Muscles, joints, tendons and ligaments Flashcards
Filaments in each myofibril are arranged into what? Thick filaments made of? Contains what act as molecular spring too? Dark bands called what?Proteins that link central region of A band?
Sarcomeres Myosin Titin A bands M line
Length and diameter of thick filament? How many per filament? How many heavy and light chains? Thin filament made of? Light band just actin called what?
1.6 micrometers long and 15nm diameter
300
2 heavy and 4 light chains
I band
I bands anchored to what? Length and diameter of thin filament? How many per filament? Filaments (F-actin) made of monomers of what? F-actin makes a chain of 2 what?
Z line 1 micrometer long and 8nm diameter 380 per filament Globular protein G-actin 2 alpha helices
What is tropomyosin and what does it do? 3 troponin types? What does each do?
Double alpha helix around actin- partially covers myosin binding sites on actin filament
Tn I- inhibitory
Tn T- binds tropomyosin
Tn C- binds calcium
Membrane AP propagates through what? Ca2+ in sarcoplasm combines with what causing what? Energised by what? What breaks link between actin and myosin? When does contraction end?
T- tubules
Troponin- allows tropomyosin to move away from myosin binding site on actin
ATP hydrolysis
Binding of new ATP molecule
When Ca2+ returns to ECF by Ca2+/ATPase pumps and Na+/Ca2+ counter transporters
What is needed for energy for muscle contraction? When is creatinine kinase released?
High energy from ATP and creatinine phosphate- short term energy store, replenished by creatinine kinase- released on muscle fibre damage
Functions of joints? 3 structural joint types? Examples of each?
Allows movement, weight bearing and transfers load evenly to MSK system
Fibrous, cartilaginous and synovial
Fibrous= teeth sockets, cartilaginous= intervertebral discs, synovial= metacarpophalangeal
3 functional joint types and examples?
Syntharthroses- immovable joints e.g. skull sutures
Ampiathroses- slightly moveable e.g. intervertebral discs
Diarthroses- freely moveable joints e.g. hip
What are sutures?
Between bones of skull- allow growth in development, adjacent ones interdigitate and filled with short connective tissue
What are syndesmoses?
Bones connected by a ligament/ sheet of fibrous tissue e.g. interosseous membrane between trivia fibula
What are gomphoses?
Peg in socket fibrous joint found inly in tooth articulation
What are 3 fibrous joint types? 2 types of cartilaginous types?
Sutures, syndesmoses, gomphoses
Synchondroses and symphyses
What are synchondroses?
Bones directly connected by hyaline cartilage e.g. costal cartilage of ribs
What are symphyses?
Connecting cartilage is a pad/ plate of fibrocartilage e.g. intervertebral discs
What are synovial joints known as? The 5 components of synovial joints?
Freely moveable joints
1) Articular cartilage 2) Joint capsule 3) Joint (synovial) cavity 4) Synovial fluid 5) Reinforcing ligaments
Features of articular cartilage?
Almost frictionless surface, resists compressive loads, high water content, low cell content, no blood supply
What is the inner layer of the joint capsule? What is the external layer? Features of the synovial membrane?
The synovial membrane
It’s continuous with periosteum (tough, fibrous)
Only few cells thick, can have villi and projections to increase SA, secretes synovial fluid components
What is the synovial cavity filled with? What does the synovial fluid cover, what is it modified from and what is in it?
Synovial fluid
Covers articulating surfaces with thin film- reducing friction during articulation
By plasma from synovial membrane
Fluid, proteins, charged sugars that bind water e.g. hyaluronate
3 types of reinforcing ligaments in synovial joints? What do ligaments do?
Intrinsic- thickened part of fibrous capsule
Extrinsic- outside capsule
Intracapsular- deep to capsule covered with synovial membrane
They connect bone to bone, stabilise joints and have less regularly arranged fibres than a tendon
What do tendons do and what do they have?
Connect bone to muscle, stabilise joints, allow muscles to be accommodated at a distance from their insertion, provides solid base on which muscles can pull
Dense, regular connective tissue
3 types of cartilage? Composition? What are proteoglycans made of and what do they do?
