Musculature I (lecture) Flashcards
what are the functions of the musculature system?
movement, resist opposing forces, movement within body organ systems (digestion, respiration, circulation, reproduction excretion), body posture, support weight, generate heat, protection, general physique
What are the three stypes of muscle tissue in vertebrates?
skeletal, cardiac, smooth
what are the characteristics of skeletal muscle? Is it associated with voluntary or involuntary movement?
striated, bulk of muscle tissue, attached to skeletal system
voluntary movement
what are the characteristics of smooth muscle? is it voluntary or involuntary movement?
walls of hollow organs, changes diameter of lumen
involuntary movement (pupillary dilators for example)
what are the characteristics of cardiac muscle? is it voluntary or involuntary?
wall of heart, pumping action
involuntary
what forms muscle fibers?
fusion of plasma membranes of multiple mononucleate cells
what is a syncytium?
fusion of mononucleate cells
what is a myocyte?
a syncytium consisting of repeating sarcomeres
what are sarcomeres composed of?
long fibrous proteins: actin and myosin
what is the fucntion of actin and myosin in sarcomeres?
long fibrous proteins that slide past each other when muscles contract and relax
What causes striation in muscles?
sections of sarcomeres where myosin and actin overlap or don’t overlap
what are myofibrils?
chains of sarcomeres
Skeletal mucles move joints through _______
contraction
what is a gaster?
muscle belly, fleshy portion containing contractile muscle fibers (actin and myosin)
what is a tendon?
collagenous dense regular connective tissue that attaches muscle to bone
what is the enthesis?
point at which tendon inserts into the bone
tendons transmit force produced by ________ tissue
contractile
T/F: tendons can transmit force from a distant point, permitting delicate control
true
what is fascia?
a layer of connective tissue that surrounds muscles, groups of muscles, internal organs, blood vessels, nerves etc..
What is the function of fascia?
binds structures, permits muscles to slide smoothly over eachother
what are some examples of fascia in the body?
the rectus sheath, thoracolumbar fascia
Why is the evolutionary history of muscles so complex?
lots of fusion and splitting, expansion and reduction
T/F: information on muscle history is gained through muscle scars
true, muscles most often don’t leave a fossil record
What is muscle classification based on?
attachment similarity, functional similarity, nervous innervation, embryonic origin