Anatomy and Physiology 3: Muscle and Heart Review

Comprehensive vocabulary flashcards covering skeletal muscle anatomy, excitation-contraction coupling, heart anatomy, and circulatory pathways based on lecture notes.

Epimysium

The connective tissue that surrounds the entire muscle.

Perimysium

The connective tissue that surrounds groups of muscle cells known as fasicles.

Endomysium

The connective tissue that surrounds an individual muscle cell or myofiber.

Fasicle

A group of muscle cells within a muscle.

Sarcolemma

The plasma membrane of a muscle cell or fiber.

Sarcoplasm

The cytoplasm of a muscle cell.

Myofibril

An organelle within the muscle cell that contains actin and myosin filaments.

Myosin

A contractile protein that makes up thick filaments and has binding sites for both Actin and ATP.

Actin

A contractile protein that makes up thin filaments and has binding sites for Myosin.

Tropomyosin

A regulatory protein that, in a resting state, blocks the Myosin binding site on the Actin.

Troponin

A regulatory protein in skeletal muscle that holds Tropomyosin in place and binds with Calcium during contraction.

Calmodulin

The protein that replaces troponin in smooth muscle.

T-tubules

Many thin channels in the sarcolemma that dive deep into the muscle fiber.

Terminal Cisterns

Areas in the sarcoplasmic reticulum where T-tubules terminate and where a huge amount of Calcium is stored.

Depolarization

The process of making a cell more positive, such as when Na+ enters a muscle cell after Acetylcholine (ACH) binds to receptors.

Sliding Filament Mechanism

The process where myosin heads engage actin and generate a power stroke to pull actin across myosin if ATP is available.

Sarcomere

The basic functional unit of skeletal muscle represented by the areas of overlap between actin and myosin.

Mediastinum

The specific area within the thoracic cavity where the heart is located.

Endocardium

The innermost layer of heart tissue.

Myocardium

The middle layer of heart tissue, specifically the heart muscle.

Epicardium

The outermost layer of the heart, also known as the visceral pericardium.

Superior Vena Cava

A vessel that brings blood from the head and arms into the Right Atrium.

Inferior Vena Cava

A vessel that brings blood from the trunk and legs into the Right Atrium.

Coronary Sinus

One of the three vessels (along with the Vena Cavas) that bring blood into the Right Atrium.

Pulmonary Trunk

The vessel that takes blood out of the Right Ventricle and leads to the Left and Right Pulmonary Arteries.

Aorta

The large vessel that takes blood out of the Left Ventricle to the rest of the body.

Tricuspid Valve

The valve that separates the Right Atrium from the Right Ventricle.

Bicuspid Valve (Mitral Valve)

The valve that separates the Left Atrium from the Left Ventricle.

Semilunar Valves

A collective term for the Pulmonary and Aortic valves.

Chordae Tendonae

Structures attached to the underside of the Tricuspid and Mitral valves that connect to Papillary muscles.

Systole

The contraction phase of a heart chamber.

Diastole

The relaxation phase of a heart chamber.

S1

The heart sound produced by the closing of the atrioventricular (AV) valves.

S2

The heart sound produced by the closing of the semilunar valves.

Venous Return

The volume of blood returning to the right atrium per minute.

Cardiac Output (CO)

The volume of blood ejected from the left ventricle per minute, calculated as $CO = SV \times HR$.

Systemic Circulation Pathway

Left Ventricle $\rightarrow$ Aorta $\rightarrow$ Arteries $\rightarrow$ Arterioles $\rightarrow$ Capillaries $\rightarrow$ Venules $\rightarrow$ Veins $\rightarrow$ Vena Cava $\rightarrow$ Right Atrium.

Pulmonary Circulation Pathway

Right Ventricle $\rightarrow$ Pulmonary Trunk/Arteries $\rightarrow$ Lungs $\rightarrow$ Pulmonary Veins $\rightarrow$ Left Atrium.