Elastic, fibrocartilage, hyaline cartilage
Water, proteoglycan, collagen and ions
PPC to which are covalently attached chains of sulphated disaccharide repeating units
High density of -ve charges allows binding of water, conferring properties of compressive stiffness and friction-free surfaces e.g. aggrecan
3 synovial joint lever types? Where is fulcrum, weight and resistance in 1st class levers?
1st, 2nd and 3rd class levers. Fulcrum in middle, force is at one end and resistance is at other e.g. elbow joint and triceps muscle
Fulcrum, weight and resistance in 2nd class lever?
Fulcrum at one end, force at other end and resistance in centre e.g. mandible joint
Fulcrum, resistance and force in 3rd class lever?
Fulcrum at one end, resistance at other end and force in middle e.g. below joint and biceps muscle
Movements of synovial joints and examples?
Ball and socket e.g. hip, shoulder
Condyloid e.g. metacarpal
Gliding joint e.g. intercarpals, femur/patella, humerus/ radius
Hinge joint e.g. humerus/ ulna
Pivot joint e.g. Atlanta-axis joint
Saddle joint e.g. between trapezius and 1st metacarpals
What is the major component of the tendon and ligament fibres? What makes up 1-5% of the dry weight? What does this act to do?
Collagen- mainly type 1 (90-95% dry weight)
Proteoglycan
Regulates fibre diameter, keeps fibrils together, acts as a lubricant to aid collagen fibres gliding over each other
Where are collagen molecules synthesised and as what? Consists of what? 3 alpha chains combine in a what? What between alpha chains enhances strength of molecules?What occurs after secreting outside the cell?
In fibroblasts as procollagen
3 individual PPCs each coiled in left hand helix
A right handed triple helix
Bonding(cross-linking)
Processed to remove terminal peptides- for tropocollagen and self assembles into collagen fibrils
Hierarchal structure of collagen–> tendons? (fibrillogenesis) What are fascicles separated by? What is the tendon surrounded by?
Collagen molecules–> microfibrils–> sub fibrils–> fibrils–> fibres–> fascicles–> tendon
Endotenon
Epitenon
What other molecule do tendons and ligaments contain? How does collagen I content, elastin content and fibre organisation differ between ligaments and tendons?
Elastin- more elasticity, proportion varies by function
Ligaments= lower collagen I, higher elastin, fibre organisation more random
What are the major ligaments of the knee? Function of each?
ACL- provides rotational stability and resists anterior translation of the tibia.
PCL- resists posterior translation of the femur.
MCL- resists valgus force on the knee
LCL- resists varus force
6 degrees of freedom of the knee?
Internal/ external rotation
Varus/ valgus
Flexion/ extension
What is locking of the knee? What isn’t true locking?
An inability to fully straighten the knee due to a mechanical block, usually a piece of cartilage/ loose body.
If cannot flex/extend/ if fully flexed or fully extended.
Are MCL and LCL injuries common or rare? Are PCL or ACL injuries more common?
MCL= common, LCL= rare
PCL less common than ACL
What is valgus knee also known as? What is varous knee also known as?
‘Knee-knock’
‘Bowed knee’
What is not part of the wrist joint? Articulates as what instead? Prevented from articulating with carpal bones by what?
Ulna
Distal radioulnar joint
Articular disk
Four ligaments of the wrist?
Palmar radiocarpal
Dorsal radiocarpal
Ulnar collateral
Radial collateral
What type of joint is the wrist joint? What movements can it perform? Why is the scaphoid at wrist of avascular necrosis?
Ellipsoidal
Flexion, extension, adduction, abduction
Its retrograde blood supply entering at its distal end- fracture to the middle may interrupt blood supply to the proximal part
Most common fracture of the wrist? This clinical condition produces what?
Colles’ fracture- radius fractures with the distal fragment being displaced posteriorly
‘Dinner fork deformity’
How can the lunate be dislocated anteriorly? Causing what symptoms? What can also happen?
By falling on a dorsiflexed wrist
Carpal tunnel symptoms
Avascular necrosis
Types of distal radius fracture? What is less common than distal radius fractures and how does it present?
