Chapter 1 Flashcards
(28 cards)
What is the basic unit of skeletal muscle?
The muscle fiber.
What are the two main protein filaments in muscle contraction?
Actin (thin) and Myosin (thick).
What is the sarcomere?
The functional unit of a muscle fiber where contraction occurs.
What initiates muscle contraction?
Release of calcium from the sarcoplasmic reticulum.
What is the role of the neuromuscular junction?
Transmits signals from a motor neuron to a muscle fiber.
Define motor unit.
A motor neuron and all the muscle fibers it innervates.
What principle governs muscle fiber activation?
The all-or-none principle.
What is the function of the Golgi tendon organ?
Senses muscle tension and inhibits contraction to prevent injury.
What do muscle spindles detect?
Changes in muscle length and rate of stretch.
What are the three types of muscle fibers?
Type I (slow-twitch), Type IIa, and Type IIx (fast-twitch).
Which muscle fiber type is most fatigue-resistant?
Type I (slow-twitch).
What is the primary function of the cardiovascular system?
Transport oxygen, nutrients, and waste products.
Name the four chambers of the heart.
Right atrium, right ventricle, left atrium, left ventricle.
What is stroke volume?
The amount of blood ejected by the heart in one beat.
What controls the heart’s electrical rhythm?
The sinoatrial (SA) node.
What is cardiac output?
The amount of blood pumped by the heart per minute.
How does the respiratory system aid performance?
By supplying oxygen and removing carbon dioxide.
Where does gas exchange occur in the lungs?
In the alveoli.
What is the function of hemoglobin?
To carry oxygen in the blood.
What muscle is primarily responsible for breathing?
The diaphragm.
What is tidal volume?
The amount of air inhaled or exhaled per breath.
How are muscle contractions powered?
By ATP (adenosine triphosphate).
What is the function of the pulmonary circuit?
To carry deoxygenated blood to the lungs and return oxygenated blood to the heart.
What is the systemic circuit?
Carries oxygenated blood from the heart to the body.
