Introduction to the MSK System Flashcards
Appendicular skeleton:
bones of the pectoral and pelvic girdles, bones of the lower limbs
Axial skeleton:
bones of the skull, neck and trunk
Upper limbs
1 long bone in arm - humerus
2 long bones in forearm - radius and ulna
Hand: carpal bones → metacarpals → phalanges
Lower limbs
1 long bone in thigh - femur
2 long bones in leg - tibia and fibula
Foot: tarsal bones → metatarsals → phalanges
Bony feature:
functional hole, bump or groove found on bone which develops during bone growth
what happens when adjacent structures apply force to the bone
it moulds its shape or it causes the adjacent structure to develops at the same time as bone and the bone has to grow around the other structure - forms a foramen
tuberosity:
rough area of bone where muscles attach e.g. ischial tuberosity
what is bone
Hard, connective tissue
what is cartilage
- Less rigid than bone
- Located where mobility is required - articulations
what are the 3 types of joints
synovial, cartilaginous and fibrous
the more mobile a joint…
the more easily it is dislocated
what do joints have
an excellent sensory nerve supply
describe fibrous joints
quite stable
limited mobility
(example = syndesmoses, sutures)
describe cartilaginous joints
fairly limited mobility
relatively stable
(types = primary and secondary)
describe synovial joints
2 or more bones articulating with each other
what are the subtypes of joints
- ball & socket
- hinge
- plane
decreasing mobility and increasing stability of joints =
synovial > cartilaginous > fibrous
where is skeletal muscle usually found
deep to deep fascia
how many points of attachment foes skeletal muscle have
usually 2 to the bone one - origin and insertion
what happens during contraction regarding the skeletal muscle
the origin and insertion move closer together
and muscle fibres shorten along the long axis
what does a tendon do?
attach muscle usually to a bone and don’t contract themselves
what is aponeurosis
- Flattened tendon
- Most commonly associated with flat muscles
- Attach muscle to soft tissue
where does the long head of a bicep brachia attach
it originates from the supraglenoid tubercle of the scapula
where does the short head of a bicep brachii attach
originates from the coracoid process of the scapula
bicep brachii innervation:
musculocutaneous nerve
bicep brachii actions:
supination of the forearm (spans proximal radioulnar joint anteriorly) and flexion of the shoulder and elbow joint (spans shoulder and elbow joint anteriorly)
deltoid muscle attachments
originates from the lateral third of the clavicle, the acromion and the spine of the scapula, attaches to the deltoid tuberosity on the lateral aspect of the humerus
deltoid muscle innervation
axillary nerve
Anterior fibres:
flexion and medial rotation of the shoulder
Posterior fibres:
extension and lateral rotation of the shoulder
Middle fibres:
the major abductor of the arm
what are reflexes
protective and automatic
what does testing reflexes do
tests the ability to move and power of movement - testing muscle and nerve(s) supplying it
what are the 2 main skeletal muscle reflexes
stretch and flexion withdrawal
describe the steps of the reflex arc
- Sensory nerve (muscle) detects stretch and tells spinal cord
- Motor nerve from spinal cord passes message to contract
- Neuromuscular junction - synapse where motor nerve communicates with skeletal muscle
what are the deep tendon relaxes
Biceps jerk, triceps jerk, knee jerk and ankle jerk reflexes
describe a flexion withdrawal reflex
- Touch something potentially damaging
- Sudden flexion to withdraw from the danger
Muscle strain:
overstretched, torn or twisted muscle
paralysis:
a muscle without a functioning motor nerve supply - can’t
contract
- therefore muscle would have a reduced tone
spasticity:
muscle has intact and functioning motor nerve but the descending controls from the brain aren’t working
atrophy:
‘wasting’ of the muscles through inactivity, myocytes become smaller
hypertrophy:
individual myocytes enlarge