Colles’= extra-articular with dorsal displacement
Smith’s= extra-articular with volar displacement
Barton’s= intra-articular with dislocation of the radiocarpal joint
Fracture of the radial shaft- ROM= typically pain-free
What forms the glenohumeral joint? Humerus articulates with what distally?
Proximal humerus–> glenoid fossa of the scapula
Head of the radius and trochlear notch of the ulna
Attachment site for supraspinatus, infraspinatus and teres minor? Attachment for subscapularis? Separating the 2x tuberosities? What attaches to the lips of this?
Greater tuberosity
Lesser tuberosity
Inter-tubercular sulcus= pec major, teres major and latissimus dorsi
Neurovascular structures lying against surgical neck of humerus? Axillary nerve damage would paralyse which muscles? Difficulty doing what movement? Also innervates what area?
Axillary nerve and posterior circumflex artery–> deltoid and teres minor paralysis
Abduction of the affected limb
Regimental badge area
Lateral side on humeral shaft where deltoid attaches? Shallow depression on posterior surface? What lies in this groove?
Deltoid tuberosity
Radial groove= radial nerve and profunda brachii artery
Muscles attaching anteriorly to the humeral shaft? Posteriorly?
Coracobrachialis, deltoid, brachialis, brachioradialis
Medial + lateral heads of triceps
What would happen to the wrist if there was a mid-shaft fracture?
‘Wrist drop’- wrist extensors affected, can be some sensory loss over dorsum of the hand and proximal ends of lateral 3 1/2 fingers dorsally
What do the lateral and medial borders of the distal humerus form? What are immediately distal to the ridges? What runs in a groove on posterior of medial epicondyle?
Medial and lateral supraepicondylar ridges
Lateral and medal epicondyles
Ulnar nerve
Where is trochlea located distally on humerus? Articulates where? Lateral to this is what? Articulates with what? 3 depressions on distal humerus?
Medially- trochlear notch of the ulna
Capitulum
Radius
Coronoid, radial and olecranon fossae
Head of radius forms what joint? Radial tuberosity attaches what? Middle of lateral shaft surface, roughening for attaching what?
Proximal radioulnar joint
Biceps brachii
Pronator teres muscle
Lateral distal radius projects as what? What in medial surface concavity called what articulating to form what?
Styloid process
Ulnar notch–> distal radioulnar joint
What attaches the radius and ulna? What bone is fractured and dislocated in Monteggia fracture? Galleazi? Way of remembering?
Interosseous membrane
Ulna/ radius
Radius/ ulna
MU/GR–> MUGGER
Landmarks of proximal ulna? Muscle attaching to superior olecranon surface? What attaches to tuberosity of ulna?
Olecranon Coronoid process Trochlear notch Radial notch Tuberosity of ulna
Triceps brachii muscle
Brachialis muscle
Anterior of ulnar shaft attaches what? Rounded head with distal projection of distal ulna?
Pronator quadratus muscle
Styloid process
Articulating surfaces of the elbow joint?
Trochlear notch of ulna and trochlea of humerus
Head of radius and capitulum of humerus
Ligament found on lateral side of elbow joint? Blends with what? What ligament originates from medial epicondyle?
Radial collateral ligament
Annular ligament
Ulnar collateral ligament
Muscles needed to extend elbow? Flex?
Triceps brachii and anconeus
Brachialis, biceps brachii, brachioradialis
Intratendinosus bursa formed where in elbow joint? Subtendinosus? Subcutaneous?
Within the tendon of the triceps brachii
Between the olecranon and tendon of triceps brachii- reduces friction
Between olecranon and overlying tissue
Clavicle extends between what?
Sternum and acromium of scapula?
3 main functions of the clavicle?
1) Attaches upper limb to trunk
2) Protects underlying NV structures supplying upper limb
3) Transmit force from upper limb–> axial skeleton
Where does conoid ligament of clavicle attach? Trapezoid ligament? At what end of the clavicle?
Conoid tubercle
Trapezoid line
Acromial end
Sternal end of clavicle has facet called what? Inferior surface has what depression?
Clavicular shaft acts as a point of origin for what muscles?
Sternoclavicular joint
For costoclavicular ligament
Deltoid, trapezius, subclavius, pec major, sternocleidomastoid and sternohyoid
Concave depression on anterior surface of scapula? Muscle originating from this? Hook like process attachment for biceps brachii and pec minor?
