1skeletal muscle
contractions speed can vary
force generation can vary
innervated by somatic nervous system
2skeletal muscle characteristics
origin- muscle attachment to the bone that typically does not move
insertion- muscle attachment to the bone that is moved during contraction
flexors-muscles that decrease joint angles
extensors-muscles that increase joint angles
3convergent
broad at the origin and then taper to a narrow tendon
4circular
fibers form a ring around an opening
5fusiform
fibers are thicker in the middle and they taper at both ends "football shaped"
6parallel
fibers run parallel to each other with no obivious taper to a tendon
7unipennate
fibers are going to connect obliquely to a tendon in ONE direction
8bipennate
fibers connect obliquely to a tendon in TWO directions feather type orientation
9mutlipenneate
fibers connect obliquely to tendon in mulitple central tendons grouping of feathers but all connect to one stem
10connective tissue
bind together muscle fibers
keeos muscles fibers in parallel aligment
11epimysum
surround whole muscle
12perimysium
surrond fascicles
13endomysium
surround muscle fibers
14muscle fibers similiartites
mito have a lot of them for energy
nuclei have multiple in one cell
cell membrane- called sarcolemma in skeletal muscles
cytoplasm- called sarcoplasm
15muscle fibers different
have satellite cells allows for help in muscle growth and repair
-outside the sacrolemma but inside basel lamina
- when muscle grows nucleli as they intergrate into the cell
16myofibrils
contain contractile proerties
lots of proteins
17sarcoplasmic reticulum
net like structure
holds Ca
network of membranous channels that surrounds each myofibrils
18TRANSVERSE TUBLES
continuous with the sacrolemma
meranous channel that enxtends inwards from sacrolemma and passes trhough the fiber
19striations in sacromeres
from the actin and myosin
20A band
length of mysion and it is the dark band
21I band
light band
from the end of one mysin the the start of the next one
22titan
helps the strucutre and stability for myosin
24zdics
the zig zag of the at the end of actin and between the actin below it
25cap z
is what aatches actin to the z dics
26h zone
end of actin to end of actin
27m line
middle point of the sacromere
28what move in contraction
actin not myosin
h zone gets smaller
i band gets smaller
a band stays the same
29actin
thin filament
tropnin- balls
tropmysion-rope
30myosin
tail-heavy chain
heads-hevay chain
2 rings round heads-light chain (helps sturcture and stability)
31desmin
intermediate filaments that hold adjecnt sacrmeres together z dis to z dics
allows for more power and cohesiveness by having sacromese all aligned
32dystrophin
protein tht holds action to the sacrolemma vvery important to organization of sacromeres