BONES OF THE UPPER LIMB Flashcards
what forms the superior appendicular skeleton?
the pectoral girdle and bones of the free part of the upper limb
where does the superior appendicular skeleton articulate with the axial skeleton?
at the sternoclavicular joint — allows great mobility. saddle type synovial joint
what muscles support, stabilise and move the clavicles and scapulae?
the axio-appendicular muscles
describe the clavicle
- an S-shaped bone
- superior surface is relatively smooth in comparison to the much rougher inferior surface
- posterior: RHS clavicle = z-shaped, LHS clavicle = s-shaped
- RHS clavicle is usually much stronger and shorter than the LHS clavicle
why is the inferior surface of the clavicle rougher than the smoother superior surface?
muscles attach to the inferior surface
what articulates with the lateral end of the clavicle?
the acrimon of the scapula
what articulates with the medial end of the clavicle?
the sternum
purpose of the clavicles
- transmits shock from the upper limb to the axial skeleton
- provides protection to the important neurovascular bundle supplying the upper limb
- provides rigid support
what is the scapula?
the shoulder blade
describe the scapula
- a triangular flat bone
- lies on the posterolateral aspect of the thorax
- has 3 angles: lateral, superior, inferior
- has 3 borders: superior, lateral, medial
- has 2 surfaces: costal, posterior
- has 3 processes: acromion, spine, coracoid
- overlies 2nd-7th ribs
what is the name of the joint joining the glenoid cavity with the head of the humerus? describe the joint
the glenohumeral joint = synovial joint, ball and socket. permits flexion, extension, ab/adduction, circumduction, medial and lateral rotation. articulating surfaces covered in hyaline cartilage
what attaches to the infraglenoid tubercle?
the long head of the triceps brachii muscle
what attaches to the supraglenoid tubercle?
the long head of the biceps brachii muscle
what does the spine of the scapula on the posterior border divide the scapula into?
subdivides the posterior surface into the small, superior supraspinous fossa and the much larger inferior infraspinous border
describe the humerus
a long bone in the arm that runs from the shoulder to the elbow
where does the humerus articulate with the radius and ulna?
the elbow joint — a synovial hinge joint. permits flexion and extension
what are the articulating surfaces of the elbow joint and what are they covered with?
2 separate articulations: trochlear notch of the ulnar and the trochlea of the humerus. head of the radius and the capitulum of the humerus.
hyaline covers the articular surfaces
what ligaments support the elbow joint?
- radial collateral ligament — stabilises lateral surface of the joint
- ulnar collateral ligament — stabilises medial surface of the joint
annular ligament of radius
ulna vs radius (how to remember)
ulna —> pinky . ulna is thinner at the bottom
radius —> thumb
what are the 2 necks of the humerus?
the anatomical neck (very short and lies between the greater and lesser tubercles laterally and between the head and shaft more medially) and the surgical neck (common fracture site)
what separates the greater and lesser tubercles of the humerus and provides a protected passage for the slender tendon of the long head of the biceps?
the intertubercular/bicipital groove
what is the olecranon fossa of the humerus?
on the posterior surface of the distal humerus, provides space for the olecranon of the ulna during extension of the forearm
describe the ulna
the stabilising bone of the forearm. the medial and ulna of the 2 forearm bones. doesn’t reach the wrist joint.
for articulation with the humerus, the ulna has 2 prominent projections. what are they and what do they form?
- the olecranon = projects proximally from the posterior aspect and serves as a short level for extension of the elbow.
- the coronoid process = projects anteriorly from the anterior aspect
together they from the walls of the trochlear notch : “grips” the trochlea of the humerus
on the ulna, what serves as an attachment for the tendon of the brachial is muscle?
the tuberosity of the ulna (located just inferior to the coronoid process)
what is the radial notch?
on the lateral side of the coronoid process. receives the broad periphery of the head of the radius
role of the supinator crest and fossa of the ulna
deep part of supinator muscle attaches here
what do the ulna and radius both have at the distal end of them?
a styloid process
describe the radius
= the lateral, shorter forearm bone
why is the head of the radius concave?
concave for articulation with the capitulum of the humerus during flexion and extension of the elbow joint
what is the ulnar notch?
a notch on the radius which accommodates the head of the ulna
how many bones are there in the rest and what is the collective name for them?
carpal bones - 8 in proximal and distal rows of 4
name the carpal bones
Scaphoid Lunate Triquetrum Pisiform Trapezium Trapezoid Capitate Hamate
SOME LOVERS TRY POSITIONS THAT THEY CANT HANDLE
what carpal bones articulate with the radius to from the radio-carpal joint?
scaphoid and lunate
how are the metacarpal bones labelled?
1 (thumb), 2 (index), 3 (middle), 4 (ring), 5 (pinky)
what does each metacarpal consist of?
a base, shaft, and a head
what is the name of the joint joining the metacarpals and the phalanges?
metacarpophalangeal joint
what are the sections of the phalanges?
proximal, middle, distal — except thumb = just proximal and distal
what type of joint is the proximal radioulnar joint and what are the articulating surfaces?
= pivot joint
radial head and radial notch of the ulna and the annular ligament
what type of joint is the distal radioulnar joint and what are its articulating surfaces?
= pivot joint
head of ulna and ulnar notch on distal end of radius
what type of joint is the radiocarpal joint and what are its articulating surfaces?
= condyloid joint — flexion, extension, abduction and adduction
ULNA IS NOT PART OF THE WRIST JOINT
distally, proximal row of carpal bones (except pisiform).
proximally, distal end of radius and the articular disk
name 3 ligaments of the wrist joint
- radial collateral ligament ( runs from the radius to the scaphoid and trapezium)
- ulnar collateral ligament (runs from the ulna to the triquetrum and pisiform)
- palmar radiocarpal joint
a complication which may arise following a fracture of the medial epicondyle of the humerus is what?
damage to the ulnar nerve
