Chapter 9: Muscle Tissue and Cells Flashcards
3 Types of muscle tissue
Skeletal
Cardiac
Smooth
packaged into skeletal muscles: organs that are attached to the bones and skin
contains: epithelial tissue, connective tissue, nervous tissue, muscle tissue
Skeletal Muscle Tissue
multinucleate cells
voluntary muscle
contract rapidly; tire quickly; powerful
are the longest of all muscles and have striations (stripes)
keywords: skeletal, striated, voluntary
Skeletal Muscle Fibers
striated
involuntary
makes up the bulk of heart walls
keywords: cardiac, striated, involuntary
Cardiac Muscle
found in the walls of hollow organs
ex: stomach, urinary bladder, airways
not striated
involuntary: can also contract on its own without nervous system stimulation
Smooth Muscle
4 main characteristics of muscles
Excitability
Contractibility
Extendability
Elasticity
Important functions of muscles
Movement
Posture
Extendability
Elasticity
attach muscle to bone
Tendons
attach bone to bone
Ligaments
connective tissue layer surrounding the entire muscle
Epimysium
Wraps the fascicle
Perimysium
Wraps individual muscle cells
Endomysium
Bundles of muscle fibers
Fascicles
individual muscle cells
Muscle fibers
Attachment to the movable bone
Insertion
attachment to immovable or less moveable bone
Origin
epimysium fused to the periosteum of bone or perichondrium of cartilage
Direct (fleshy) attachment
connective tissue wrappings extend beyond muscle as rope-like tendon or sheet-like aponeurosis (big broad flat tendon)
Indirect
muscle fiber plasma membrane
Sarcolemma
muscle fiber cytoplasm
contains: glycosomes (for glycogen storage) and myoglobin (for O2 storage)
Sarcoplasm
The modified organelles of a muscle cell
Myofibrils
Sarcoplasmic reticulum
T tubules
stripes formed from a repeating series of dark and light bands along length of each myofibril
Striations
the dark region consisting of organized overlapping actin and myosin filaments
A bands
the band that consists of thick bands only
in the A band
H zone
line of protein (myomesin) that bisects H zone vertically
M line
light regions of the sarcomere that consists of actin (thin) filaments
I bands
coin-shaped sheet of proteins on the midline of light I band
Z disc (line)
elastic myofilaments
Titin
Thin myofilaments
Actin
Thick myofilaments
Myosin
Thick filaments consist of
myosin heads
myosin tails
actin binding sites
atp binding sites
Thin filaments consist of
regular proteins:
tropomyosin and troponin
actin
do the act of contracting
Actin and Myosin
Controls and manages contractions
Tropomyosin Troponin
Function in the regulation of intercellular Ca 2+ levels
Stores and releases Ca 2+
Network of smooth ER tubules surrounding each myofibril
Sarcoplasmic Reticulum
Allows for electrical nerve transmissions to reach deep into interior of each muscle fiber
tube formed by protrusion of sarcolemma deep into cell interior
T tubule
