Cardiovascular SystemCardiovascular System

Blood VesselsBlood Vessels

Heart Heart Organization and FunctionsOrganization and Functions

Blood VesselsBlood Vessels

Carries blood away from the

heart

Returns blood to the heart

Allows blood to reach tissues

Contains smooth muscle and

elastic tissue

Capillary ExchangeCapillary Exchange

•Balance of blood pressure and osmotic pressure Balance of blood pressure and osmotic pressure

controls flow of materials controls flow of materials•Water, Oxygen and Nutrients leave capillaryWater, Oxygen and Nutrients leave capillary at arterial end at arterial end •Diffusion of small molecules continues Diffusion of small molecules continues through middle of capillary through middle of capillary•Water, Carbon Dioxide and Wastes enter Water, Carbon Dioxide and Wastes enter capillary at venous end capillary at venous end

Blood Return Through Veins Blood Return Through Veins

• Skeletal muscles Skeletal muscles help return blood help return blood to the heartto the heart(skeletal muscle pump)(skeletal muscle pump)

• Valves prevent Valves prevent back-flowback-flow

• Pressure changes Pressure changes in respiration also in respiration also assist in moving assist in moving blood through blood through veinsveins(respiratory pump)(respiratory pump)

Heart Chambers and Valves

LeftLeftVentricleVentricle

RightRightAtriumAtrium

Right VentricleRight Ventricle SemilunarSemilunarValvesValves

Left AtriumLeft Atrium

AtrioventricularAtrioventricularValveValve

AtrioventricularAtrioventricularValveValve

Tissues of the HeartTissues of the Heart

Endocardium- liningEndocardium- lining

Myocardium- muscleMyocardium- muscle

Pericardium- outsidePericardium- outside

Layers of Heart TissueLayers of Heart Tissue

FibrousFibrouspericardiumpericardium

Visceral Visceral pericardiumpericardium

Cellular Structures of Cardiac MuscleCellular Structures of Cardiac Muscle

Intercalated disk: double membrane structure

where cardiac muscle fibers

are joined

Mitochondrion

Cardiac Muscle cell

Gap junctions of intercalated

disks allow simultaneous contraction of adjacent cells

The Cardiac CycleThe Cardiac Cycle

Atria ContractAtria Contract

DeoxygenatedDeoxygenatedblood from bodyblood from body

OxygenatedOxygenatedblood from lungsblood from lungs

Ventricles ContractVentricles Contract

DeoxygenatedDeoxygenatedblood to lungsblood to lungs

OxygenatedOxygenatedblood to bodyblood to body

Heart Relaxes;Heart Relaxes;atria fill passivelyatria fill passively

Connecting Vessels

AortaAorta

Descending AortaDescending Aorta(to lower body)(to lower body)

Inferior Vena CavaInferior Vena Cava(from lower body)(from lower body)

SuperiorSuperiorVena CavaVena Cava(from upper body)(from upper body)

Pulmonary ArteryPulmonary Artery(to right lung)(to right lung)

Pulmonary Artery Pulmonary Artery (to left lung)(to left lung)

Pulmonary VeinsPulmonary Veins(from right lung)(from right lung)

Pulmonary VeinsPulmonary Veins(from left lung)(from left lung)

Pulmonary and Systemic CircuitsPulmonary and Systemic Circuits

Circulates blood through

the lungs

Circulates blood through body tissues

Blood Vessels of the HeartBlood Vessels of the Heart

Coronary arteries (red) Coronary arteries (red) and cardiac veins (blue) and cardiac veins (blue) serve heart muscleserve heart muscle

Imaging methods can Imaging methods can detect blockages in detect blockages in coronary arteries coronary arteries

Control of Heartbeat

Sinoatrial (SA) Sinoatrial (SA) NodeNode

Atrioventricular Atrioventricular (AV) Node(AV) Node

PurkinjePurkinjeFibersFibers

SA Node = pacemaker, initiates atrial contraction

AV Node receives signals from SA node, sends signal through Purkinje fibers for ventricles to contract simultaneously

Heart FunctionHeart Function

Heartbeat Heartbeat visualized visualized with ECGwith ECG

Atria Contract

VentriclesRelax

Atria RelaxVentriclesContract

AtrioventricularValves Close“lubb” sound

SemilunarValves Close“dup” sound

Irregular heart rhythmIrregular heart rhythm

Ventricular fibrillationVentricular fibrillation

Blood PressureBlood Pressure

Blood pressure =Blood pressure =

Systolic pressureSystolic pressure

Diastolic pressureDiastolic pressure

Systolic: pressure during Systolic: pressure during ventricular contractionventricular contraction

Diastolic: pressure during Diastolic: pressure during ventricular relaxationventricular relaxation Normal blood pressureNormal blood pressure

Is below 120/80.Is below 120/80.

