Bones and Joints Flashcards
What is a joint?
The union of two or more bones
State type of joint enclosed in a joint capsule and separated by a fluid-fill cavity
Synovial joint
What is a lever?
Rigid structure rotating around fulcrum (skeleton)
What are the components of synovial joint?
Synovial fluid- reduces friction between bones
Articular cartilage- surrounds bones edges
Ligaments- Conect band bone-bone
tendons- bone-muscle generates force to move bone
Collagen- rigid and resistant protein (cartilage, ligaments and tendons)
Name the types of movements
Extension, flexion, rotation, abduction, adduction and circumduction
What is ROM?
The range of movement possible for a joint
What is the medical instrument to measure angle of joints?
Goniometer
What is the name of the muscle cells?
Muscle fibres, multinucleated (muscle cells)
State the relation of sarcomere structure
Muscle cell - myofibrils - sarcomere - myosin and actin
Explain the regions of a sarcomere
M line- medium
Z discs- delimits sarcomere
I bands- only actin
A band- actin overlapping with myosin
H band- only myosin
What is tropomyosin?
Subunit along actin closes myosin binding sites
Explain Sliding Filament Theory
Increases A band, decreases H and I
Z discs more together
Tropomyosin retires with calcium ions
Detachment of myosin head with ATP
Next binding site and attaches, cross-bridge
Pulls actin to original position, power stroke
What is the role of titin in muscle relaxation?
It is a molecular spring when muscle is strechted it stores potential energy. When it it released returns muscle to its normal size
What is the neurotransmitter secreted by motor neurons?
Acetylcholine
What are the types of intercostal muscles?
Internal, External and innermost (forcefully exhalation)
What are the reasons for locomotion?
Foraging for food, Search a mate, migration, escaping from danger,
What are the adaptation of marine mammals for swimming?
Streamlined bodies- minimise drag
Tails form a fat and wide fluke- propulsion
Changes airflow- periodic breathing in dives
Limbs form flippers- steering, lift and streamlined shape
Higher conc of myoglobin in muscle tissues
Large lungs and more capillaries
High volumes of blood- more RBC/haemglobin
Large size, reduces SA:V and prevents heat loss
