Cardiovascular System

3 Major cardiovascular components

1. The heart (the pump)

2. Blood vessels/vasculature (pathways for blood)

3. Blood (transport medium)

3 Principal functions

1. Transports substances from one part of the body to another

2. Uses white blood cells to defend the body against foreign invaders

3. Uses blood clots to prevent fluid loss

2 Circulatory Loops

1. Pulmonary circulation: Blood flow between the heart and lungs

2. Systemic circulation: Blood flows between the heart and another body part

Describe the difference between arteries and veins

Arteries lead blood away from the heart chambers

Veins lead blood back toward the heart chambers

Mediastinum

Houses the heart, located in the thoracic cavity between the lungs

Pericardium parts and function

The pericardium is a sac surrounding the heart

It has pericardial fluid, with fills the cavity between layers

Anchors the heart, and the fluid reduces friction

Myocardium

Cardiac muscle

Endocardium

Lines vessels

Describe the difference between the pericardium, myocardium, and endocardium

Pericardium: A sac that surrounds the heart

Myocardium: Cardiac muscle that makes it beat

Endocardium: Tissues that line vessels

Atria

The two upper chambers that receive blood from veins

Describe the differences between the right and left atrium

Right: It receives low-oxygenated blood from the body (systematic)

Left: It receives high-oxygenated blood from the lungs (pulmonary)

Ventricles

Lower chambers that pump blood from the heart into arteries

Describe the right and left ventricles

Right: ¼” thick, pumps low-oxygenated blood into the body (systematic)

Left: 3/4’’ thick, pumps high-oxygenated blood into the lungs (pulmonary)

Describe the difference between the interatrial and interventricular septums

Interatrial: Separates the right and left atria

Interventricular: Separate the right and left ventricles

Valve’s function

Prevent backflow

List and describe the 4 valves

Tricuspid: Between the right atrium and right ventricle

Mitral/bicuspid: Between the left atrium and left ventricle

Aortic valve: Between the left ventricle and aorta

Pulmonary valve: Between the right ventricle and pulmonary trunk

Large arteries are…

Elastic and recoil

The superior and inferior vena cava leads…

into the right atrium

The pulmonary trunk leads…

From the right ventricle and branches into right and left pulmonary arteries

The left and right pulmonary veins lead….

From the lungs and into the left atrium

The aorta leads…

from the left ventricle

Specialized heart muscle cell function

Initiate action potential

Make up the conduction system

SA node function

The heart’s natural pacemaker

AV node function

An area of specialized tissue between the atria and ventricles of the hear

What doe AV bundles, R/L bundle branches, and Purjunke fibers have in common?

These are large-diameter fibers that rapidly conduct impulses to all parts of the ventricles

Sympathetic and parasympathetic stimulations stem from _____ control

Autonomic

Sympathetic stimulation

T1-T5

Increases the heart rate of muscle contraction.

Norepinephrine is the neurotransmitter

Parasympathetic stimulation

Decreases the heart rate and the strength of muscle contraction

Acetylcholine is the neurotransmitter

Echocardiogram

Records of electrical activity within the heart.

Provide info on heart’s tilt, rate, rhythm, myocardium thickness, and conduction issues

Describe the differences between systole and diastole

Systole is the period of heart/chamber contraction

Diastole is the period of heart/chamber relaxation

Atrial systole is followed by ____ systole

Ventricular

Cardiac Output (CO) equation

Heart rate (HR) x Stroke Volume (SV)

How is the heart rate measured?

By the number of heart contractions per minute