Circulatory System Lecture Notes

Vocabulary flashcards for the Circulatory System Lecture Notes.

Functions of the Circulatory System During Exercise

Delivers O₂ to muscles

Returns blood to lungs for reoxygenation

Transports heat from core to skin

Delivers fuel nutrients to active tissues

Two Circulatory Systems

Pulmonary (right side) and systemic (left side)

Heart Septum Function

Divides left and right sides to prevent blood mixing

what does an Echocardiogram measure?

Heart structure and function using ultrasound

Atrioventricular Valves

Prevent backflow of blood between atria and ventricles

Path of Blood Through Heart and Lungs

RA → RV → Pulmonary artery → Lungs → Pulmonary vein → LA → LV → Aorta → Body

Main Function of Arteries

Carry oxygenated blood away from the heart

Arterioles as Resistance Vessels

They regulate blood flow into capillaries via vasodilation/constriction

Capillaries Composition

A single layer of endothelial cells

Control of Blood Flow into Capillaries

Precapillary sphincter muscles

Reason for Slow Blood Flow in Capillaries

To allow efficient gas and nutrient exchange

Function of Venules

Collect blood from capillaries and merge into veins

Two Major Veins Returning Blood

Superior and inferior vena cava

Assistance to Venous Return

Skeletal muscle milking, Flap-like valves, Breathing action

Venous Pooling

Blood accumulation in lower extremities after exercise

Importance of Active Cool Down

Helps maintain venous return and prevents dizziness

Difference between Varicose and Spider Veins

Varicose = large, twisted veins; Spider = small, superficial veins

Blood Pressure Formula

BP = Cardiac Output × Total Peripheral Resistance

Systolic Pressure

Pressure during heart contraction

Diastolic Pressure

Pressure during heart relaxation

Normal Blood Pressure

Approximately 120/80 mmHg

Two Types of Stroke

Thrombotic (clot) and Hemorrhagic (bleed)

Hypertension

Chronic high blood pressure

Effect of Aerobic Exercise on Blood Pressure

Systolic increases, diastolic remains the same or slightly decreases

Conditioning Effect on Blood Pressure

Trained individuals have more efficient and lower BP responses

Blood Pressure During Resistance Training

Both systolic and diastolic can rise significantly

Effect of Body Inversion on Blood Pressure

Temporarily increases venous return and BP

Blood Pressure During Recovery

Gradually returns to resting levels

Aerobic Training Effect on Blood Pressure

Lowers resting and submaximal BP

Resistance Training Effect on Blood Pressure

Improves long-term control of blood pressure and vascular tone

Coronary Circulation

The heart’s own blood supply network

Heart's Reliance on Aerobic Metabolism

It has limited ability to generate energy anaerobically

Factors Increasing Coronary Blood Flow

Increased myocardial metabolism and aortic pressure

Myocardial Infarction

Heart attack caused by interrupted blood supply

Thrombus

A blood clot that can block coronary arteries

Estimation of Myocardial Workload

Rate-Pressure Product = HR × Systolic BP

Fuels Used by the Heart for Energy

Primarily fatty acids and glucose via aerobic metabolism

Structure Initiating Heart's Electrical Impulse

Sinoatrial (S-A) node

Atrioventricular (A-V) Node Function

Delays signal to allow full atrial contraction before ventricles

Impulse Conduction Through Ventricles

AV Bundle (Bundle of His) and Purkinje fibers

What does the P wave represent?

Atrial depolarization

what does the QRS Complex represent

Ventricular depolarization

what does the T Wave represent?

Ventricular repolarization

Effect of Sympathetic Stimulation on Heart

Increases heart rate and contractility via epinephrine/norepinephrine

Effect of Parasympathetic Stimulation

Decreases heart rate via acetylcholine

Adaptation to Endurance Training

Lower resting heart rate due to increased parasympathetic tone

Improvements with Cardiac Training

Stroke volume and heart efficiency

Anticipatory Heart Rate

HR increases before exercise due to brain input

Role of Nitric Oxide in Circulation

Acts as a vasodilator to enhance blood flow