Major portion of the heart

Made largely of cardiac muscle

Thickest portion of the heart

Cavities in an organ

-strongest pumping chambers

(vs atria)

Structure that opens & closes ensuring one-way flow

-prevents backflow

Recieves O2 rich blood (from lungs)

-pulmonary veins carry blood from lungs

-bicuspid valve seperates the Left Atrium from the Left Ventricle

Mitral valve

-AV valve between the Left Atrium & Left Ventricle

-seperates

Carries O2 rich blood from the lungs to the Left Atrium

Artery that supplies blood to the wall of the heart (myocardium)

Sinoatrial Node

-initiates the heartbeat

-sends out an excitation impulse every 0.85 seconds

-called the 'pacemaker' of the heart

-if SA node fails, artificial pacemaker may be implanted

The primary structural components of cardiac muscle cells; which allow for electrical current to flow from cell to cell

CO-the volume of blood pumped out of a ventricle in 1 minute

Dependent on:

-heartrate/beats per minute

-stroke volume- amount of blood pumped by a ventricle each time it contracts

Due to valves closing

-first sound-LUB, heard when ventricle contracts, lasts longer, lower pitch

-second sound-DUP, when ventricles relax

LUB-DUP

A heartbeat above 100 beats per minute

All events that occur during one heartbeat

-systole

-diastole

Contraction of heart muscle

Relaxation of heart muscle

Microscopic blood vessels

-one layer endothelial cells

-site of nutrient & gas exchange

Small arteries

-constriction & dialation affect blood distribution & blood pressure

-ANS regulates # of arterioles contracted

Small veins

-drain blood from capillaries

-join together to form veins

Transport blood AWAY from the heart

-thick, strong walls

-elasticity allows an artery to expand & recoil

Carry blood to the heart "visiting"

-walls thinner than arterial walls

-have valves to prevent backflow

The force of blood against blood vessel walls

-accounts for blood flow in the arteries

-greatest in arteries (& aorta)

-lowest in the inferior & superior vena cavas

The resistance to flow between blood & the walls of a blood vessel

-the smaller/longer the blood vessel the greater the resistance

-higher the resistance, higher the blood pressure

Includes all other arteries & veins of the whole body

Involves the lungs primarily

Goes to the stomach

Goes to the leg

Drains blood from the head & neck