Transcript Figure 19.4E Gross anatomy of the heart

The Closed Circulatory System
•Humans have a closed circulatory system,
typical of all vertebrates, in which blood is
confined to vessels and is distinct from the
interstitial fluid.
–The heart pumps blood into large vessels
that branch into smaller ones leading into the organs.
–Materials are exchanged by diffusion between the
blood and the interstitial fluid bathing the cells.
The Cardiovascular System
•Three Major Elements –
Heart, Blood Vessels, &
Blood
–1. The Heart- cardiac
muscle tissue
–highly interconnected
cells
–four chambers
•Right atrium
•Right ventricle
•Left atrium
•Left ventricle
•Superior Vena Cava
Pathway of
•Right Atrium
blood
•Tricuspid Valve
•Right Ventricle
•Pulmonary Semilunar Valve
•Lungs
•Pulmonary Vein
•Bicuspid Valve
•Left Ventricle
•Aortic Semilunar Valve
•Aorta
•To the bodies organs & cells
the
Circuits
•Pulmonary circuit
–The blood pathway
between the right side of
the heart, to the lungs,
and back to the left side
of the heart.
•Systemic circuit
–The pathway between
the left and right sides of
the heart.
Figure 20.17A Pulmonary circulation
Figure 19.5 Systemic & pulmonary circuits
Blood from body enters
Right Atrium
Arteries carry blood AWAY
from the heart
Blood from lungs enters
Left Atrium
Right Ventricle sends blood
to lungs
Left Ventricle sends blood
to rest of body
Veins carry blood
to the heart
(like ven in Spanish)
The Cardiovascular System
Blood Vessels -A network of tubes
–Arteriesarterioles move away from the heart
•Elastic Fibers
•Circular Smooth Muscle
•Not always Red (notice the pulmonary artery carries blue blood deoxygenated blood)
–Capillaries – where gas exchange takes place.
•One cell thick
•Serves the Respiratory System
–VeinsVenules moves towards the heart
•Skeletal Muscles contract to force blood back from legs
•One way values
•When they break - varicose veins form
•Not always Blue (notice the pulmonary veins carry red blood –
oxygenated blood)
Figure 20.17B Pulmonary circulation
Figure 19.6 Anatomical differences in the right & left ventricles
Figure 19.9A Operation of atrioventricular valves of the heart
Figure 19.9B Operation of atrioventricular valves of the heart
The AV valves shown here are responsible for the Dub sound in the heart.
When the valves close, they slam together and make a dub sound.
Figure 19.10A Operation of semilunar valves
Figure 19.10B Operation of semilunar valves