Exs 323: Chap09 Circulatory

Vocabulary flashcards based on key terms related to the circulatory responses to exercise as discussed in the lecture.

Fascia

A connective tissue that surrounds muscles and organs.

Myofibrils

Cylindrical structures within muscle fibers containing myofilaments.

Sarcomere

The basic functional unit of a muscle fiber, bordered by Z-lines.

Excitation-Contraction Coupling

The process linking muscle excitation to contraction, involving action potentials and calcium release.

Calcium Ions (Ca2+)

Essential ions that trigger muscle contraction by binding to troponin.

Fast Fibers (Type 2x)

Muscle fibers characterized by low mitochondria content and high ATPase activity.

Slow Fibers (Type 1)

Muscle fibers with high resistance to fatigue and predominately aerobic energy system.

Cardiac Output (Q)

The amount of blood pumped by the heart per minute.

Heart Rate (HR)

The number of beats per minute of the heart.

Stroke Volume (SV)

The amount of blood ejected from the heart with each beat.

Mean Arterial Pressure (MAP)

The average pressure in a person's arteries during one cardiac cycle.

Vasodilation

The widening of blood vessels, increasing blood flow.

Vasoconstriction

The narrowing of blood vessels, decreasing blood flow.

Systole

The phase of the cardiac cycle when the heart contracts and pumps blood.

Diastole

The phase of the cardiac cycle when the heart relaxes and fills with blood.

Electrocardiogram (ECG or EKG)

A test that records the electrical activity of the heart.

Atrial Depolarization

The electrical activity that represents the contraction of the atria, seen as a P wave in ECG.

Ventricular Depolarization

The electrical activity that represents the contraction of the ventricles, seen as the QRS complex in ECG.

Ventricular Repolarization

The process of the ventricles recovering from contraction, represented by the T wave in ECG.

Baroreceptors

Sensors located in arteries that detect changes in blood pressure.

Nitric Oxide (NO)

A vasodilator produced in blood vessels that increases blood flow.

End-Diastolic Volume (EDV)

The volume of blood present in the ventricles at the end of diastole.

Afterload

The resistance the ventricles must overcome to eject blood.

Frank-Starling Mechanism

The relationship between stroke volume and end-diastolic volume, where greater volume leads to stronger contraction.

Ventricular Contraction (Contractility)

The strength of the ventricular contractions during systole.

Cardiac Output Equation

Q = HR x SV, describing the relationship between heart rate, stroke volume, and cardiac output.

VO2 max

The maximum rate of oxygen consumption measured during incremental exercise.