Subscap fossa
Subscapularis
Coracoid process
Attaches to supraglenoid tubercle? Attaches to infraglenoid tubercle?
Long head of bicep
Long head of triceps
Site of supraspinatus origin? Projection on posterior surface of clavicle that arches over glenohumeral joint and articulates with clavicle?
Supraspinous fossa
Acromion
Articular surfaces of AC joint lined with what? Partially divided by what?
Fibrocartilage
Articular disc-wedge of fibrocartilage
3 ligaments of AC joint?
Intrinsic= AC ligament- runs horizontally, covering joint capsule reinforcing superior aspect Extrinsic= conoid and trapezoid ligaments Conoid= from coracoid process to conoid tubercle of clavicle Trapezoid= from coracoid process to trapezoid line of clavicle
Movements of AC joint? NV supply?
Axial rotation and anteroposterior movement
Suprascapular artery and thoraco-acromial artery
Suprascapular and lateral pectoral from brachial plexus
Type of joint is the shoulder joint? Articulating surfaces? Fossa deepened by what fibrocartilage rim? Why is the joint instable and has a wide range of movement?
Ball and socket between scapula and the humerus
Head of the humerus–> glenoid fossa of the scapula
Both surfaces covered in hyaline cartilage
Glenoid labarum
Humeral head= much larger than glenoid fossa
2 important bursae in the shoulder joint?
1) Subacromial= deep to deltoid and acromion, superficial to supraspinatus tendon
2) Subscapular= between subscap tendon and scapula
5 ligaments of the shoulder joint?
1) Glenohumeral ligament= glenoid fossa–> humerus- stabilises anterior aspect
2) Coracohumeral ligament= base of coracoid process–> greater tubercle of humerus- supports superior joint capsule
3) Transverse humeral ligament= between 2 tubercles of humerus- holds tendon of long head of biceps
4) Coraco-clavicular ligament= clavicle–> coracoid process- can be injured in ACJ injuries
5) Coracoacromial ligament= between acromion and process of scapula–> coraco-acromial arch= prevents superior displacement
Muscles needed for extension(behind) of shoulder joint? Flexion(in front)?
Posterior deltoid, lat dorsi and teres major
Biceps brachii, pec major, anterior deltoid and coracobrachialis
Muscles needed for abduction of the shoulder? Adduction?
1st 15 degrees= supraspinatus, 15-90= middle fibres of deltoid, >90 degrees= trapezius + serratus anterior to rotate scapula
Pec major, lat dorsi and teres major
Muscles needed for internal rotation of the shoulder? External rotation? Circumduction?
Subscapularis, pec major, lat dorsi, teres major and anterior deltoid
Intraspinatus and teres minor
Combination of movements
Arteries supplying shoulder joint? Nerves?
Anterior and posterior circumflex humeral arteries
Axillary, suprascapular and lateral pectoral nerves
Where do extrinsic muscles of the shoulder originate and attach to? Intrinsic muscles?
From torso–> shoulder bones
From scapula and/ or clavicle–> humerus
6 intrinsic muscles of shoulder?
Deltoid, teres major and four rotator cuff muscles(supraspinatus, infraspinatus, subscapularis and teres minor)
Origin of supraspinatus? Insertion? Nerve supply? Action?
Medial 2/3 supraspinous fossa
Capsule of joint + greater tubercle of humerus
Suprascapular nerve
ABDuction
Origin of infraspinatus? Insertion? Nerve supply? Action?
Medial 2/3 infraspinous fossa
Greater tubercle of humerus
Suprascapular nerve
Lateral rotation
Origin of teres minor? Insertion? Nerve supply? Action?
Lateral border of scapula
Capsule of joint + greater tubercle of the humerus
Axillary nerve
Lateral rotation
Origin of subscapularis? Insertion? Nerve supply? Action?
Subscapular fossa
Lesser tubercle of humerus
Upper and lower subscapular nerves
Medial rotation
Origin of deltoid? Insertion? Nerve supply? Action?
