Mod5 (Muscular) Flashcards
Microfilaments
cytoskeleton element involved in movement; component of muscle tissue
Myofilaments
a single muscle cell; various arrangements create different muscles (ie. striated have traverse bands of filaments)
Hypodermis layer
connective tissue component of muscle; provides pathway for nerves, blood/lymph vessels to enter/exit muscle; seperates muscle from skin (areolar and adipose)
Fascia
part of muscle connective tissue; lines body walls and limbs(surrounds muscles/organs); allows free movement of muscle, carries nerves and vessels
Fascicle
bundle of 10-100 muscle fibers; found in perimysium layer of muscle tissue
Neuromuscular Junction
point of contact btw motor neuron and muscle fiber (cell); this includes the axon terminal of the motor neuron and the motor end plate of the muscle fibre
Motor Unit
single motor neuron; with all the muscle fibres it stimulates
Sarcolemma
plasma membrane that covers each muscle fiber (Cell); many nuclei lie at periphery of fibre under sarcolemma
Transverse Tubules (T tubules)
tunnel from surface to centre of each muscle fibre
Sarcoplasm
this is the muscle fibres cytoplasm; contains many mitochondria producing large amounts of ATP during contraction
Sarcoplasmic Reticulum
extends throughout sarcoplasm; this is a network of fluid filled membrane enclosed tubules that store calcium ions needed for contraction
Myoglobin
found in sarcoplasm; reddish pigment that stores O2 until needed by mitochondria to produce ATP
Myofibrils
extend the entire length of muscle; consists of thin and thick filaments
thick filaments
1/2 part of myofibrils; these don’t extend entire length of muscle fibre; composed of Myosin (tail forms shaft of filament, head projects outward)
thin filaments
1/2 part of myofibrils; composed of Actin; each mlc consists of myosin binding site where a myosin head will attach
Sarcomeres
compartments formed from overlapping filaments; these are the basic functional unit of striated muscle fibre (alternating dark and light bands give muscle its striated appearance)
Intercalated Discs
link cardiac muscle fibres together so they do not pull apart
angular movements
an increase or decrease in angle btw articulating bones
flexion
decrease in angle btw articulating bones (ie. bending head towards chest, moving forearm towards arm)
Extension
increase in angle btw articulating bones (ie. reverse of flexion)
Hyperextension
continuation of extension beyond anatomical position (bending head backwards)
Abduction
movement of bone away from midline (ie. lateral movement of palm/femur away from body)
Adduction
movement of bone toward midline
Circumduction
movement of distal end of part of body in a circle; a continous sequence of flexion, abduction, extension and adduction (ie. making a circle with your arm (movement of shoulder joint))
Plantar Flexion
bending the foot in direction of plantar (bottom surface)
Dorsiflexion
bending of foot in direction of dorsal surface (Top)
Origin
stationary attachment of muscle to bone
Insertion
moveable attachment of muscle to bone
Belly
fleshy portion of muscle btw origin and insertion
Agonist/Prime Mover
muscle that causes the desired action
Antagonist
muscle that relaxes and stretches during movement
Synergists
assist the prime mover by adding a bit of extra force to same movement OR by reducing unnecessary movements as prime mover contracts
Fixator
synergists that stabilize origin so that prime mover can act efficiently
Rectus
parallel to midline
transverse
perpendicuar to midline
oblique
diagonal to midline
Longissimus
longest
Latissimus
widest
magnus
large
vastus
great
serratus
saw-toothed
obicularis
circular
platys
flat
gracillis
slender
pectinate
comblike
piriformus
pear shaped
rhomboid
diamond shaped
