Muscle Types
Which muscle type is found in the walls of hollow organs and is involuntary?
What is smooth muscle?
What neurotransmitter is released at the NMJ?
What is acetylcholine?
Blood enters the heart through these two major veins.
What are the superior and inferior vena cava?
What is the formula for cardiac output?
What is HR × SV?
This term describes a muscle's ability to return to resting length.
What is elasticity?
This muscle type has striations and is under voluntary control.
What is skeletal muscle?
What protein does calcium bind to in skeletal muscle?
What is troponin?
What valve separates the left atrium and left ventricle?
What is the mitral (bicuspid) valve?
Which chamber generates the highest pressure?
What is the left ventricle?
What are long contractile threads inside muscle fibers?
What are myofibrils?
Name the muscle type that contracts at a steady rate due to pacemaker cells.
What is cardiac muscle?
What’s the sequence starting from action potential to power stroke?
Action potential → T-tubules → Ca²⁺ → troponin → cross-bridge → power stroke.
Name the five phases of the cardiac cycle.
Late diastole, atrial systole, isovolumic contraction, ventricular ejection, isovolumic relaxation.
What factor most strongly affects vascular resistance?
What is vessel diameter?
These structures mark the boundary of a sarcomere.
What are Z discs?
What’s the difference in energy use between fast and slow twitch fibers?
Fast uses anaerobic glucose; slow uses aerobic fatty acids & glucose.
What enzyme breaks down ACh at the synaptic cleft?
What is acetylcholinesterase?
What causes the “lub” and “dub” sounds?
AV valve closure (lub), semilunar valve closure (dub).
What do baroreceptors detect?
What is changes in blood pressure?
What is the functional unit of contraction in muscle?
What is the sarcomere?
Which training type increases mitochondria and oxidative enzymes?
What is endurance training?
Compare skeletal and smooth muscle contraction mechanisms.
Skeletal uses troponin; smooth uses calmodulin & myosin kinase.
Trace the complete flow of blood from right atrium to aorta.
RA → tricuspid → RV → pulmonary valve → pulmonary artery → lungs → pulmonary vein → LA → mitral → LV → aortic valve → aorta.
Explain preload, afterload, and contractility.
Preload: blood volume before contraction; Afterload: pressure to overcome; Contractility: strength of contraction.
What is the role of calmodulin in smooth muscle?
Binds Ca²⁺ and activates myosin light chain kinase for contraction.