Clavicle, acromion, spine of scapula Deltoid tuberosity of the humerus Axillary nerve Anterior fibres= flex arm Middle= major ABDuctor beyond 15 degrees Posterior= extends arm
Origin of teres major? Insertion? Nerve supply? Action?
Posterior surface of inferior surface of scapula
Intertubecular/ bicipital groove of humerus
Lower subscapular nerve
ADDucts at shoulder + medially rotates arm
Origin of trapezius? Insertion? Nerve supply? Action?
Skull, nuchal ligament and spinous processes of C7-T12
Clavicle, acromion + scapula
Accessory nerve + CNXI(spinal part)
Elevates scapula and rotates scapula during abduction of humerus above horizontal
Middle fibres= retract scapula, lower= depress scapula
Origin of latissimus dorsi? Insertion? Nerve supply? Action?
T6-T12, iliac crest, thoracolumbar fascia, inferior 3 ribs
Bicipital groove
Thoracodorsal nerve C6-8
Extends, adducts and medially rotates upper limb
Origin of levator scapuli superioris? Insertion? Nerve supply? Action?
C1-C4 transverse processes
Medial border of scapula
Dorsal scapular nerve
Elevates the scapula
Origin of rhomboid major? Insertion? Nerve supply? Action?
T2-T5 vertebrae
Posterior surface of medial scapula
Dorsal scapular nerve
Elevates and retracts the scapula
Origin of rhomboid minor? Insertion? Nerve supply? Action?
C7-T1
Posterior surface of medial scapula
Dorsal scapular nerve
Elevates and retracts the scapula
Type of joint knee joint? Articulations? Articulation surfaces?
Bicondylar
Patella, femur + tibia
Tibiofemoral: between medial + lateral condyles of femur + tibia (weightbearing)
Patellofemoral: anterior + distal part of femur–> patella- allows quad femoris tendon to insert over knee
Neurovascular supply to knee joint? Proximal end of tibia is covered by 2 what? What are they? Function of them?
The genicular anastomoses- from genicular branches of the femoral and popliteal arteries
Femoral, tibial + common fibular nerves
Menisci
C-shaped fibrocartilage structures
Deepen articular surface of tibia–> increased stability + shock absorbers
Menisci attached to what? Medial meniscus also attached where? Which is smaller? 4 bursae of the knee?
The intercondylar area of the tibia
Tibial collateral ligament + joint capsule
Lateral meniscus
Suprapatellar, prepatellar,, infrapatellar, semimembranosus
Where is the suprapatellar bursa found? Prepatellar? Infrapatellar? Semimembranosus?
Between quadriceps femoris + femur
Between apex of patella and skin
Deep= between tibia + patella ligament, superficial= between patellar ligament + skin
Posteriorly between semimembranosus muscle + medial head of gastrocnemius
5 ligaments of the knee? Attachments?
Patellar: quad femoris tendon–> tibial tuberosity
Medial collateral: medial epicondyle of femur + medial tibia
Lateral collateral: lateral epicondyle of femur, lateral surface of fibular head
Anterior cruciate: at anterior intercondylar region of the tibia–> in intercondylar fossa of femur
Posterior cruciate: at posterior intercondylar region of tibia–> intercondylar fossa of femur
Muscles producing extension of knee? Flexion? Lateral rotation? Medial rotation?
Quadriceps femoris–> tibial tuberosity
Hamstrings, gracilis, sartorius and popliteus
Biceps femoris
5 muscles: semimembranosus, semitendinosus, gracilis, sartorius + popliteus
Ankle joint between what bones? Articulating surfaces? What bone fits into the mortise?
Hinge joint between tibia, fibula + talus
Tibia + fibula by tibiofibular ligaments–> socket= mortise
Talus bone
Ligaments of the ankle? Resists what motions?
1) Medial ligament- x4 ligaments from malleolus–> talus, calcaneus + navicular bones
Over-eversion
2) Lateral ligament- from lateral malleolus
a) Anterior talofibular–> lateral talus
b) Posterior talofibular–> posterior talus
c) Calcaneofibular–> calcaneus
Over-inversion
Plantarflexion of the knee caused by what muscles? Dorsiflexion?