Disorders of the Cardiovascular SystemDisorders of the Cardiovascular System

• Hypertension: high blood pressureHypertension: high blood pressure• Atherosclerosis: buildup of plaque Atherosclerosis: buildup of plaque

deposits in blood vesselsdeposits in blood vessels• Stroke: loss of blood flow to brain tissue Stroke: loss of blood flow to brain tissue

due to blockage or bursting of blood due to blockage or bursting of blood vesselvessel

• Heart Attack: damage to heart tissue Heart Attack: damage to heart tissue due to lack of blood flowdue to lack of blood flow

Applying Your KnowledgeApplying Your Knowledge

A.A. Which structure receives blood returning Which structure receives blood returning from the lungs? from the lungs?

B.B. Which structure prevents blood from flowing Which structure prevents blood from flowing back into the ventricles?back into the ventricles?

C.C. Which structure pumps blood to the body Which structure pumps blood to the body (systemic) circuit?(systemic) circuit?

1.1. Left VentricleLeft Ventricle2.2. Semilunar ValveSemilunar Valve3.3. Right AtriumRight Atrium4.4. Left AtriumLeft Atrium5.5. Atrioventricular valveAtrioventricular valve

Functions of Blood Functions of Blood

1. Transport of gases, nutrients, 1. Transport of gases, nutrients, hormones hormones

Red blood cells transport oxygen Red blood cells transport oxygen and assist in carbon dioxide transportand assist in carbon dioxide transport

Red blood cells usuallyRed blood cells usually have a concave shape have a concave shapeRed blood cell from Red blood cell from

patient with patient with sickle-cell anemiasickle-cell anemia

Functions of Blood Functions of Blood

2. Defense: protection against2. Defense: protection against invaders invaders

White blood cells engulf invaders or White blood cells engulf invaders or produce substances to fight against themproduce substances to fight against them

Monocytes give riseMonocytes give riseto macrophagesto macrophages

Macrophages Macrophages engulf invadersengulf invaders

Functions of Blood Functions of Blood

2. Defense: protection against2. Defense: protection against invaders invaders

White blood cells engulf invaders or White blood cells engulf invaders or produce substances to fight against themproduce substances to fight against them

Lymphocytes target Lymphocytes target specific invaders specific invaders or infected cellsor infected cells

B lymphocytes produce antibodiesB lymphocytes produce antibodies against an invader against an invaderAntibodies mark the invader Antibodies mark the invader for destruction for destruction

T lymphocytes destroy body cellsT lymphocytes destroy body cellsthat are infected with the invaderthat are infected with the invader

Functions of Blood Functions of Blood

3. 3. Blood ClottingBlood Clotting–Platelets initiate Platelets initiate

the processthe process

–Clotting factors Clotting factors produce fibrin produce fibrin threadsthreads

1. Blood vessel is punctured.

2. Platelets congregate and form a plug.

3. Platelets and damaged tissuecells release prothrombinactivator, which initiates acascade of enzymatic reactions.

4. Fibrin threads form and trap red blood cells.

Prothrombin activator

Prothrombin

Ca2+

Ca2+

Thrombin

Fibrinogen Fibrin threads

fibrin threads

red blood cell

Functions of BloodFunctions of Blood

4. 4. Regulation of Regulation of –body temperaturebody temperature

–water/salt balancewater/salt balance

–pHpH

Plasma is responsible Plasma is responsible for these functions.for these functions.

plasma55%

cells, platelets45%

Percent by Volume

Water, 91%

Percent by Weight

Proteins, 7%

Solutes, 2% (ions,nutrients, wasteproducts, gases,hormones, vitamins)

Applying Your KnowledgeApplying Your Knowledge

A.A. Which one regulates blood pH? Which one regulates blood pH?

B.B. Which one fights foreign invaders?Which one fights foreign invaders?

C.C. Which one transports gases?Which one transports gases?

1.1. PlasmaPlasma

2.2. Red blood cellsRed blood cells

3.3. White blood cellsWhite blood cells