Lecture 12 - Musculoskeletal 1 Flashcards
which is more ‘important’ in terms of the brain processing power, the upper limb or the lower limb?
upper, since it has a larger representation of the upper limb on the sensory and motor homunculus
why are our upper limbs so important?
interaction with our environment gave us success
the upper limb is all about?
movement
where does the upper limb articulate with the axial skeleton?
at the sternoclavicular joint, which is between the manubrium (sternum) and the clavicle
everything between the connection with the axial skeleton and the shoulder joint is called?
the pectoral girdle, spans from shoulder to shoulder, so one arm
what is the anatomy arm?
between the shoulder and the elbow joint
- arm aka brachium
what is the forearm aka?
antebrachium
carpals make up the?
wrist
how can we best describe the function of the pectoral girdle?
a mobile base that adds to the plane of movement
how is the upper body made for movement?
in comparison to the hip (which has only immobile joints) the upper body is a very mobile base due to synovial joints there
what is the anterior and posterior movement of the scapula called?
protraction (anteriorly)
retraction (posteriorly)
what is the superior and inferior movement of the scapula called?
elevation and depression
what is scapula inferior and superior rotation
try wave down an airplane
what are the two things that scapula abduction could be
superior rotation or protraction
what are the two things that scapula adduction could be?
inferior rotation or retraction
why dont we use the terms scapular abduction and adduction?
because they are subjective
how do we name joints?
proximal articulating surface, then distal articulating surface
where is the acromio-clavicular joint?
between the clavicle and the acromion
what bone is the strut between our scapula and our axial skeleton?
clavicle
what does it mean to say the clavicle is a strut for the scapula?
there are big muscles on the anterior and posterior sides of our scapula that are are under tonal contraction, and without the clavicle, the scapula would be pulled towards the axial skeleton/ribcage. this allows more movement of the scapula
what are the roughened areas of the inferior clavicle bone?
areas where ligaments attach to
- costoclavicular ligament attachment
- subclavian groove muscle attachment
- coracoclavicular ligament attachment
what is the main difference in the clavicle from the superior view?
deltoid tubercule, where the deltoid origin is.
what muscles attach onto the clavicle?
the deltoid (clavicle is the origin)
trapezius (clavicle is the insertion)
pectoralis major (clavicle is origin)
where is our clavicle most often fractured?
where there are no muscled attached
what is treatment for a greenstick fracture vs a break in the clavicle?
greenstick - sling, take the weight off the arm
broken: plates and screws to hold in place while heals
what do soft clavicles do?
not act as a very good strut
what are the three angles of the scapula?
- superior angle
- inferior angle
- glenoid fossa (lateral)
what are the three borders of the scapula?
- superior border
- medial border
- lateral border
which border contains most muscle attachments of the scapula?
the lateral border
what are the 3 protuberances of the scapula?
- coracoid ‘crows beak’ aka coracoid process
- acromion (continuous with spine along posterior side of scapula)
- spine
what are the 3 surfaces of the scapula?
- supraspinous fossa
- infraspinous fossa
- subscapula fossa
what group of muscles are associated with the 3 surfaces of the scapula?
the rotator cuff muscles
describe the sternoclavicular joint
- saddle shaped synovial joint
- 30º rotation (so pretty mobile)
what makes the sternoclavicular joint a complex joint?
menisci of the sternoclavicular joint
what is the only connection between the two sides of your pectoral girdle
interclavicular ligament
what provides the most strength between the clavicle and the sternum?
costoclavicular ligament
- from 1st rib to underside of clavicle
what is the main function of the subclavius muscle in day to day life?
shunt muscle
prevents the dislocation of the sternoclavicular joint by pulling clavicle back towards the midline
what is the origin and insertion of the subclavius muscle?
from 1st rib to the subclavian groove of the inferior clavicle
why do we need an acromioclavicular joint
if we didn’t have one, when you move the clavicle, the scapula would be forced into rotation
- gives and extra degree of movement
what makes the acromioclavicular joint complex?
a wedge shaped intra-articular disc
- also fibrocartilage
which muscles support the AC joint?
the deltoid and the trapezius
where is the coracoclavicular ligament
connects the clavicle to the scapula, but is not really a part of the acromioclavicular joint
what is the function of the coracoclavicular ligament
- very strong
- used to passively hold the scapula under the clavicle
which muscle actively moves and stabilises the scapula?
the trapezius
what is the conceptual joint of the pectoral girdle?
where the medial border of the scapula moves against the thorax due to muscles and ligaments acting on it
- stabilises the scapula
- no cartilage or synovial fluid
what is the origin and insertion of the pectoralis major?
origin: clavicular head and sternocostal head
insertion: intertubercular groove
what are the three movements of the pectoralis major?
- adducts the humerus
- internally rotates the humerus
- can help protract scapula by pulling on humerus (2º action)
what are the primary movements of the subclavius?
- braces the clavicle (1º)
- weak depressor of the scapula
what is the origin and insertion of the pectoralis minor?
origin: anterior sufaces of ribs 3-5
insertion: coracoid process of the scapula
what is the brachial plexus?
watch lec
what is the origin and insertion of the serratus anterior?
origin: ribs
insertion: medial border of the scapula
- packs a punch
what are the primary movements of the serratus anterior?
protracts scapula
lower fibres help superiorly rotate scapula
