocation.
A
the head of the humerus is forced out of the glenoid fossa
25
What direction is the head of the humerus usu pushed in when you experience a shoulder dislocation?
usu anteriorly & inferiorly.
26
Describe a physical position that would make it easier to dislocate your shoulder. Why is this such a vulnerable position?
when your arms are fully abducted above your head...if someone came from behind & smacked your shoulder.
vulnerable b/c the head of the humerus in this position isn't in contact w/ the glenoid fossa...when articular surfaces aren't touching called a loose packed jt & is more vulnerable...once it is dislocated...muscles contract, forcing the head of humerus into the axillary fossa.
27
What is the glenoid labrum & how does it relate to shoulder dislocation?
this is an extension of cartilage that is found in the shoulder. It is easy to tear during shoulder dislocation.
28
How can you put a shoulder back into its socket after shoulder dislocation?
if you have had multiple dislocations, maybe you can just pop it back...usu need muscle relaxants & a doctor's assistance.
29
Describe the sternoclavicular joint.
It is a synovial joint w/ 2 synovial cavities and a fibrocartilage articular disc.
30
Describe the ligaments surrounding the SC joint.
```
sternoclavicular ligament
costoclavicular ligaments (clavicle-->ribs)
```
31
Describe all the possible movements of the SC joint & their axes.
Elevation/Depression --AP Axis
Retraction/Protraction--Vertical Axis
Medial/Lateral rotation--Oblique Axis
32
What defines lateral or medial rotation @ the SC joint?
lateral or medial rotation of the inferior angle of the scapula
33
If you had a muscle that was attached around the neck/head area & attached to the superior angle of the scapula (levitator scapulae)...what would contracting this muscle do on the AP axis & the oblique axis?
AP axis: options are up & down. It would pull the scapula up.
Oblique axis: options are lateral & medial rotation. It would cause medial/internal rotation.
34
Describe the 2 things that are required for full abduction of the arm.
Can achieve 120 degrees of abduction via the glenohumeral joint.
Achieve the other 60 degrees of abduction via the sternoclavicular joint.
Combination of the 2 is called scapulohumeral rhythm.
35
If you want to help out your arm in its abduction efforts...what is the best position to put it in? What is the worst position-why?
Best position: laterally rotated
| Worse position: medially rotated b/c the greater tubercle of the humerus will hit the acromion.
36
What is the primary abductor of the arm?
deltoid muscle
37
Where does the trapezius medially attach?
spinous processes of vertebrae
| && superior nuchal line of the head
38
The trapezius muscle kind of has 3 parts. What are these different sections & in what direction do their fibers run?
Superior: fibers run inferolaterally
Intermediate: fibers run straight laterally
Inferior: fibers run superolaterally
39
Where is the oblique axis located relative to the trapezius muscle? What direction does the oblique axis run?
it is located beneath the superior & intermediate sections of the trapezius & superior to the inferior section.
**it runs anteromedially to the SC joint
40
T/F The trapezius muscle is an upper limb muscle that is innervated by the brachial plexus.
FALSE
It IS an upper limb muscle.
It is NOT innervated by the brachial plexus. But by a cranial nerve.
41
Which cranial nerve supplies the trapezius muscle?
Cranial nerve 11, the spinal accessory nerve supplies the trapezius.
42
If something happened to the brachial plexus...what would happen to upper limb muscles?
They would be in trouble! Except for the trapezius b/c it is innervated by cranial nerve 11, and not the brachial plexus.
43
If you were to briefly describe the brachial plexus, how would you describe it?
ventral rami of spinal nerves
44
What are the actions of the superior, intermediate, and inferior portions of the trapezius muscle on the following axis?
Vertical Axis?
All sections of the trapezius muscle retract on the vertical axis. It makes sense b/c they all attach medially in the back. When they shorten, they encourage retraction.
45
What are the actions of the superior, intermediate, and inferior portions of the trapezius muscle on the following axis?
AP axis?
Superior: Elevates
Intermediate?
Inferior: depresses
46
What are the actions of the superior, intermediate, and inferior portions of the trapezius muscle on the following axis?
