Transcript Chp.6 Circulatory System 1

Circulatory System
Also referred to as cardiovascular or
vascular system; controls the steady
circulation of blood
Blood-vascular System
• Consists of heart and blood vessels (arteries,
capillaries and veins) for circulation of
blood
Lymph-vascular (Lymphatic)
System
• Consists of lymph glands and vessels
through which lymph circulates
• Lymph is derived from blood and gradually
shifted back into bloodstream
Heart
Heart is muscular
Conical-shaped
Organ about size of a
closed fist
Weighs approximately
9 ounces
Located in the chest cavity
Heart
• Pericardium
– Membrane which encloses the heart
• Resting heart rate
– Normally about 72-80- times a minute
• Vagus
– Tenth cranial nerve
• Helps regulate heartbeat
• Autonomic Nervous system
– Also helps regulate the heartbeat with the vagus
Chambers and valves of heart
interior
• Right and left atrium
– Also called auricle
– Upper, thin-walled chambers
• Right and left ventricle
– Lower thick-walled chambers
Chambers and valves of heart
interior
• Valves
– Allow blood to flow in only one direction
• Atria
– When heart contracts and relaxes,the blood
flows in, traveling from the atria to the
ventricles; it’s then driven out to be distributed
throughout the body
Blood circulation
• The blood is in constant and continuous
circulation from leaving the heart upon
returning to the heart
Blood circulation
• Pulmonary circulation
– Brings blood from heart to lungs to be purified
• System or general circulation
– Carries blood from heart throughout body and
back to heart as follows:
• Blood flows atrium, flows through the tricuspid
valve into right ventricle
Blood circulation
con’t
– Right ventricle pumps blood to lungs where it
releases waste gases and receives oxygen;
blood is then oxygen rich
– Oxygen-rich blood returns to heart, entering the
left atrium
– From left atrium, blood flows through the
mitral valve into left ventricle
– Blood then leaves left ventricle and travels to
all body parts