Name ______________________________The Heart: Notes

Function of the Circulatory System• Transportation system by which

______________________________________________________, and ____________________________________________________________________________.

• Also carries substances called ______________________, which control body processes, and ___________________________ to fight invading germs.

Three major parts– The ____________________ – The ____________________ – The _____________________________

Circulation• Two parts • Heart acts as _________________________________

– Blood from the _________________________ pump is _______________________ and ________________________________ (oxygen-poor)• Travels through ____________________________________________ where

it gets fresh oxygen and becomes ___________________________– Blood ___________________________ through

__________________________________ back to the heart's left side pump• Pumped out into the ________________

Three Kinds of Circulation:• Pulmonary circulation

– Movement of blood __________________________________________________________

• Coronary circulation– Movement of blood

__________________________________________________________ • Systemic circulation

– _________________________________________________________________ , except for the heart and lungs

The Heart’s Role in Blood Circulation• Systemic circulation

– Blood flows from the ______________ of the heart through the ___________ tissues and back to the ________________ of the heart

• Pulmonary circulation– Blood flows from the __________________ of the heart to the

_______________ and back to the ______________________ of the heart

Cardiac Circulation• Blood in the heart chambers does not nourish the myocardium• The heart has its own nourishing circulatory system consisting of

– ______________________________—branch from the aorta to supply the heart muscle with oxygenated blood

– ______________________________—drain the myocardium of blood– ______________________________—a large vein on the posterior of the heart,

receives blood from cardiac veins• Blood empties into the right atrium via the coronary sinus

The Heart• Location

• Thorax between the lungs in the inferior _____________________• Orientation

• Pointed apex directed toward left hip• Base points toward right shoulder

• About the ____________________________

Coverings• _____________________________—a double-walled sac

– Fibrous pericardium is loose and superficial– Serous membrane is deep to the fibrous pericardium and composed of

two layers

• _____________________________– Next to heart; also known as the epicardium

• _____________________________– Outside layer that lines the inner surface

of the fibrous pericardium– Serous fluid fills the space between the layers of pericardium

Wall• Three layers

– ________________________• Outside layer• This layer is the visceral pericardium• Connective tissue layer

– ________________________• Middle layer• Mostly cardiac muscle

– ________________________• Inner layer• Endothelium

Chambers• Right and left side act as separate pumps• Four chambers

– ______________• Receiving (_______) chambers

– Right atrium– Left atrium

– _________________• Discharging (_________) chambers

– Right ventricle– Left ventricle

Septum• _____________________ septum

– Separates the two ventricles• _____________________ septum

– Separates the two atria

Valves• Allow blood to flow in only one direction to prevent backflow• _____________ valves

– Atrioventricular (AV) valves—between atria and ventricles• _______________ (mitral) valve (_______ side of heart)• _______________ valve (__________ side of heart)

– Semilunar valves—between ventricle and artery• ___________________ semilunar valve• ___________________ semilunar valve

• AV valves – Anchored in place by ____________________________ (“heart strings”)

– __________________________________________ and closed during ventricular contraction

• Semilunar valves– __________________________________________ but open during ventricular

contraction• Notice these valves operate opposite of one another to force a one-way path of

blood through the heart

Heart Sounds• Heart sounds are _____________________________ as they open and close• Valves _______________________________ from one chamber to another• Prevent ____________________

Associated Great Vessels• Arteries

– _______________• Leaves left ventricle

– _____________________________• Leave right ventricle

• Veins– ____________________________________

• Enter right atrium– _______________________________ (four)

• Enter left atrium

Blood Flow Through the Heart• ______________________________________________________ dump blood into the

right atrium• From _______________________, through the _______________________, blood

travels to the right ventricle• From the ________________________, blood leaves the heart as it passes through

the ___________ _________________________________ into the pulmonary trunk• _________________________ splits into right and left

____________________________________ that carry blood to the lungs• Oxygen is picked up and carbon dioxide is dropped off by blood in the

__________________• Oxygen-rich blood returns to the heart through the four

________________________________• Blood enters the ______________________ and travels through the

__________________________ into the left ventricle• From the _______________________, blood leaves the heart via the

_________________________ valve and ___________________

How does the heart work?

Heart Beats (Lub Dub)• _______________________________________

– Group of cells on the ______________________________________ near the entrance of the superior vena cava

– “___________________” of the heart• _______________________________________

– Electrically ________________________________________________– Signals go from the ____________________ through the

____________________________ allowing the ventricles to contract