Muscular System Flashcards
The main function of the muscular system is ________.
movement
The muscular system helps support _______ and creates _______.
posture/heat
Name the 3 types of muscle in the body.
Visceral (smooth)
Cardiac
Skeletal
Visceral muscle is the _______ type of muscle and is found in the _____, ______, and _____ _____.
weakest; stomach; intestines; blood vessels
Visceral and cardiac muscle are controlled by the ________ part of our brain.
unconcious
Cardiac muscle is only found in the _______ and is much _______ than visceral muscle.
heart; stronger
Cardiac muscle is made up of cells called __________.
cardiomyocytes
Cardiomyocytes are joined together by _____ _________. These allow the cells to contract in sync.
intercalated discs
What causes light and dark stripes in cardiac muscle when viewed under a microscope?
The arrangement of proteins.
Skeletal muscle is sometimes referred to as _______ muscle because of the way it appears under a microscope.
striated
Skeletal muscle is muscle that _______ and ______ by voluntary action.
contracts; relaxes
How does skeletal muscle attach to our bones? What are these made out of?
through tendons made out of connective tissue, rich in collagen fibers
Muscle cells are lumped together to form fiber structures, and they are covered by the cell membrane called the ________.
sarcolema
The sarcolemma tells muscle cells to do what?
to expand and contract by serving as a conductor for electrochemical signals
What helps the sarcolemma transfer electrochemical signals even deeper into the tissue?
transverse tubules
Where are calcium ions stored in the muscle?
sarcoplasmic reticulum
The sarcoplasmic reticulum is a complex of membranes that form a network of _______ ______ ______.
interconnected hollow tubes
The sarcoplasmic reticulum releases calcium ions during _______ and absorbs them during ______.
contraction; relaxation
What is the contractile subunit of the muscle fiber that extend from one end of the fiber to another?
myofibrils
Myofibrils are surrounded by the _______ ______.
sarcoplasmic reticulum
Myofibrils are made up of _______.
sarcomeres
Sarcomeres are made up of precise arrangements of _____ and _____ filaments.
actin; myosin
Actin form the _____ filaments while myosin forms the ______ filaments.
thin; thick
Sarcomeres are attached end to end throughout the length of the myofibril. The junction points, where each sarcomere meets, is called the ____ _____.
Z - line
Why do myofibrils have a striped appearance?
the alternating thick and thin filaments
Muscle contraction is based on the ______ _____ theory.
Sliding Filament
When at rest, where to the actin and myosin filaments sit in the muscle?
Actin - sits at the end of the muscle
Myosin - resides towards the center of the muscle
During contraction, myosin attaches to actin filaments and pulls them towards the _____ of the _______.
center of sarcomere
During contraction, the entire sarcomere shortens because the acting filaments are sliding ______
inward
A sarcomere is made up of different bands and zones. The ___ band are the thick myosin filaments, but they do not shorten during contraction.
A - band
A sarcomere is made up of different bands and zones. The ___ band is between the thick, myosin filaments where only actin filaments are found.
I - Band
The ___ - _____ is between the actin filaments, and it contains only thick myosin filaments.
H - Zone
There are two types of skeletal muscle. Type I and II. Which type contracts slowly, and used for stamina and posture?
Type I
Type I skeletal muscle produces energy from sugar using _____ _____ and is resistant to _____.
aerobic respiration; fatigue
Type II skeletal muscle contract _______.
quickly
Type II A skeletal muscle is found more in the _____ and larger muscle groups as it has more endurance than type B.
legs
Type II B skeletal muscle is found more in smaller muscle groups such as the ____ as it does not have as much endurance as type II A.
arms
Skeletal muscles work by contracting and shortening the length in the middle part of the muscle called the _____ _____.
muscle belly
The stationary bone when moving is called the ______, while moving bone is called the _______.
origin; insertion
The _____ is the muscle responsible for the action while the _______ does the opposite of the action.
agonist; antagonist
When the elbow is flexed, the bicep is the _____ and the tricep is the _______.
agonist; antagonist
What muscles help support the agonist, and stabilize and reduce unnecessary movement?
synergists
What muscles help support to keep the origin stable?
fixators
Muscles can be named in many different ways. \_\_\_\_\_\_ of body Number of \_\_\_\_\_ Bones to which they are \_\_\_\_\_\_ Function Relative \_\_\_\_\_
Region of body Number of origins Bones to which they are attached Function Relative Size
________ contractions generate force by changing the length of the muscle while _______ contractions generate force without changing the length of the muscle.
isotonic; isometric
The neurons that control muscles are called ______ ______.
motor neurons
Motor neurons control muscle cell groups called ______ _____.
motor units
The larger the muscle the ______ cells in the unit; the smaller the muscle, the _____ cells in the unit.
more; less
There are 2 ways that muscles get energy. What are they?
Aerobic respiration; Lactic Acid fermentation
What is the most effective way a muscle gets energy?
aerobic respiration
Lactic Acid fermentation is a process that goes by _______ respiration. It is less effective and only used when blood cannot get to the muscle due to _______ contraction
anerobic; prolonged
What is the goal of aerobic respiration and lactic acid fermentation?
to produce ATP from glucose
The most important energy molecule in for our bodies is ______.
ATP
Muscles also use other sources for energy. ______ stores oxygen and allows for aerobic respiration even when blood cannot get to the muscles.
Myoglobin
Muscles also use other sources of energy. ______ ______ helps created energy by helping ATP be created by a donated phosphate group going to depleted ADP.
creatine phosphate
What molecule is made out of glucose that helps muscles make ATP?
glycogen
When a muscle is out of energy it is said to be _______. That means there is little to no oxygen, ATP, or glucose, and ____ _____ levels and ______ are high.
fatigued; lactic acid; ADP