Oblique axis?
all 3 laterally rotate
47
Does the trapezius act as a unit or as 3 separate parts?
depends...
when working on the vertical or oblique axis, it works as a unit, b/c they all accomplish the same thing.
when working on the AP axis, it works as individual parts b/c they accomplish different actions.
48
What supplies motor innervation to the trapezius muscle? What supplies proprioceptive innervation--so that you know what level of contraction that muscle is under?
Motor innervation: spinal accessory nerve (cranial nerve 11)
| Proprioception: C3, C4 cervical segments (these little guys jump onto CN 11).
49
Describe the location of the latissimus dorsi muscle.
it is attached to the inter tubercular groove (b/w the greater & less tubercle of the humeral head)
it then runs horizontally & is attached to the thoracolumbar fascia.
50
What are the joints that the latissimus dorsi muscle acts on?
Mainly: glenohumeral joint
| Also (if glenohumeral joint is stabilized): sternoclavicular joint
51
What are the actions of the latissimus dorsi muscle @ the glenohumeral joint? What is the axis of these actions? What types of sports does this support?
```
Extends & Medially rotates & adducts
Extension on the transverse axis.
Medial Rotation on the vertical axis
Adduction on the AP axis
**good for swimming & rock climbing
```
52
What are the actions of the latissimus dorsi @ the SC joint when the glenohumeral joint is stabilized?
retraction & depression of the shoulder girdle
53
What is the nerve supply to the latissimus dorsi muscle?
thoracodorsal nerve aka middle sub scapular nerve
| **found on the posterior cord of the brachial plexus
54
T/F The latissimus dorsi is a deep back muscle.
False. It is superficial & extrinsic.
55
T/F The latissimus dorsi passes medial to the vertical axis.
true. I have no idea why.
56
What are some superficial back muscles that act on the scapula?
trapezius
rhomboids major & minor
levator scapulae
57
What joint does the rhomboid major & minor work @? What is its action there? Which axis?
Works @ the SC joint
retracts & medially rotates the scapula
retraction is on the vertical axis
58
What does it really mean that the rhomboids medially rotate the scapula upon contraction?
it means that if you look @ the inferior angle of the scapula...it is pulled inward with contraction. It is pulled medially as the scapula is retracted.
59
What is the nerve supply to the rhomboid major & minor?
dorsal scapular nerve
| this is a part of the brachial plexus coming off of C5.
60
Where is the levator scapulae located?
it is connected to the transverse processes of the cervical vertebrae & it runs down to the superior angle of the scapula
61
What is the action of the levator scapulae?
It elevates & medially rotates the scapula.
62
What is the nerve supply to the levator scapulae?
dorsal scapular nerve
63
What are some anterior muscles that affect the SC joint?
pectoralis minor muscle
| serratus anterior muscle
64
What is the pec minor muscle attached to?
coracoid process
65
What is the innervation of the pec minor?
medial pectoral nerve (also innervates the pec major)
66
What actions does the pec minor do @ the SC joint--that is, what does it do to the shoulder girdle?
depresses (AP axis)
protracts (vertical axis)
medially rotates (oblique axis)
67
What is the location of the serratus anterior? Aside from its SC joint function, what is its other function?
it is on the anterior surface of the body, connected to ribs & a part of the scapula.
next to the subscapularis
**holds the scapula tight against the body wall, keeps it from popping out when you push against something.
68
What are the actions of the serratus anterior on the shoulder girdle @ the SC joint?
Depresses (AP axis)
Protracts (vertical axis)
Laterally Rotates (Oblique axis)
69
What is the innervation of the serratus anterior?
long thoracic nerve (this comes from the roots of the brachial plexus)
it is located superficially to the muscle which is unique & makes it more prone to damage.
70
What happens if you damage the long thoracic nerve of the serratus anterior?
you can get winging of the scapula
71
At the SC joint, what can cause protraction?
serratus anterior
| pec minor
72
At the SC joint, what can cause retraction?
trapezius (middle portion)
rhomboid major
rhomboid minor
73
At the SC joint, what can cause elevation?
trapezius (upper part)
levator scapulae
rhomboid major
rhomboid minor
74
At the SC joint, what can cause depression?
serratus anterior
pec minor
trapezius (lower part)
75
At the SC joint, what can cause medial rotation?
pec minor
rhomboid major
rhomboid minor
levator scapulae
76
At the SC joint, what can cause lateral rotation?
trapezius (all parts)
| serratus anterior
77
T/F Movements at the scapula are transmitted to the humerus.
