Cardiovascular Systemheart and blood vessels

Systemic Circulation – delivers blood to all body cells and carries away wastePulmonary Circulation – eliminates carbon dioxide and oxygenates blood (lung pathway)

Structure of the HeartHeart Size – about 14 cm x 9 cm (the size of a fist). Located in the mediastinum (space between lungs, backbone, sternum), The distal end of the heart is called the apex.

Fibrous Pericardium encloses the heart (like a bag) and has 2 layers

•visceral pericardium (inner)

•and parietal pericardium (outer, attached to diaphragm, sternum and vertebrae)

Pericardial cavity – contains fluid for the heart to float in, reducing frictionWall of the Heart

Epicardium – outer layer, reduces frictionMyocardium – middle layer, mostly cardiac muscleEndocardium – thin inner lining, within chambers of the heart

Heart Chambers & Valves•Your heart is a double pump. Circulation

is a double circuit: Pulmonary (lungs only) and systemic (rest of the body)

•Heart has 4 chambers: o2 Atria – thin upper chambers that receive blood

returning to the heart through veins.. Right and Left Atrium

o2 Ventricles – thick, muscular lower chambers. Receive blood from the atria above them. Force (pump) blood out of the heart through arteries. Right and left ventricle.

•Septum – separates the right and left sides of the heart

•Valves of the Heart – allow one-way flow of blood. 4 total

•(2 Atrioventricular Valves (AV) & 2 Semilunar valves) oLeft Atrioventricular valve – also called the bicuspid

valve or mitral valve. Between left atrium and ventricleoRight Atrioventricular valve – also called the tricuspid

valve. Between right atrium and ventricle

•Aortic Semilunar – or just aortic valve. Between the left ventricle and the aorta

•Pulmonary Semilunar, or just pulmonary valve. Between the right ventricle and the pulmonary artery.

Mitral = bicuspid (left side)Tricuspid (right side)

Aortic and Pulmonary are both semilunar valves

Check your labels!

Heart Actions•Cardiac Cycle: One complete heartbeat. The

contraction of a heart chamber is called systole and the relaxation of a chamber is called diastole.

•The beginning of ventricular systole- lub•The end of ventricular systole- dub•http://www.youtube.com/watch?v=riDPxasIz_I

Blood pressure is the force of blood against the walls of arteries.

Blood pressure is recorded as two numbers—the systolic pressure (as the heart beats) over the diastolic pressure (as the heart relaxes between beats). 

The average (normal) blood pressure for an adult is 120/80.  This number varies by person and it is best if you know what is *normal* for you, so that you (or your doctor) recognize when something is not normal. 

SPHYGMOMANOMETER

The cusps (flaps) of the bicuspid and tricuspid valves are anchored to the ventricle walls by fibrous “cords” called chordae tendineae, which attach to the wall by papillary muscles. This prevents the valves from being pushed up into the atria during ventricular systole.

Can you identify these parts?

Animation of Heart Contraction

http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter22/animation__the_cardiac_cycle__quiz_1_.html

13.4  BLOOD VESSELS

Blood Vessels:  arteries, veins, capillaries

ARTERIES :  strong elastic vessels which carry blood moving away from the heart.   Smallest ones are arterioles which connect to capillaries.

 VEINS - Thinner, less muscular vessels carrying blood toward the heart.  Smallest ones are called venules which connect to capillaries.  Contain valves.

Capillaries:  Penetrate nearly all tissues.  Walls are composed of a single layer of squamous cells – very thin.  Critical function: allows exchange of materials (oxygen, nutrients) between blood and tissues.

Blood Clots can occur if blood does not flow properly through the veins - can occur if a person does not move enough

Major Blood Vessels Aorta  -  Ascending Aorta, Aortic Arch, Descending Aorta, Abdominal Aorta.  The aorta is the largest artery. (leaves  left ventricle) Pulmonary Trunk – splits into left and right, both lead to the lungs (leaves left ventricle) Pulmonary Veins – return blood from the lungs to the heart (connects to left atrium)

   Superior and Inferior Vena Cava – return blood from the head and body to the heart (connects to right atrium)