Musculoskeletal System Flashcards
What are joints?
Places where 2 or more bones make contact
How can joints be structurally classified?
- Fibrous; bones joined by dense fibrous connective tissue (Eg. sutures)
- Cartilaginous; bones joined by cartilage (eg. IVD’s)
- Synovial; bones not directly joined, allows movement, limited by shape of synovial joint (eg. shoulder)
How can joints be functionally classified?
- Synarthrosis; no movement eg. sutures, synchondrosis, synostosis
- Amphiarthrosis; little movement eg. distal tibiofibular, pubic symphysis
- Diarthrosis; free movement eg. synovial joints
What are some of the features that synovial joints have?
- Synovial membrane
- Ligaments (connect bone to bone)
- Hyaline cartilage
- Joint capsule
Other possible featues;
- bursa
- Meniscus
- Labrum
What shapes can synovial joints be?
- Pivot, hinge, plane = uniaxial (eg. elbow, AC, atlantoaxial)
- Candyloid, saddle = biaxial (eg. MCP, carpometacarpal)
- Ball and socket = multiaxial (eg. hip)
What are types of muscle tissue?
- Skeletal = voluntary, eg.MSK
- Cardiac = involuntary, eg.heart
- Smooth = involuntary, eg. viscera, blood vessels, iris
What are the functions of the muscular system?
- Locomotion
- Stability
- Respiration
- Childbirth
- Circulation
- Vision
- Posture
- Digestion
- Temperature
- Protection
- Urination
What are features of skeletal muscles?
- Consists of bundles of muscle fibres
- Muscle fibres are grouped into muscle fascicles - grouped, forming one or more heads or bellies.
- Strength depends on no. of fibres
- Range of movements depends on fibre length, muscles contract by about 30% of their length.
What are tendons?
Tendons usually connect muscle to bone
What are aponeurosis?
Connects bone to muscle (flat and short)
How can skeletal muscle be classified?
- Flat muscle; paralell fibres often with an aponeurosis
- Pennate muscles; feather like, can be unipennate, bipennate and multipennate
- Fusiform muscles; spindle shaped with a round, thick belly and tapered ends
- Convergent muscles; arise from a broad area and converge to form a single tendon
- Quadrate muscle; have 4 equal sides
- Circular or sphincteral muscles; surround a body opening or oriphice
Can muscles have more than 1 head or belly and act on more than 1 joint?
YES
What do extrinsic back muscles act on and how are they innervated?
- Act on structures outside of the back (appendicular skeleton)
- Innervated by anterior rami of spinal nerves
What do intrinsic back muscles act on and how are they innervated?
- Act on structures within the back
- Innervated by dorsal rami of spinal nerves
What are attatchments of the trapezius?
Origins= superior nuchal line, nuchal ligament, C7-T12 spinous processes
Insertions= Descending; lateral third of clavicle
Horizontal; acromion of scapulae
Ascending; spine of scapula
How is the trapezius innervated?
By Cranial Nerve XI (accessory)
What are the actions of the trapezius?
On shoulder girdle= descending; keeps girdle up, tilis scapulae for arm elevation
horizontal and ascending; depress and pull scapula medially
On head and neck= descending; with fixed shoulder, contralateral rotation or extension
On vertebral column= flattens the thoracic kyphosis
What are the attachments of the latissimus dorsi?
Origins- spinal process T7-T12, dorsal surface of sacrum, 10th-12th rib, thoraco lumbar aponeurosis, dorsal third of iliac crest, inferior angle of scapula
Insertion- bicipital groove of humerus
What are actions of latissimus dorsi?
On arm; adduction, internal rotation, extension
On trunk; elevation
On shoulder girdle; depression, pulls scapula medially
How is latissimus dorsi innervated?
Thoraco dorsal nerve from brachial plexus
What are the attachments of the rhomboids?
Origins; Major- spinous processes of T1-T4
Minor- spinous processes of C6-C7
Insertions; medial margin of scapula
Minor- root of scapular spine
Major- below scapular spine
What are actions of rhomboids?
On shoulder girdle; retract scapula, rotate glenoid inferiorly, fix scapula to trunk
How are rhomboids innervated?
Dorsal scapular nerve from brachial plexus
What are attatchments of levator scapulae?
Origin- vertebrae C1-C4 tranverse processes
Insertion- superior angle of scapula
What are action of levator scapulae?
On shoulder girdle; elevates scapula and rotates glenoid inferiorly
On vertebral column; with fixed shoulder girdle it extends the neck
How is levator scapulae innervated?
Dorsal scapular nerve form brachial plexus
What are the functions of the vertebral column?
- Support
- Movement
- Protection
What are the 2 major components of a typical vertebra and their functions?
- Vertical Body:-for weight transfer
- IVD’s between - Vertebral Arch:- forms vertebral foramen
- surrounds and protects spinal chord
What components make up the typical vertebra?
