AP1E2
Motor Unit
Single motor neuron + ALL innervated fibers All fibers respond with same amount of tension
perforating (Sharpey's) fibers
collagen fibers that anchor periosteum to compact bone
red bone marrow
contains reticular fibers
Periosteum
dense irregular CT covers long bones rich supply of veins/nerves
most growth in bone
epiphyseal plate on diaphysis side replicate chondrocytes Reserve, proliferation, hypertrophy/maturation, calcification, ossification
type 2
fast glycolytic light
bursae
fiber sacs filled w synovial fluid connected to/seperate from joint cavity
Gomphosis
fibrous!
Syndesmosis
fibrous! ampiarthrosis ex. interosseus membrane
inter membranous
flat bones! 1. Meysenchymic cell -> osteoblasts in the PRIMARY ossification center 2. secrete organic matrix, calcify/trap (osteocytes) 3. trabeculae of spongy bone + periosteum (mes. Cells) - 4. periosteum osteoblasts lay compact bone
k nee joint
largest/mostcomplex diarthrosis
3 stages twitch
latent period, contraction phase, relaxation phase
endosteum
lines inner medullary cavity
symphasis
cartilaginous ex. vertebral discs
Synchondrosis
cartilaginous! costochondral joints!
endochondral
1. chondroblasts -> osteoblasts 2.a. ossify bone collar OUTSIDE 2.b. internal cartilage calcify (chondrocytes die) 3. in primary center, osteoblasts replace calcified chondrocytes w spongey bone 4. . medullary cavity expand, epiphyses finish ossifying
3 methods of ATP generation
1. creatin phosphate 2. glycolytic catabolism (cytosol) 3. oxidative glycolysis (mitochondrion.)
synovial classifications
1. movement (Axis) 2. shape
ATP in muscle contraction
1. na/k pump (ap potential) 2. relase from myosin head for NEXT power stroke 3. pump SR (Relax)
bone repair steps
Fracture bleed hematoma soft callus bony callus secondary bone Fibroblasts/chondroblasts infiltrate hematoma... form soft callus Soft callus calcified by osteoblasts in periosteum Bone callus remodled... primary replaced with secondary
articular joint capsule
Inner synovial membrane (loose CT) Outer fibrous layer (dense irregular CT)
muscle growth
NO more fibers! just enzymes/number of myofibrils satelite cells for repair
Excitation-contraction coupling
Sarcolemma, T-Tubules, Sarcoplasmic Reticulum
muscle tone
alternating which motor units activated
Ligaments
bone to bone dense regular
molecule excitation order
ca- axon ach- synapse na - motor endplate ca- SR post t tubules
tendons
muscle to bone
length/tension
optiomial length for relationship
skeletal muscle
organ!!
Isotonic concentric contractions
pick cup up - shorten + constant force
endocondral vs intermembranous simmilarities
produce primary bone that is replaced by lamellar/mature bone
Isotonic eccentric contractions
put cup down - length + constant force
type 1
slow, oxidative dark
least to most mobile
suture syndesmosis (inter. oss) synchondosis (epiphyseal plate!) symphysis plane piviot/hinge condylar ball/socket
knee injury
• tear in the ACL or tibial collateral ligament •ACL prevents hyperextension •Tibial collateral ligament normally prevents hyperabduction of the leg at the knee