Musculoskeletal System- Movement Flashcards
What is the musculoskeletal system
The skeleton (which includes bones, ligaments, tendons, and cartilage) and muscles that are attached to it
-Gives basic structure of body, posture and ability to move
What sensations are detected by sensory receptors of joint nerves
- Pain
- Touch
- Temperature
- Proprioception (lets us perceive the location, movement, and action of parts of the body)
where do arteries supplying joints arise from
Large named arteries located near the joint- articular branches
What is an arterial anastomoses
Provides wider path for blood to flow round joints
What are the subtypes of joints
- Synovial
- Cartilaginous
- Fibrous
What is a compromise profile of joint subtypes
Each subtype compromises between mobility and stability:
-Increased mobility= decreased stability
-Decreased mobility= increased stability
What are fibrous joints
Have generally limited mobility with high stability
There are 3 types
What are the 3 types of fibrous joints
Syndesmoses
Sutures
Fontanelles
What is a syndesmoses fibrous joint
unites bones with fibrous sheet
fibrous membrane
e.g. interosseous membranes
partially movable
What are sutures fibrous joint
between bones of skull
e.g. coronal suture
highly stable
What are fontanelles fibrous joint
Wide sutures in neonatal skull
Get: anterior, posterior and lateral fontanelles
Allow skull to move relative to each other when passing through the birth canal- head is smaller
allow the growing frontal, parietal, temporal and occipital bones to ‘slide’ over each other
What are cartilaginous joints
have fairly limited mobility but relative stability
There are 2 types
What are the 2 types of cartilaginous joint
-Primary cartilaginous
-Secondary cartilaginous
What is primary cartilaginous
- synchondroses
- bones joined by hyaline cartilage
- e.g. long bone epiphyseal growth plate
- permit growth in length of bone
- ossification and fusion
slips= slipped femoral epiphysis
what is secondary cartilaginous
- symphyses
- strong
- slightly movable
- fibrocartilage
- e.g. intervertebral discs
Slips= slipped disc, can compress spinal cord
What are typical features of synovial joints
- 2 or more bones articulating with each other
- articular surfaces are covered in hyaline ‘articular’ cartilage
- a capsule wraps around the joint
- contains a joint cavity
contains synovial fluid (cushions, nourishes and lubricates) - supported by ligaments
- associated with skeletal muscles and their tendons
- associated with bursae
prevent friction around joint
extensions of joint cavity or closed sacs separate from the joint cavity - often have special features
unique features found in different synovial joints e.g. articular disc in TMJ joint
What does hyaline do
Prevents friction between bones
What do ligaments do
Connect bone to bone
What do tendons do
Connect bone to muscle
Non-contractile and only transfer force
What are the 5 subtypes of synovial joints
- Ball & socket
- Hinge
- Plane
- Pivot
- Biaxial
What are ball & socket joints
Have good range of multi-axial movement e.g. circumduction
What are hinge joints
Have reasonable range of movement in one plane
What are plane joints
Minimal movement in 1 plane
what are pivot joints
> 45 degree angle of ‘Shaking the head’ rotation
What are biaxial joints
Have reasonable range of movement in one plane and less in another
What is decreasing order of joint mobility in adult body
- Synovial (Although least stable)
- Cartilaginous
- Fibrous
What is hypermobility
Joints are more mobile and flexible than normal
What ball and socket joint has a tighter fit: Shoulder or hip
Hips are tighter so more stable
= However hip joints have less mobility than shoulder
The shape of what surface determines joints possible movements
articular surface (Where ends of bones meet)
What is subluxation
There is a reduced ares of contact between articular surfaces
What is dislocation
There is a complete loss of contact between articular surfaces
What are some common dislocations
- Craniovertebral joints( connects
skull to vertebrae) - temporomandibular joints
- Shoulder joints
- Elbow joints
- Hip joints
- Knee joints
- Ankle joints
What are temporomandibular joints
(TMJ’s)
SYNOVIAL articulation between:
- the mandibular fossa & the articular tubercle of the temporal bone superiorly
- the head of the condylar process of the mandible inferiorly
Where are skeletal muscles usually found
Deep to deep fascia
with tough fibrous connective tissue coverings
What do longer muscle fibres have greater potential ranges of (x2)
- Shortening
-Movement produced at a joint
What is the function of skeletal muscle
Move origin and insertion closer together during contraction - muscle fibres shorten along axis
What is an Aponeurosis
A flattened tendon- associated with flat muscles
Attaches muscle to soft tissue instead if bone
What must you know for each muscle
Name
Attachments
Main Actions
Nerve Supply
How to clinically test it
How are clinical examinations of skeletal muscles carried out
Testing ability to move and power of movement
Testing muscle itself and the nerve(s) supplying it
Can be carried out by asking patient to make movements
Or by testing reflexes
What are the 2 main reflexes in skeletal muscles
- Stretch Reflex
- Flexion withdrawal reflex
What is a Flexion withdrawal reflex
Touch something potentially damaging- Sudden flexion to withdraw from the danger
(nerve connections only at spinal cord level BRAIN NOT INVOLVED)
What is a stretch reflex
a tendon hammer is used to apply a brief, sudden stretch to the muscle via its tendon
normal reflex response to being stretched is to contract
reflex contraction results in a brief twitch of the muscle belly or a movement in the normal direction
reflexes are protective against overstretching
Examples of stretch reflexes
biceps jerk
triceps jerk
knee jerk
ankle jerk
Deep tendon reflexes
Sensory nerve from muscle detects stretch and tells spinal cord
Motor nerve (synapse between sensory and motor nerves) from spinal cord passes message telling muscle to contract
Whole route taken by action potentials is reflex arc (brain prevents reflex from being overly brisk
What does a normal stretch reflex indicate is working normally
The muscle
Sensory nerve fibres
Motor nerve fibres
Spinal cord connections between the 2
Neuromuscular junction
Brains descending controls
What is muscle paralysis
Muscle without a functioning motor nerve supply - cannot contract
(Examination- Muscle would have reduced tone= floppy)
What is muscle Spasticity
Muscle has intact and functioning motor nerve but descending controls from brain are not working
(Examination- Muscle would have increased tone= Tighter)
What is muscle atrophy
‘Wasting’ of the muscles
- Muscle fibres become smaller reducing muscle bulk
Why does muscle atrophy occur
Due to result of inactivity e.g.
immobilisation after fracture
damage to motor nerve supply
What is muscle hypertrophy
Skeletal muscles enlarge as each individual myocyte enlarges