True. Like if you fixed the arm in the glenoid fossa & lateral rotated the scapula...it could facilitate slight arm movement.
78
Where do arm movements occur?
glenohumeral joint
79
T/F Muscles change their actions based off of the anatomical position of the body.
True.
80
Anterior compartment muscles are ______ & posterior compartment muscles are ______. Anterior compartment muscles are innervated by _______ _______ _______.
Anterior compartment muscles are flexors & posterior compartment muscles are extenders. Anterior compartment muscles are innervated by anterior division nerves.
81
What are the possible movements of the glenohumeral joint & what axis is it on?
Flexion/Extension @ the Horizontal Transverse Axis
Abduction/Adduction @ the Horizontal AP Axis
Rotation @ the Vertical Axis
82
What happens when your long thoracic nerve is damaged?
you get a winged scapula
83
The acromion is a part of the ________.
scapula.
84
What is the glenohumeral joint?
synovial ball & socket joint that involves articulation b/w the glenoid fossa & the scapula.
most mobile joint in the body
**there is a synovial membrane involved in the joint, covering the head of the humerus as its articular surface
85
What is the glenoid fossa?
this is a depression in the scapula
| this is where the head of the humerus floats
86
Which tendon is a part of the glenohumeral joint & is above the head of the humerus? It is considered a rotator cuff muscle.
the tendon of the suprspinatus muscle
87
The glenohumeral joint is super moveable. What is the trade off for this motion?
the joint is inherently unstable
88
B/c the glenohumeral joint is unstable, we need some things to stabilize it. What do we use to help stabilize it?
glenoid labrum is found there (triangular pieces of cartilage that stabilize the joint)
also have a strong capsule & strong tendons (the tendons of the rotator cuff muscles)
89
What actions are possible at the glenohumeral joint?
```
external & internal rotation
abduction
adduction
extension
flexion
```
90
The deltoid muscle tendon is attached to what?
attached to the acromion.
91
What's super cool about the deltoid muscle?
it can perform every motion. b/c it has anterior, intermediate, and posterior fibers.
sorta like the trapezius in this way.
92
What is special that is found underneath the deltoid muscle?
the sub deltoid bursa.
93
What is something weird that can happen with the humerus when you keep abducting without limit? If you are a swimmer & you keep having this problem--what is sometimes done to fix it?
the greater tubercle of the humerus can hit the acromion.
| sometimes people shave off a part of the acromion.
94
What is the function of a bursa? What are some of the bursa surrounding the glenohumeral joint?
bursa: protects the muscle from a bony structure
* *subdeltoid bursa: protects deltoid muscle from greater tubercle of the humerus
* *subacromial bursa
* *bursa surrounding the bicep brachii tendon.
95
What is the innervation of the pectorals major muscle?
medial & lateral pectoral nerves
96
What are the actions of the pec major? Which joint does it affect?
Actions @ the glenohumeral joint
Flexion
Adduction
Medial Rotation
97
What's super special about the deltoid muscle?
it can perform all the actions b/c it has anterior, middle, & posterior fibers
98
Which joint does the deltoid muscle act on?
glenohumeral joint, not the SC joint b/c it isn't attached to the axial skeleton
99
What are the actions of the deltoid muscle on the GH joint & which part of the muscle performs these actions?
```
Flexion (Anterior Fibers)
Extension (Posterior Fibers)
Medial Rotation (Anterior Fibers)
Lateral Rotation (Posterior Fibers)
Abduction (Middle Fibers)
Adduction (Anterior & Posterior Fibers)
```
100
Which joints can the latissimus dorsi act on?