- Pedicle; foot of arch
- Transverse Process; muscle/ligament attachment
- Lamina; lateral and posterior part of arch
- Spinous Processes; muscle/ligament attatchment
- Superior/inferior articular processes; form joints
- Superior/inferior vertebral notches; form intervertebral foramen
Where does the spinal chord end?
Around L1-L2
Where would you go in to take spinal fluid?
Around L3-L5 to take spinal fluid
How many cervical spinal nerves and why?
8 as C1 nerve exists above C1 vertebra
What parts of the vertebral column are most and least mobile?
- Cervical; most mobile
- Thoracic; least mobile for flexion/extension/lateral bending.
- Lumbar; least rotation
What joints can we expect to see in a typical vertebra?
-Zygapophyseal joints; synovial, plane
-Symphysis joints; secondary cartaliginous (IVD’s)
A typical vertebra forms 6 joints; 4xzygapophyseal, 2xIVD
Where is the atlanto-occipital joint?
At C1-Base of skull
Often termed the ‘‘nodding/yes’’ joint
What is the atlas?
Name for C1 vertebra
What is the axis?
Name for C2 vertebra
What is the atlanto-axial joint?
C1-C2 synovial pivot
Can be termed ‘‘no’’ joint
What are IVD’s and their function?
-Are fibrocartaliginous joints of vertebral bodies.
- Provide stability and flexibility
- Pressure regulation
- Water, cushion function (shock absorber)
What are the two parts of the IVD and their functions?
- Annulus Fibrosis; high tensile strength, fibrous sheath on outer surface-collage layers in rings.
- Nucleus Pulposus; high resillience, gelatinous structure
What are the functions of the ligaments of the spine?
- Connect bone-bone
- Provides support to joints
- Restrict movement at joints
Where is the anterior longitudinal ligament and what is its function?
- Base of skull to anterior surface of sacrum
- Attatched to anterior surface vertebral bodies and IVD’s
- Prevents hyperextension
Where is the posterior longitudinal ligament and what is its function?
- Attatched C2 to sacrum
- Attatched to posterior surface vertebral bodies and IVD’s
- Lines anterior surface of the vertebral canal
- Weakly resists hyperflexion
Where is the supraspinous ligament and what is its function?
- C7-sacrum
- Connects tips of spinous processes
- Cord like
Where is the nuchal ligament and what is its function?
- Base of skull to C7
- Supports head on neck
- Strong fibroelastic tissue
- Provides attatchment for muscle eg.trapezius
Where is the ligamenta flava ligament and what is its function?
- Pass between lamine
- Form part of vertebral canal
- Resist separation of verts during felxion
Where is the interspinous ligament and what is its function?
-Between spinous processes
Where is the intertransverse ligament and what is its function?
-Between transverse processes
What are the functions of the intrinsic muscles of the back?
- All act directly on spine
- All supplied by posterior rami of spinal nerves
- Maintain posture and control movement of vertebrae
What is the thoracolumbar fascia and its role?
- Covers deep muscles of the back
- Critical to organisation and integrity of the region
- Lat.dorsi and trapezius attatched to it.
What are the superficial intrinsic back muscles?
-Splenius Capitis
-Splenius Cervicis
They are thick and flat
What are the origins and insertions of the splenius muscles?
Origin= spinous processes (+bottom of nuchal ligament)
Insertions= Base of skull
Cervicis- transverse processes C1-C3
Capitis- mastoid process
What movements do the splenius muscles do?
- Bilateral= extend neck
- Unilateral= rotate head to one side (turn face to same side as muscle)
What are the intermediate (erector spinae) back muscles?
-Spinalis
-Longissimus
-Iliocostalis
These act as the primary extensors of the vertebral column
What are the origins and insertions of the intermediate back muscles?
Common origin= broad tendon attatched to sacrum, spinous processes of L and lower T verts, iliac crest.
Insertions:
- Spinalis= (thoracic, cervicis, capitis) - inserts T spinous processes and skull
- Longissimus= (thoracic, cervicis, capitis) - inserts T and C transverse processes and mastoid processes
- Iliocostalis= (lumborum, thoracic, cervicis) - inserts angles of ribs and C transverse processes
What are the deep muscles of the back?
- Transverseospinalis; semispinales, rotatores, multifidus
- Levatores costarum
- Interpsinales and intertransversarri
Where are the transverseospinalis and its function?
- Fill groove between transverse and spinous processes
- Extend and rotate
- Cross multiple vertebra
What happens to the VC when you have a slipped disc?
- Caused by tear in annulus fibrosis, meaning nucleus pulposus can protrude
- Can impinge on spinal cord or nerves
What are the symptoms and treatment of a slipped disc?
Symptoms= numbness, tingling, pain in lower limb (sciaticca symptoms) Treatment= rest, painkillers, sometimes surgery
What is kyphosis?
Outward curvature of spine/back (C-shaped)
Primary curvature
What is lordosis?
Inward curvature of spine/back
Secondary curvature
