[Medterm] Cardiovascular System Part 1

Cardiovascular System

omposed of the heart and blood vessels. The heart is a hollow, muscular organ lying in the mediastinum, the center of the thoracic cavity between the lungs.

transport blood as a vehicle

major function of cardiovascular system

pumping action of the heart

propels blood that contains Oxygen (O2), nutrients, and other vital products from the heart to body cells through a vast network of blood vessels called arteries

Arteries branch into smaller vessels until they become microscopic vessels (capillaries)

Capillaries exchange of products between body cells and blood

Capillaries merges

they form Arterioles / Venules

venules combines

they form Arteries / veins (returns blood to the heart to begin the cycle again)

Process of exchange of products between body cells and blood

mediastinum in the thoracic cavity

location of the heart

Pericardium

- tough membrane that separates the heart from other mediastinal structures

- pericardial sac

- membranes that surrounds the heart and the roots of the great vessels

Great vessels

carry blood to and the heart, are attached to the superior surface of the heart

base

superior surface of the heart

apex

- inferior tip of the heart

- lies just to the left of the sternum between the junction of the 4th & 5th ribs

Outer serous pericardium

fibrous and sturdy, made of tough , dense connective tissue and holds heart in position

Inner serous pericardium

- contains pericardial fluid

- has two layers

outer parietal pericardium

inner visceral pericardium

two layers of inner serous pericardium

outer parietal pericardium

fused to the fibrous pericardium

inner visceral pericardium

- epicardium

- fused to the heart and forms the outer layer of the heart wall

epicardium

myocardium

endocardium

3 layers of heart wall

Epicardium

- visceral pericardium

- outer layer of heart wall

Myocardium

thick, middle part that is made of muscle tissue and gives the heart its ability to contract

Endocardium

inner part that lines the heart chambers and is the main component of the heart valves.

Right atrium

Left atrium

Right ventricle

Left ventricle

Four chambers of the heart

Atria

upper chambers of the heart

Ventricles

lower chambers of the heart

Atrioventricular valve (AV)

separates each side of the heart atrium and ventricle

Right AV valve or tricuspid valve

separates the right atrium and right ventricles

Left AV or bicuspid valve (mitral valve)

separates the left ventricle and left atrium.

Two semilunar valves

valves leading into the pulmonary artery and the aorta have three cups

Pulmonary/Pulmonic valve

separates the right ventricle from the pulmonary trunk

Aortic valve

separates the left ventricle from the aorta

leaflets

flat, leaf-shaped structures that comprise the valves of the heart and prevent the backflow of blood

lumen

tubular space or channel within an organ or structure of the body; space within an artery, vein, intestine, or tube

regurgitation

backflow or ejecting of contents through an opening

sphincters

circular muscles found in a tubular structure or hollow organ that constrict or dilate to regulate passage of substances through its opening

vasoconstriction

narrowing of the lumen of a blood vessel that limits blood flow, usually as a result of diseases, medications, or physiological processes

vasodilation

widening of the lumen of a blood vessel caused by the relaxing of the muscles of the vascular walls

viscosity

thickness or a measure of how resistant a liquid is to flowing

Cardiac Cycle

The process of pumping and circulating blood is active, coordinated and rhythmic.

Each heartbeat represents one cycle of the heart receiving blood and ejecting blood

Systole

portion of heart cycle in which the heart contracts

Diastole

portion of the heart cycle in which the heart is relaxed

Sytemic Circulation

Left ventricle pumps oxygen-rich blood into the main artery(aorta) -> blood travels to larger and smaller arteries and into the capillary network- blood drops oxygen.nutrients and other substances & picks up carbon dioxide and waste products. -> blood now low in oxygen, is collected in veins & travels to the right atrium & into the right ventricle

type of circulation provides organs, tissues and cells with blood so that they get oxygen and other vital substances?

Pulmonary Circulation

Right ventricle pumps low oxygen blood into the pulmonary artery -> branches into smaller and smaller arteries and capillaries. Capillaries form a fine network around the pulmonary vesicles. -> Carbon dioxide is released from the blood into the air inside the pulmonary vesicles, and fresh oxygen enters the blood stream.