SC joint b/c it is attached to the axial skeleton
| GH joint
101
Which joints can the teres major act on?
the GH joint
| not SC b/c attached to the scapula, not the axial skeleton
102
What is the relationship b/w the latissimus dorsi & the teres major?
they have the same insertion but different origins. Thus, they have the same actions on the GH joint
103
What are some examples of muscles that act on the SC joint?
pec major
latissimus dorsi
rhomboids
levator scapulae
104
What is the innervation of the latissimus dorsi?
middle subscapular (thoracodorsal)
105
What is the innervation of the teres major?
lower subscapular
106
What are the actions of the latissimus dorsi & the teres major on the GH joint?
Extension
Adduction
Medial Rotation
107
What are the muscles of the rotator cuff?
```
SITS muscles
Supraspinatus
Infraspinatus
Teres Minor
Subscapularis
**all perform rotatory functions & add stability to the GH joint
```
108
What is a way to prevent the greater tubercle from hitting the acromion during flexion or abduction @ the GH joint?
external rotation of the humerus when you flex or abduct
109
Which ones of the sits muscles can be seen on the posterior side of the scapula? Anterior side?
```
Posterior Side (from top to bottom)
Supraspinatus
Infraspinatus
Teres minor
Anterior Side:
subscapularis
```
110
Which ones of the sits muscles attach to the greater tubercle? Which attach to the lesser tubercle?
```
Greater Tubercle:
Supraspinatus
Infraspinatus
Teres Minor
Lesser Tubercle:
Subscapularis
```
111
The SITS muscles are awesome at external & internal rotation. Which do which?
S: Supraspinatus: neither b/c located in the vertical axis
I: Infraspinatus: external rotator
T: Teres Minor: External rotator
S: subscapularis: medial rotator (arm wrestling muscle)
112
What is the fcn of the tendons of the SITS muscles? Where is the arm most susceptible to dislocation?
the tendons strengthen the capsule posteriorly, anteriorly, posteroinferiorly, superiorly.
Not so much inferiorly-->thus, the easiest location to dislocate the arm.
113
What are common sports that cause rotator cuff tears in players?
swimmers
pitchers
linesmen
volleyball players
114
The supraspinatus & infraspinatus are supplied by which artery & nerve?
Artery: suprascapular artery
Nerve: suprascapular nerve
115
Where does the suprascapular nerve pass thru? Does the suprascapular artery pass thru there too?
Nerve passes thru the suprascapular notch covered by the transverse scapular ligament
* *weight lifters sometimes impinge this nerve
* *the suprascapular artery doesn't pass thru that too.
116
Which nerve & artery supply the teres minor? What space must they pass thru to get there?
Nerve: Axillary Nerve
Artery: posterior humeral circumflex artery
**this nerve & artery must pass thru the quadrangular space to get there
117
What makes up the quadrangular space?
the teres minor & teres major form the quadrangular space
| Note: the teres minor attaches to the humerus & the teres major passes anterior to the humerus
118
What does the posterior humeral circumflex anastomose w/?
the anterior humeral circumflex artery
119
Where does the suprascapular nerve come from?
upper trunk of the brachial plexus
120
Which nerves & arteries supply the subscapularis muscle?
Nerve: Upper & Lower Subscapular nerves
Artery: Circumflex scapular artery<--subscapular artery
**a branch of this is the thoracodorsal artery
121
Describe all of the collateral flow of the scapula.
Dorsal Scapular, Suprascapular, & Circumflex Scapular all kind of contribute to the main part of the scapula
The posterior circumflex humeral artery connects w/ the anterior circumflex humeral artery
Intercostal arteries contribute to the dorsal scapular artery
122
Where does the circumflex scapular artery come from?
subscapular artery that branches into circumflex scapular & thoracodorsal artery
123
Where do the intercostal artery contributions come from?
internal thoracic artery
124
The olecranon is found on which bone?
ulna
125
The coronoid process is found on which bone?
ulna
126
The capitulum articulates w/ which bone?
radius
127
The trochlea articulates w/ which bone?
ulna
128
Which one is found on the posterior & which one is found on the anterior humerus?
