Chapter 6: Lesson 1 Flashcards
Cardiorespiratory system
A system of the body composed of the heart, blood, blood vessels, lungs, and airways.
Cardiovascular system
A system of the body, also known as the circulatory system, that transports blood to tissues of the body.
Thoracic cavity
Chamber within the chest that contains the heart and lungs.
Mediastinum
The space in the chest between the lungs that contains all the internal organs of the chest (e.g., heart, esophagus) except the lungs.
Cardiac muscle
Muscle of the heart.
Skeletal muscle
The type of muscle tissue that connects to bones and generates the forces that create movement.
Smooth muscle
An involuntary nonstriated muscle type that is found in organs.
Myofibrils
The contractile components of a muscle cell; the myofilaments (actin and myosin) are contained within a myofibril.
Sarcomere
The structural unit of a myofibril, composed of actin and myosin filaments between two Z-lines.
Atrium (atria)
Superior chamber(s) of the heart that gathers blood returning to the heart.
Ventricle
Superior chamber(s) of the heart that gathers blood returning to the heart.
Intercalated discs
Resting heart rate (RHR)
Sinoatrial (SA) node
Located in the right atrium, this node initiates an electrical signal that causes the heart to beat.
Atrioventricular (AV) node
Located between the atria and ventricles, this node delays the impulse from the sinoatrial node before allowing it to pass to the ventricles.
Stroke volume
The amount of blood pumped out of the heart with each contraction.