Download Cardiovascular-System

The Human
Cardiovascular System
*In preparation for a pig’s heart dissection
Larry M. Frolich, Ph.D.,Human Anatomy
Location of Heart
in Thorax
CV System Function:
Circulate blood through entire body for
•
•
•
•
Transport of oxygen to cells
Transport of CO2 away from cells
Transport of nutrients (glucose) to cells
Movement of immune system components
(cells, antibodies)
• Transport of hormones
How?
• Heart is pump
• Diffusion in
capillaries
Veins = Return
Arteries = Away
Artery/Vein Differences
Arteries
Direction Blood Away from
of flow
Heart
Pressure Higher
Veins
Blood to Heart
Walls
Lumen
THICKER: Tunica
media thicker than
tunica externa
Smaller
THINNER: Tunica
externa thicker
than tunica media
Larger
Valves
No valves
Valves (see next)
Lower
Capillaries
• Microscopic: 1 cell thick
• Network
• Entire goal of C-V system is
to get blood into capillaries
where diffusion takes place
GREAT VESSELS
•Aorta
•IVC, SVC
•Pulmonary Trunk
•Pulmonary Veins
2 Circulatory Paths
heartarteries arterioles


veinsvenules capillaries
Systemic
Pulmonary
Heart Chambers and Valves
Larry M. Frolich, Ph.D.,Human
Anatomy
Right Heart Chambers: Pulmonary Circuit
• Right Atrium (forms most of posterior of heart)
– Receives O2-poor blood from body via IVC,
SVC, Coronary sinus
• Right Ventricle
– Receives O2-poor blood from right atrium
through tricuspid valve
– Pumps blood to lungs via Pulmonary Semilunar
Valve in pulmonary trunk
– Septum
Left Heart Chambers: Systemic Circuit
• Left Atrium
– Receives O2-rich blood from 4 Pulmonary Veins
• Left Ventricle (forms apex of heart)
– Receives blood from Left Atrium via bicuspid valve
– Pumps blood into aorta via Aortic Semilunar
Valve to body
Heart Valves: Lub*-Dub**
• *Tricuspid Valve: Right AV valve
– 3 Cusps (flaps) made of endocardium and CT
– Flow of blood pushes cusps open
– When ventricle in diastole (relaxed), cusps hang limp in ventricle
– Ventricular contraction increases pressure and forces cusps closed
• *Bicuspid (Mitral) Valve: Left AV valve
– 2 cusps anchored in Lft.
Functions same as Rt. AV valve
• **Semilunar valves: prevents backflow in lg arteries
-Pulmonary Semilunar Valve: RV & Pulmonary Trunk
-Aortic Semilunar Valve: LV & Aorta
-3 cusps: blood rushes past they’re flattened, as it settles
they’re pushed down (valve closed)
Chamber contraction/relaxation
Blood supply to heart wall