Muscular System Flashcards
Muscle Tissues consists of fibers to provide:
- motion
- maintain posture
- produce heat
Three types of muscle tissue
- Skeletal muscle
- cardiac muscle
- smooth muscle
Skeletal Muscle Appearance & Features:
- long cylindrical fibers
- many peripherally located nuclei
- unbranched & striated
Skeletal muscle location:
most commonly attached by tendons
Skeletal muscle connective tissue components:
- endomysium
- perimysium
- epimysium
are skeletal muscle contractile proteins organized into sarcomeres & how much sarcoplasmic reticulum does it have
yes & abundance
Cardiac Muscle appearance & features:
- branched cylindrical fiber
- one centrally located nuclei
- intercalated discs join neighboring fibers
- striated
Cardiac Muscle Location:
Heart
Cardiac Muscle connective tissue components
endomysium & perimysium
are Cardiac muscle contractile proteins organized into sarcomeres & amount of sarcoplasmic reticulum?
yes & some
Smooth muscle appearance & features
- fiber thickest in middle & tapered at each end
- one centrally located nucleus
- not striated
Smooth Muscle location:
walls of hollow viscera, airways, blood vessels, iris, ciliary body of eye, & arrector pili muscles of hair follicles
Smooth muscle connective tissue components:
Endomysium
Are smooth muscle’s contractile proteins organized into sarcomeres & amount of sarcoplasmic reticulum?
no & very little
Skeletal Muscle Role & function:
- conscious control
- acts as pulley system
- accounts for half of body weight
- ~600 in body
- striated: actin & myosin
Three layers of connective tissue:
Epymysium
Perimysium
Endomysium
Epimysium:
- outermost layer
- surrounds entire muscle
Perimysium:
- surrounds groups of muscle fibers called fascicles
Endomysium:
- deepest layer
- separates individual muscle fibers
Connective tissue layer function
- provides access for nerves and blood vessels. inserts into tendon
A Muscle Fiber / Muscle Cell is made up of:
- Sarcolemma = plasma membrane
- sarcoplasm = cytoplasm
- myofibrils = long strands of sarcomeres
- sarcoplasmic reticulum (storage for calsium)
Sarcomeres:
- contractile units of muscle
- made up of overlapping myosin (thick) and actin (thin) filaments
Myosin:
- thick filaments
- head links thick and thin filaments
Actin:
- thin filaments
- composed of actin, troponin, & tropomyosin
- provide anchor point for myosin heads
- either blocks or allows movement of sarcomeres