Posterior leg: gastrocnemius, soleus, plantaris + posterior tibialis
Anterior leg: tibialis anterior, extensor hallucis longus + extensor digitorum longus
NV supply of ankle joint?
Malleolar branches of anterior tibial, posterior tibial and fibular arteries
Type of joint hip joint articulates with? What is the cavity of the acetabulum deepened by? Both covered by what?
Ball + socket= acetabulum--> head of femur Acetabular labrum( fibrocartilaginous collar) Articular cartilage
Acetabulum made of what 3 bones?
Ilium, ischium + pubis bones
Greater trochanter attaches what muscles? Lesser trochanter? What connects these anteriorly? Posteriorly?
Abductor and lateral rotator muscles
Psoas major and iliacus
Intertrochanteric line= ilio-femoral ligament
Intertrochanteric crest- attaches quadratis femoris
Roughened ridges on posterior shaft of femur? Splits distally and also proximally into what? Medial supracondylar line ends in what where what attaches?
Linea aspera
Medial + lateral supracondylar lines + floor of the popliteal fossa
Medial border–> pectineal line, lateral border–> gluteal tuberosity where gluteus maximus attaches
Adductor tubercle= adductor magnus
Rounded ends of femur? What is depression between these? What is on the medial wall of the intercondylar fossa? Lateral wall?
Medial + lateral epicondyles
Intercondylar fossa
Facet for attaching PCL
Facet for ACL
Where is patella located? Attached superiorly and inferiorly to what? What type bone?
Within patellofemoral groove
Quad tendon and patellar ligament
Sesamoid type due to position within quad tendon
What is apex inferiorly connected to by? What attaches the quad tendon superiorly? 2 facets on posterior surface?
Tibial tuberosity by patellar ligament
The base
Medial–> medial condyle of femur
Lateral–> lateral condyle of femur
2 functions of patella?
Leg extension
Protection of anterior knee from trauma
Proximal tibia widened by what? Form what flat surface? Region located between condyles? Projects upwards on either side as what? Attach what?
Medial + lateral condyles–> tibial plateau
Intercondylar eminence
Medial + lateral intercondylar tubercles
Knee ligaments + menisci
How many borders/ surfaces to tibial shaft? What shape? Proximal anterior border called what? Attaches what? Posterior surface marked by what? Site of origin for part of what? Lateral border attaches what?
Prism-shaped 3: anterior, posterior + lateral Tibial tuberosity= patellar ligament Soleal line- soleus muscle Interosseous membrane
On posterior tibia, groove where what passes through? Laterally is what where what is bound?
Tendon of tibialis posterior
Fibular notch= fibula–> tibia
Main function of fibula? 3 main articulations?
Muscle attachment- not a weight-bearer
1) Proximal tibiofibular joint–> lateral condyle of tibia
2) Distal tibiofibular–> fibular notch of tibia
3) Ankle joint= talus bone
Proximal fibula contains facet for articulation with what? What nerve runs on posterior and lateral surface of fibular neck? 3 surfaces of shaft?
Lateral condyle of tibia
Common fibular nerve
Anterior, lateral and posterior
Intracapsular ligaments of the hip? Extracapsular? Prevents what movements?
Ligament of head of femur= acetabular fossa–> fovea of femur
1) Iliofemoral: anteriorly ilium–> intertrochanteric line- hyperextension
2) Pubofemoral: anteriorly + inferiorly= pelvis–> iliopubic eminence + obturator membrane- abduction + extension
3) Ischiofemoral: posteriorly= ischium–> greater trochanter- excessive extension
NV supply of the hip? Major supplier? Damage can lead to what?
Medial + lateral circumflex femoral arteries= anastomose at base of femoral neck–> a ring
Medial artery–> avascular necrosis of the HOF
Sciatic, femoral and obturator nerves
Muscles needed to flex the hip? Extend? Abduct? Adduct? Laterally rotate? Medially rotate?
Iliopsoas, rectus femoris, sartorius and pectineus
GMax, semimem, semitend, biceps femoris(hammies)
GMed, GMini, piriformis and tensor fascia latae
Adductors longus, brevis and magnus, pectineus and gracilis
BF, Gmax, piriformis, obturators, gemilli + QF
Anterior GMed and mini fibres, tensor fascia latae
