Muscles and Movement Flashcards
2 attachments and must cross at least one joint, m+
muscle
always pull and get shorter (distal moves proximal; insertion moves to origin (anchor))
movement of muscle
“striations” always point to their attachments and show direction of pull
muscle fibers
when a muscle moves ventral to ventral (angle DECREASES)
flexor
muscles move the dorsal side to dorsal side (angle INCREASES)
extensor
smallest components of m+ tissue
filaments
filaments clustered together
myofibrils
myofibrils clustered together
muscle fibers
a cluster of muscle fibers
fascicle
fascicles clustered together
muscle
layer of connective tissue around whole tissue
epimysium
surrounds individual fascicles within each muscle
perimysium
covering each muscle fiber
endomysium
This is the “functional unit” of the muscle cell/fiber where the actual contraction happens
sarcomere
thin actin filaments are anchored here
Z-lines 1
thick myosin filaments
A band 2
thin actin filaments
I band 3
space between actin filaments
H zone 4
Z line to Z line
one sarcomere
Long tail (c), double heads (b), cross bridge (a) located at the top of the heads, cross bridges are the part of the head that are going to grab the actin and pull, there is a hinge (d) at the bottom of the heads that allow the heads to move the actin into the center of the sarcomere
myosin filaments
a strand of beads, each bead is known as G (globular) ___ , the stand is known as F (Fibrous) ____,
Actin Filaments
The protein that runs along the actin to give it its strength blocks binding sites
Tropomyosin
helps move the tropomyosin out of the way so that a contraction can occur, in the middle has a building site for calcium, when the calcium binds to it the tropomyosin is moved out of the way
troponin complex
Job is to pump and transport calcium in and out of myofibrils
Sarcoplasmic Reticulum (SR)
A tube made by the SR with extensions that go around the middle of the sarcomere
Transverse tubule or T Tubule
Extensions from SR
Terminal Cisterna
A T Tubule and the terminal cisterna that come off in both directions
Triad
allows for excellent release of calcium into the sarcomere in order to get a quick reaction
pattern of the SR
has sodium potassium pumps in their membranes, they use ATP to force 3Na+ out of it and 2 K+ into it, continual process resulting in an imbalance of charges more + in the interstitial matrix and more - in it
every cell
charge of your cell usually around 70 mv,
Resting Membrane Potential