Coronoid fossa
Olecranon fossa
Anterior: coronoid fossa
Posterior: olecranon fossa
129
At the glenohumeral joint, which actions happen on the AP axis?
abduction
| adduction
130
At the GH joint, which actions happen on the vertical axis?
rotation
131
At the GH joint, which actions happen on the transverse axis?
flexion
| extension
132
At the humeroulnar joint, which actions happen on the transverse axis?
flexion
| extension
133
At the humeroradial joint, which actions happen on the transverse axis? Vertical axis?
```
Transverse:
flexion
extension
Vertical:
pronation
supination
```
134
The axillary artery supplies blood to the upper extremity. Where does it begin & end? What is it called before & after it is considered an axillary artery?
Begins after it passes the 1st rib: before that-->called subclavian artery
Ends after it passes the teres major: after that-->called brachial artery
135
What is a fancy name for the arm & forearm?
Arm: brachium
Forearm: antebrachium
136
The lateral thoracic artery follows the course of which nerve ? What does it supply?
follows the long thoracic nerve
| ends up at the serratus anterior
137
The _______ muscle breaks up the axillary artery into ___ segments. How many arteries come off of each segment?
pec minor muscle breaks up the axillary into 3 segments. It covers the 2nd segment.
1st segment: 1 branch
2nd segment: 2 branches
3rd segment: 3 branches
138
What is the branch off of the first segment of the axillary artery?
superior thoracic artery aka supreme thoracic artery
139
What are the 2 branches off of the 2nd segment of the axillary artery?
thoracoacromial trunk
| lateral thoracic artery
140
What are the 3 branches off of the 3rd segment of the axillary artery?
subscapular artery
anterior humeral circumflex artery
posterior humeral circumflex artery
141
What does the sub scapular artery break into?
thoracodorsal artery
| circumflex scapular artery
142
Where is most of the blood supply of the elbow located? Which action of the arm compromises this blood flow? Why is this not a problem though?
most bl supply located on the anterior of the elbow
when you flex--compromise this blood supply
not a problem b/c there is a LOT of collateral flow from the deep brachial artery (if you ligated brachial after gave off profunda you would be fine)
143
Collaterals travel _____; recurrents travel _______.
Collaterals travel downwards, recurrents travel upwards
144
Where is the axilla located?
basically it is the armpit
| the space beneath the shoulder joint
145
```
What are the following borders of the axilla?
Anterior
Posterior
Medial
Lateral
Inferior
```
```
Anterior: pectoralis major muscle
Posterior: latissimus dorsi muscle
Medial: Serratus anterior muscle
Lateral: Humerus
Inferior: bound by a fascia
```
146
What is contained w/i the axilla?
the brachial plexus (lateral cord, medial cord, posterior cord) & axillary artery & vein
147
What do you see on the medial wall of the axilla?
serratus anterior muscle
| long thoracic nerve
148
What are the different sections of the brachial plexus & how much of each are there?
```
Roots 5
Trunks 3
Divisions 3
Cords 3
Branches 5
```
149
What are the roots? What are the branches?
```
Root: C5-T1
Branches: Musculocutaneous
Axillary
Radial
Median
Ulnar
```
150
Which artery goes thru the brachial plexus?
axillary artery
151
Which roots supply the GH joint? We're talking myotomes here.
C5, C6
152
Which roots supply the elbow joint? We're talking myotomes here.
C6, C7
153
Which roots supply the wrist? We're talking myotomes here.
C7, C8
154
Which roots supply the hand? We're talking myotomes here.
C8, T1
155
The musculocutaneous nerve has contributions from which roots?
C5, C6, C7
156
The axillary nerve has contributions from which roots?
C5, C6
157
The radial nerve has contributions from which roots?
C5, C6, C7, C8, T1
158
The median nerve has contributions from which roots?
C5, C6, C7, C8, T1
159
The ulnar nerve has contributions from which roots?
C7, C8, T1
160
The anterior arm is supplied by which branch?
musculocutaneous
161
The shoulder is supplied by which branch?
axillary nerve (supplies the deltoid & teres minor)
162
The posterior arm is supplied by which branch?
radial nerve
163
What are the branches from the roots?
dorsal scapular
| long thoracic
164
What are the branches from the trunks?
suprascapular
165
What are the branches from the cords?
