5: Quiz 5 Chapter 5: Muscular System (Anatomy & Physiology)

_______ are represented by the letters A, H, and I.

Muscle bands

_______ are the basic units of muscle contraction.

Sarcomeres

_______ contraction occurs when muscles shorten and thicken.

Isotonic

_______ contraction occurs when the muscle length does not appreciably change but muscle tension increases

Isometric

_______ muscle is the voluntary muscle attached to bones.

Skeletal

A _______ is a nerve that controls muscle contractions.

motor nerve

A muscle that extends the elbow is the _______.

triceps brachii

A waste product called _______ is produced during the anaerobic metabolism of glucose.

lactic acid

A(n) _______ releases the neurotransmitter acetylcholine.

motor neuron

About _______ skeletal muscles, working together, allow us to carry on our daily activities and move effectively through our world.

600

Each muscle fiber is almost filled with thread-like structures called _______.

myofibrils

Each muscle is surrounded by a covering of connective tissue called _______.

epimysium

Each skeletal muscle is an organ made up of hundreds, sometimes thousands, of muscle cells, referred to as _______.

muscle fibers

Even when we are not moving, our muscles are in a state of partial contraction that gives us _______.

muscle tone

Excess acetylcholine is broken down by an enzyme called _______.

acetylcholinesterase

Extensions of epimysium form tough cords of connective tissue, the _______, that anchor muscle to bones.

tendons

In muscle fibers, the _______ has/have many inward extensions that form a set of transverse tubules.

plasma membrane

Myofibrils are composed of smaller structures called _______ that are made of protein threads.

filaments

Oxygen debt is paid back during the period of _______.

rapid breathing

Rapid breathing pays back the _______ debt by breaking down lactic acid.

oxygen

Synergists are muscles that _______.

stabilize joints

The _______ muscle adducts the scapula and rotates it and draws the shoulders upward.

trapezius

The _______ muscle elevates the upper corners of the mouth.

zygomatic

The _______ muscle extends and rotates the thigh laterally and tilts the pelvis.

gluteus maximus

The _______ muscle flexes the trunk and compresses the abdominal contents.

rectus abdominis

The attachment of the muscle to the less movable bone is called its _______.

origin

The attachment of the muscle to the more movable bone is its _______

insertion

The biceps (brachii) and triceps work _______ to one another.

antagonistically

The biceps brachii _______.

flexes the elbow

The depletion of ATP results in weaker contractions and _______.

muscle fatigue

The external intercostals are important in _______.

breathing

The gastrocnemius muscle _______.

flexes the knee

The gluteus maximus _______.

extends and rotates the thigh laterally

The immediate source of energy for muscle contraction is _______.

ATP

The immediate source of energy for muscle contractions comes from _______.

ATP

The masseter muscle _______.

is important in chewing

The muscle fibers are arranged in bundles known as _______.

fascicles

The muscle that contracts to produce a particular action is known as the _______.

agonist

The overlapping of myosin and actin filaments _______.

produces a pattern of bands or striations

Thin filaments, called _______ filaments, consist of the protein actin.

actin