When we breathe out, CO2 leaves our body

Conduction tissues

initiating and spreading contraction impulses. This tissue consists of the following four masses of highly specialized cells that possess characteristics of both nervous and cardiac tissue:

Sinoatrial (SA) node

Atrioventricular (AV) mode

bundle of His (AV bundle)

Purkinje fibers

Four masses of highly specialized cells

Sinoatrial (SA) node

located in upper portion of the right atrium and possesses its own intrinsic rhythm. Commonly known as the pacemaker of the heart.

Atrioventricular (AV) mode

causes atria to contract,located at the base of the right atrium

bundle of His (AV bundle)

relays the impulse to the Purkinje fibers

Purkinje fibers

transmit the impulse to the right and left ventricles, causing them to contract

Impulse transmission through the conduction system

generates weak electrical impulses on the surface of the body.

Electrocardiograph (ECG)

instrument that record electrical impulses of conduction system of the heart on graph paper

P wave

depolarization (contraction) of the atria

QRS complexes

depolarization (contraction) of the ventricles

T waves

repolarization (recovery) of the ventricles

Blood Pressure

the force exerted by blood against the arterial walls during two phases of a heartbeat: systole and diastole

systole

contraction phase

diastole

relaxation phase

Sphygmomanometer

measures blood pressure

resistance of blood flow in blood vessels

pumping action of the heart

viscosity of blood

elasticity of arteries

quantity of blood in the vascular system

Factor that influences BP

Arteries

Capillary

Vein

Three Major Types of vessels in the Vascular System

Arteries

Carry blood from the heart to all cells in the body

Capillary

- Microscopic vessels that join the arterial system with the venous system

Vein

- It returns blood to the heart

- they are formed from smaller vessels (venules)

- carries oxygen with low concentration and co2 with higher concentration (except for the blood during pulmonary circulation)

Tunica Externa

outer coat,composed of connective tissue that provides strength and flexibity

Tunica Media

middle layer ,composed of smooth muscle.

this muscle can alter the size of the lumen of the vessel. When it contracts, this causes vasoconstriction, resulting decreased blood flow.

When it relaxes, it causes vasodilation , resulting in increased blood flow

Tunica Intima

thin, inner lining of lumen of the vessel, composed of endothelial cells that provide a smooth surface on the inside of the vessel

Pulse

surge of blood felt in the arteries when blood is pumped from the heart

Capillary walls

are composed of only a thin single layer of endothelial cells which enables the exchange of water, respiratory gases, macromolecules, metabolites and wastes between the blood and the cells adjacent to the capillary bed

Sphincters

regulates the blood flow so that it is slow and intermittent

-skeletal muscle contraction

-gravity

-respiratory activity

-valves

Methods of returning blood to the heart

Valves of the veins

-small structures within the veins that prevent the backflow of blood.

-found mainly in the extremities

S1

"lub" caused by the closing of the AV valves

S2

"dub" caused by the closing of semilunar valves

S3

linked with flow of blood into the ventricles

S4

linked with atrial contraction

aneurysm/o

widened blood vessel

aneurysm/o/rrhaphy

suture of an aneurysm

angi/o or vascul/o

vessel (usually blood or lymph)

angi/o/plasty

procedure that reopens narrowed blood vessels and restores blood flow using a balloon-tipped catheter

vasculitis

inflammation of vessel

aort/a

aorta

aortastenosis

narrowing of aorta

arteri/o

artery

arteriorrhexis

rupture of an artery

arteriol/o

arteriole

arteriolitis

inflammation of an arteriole

atri/o

atrium

atriomegaly

enlargement of the atrium

ather/o

fatty plaque

atheroma

formed when fatty plaque builds up on the inner lining of arterial walls

cardi/o or coron/o

heart

cardiomegaly

enlargement of the heart

coronary

pertaining to heart

electr/o

electricity

electrocardiogram

helps detect many heart problems including heart attacks, arrhythmias, and heart failure

embo/o

embolus (plug)

embolectomy

performed in emergency situations to open blood vessels and reestablish blood flow

hemangi/o

blood vessel

Hemangiomas

also called strawberry marks and found mostly in neonates, are benign tumors of cells that line blood vessels and usually disappear over time

my/o

muscle

myocardial

pertaining to the muscle of the heart

phleb/o and ven/o

vein

phlebectasis

or venostasis

is an abnormally slow blood flow in the veins and is a major risk factor for clot formation

scler/o

hardening