Module 2 - Muscles Flashcards
What is the definition of a muscle?
Muscle is a group of muscle cells with the same origin, insertion, and function.
How many skeletal muscles do we have?
650 skeletal muscles
T/F: You will find muscle tissue in almost every organ.
TRUE
How much of our average body weight is muscle?
35%
T/F: Muscles need to be excited to contract
TRUE
Is Muscle shortening a contraction?
Is Muscle lengthening a relaxation?
YES. Shortening = Contraction
Lengthening = Relaxation
What are the 3 main types of muscle?
Skeletal muscle, Cardiac muscle, and Smooth muscle.
Which muscle is striated and voluntary?
Skeletal muscle
Which muscle is found in the attached to the Skeleton?
Skeletal Muscle
Which muscle is found in the in the walls of hollow organs?
Smooth Muscle
Which muscle is found in the heart?
Cardiac muscle
Which type of muscle has no striations?
Smooth muscle
What are Fasicles?
Bundles of muscle fibers (cells) wrapped with connective tissue (fascia)
What are the thick filaments of muscle called?
Myosin
What are the thin filaments of muscle called?
Actin
Which filament is light? Which is dark?
Actin - Thin- Light
Myosin - Thick - Dark
What is a Sarcomere?
contractile unit of muscle
What is a contraction?
Cross-bridges between thin and thick filaments are formed
T/F: Calcium must be present for cross-bridges to form and for contraction to occur.
TRUE
What is the three step process for a muscle to contract?
- Skeletal muscle gets excited by a nerve getting an electrical message from the brain.
- The nerve sends calcium to the muscle
- The calcium helps the muscle contract
What is the principle source of energy for muscles?
ATP
T/F: ATP is required for contraction and relaxation
TRUE
What are the two types of contractions?
Isotonic contractions and Isometric contractions
What is an Isotonic contraction: Does the muscle shorten? Force? Movement?
muscle shortens, maintains a constant force, movement occurs
What is an Isometric contraction: Does the muscle shorten? Force? Movement?
muscle doesn’t shorten, force is generated, no movement
Which muscle is the fastest?
Skeletal Muscle
Which muscle is moderate speed?
Cardiac Muscle
Which muscle is very slow, partially contracted all of the time and rarely fatigues?
Smooth Muscle
Why is exercise beneficial? (3)
- it increases blood flow and oxygen availability to the brain.
- increases growth factors that promote new brain cells and neuronal pathways in the brain.
- increases levels of neurotransmitters which increases memory retention, information processing, and cognition.
T/F: Cardiac and Smooth muscles are involuntary.
TRUE
T/F: Cardiac and Smooth Muscles are able to contract entirely on their own in absence of nerve stimulation.
TRUE
Cardiac muscles cells are joined by ______.
Intercalated discs
T/F: Intercalated discs and gap junctions in cardiac muscle cells allow their electrical current to spread from one cell to the next very quickly.
TRUE
What genetic disease causes muscle wasting and weakening?
Duchenne muscular dystrophy
An infection of a deep wound by bacteria, Clostridium tetani can cause what disease?
Tetanus
What is the degenerative disorder of the central nervous system that mainly affects the muscular system and movement?
Parkinson’s Disease
What causes muscle cramps?
dehydration and ion imbalances.
