Functional Anatomy of the Cardiovascular System

Collateral Circulation

Alternate blood flow pathways

Blood Stroke Volume

Amount of blood squeezed from apex to base

Heart Chambers

Atria and ventricles of the heart

Mean Arterial Pressure

Average pressure in the arteries

Local Control

Blood flow regulation based on tissue metabolic rate

Coronary Arteries

Blood vessels that supply the heart

Vascular System

Blood vessels that transport blood throughout the body

AV Bundle

Bundle of His that conducts electrical impulse to the ventricles

Sarcolemma

Cell membrane of a muscle fiber

Myofibril

Contractile component of muscle fiber

Myosin and Actin

Contractile proteins in muscle fibers

Ventricular Emptying

Contraction and ejection of blood from the ventricles

Vascular System Regulation

Control of blood flow through local and central mechanisms

Central Control

Control of blood flow through the autonomic nervous system

Atrioventricular Node

Delays electrical impulse from atria to ventricles

Pulse Pressure

Difference between systolic and diastolic blood pressure

Bundle Branches

Divisions of the AV bundle

Right Coronary Artery

Dominant blood supplier to the heart

Consequences of Septal Defects

Effects of abnormalities in the septum

Titin

Elastic protein that tethers myosin fiber to Z-line

T-Tubules

Extensions of the sarcolemma that transmit electrical impulses

Determinants of Blood Pressure

Factors that affect systolic and diastolic blood pressure

Regulation of Pumping Activity

Factors that control the force and rate of heart contractions

Cardiac Skeleton

Fibrous annuli and valvular function

Perfusion Pressure

Forces responsible for blood flow through the vessels

Gross Anatomy of the Heart

Heart location and external features

Hypertension

High blood pressure with detrimental effects

Venous Reservoir

Highly distensible veins that store blood

Renin-Angiotensin-Aldosterone

Hormonal regulation of blood volume and pressure

Atrial Natriuretic Peptide

Hormone that promotes diuresis and lowers blood pressure

Antidiuretic Hormone

Hormone that regulates water reabsorption and blood volume

Frank-Starling Mechanism

Increased sarcomere length leads to increased cross-bridge cycling and stronger contraction

Respiratory Vagal Stimulation

Influence of respiration on heart rate

Heart Wall

Layers of the heart: epicardium, myocardium, endocardium

Pericardium

Loose-fitting membranous sac surrounding the heart

Cardiac Muscle Syncytium

Muscle mass acts as one fiber, all fibers contract together

Sarcoplasmic Reticulum

Network of tubules that store calcium ions

Mitochondria

Organelles that generate ATP for muscle contraction

Spiral Arrangement of Muscle Fibers

Orientation of muscle fibers in the heart

Intraatrial Septum

Partition between the atria

Intraventricular Septum

Partition between the ventricles

Ventricular Filling

Passive and atrial contraction phases of filling

Ejection Fraction

Percentage of blood ejected from the ventricles

Oxygen Extraction

Percentage of oxygen extracted from coronary blood

Hematocrit

Percentage of red blood cells in the blood

Isovolumetric Contraction

Phase of ventricular contraction with all valves closed

Ventricular Relaxation

Phase of ventricular relaxation with all valves closed

Central Venous Pressure

Pressure in the central veins

Peripheral Venous Pressure

Pressure in the peripheral veins

Right Atrial Pressure

Pressure in the right atrium

Arterial Blood Pressure

Pressure of blood in the arteries

Sinoatrial Node

Primary pacemaker of the heart

Cardiac Muscle Contraction

Process of muscle fiber contraction in the heart

Venous Characteristics

Properties of veins and venous return

Ventricular Outflow

Pulmonary and aortic valves

Right Atrium

Receives deoxygenated blood from superior vena cava, inferior vena cava, and coronary sinus

Left Atrium

Receives oxygenated blood from pulmonary veins

Baroreceptor Reflex

Reflex response to changes in blood pressure

Left Ventricular Afterload

Resistance faced by the left ventricle during ejection

Systemic Vascular Resistance

Resistance to blood flow in the systemic circulation

Afterload

Resistance to ejection of blood from the ventricles

Venous Return

Return of blood to the heart from the veins

Vasomotion

Rhythmic contraction and relaxation of blood vessels

Sarcomere

Segment of a myofibril between two Z-lines

Cardiac Cycle

Sequence of events in one heartbeat

Purkinje Fibers

Specialized cardiac muscle fibers that rapidly transmit electrical impulses

Cardiac Conduction System

Specialized cardiac muscle tissue responsible for electrical conduction

Autonomic Stimulation

Sympathetic and parasympathetic control of heart rate

Diastolic Time

Time during which coronary blood flow occurs

Atrial-Ventricular Valves

Tricuspid and mitral valves

Heart Valve Function

Valve opening and closing during the cardiac cycle

Semilunar Valves

Valves that close during ventricular relaxation

Coronary Veins

Veins that parallel coronary arteries and empty into the right atrium

Jugular Venous Distension

Visible bulging of the jugular veins

Stroke Volume

Volume of blood ejected with each heartbeat

Vasodilation

Widening of blood vessels