Bone, cartilage tendon and muscle
How does a muscle allow movement of the bone?
-2 points of attachment to skeleton, -muscle belly contracts while tendons fixed -causes pulling of skeleton for movement
What does the anterior cruciate ligament connect? what is its function?
-Links femur to tibia -runs crosswise inside the centre of the knee joint stabilises movement in a backward and forward direction
why are fingers particularly prone to tendonitis?
-Very little superficial fascia and fat in finger means skin immediately covers tendon sheaths so less movement of skin over bone
what are the names of all the separate synovial sheaths of the hand?
-common flexor sheath -flexor pollicis longus sheath -individual digital sheaths
what are the functions of bone?
-support -protection -metabolic (calcium) -Movement -Haematopoiesis (immune function-gives rise to all blood cell lineages e.g. B cells.
How are tendons of the hand protected?
-synovial sheath bathes tendon in synovial fluid prevents build up of friction -can be common or individual
What are the features of ligaments?
-tough bands of white, fibrous slightly elastic tissue -essential for binding bones -supports internal organs, internal ligaments e.g. uterus, liver, gallbladder
what are examples of irregular bones?
-vertebral column -8carpal bones 7-tarsal bones -patella
What are the membranes of the bone called? features? function? what attaches periosteum?
1.Endosteum-single layer of cells lining inner surface of bone provides nutrition 2.Periosteum-several cell layers lining outer surface of bone very tightly stuck-attached to bone by strong cartilaginous fibres called sharpies fibres which extend into interstitial lamellae. Sharpies fibres also used to attach muscle to bone!
What types of cartilage are there? where are they commonly present and function?
1.Hyaline-Framework for bone deposition, smooth surfaces for articulation 2. Fibrocartilage-Found in areas requiring tough support e.g. pubic symphysis acts like superglue and knits together parts of skeleton that have little movement. 3.Elastic: wall of auditory canal and larynx present to keep tubes open.
what are the sites of endochondral ossification when are they present?
1.Primary ossification centre-in bone shaft,most present by birth 2.secondary ossification centre-appear at bone end after birth.
how is bone formed?
1.embryonic mesenchyme forms a mesenchymal model (from mesoderm soft and loose tissue model) 2.This is destroyed and replaced by an intermediate cartilaginous model (bit more solid) 3.replaced by bone during endochondral ossification (where bone replaces cartilage)
What is the epiphyseal growth plate?
Active growing area of the bone-can be mistaken for fractures.
What is the purpose of the flexor retinaculum?
All tendon pull on bone when forming a fist FR holds tendons in place stops them moving and bowstringing. over top of the synovial sheaths
What is the general structure of bone?
Compact bone=lamellar osteons Cancellous=spongy organised network of trabeculae allows maximum strength at sights of weight bearing-cells wider apart allows distribution of weight.
what are the parts of bones what is the function of the different parts?
Epiphysis-weight bearing end of bone Metaphysis diaphysis-stability of bone medulla-where bone marrow sits-development of immune system
what types of bone are there?
Long short flat irregular
what is double jointedness?
Occurs as a result of longer ligaments allows joint to have increased ROM
what are the features of bone?
Osseous tissue -hard -lightweight -formed by calcium phosphate -collagen gives it elasticity- important in birth. -well vascularised meaning good wound repair.
What are the features of cartilage?
Soft connective tissue -Collagen, elastin, chondrocytes, ECM -Avascular thus nutrients diffuse through ECM.
What are the features of short bones? examples
Still have a tubular shaft and articular surface at each end but are shorter -all metacarpals and metatarsals -all phalanges -clavicles
What is the difference between tendons and ligaments? functions?
Tendons-connect muscle to bone (collagen only) function for stability of bone interaction. Ligaments-Connect bone to bone (collagen and elastin thus more flexible) Function is to exert mechanical advantage of muscle contraction over joints.
What are the features of flat bones?
Thin with broad surfaces -Innominate bone (hip bone) -Scapula -all ribs -sternum
can tendon ruptures be repaired? what are they used for?
YES Achilles tendon can be torn completely and still repaired if ends brought back together
What is tendonitis?
happens where tendons enter a tube-e.g. tendon sheath entrance is where restraint is greatest-this is where the worst inflammation and irritation occurs.
why is it important in the knee?
knee is weight bearing joint takes large amount of body weight-prevents bones sliding off each other
Why may one muscle cause several bones to move? why is this useful?
many tendons from a single muscle enable movement of several bones multiple tendons attach to many bones. ensures contraction over wider area.
How is it damaged?
sporting from behind tibia is forced forwards.
why does dislocation once mean prone to future dislocation?
the ligaments are viscoelastic and strain under tension returning to original shape when removed but if remain extended for too long can become weakened and stretch causing hyper mobility of the joint.
how can it be repaired?
transplant of part of patellar tendon?
what are features of long bones?
tubular shaft and an articular surface at each end typical epiphysis, metaphysis and diaphysis. may be paired or unpaired e.g. tibia and fibula