Muscular System Flashcards
Smooth Muscle
Narrow cylindrical fibers, non-striated, uninucleate; occurs in walls of internal organs; is involuntary;
Types of Muscle
Smooth Muscle
Cardiac Muscle
Skeletal Muscle
Cardiac Muscle
Has striated, branched, generally uninucleated fibers; occurs in walls of heart; is involuntary;
Skeletal Muscle
Has striated, tubular, multinucleated fibers; is usually attached to skeleton; is voluntary.
Functions of the Muscular System
Support the body
Allow for movement of bones and other structures
Help maintain constant body temperature
Assist in movement of fluids in cardiovascular and lymphatic vessels
Protect
Bursa
Fluid filled sacs that provide cushioning between tendons and bones
Tendon
The connective tissue that connects muscle to bone
Origin
Attachment of a muscle to a stationary bone
Insertion
Attachment of a muscle on a bone that moves
Prime Mover
Does most of the work when moving
Synergist
Assists the prime mover
Antagonist
Works against the prime mover - purpose is to undo what was done by the prime mover
Muscles are named based on what seven characteristics?
Size Shape Location Direction of fibers Attachment Number of attachments Action
Do muscles pull or push?
Pull
T-tubule (transverse)
Portion of sarcolemma that penetrates muscle cells.
Sarcoplasmic Reticulum
Smooth endoplasmic reticulum that stores Ca+
Sarcolemma
Plasma membrane
Sarcoplasm
Cytoplasm
Sarcomere
One contracting unit of the muscle cell; made of the proteins actin and myosin
Actin
thin filaments
Myosin
Thick filaments shaped like a golf club
I Band
Region on a sarcomere where actin but no myosin is
H zone
Region where myosin is but no actin
A band
Length of the myosin fiber
How do filaments go over one another during muscle contraction?
Filaments slide over one another - do NOT crunch up!
First step of ATP in cellular work of motion…
ATP is split when myosin head is unattached (so becomes ADP)
Second step of ATP in cellular work of motion
ADP + P are bound to myosin as myosin head attaches to actin