Download Circulatory system function

Bundle of His
R
T
P
Q S
Atrial systole
P wave
Ventricular systole
QRS wave
http://www-medlib.med.utah.edu/kw/pharm/hyper_heart1.html
Sinoatrial node (PACEMAKER)
Generates electrical impulses that initiate
heartbeats.
CARDIAC CYCLE:
Diastole: Relaxation of atria and ventricles
Systole: Contraction of atria and ventricles
Circulatory system function
Digested food (as glucose) and fuel to
cook the food (oxygen) need to be carried
to every cell of the body for metabolism.
Evolution of the heart
Circulatory system
Open (Mollusks and arthropods):
Hemolymph (blood) flows through a system of
channels and cavities.
Closed (from annelids on):
Circulating fluid always enclosed within vessels that
transport blood to and from a pump (heart).
Open vs Closed
Circuits
• Pulmonary: Circulation between heart
and lungs.
• Systemic: Circulation between heart
and rest of body.
Semilunar valve
ventricle
Tricuspid valve
Semilunar valve
ventricle
Tricuspid valve
Blood vessels
• Arteries: Blood leaving heart.
Branch out to arterioles and then
capillaries.
• Veins: Blood returning to heart.
After gas exchange, blood is collected
in venules leading to veins.
Check your homework after reading this slide!
Arteries comprised of 3 layers and made up of elastic fibers.
Fat in aorta acts as shock absorber.
Composition of blood
PLASMA: extracellular environment
(proteins, ions, hormones, etc.)
BLOOD CELLS
• Erythrocytes (RBC): Oxygen transport
• Leukocytes (WBC): Immunological
defense
• Platelets: Blood clotting
Erythocytes = red; platelets = yellow; T-lymphocyte = light green (SEM x 9,900).
Copyright Dennis Kunkel, www.DennisKunkel.com