CIRCULATION AND
CARDIOVASCULAR SYSTEMS
TRANSPORT IN INVERTEBRATES
LEARNING OBJECTIVES
The student is able to use representations or
models to analyze quantitatively and qualitatively
the effects of disruptions to dynamic homeostasis in
biological systems.
The student is able to design a plan for collecting
data to support the scientific claim that the timing
and coordinator of physiological events involve
regulation.
ACADEMIC VOCABULARY
• Circulatory
system
• Open
circulatory
system
• Closed
circulatory
system
• Cardiovascular
system
• Heart
• Vessels
• Arteries
• Arterioles
• Capillaries
• Venules
• Veins
• Valves
• Cardiac cycle
• Systole
• Diastole
WHY DO ANIMALS NEED A CIRCULATORY SYSTEM?
WHY DO ANIMALS NEED A CIRCULATORY SYSTEM?
WHY DO ANIMALS NEED A CIRCULATORY SYSTEM?
• The metabolic needs of the
cells of many small animals are
met by direct exchange of
materials with the external
medium. The metabolic needs
of the cells of larger animals
are met by a circulatory system
that transports nutrients,
respiratory gases, and
metabolic wastes throughout
the body.
WHAT IS AN OPEN CIRCULATORY SYSTEM AND CLOSED
CIRCULATORY SYSTEM?
WHAT IS AN OPEN CIRCULATORY SYSTEM AND
CLOSED CIRCULATORY SYSTEM?
OPEN CIRCULATORY SYSTEMS
• Extracellular fluid leaves vessels and percolates through tissues.
CLOSED CIRCULATORY SYSTEMS
• The blood is contained in a systems of vessels. Closed circulatory
systems have several advantages, including the ability to selectively
direct blood, hormones, and nutrients to specific tissues.
HOW HAS THE VERTEBRATE CIRCULATORY SYSTEM EVOLVED?
HOW HAS THE VERTEBRATE CIRCULATORY SYSTEMS EVOLVED
• The circulatory systems of vertebrates consist
of a heart and a closed system of vessels
containing blood that is separate from the
interstitial fluid. Arteries and arterioles carry
blood from the heart; capillaries are the site
of exchange between blood and interstitial
fluid; venules and veins carry blood back to
the heart.
HOW HAS THE VERTEBRATE CIRCULATORY SYSTEMS
EVOLVED?
• The vertebrate heart evolved from two chambers in
fish to three in amphibians and reptiles and four in
crocodilians, mammals, and birds. This evolutionary
progression has led to an increasing separation of
blood that flows to the gas exchange organs and
blood that flows to the rest of the body.
HOW HAS THE VERTEBRATE CIRCULATORY SYSTEMS
EVOLVED?
• The simplest (twochambered heart) has an
atrium that receives blood
from the body, and a
ventricle that pumps blood
out of the heart. An aorta
distributes blood to arteries.
HOW HAS THE VERTEBRATE CIRCULATORY SYSTEMS
EVOLVED?
• In birds and mammals, blood
circulates through two
circuits: the pulmonary which
transports blood between the
heart and lungs, and the
systemic, which transports
oxygen-rich blood between
the heart and tissues
HOW HAS THE VERTEBRATE CIRCULATORY SYSTEMS EVOLVED?
HOW DOES THE MAMMALIAN HEART FUNCTION?
• The human heart has four chambers. Valves in
the heart prevent the backflow of blood.
• The cardiac cycle has two phases: systole, in
which the ventricles contract; and diastole, in
which the ventricles relax. The sequential
heart sounds (“lub-dub”) are made by the
closing of the heart valves.
CIRCULATION AND
CARDIOVASCULAR SYSTEMS