```
Lateral Cord:
lateral pectoral nerve
Posterior Cord:
upper subscapular
thoracodorsal
lower subscapular
Medial Cord:
Medial Pectoral Nerve
Medial Brachial Nerve
Medial Antebrachial Nerve
```
166
T/F Peripheral nerve damage follows dermatomal patterns.
FALSE. It does NOT. This has to do with you cut the musculocutaneous nerve...the sensory area that is affected on the skin will look different than if you cut C5, even tho C5, is one of the roots that supplies the musculocutaneous nerve.
167
With dermatomes we are talking ______.
| With myotomes we are talking______.
dermatomes: sensory
myotomes: motor
168
The anterior & posterior compartment of the arm is separated by what?
intermuscular septum & humerus
169
Describe the structure & location of the biceps brachii muscle.
There are 2 heads.
Long head looks shorter, is more lateral & goes into the capsule & pierces the glenoid labrum.
Short head attaches to the coracoid process.
**they both have a tendons that attach to the radial tuberosity of the radius.
170
What is the thing that comes from the biceps brachii tendon & covers some of the muscles of the forearm?
bicipital aponeuroses
171
What are the actions of the biceps brachii?
supinates the forearm
| flexes @ the elbow joint
172
What bad, (hard to heal) thing could happen if you pull the long head of the biceps brachii too hard?
the superior part of the glenoid labrum could pop off.
173
Where does the brachialis muscle come from, go to, & what is its action?
Comes from: lateral & anterior head of the humerus
Goes to: ulna
Action: mainly flexing @ the elbow joint
174
Where does the coracobrachialis muscle come from, go to? Which muscle follows a similar path?
Comes from: coracoid process
Goes to: humerus only
Follows path of: short head of the biceps brachii
175
Does the coracobrachialis cross the elbow joint? What is its action?
NO, it doesn't cross the elbow.
| Does assist in flexion of the elbow, though.
176
Which muscles are a part of the anterior compartment of the arm? Which nerves?
Anterior Compartment:
biceps brachii (long & short head)
brachialis w/ coracobrachialis
Nerves--musculocutaneous
177
Which other bundles are found in the anterior compartment of the arm?
the median nerve which travels w/ the brachial artery
&
the ulnar nerve which travels w/ the superior ulnar collateral artery (just pass thru arm, don't work until forearm)
178
Which nerve & artery supply the posterior compartment of the arm?
the deep brachial artery
| radial nerve
179
Which muscles are found in the posterior compartment of the arm?
lateral, medial, long head of the triceps brachii
180
What thing does the radial nerve pass thru?
the spiral groove of the humerus
181
Which joints do each of the heads of the triceps brachii act on?
Lateral head--elbow only
Medial head--elbow only
Long head--elbow & shoulder
182
the 3 heads of the triceps connect to one tendon which attaches to ____?
olecranon process
183
What is awesome about the triceps muscle?
it is optimized for speed & it is what pitchers need
| it works so well b/c it is close to the axis of rotation
184
Which nerve supplies the triceps muscle & how might it be damaged?
radial nerve!
could be damaged w/ midhumeral shaft fracture b/c there the radial nerve is located close to the bone going thru the spiral groove of the humerus.
185
Fracture to the anatomic/surgical neck of the humerus can cause ______ nerve damage?
surgical neck-->axillary nerve damage.
186
If axillary nerve is damaged, which actions are compromised?
weakened abduction
| weakened lateral rotation
187
If you damaged your axillary nerve & then had weakened abduction...what could kinda help make up for it?
well, you lose the deltoid
| but you could still use the supraspinatus
188
Why is the weakened lateral rotation from losing the axillary nerve not really compensated for?
b/c when you lose the axillary nerve-->you lose the deltoid & the teres minor
**bc Del puts on Ax deodorant right before he climbs up little trees.
189
If you damage the musculocutaneous nerve...which actions do you limit?
arm flexion & weakened forearm flexion
190
What actions would be limited @ the arm if the radial nerve was damaged?
no forearm extension, forearm would always be a little flexed b/c nothing to oppose that movement
