Lecture 3 Flashcards
It takes most bones years to _____
Fully develop
All bones service from
Mesenchymal tissue
Intramembranous ossification
Cranium
Endochondral ossification
Cartilage
Bone lengthens at ______ junction
Diaphyseal-epiphyseal junction
ChondrocyTes change into
Oceocytes
Closure of epiphyseal plates mark _____
End growth
Cartilage calcifies in the center of the diaphysis and then develops
Cavities
The periosteal bud invades the internal cavities and spongy bone
Forms
The diaphysis elongates and a medullary cavity forms secondary ossification centers appear in
Epiphyses
When ossification is complete, hyaline cartilage remains only in
Epiphyseal plates
Tubular shafts (levers)
Long bones
Cube shaped (articulating surfaces)
Short bones
Curved (provide protection )
Flat
Not defined very well (many muscle attachments )
Irregular
Sesamoid
Within muscles/tendons (mechanical advantage)
Tendons run parallel to
Muscle
Tendons connect
Muscle to bone
Tendons resist
Parallel tension
Tenocytes control metabolism and _____
Respond to stimuli
Tendons main function
Resist tensile loads and is REACTIVE
When injured response time is slowed,
Start pulling on bone too much (causes inflammation)
Isometric (tendon healing)
Have constant tension (resetting)
Slow eccentric and then concentric contraction tendons
How you get sore- the tendons need to allow lengthening process so they know what to do when they are longer
Progress load and speed
Concentric activity
Tendon pulling too much
Patella tendonopathy
Muscles are named for their
Length shape, function, attachment/position, and size
What muscle is named for shape
Trapezius
What muscles are named for size
Rhomboid major/minor
What muscle is named for location/position
Latissimus dorsi
What muscle is named for attachment?
Interspinalis
What muscle is named for function
Levator scapulae
Muscles attach to tendons at
Myotendinous junction
Common location for muscle injury
Myotendinous junction
Primordial muscle cells elongate and fuse to form
Myotubes
Myotubes and myoblasts fuse to produce
Growth
Muscle composition
(Water, protein, organic/inorganic compounds)
How much water is in muscle
75%
Muscle fibers=
Cells
Most muscles in the body are present at birth or
Develop within 1 year
Muscles increase in ________ based on activity
Diameter
Muscles increase in length based on ________
Skeletal system
Actin and myosin form the
Sarcomere
Bundle of myofibrils
Muscle fiber
Small group of muscle fibers
Fascicle
Smaller group of muscle fibers are innervated by a single nerve
Motor unit
Structural unit is made up of
Many sarcomeres
A functional unit is a
Motor unit
Motor neuron cell bodies begin in
Spinal cord
All motor neurons fire synchronously or
Not at all
Smaller motor units are recruited first then larger motor units
Henneman size principle
Lifting a large weight
All motor units are working
Acetylcholine released as the
Neurotransmitter
5 ms for
Skeletal muscle
200ms for
Cardiac muscles
Action potentials travel along
Sarcolemma
Action potentials travel along sarcolemma (cell membrane) and down t tubercles
Neuromuscular junction
Transmits action potential to signal CALCIUM to release at terminal cisternae
T tubule
Surrounds each myofibril
Sarcoplasmic reticulum
Calcium is released and binds to
Troponin
Troponin moves ______ out of The way so myosin can bind to actin
Tropomyosin
End of power stroke
ATP comes and releases energy of actin myosin connection
Power stroke
Myosin crawls along actin
Type 1 muscle fiber
Slow twitch , slow to fatigue , endurance
Long distance running
Type1 slow twitch, long distance
Type 2
Fast twitch, less blood supply, power/sprint/strength
Skeletal striated
Somatic nervous system (voluntary)
Single cylindrical fibers with transverse striations
Skeletal striated
Autonomic nervous system (involuntary)
Cardiac
Smooth muscle is
Involuntary (autonomic system
No striation, overlapping system
Smooth muscle
Muscles will only
Pull
Constant pull or tension of the muscle at rest
Tonic contraction
Active contraction of the muscle
Phasic contraction
Phasic contraction can either be
Isometric or isotonic
No movement/no change, holding water bottle
Isometric
Picking up water bottle to drink
Concentric
Putting water bottle down
Eccentric
Muscle strains occur when tensile force is ______ or _______ than the muscle contraction
Greater, faster
Small groups of fibers surrounded by connective tissue
Intrafusal fibers
Muscle tone is constant tension on _______
Muscle spindles
Muscle stretch initiates contraction response
Stretch reflex
Faster stretch faster response in
Healthy muscle tissues
Alpha and gamma fibers are always firing to control
Movement
Free nerve endings within the tendon and Myotendinous junction
Golgi tendon organs
Golgi tendon organs reacts to
Muscle tension
Golgi tendon organs
Patellar tendon reflex