Cardiovascular System
The components to this system
 Heart
 Blood vessels
 Blood
Heart
 The heart is a hollow, cone-shaped muscular organ located behind
and slightly to the left of the sternum or breastbone. Nestled
between the lungs, the heart sits within a protective, bony cage
formed by the sternum, ribs, and spine. The lower tip of the
heart, called the apex, points toward the left hip and rests
on the diaphragm (a membrane of muscle separating the
chest cavity from the abdominal cavity). The upper
portion of the heart, called the base, points toward the
right shoulder and lies beneath the second rib. It is from
the base that the major blood vessels of the body emerge.
 The heart is about the size of a clenched fist. At birth, an infant's
heart and fist are about the same size. As a human body develops,
the heart and fist grow at about the same rate. In adults, an average
heart weighs between 9 and 11 ounces (255 and 310 grams). It is
slightly larger in males than in females.
Heart
 The heart is divided into four chambers. A muscular
septum or partition divides it into a left and right side. Each
side is further divided into an upper and lower chamber. The
upper chambers, the atria are thin-walled. They are the
receiving chambers of the heart. Blood flows into them from
the body, which they then pump to the ventricles, the
lower heart chambers. The ventricles are the discharging
chambers of the heart. Their walls are thicker and contain
more cardiac muscle than the walls of the atria. This enables
the ventricles to contract and pump blood out of the heart to
the lungs and the rest of the body.
Pericardium
Remember the pericardium – the enclosed sack that the heart
is kept in. Major function, to prevents the heart from over
expanding when blood volume increases.
Do turtles have a pericardium???
I want you to figure this out today when you are in your
dissection, be able to explain your reasoning.
Blood Vessels
 The blood vessels form a closed transport system of tubes measuring
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about 60,000 miles (96,500 kilometers) in length—more than twice the
distance around the equator of Earth. We are going to break blood
vessels into arteries and veins.
Arteries – Most carry blood away from the heart that is normally
oxygenated.
Veins - Most veins carry deoxygenated blood from the tissues back to
the heart.
Most???
The pulmonary vein is a large blood vessel that carries blood from
the lungs to the left atrium of the heart.
The pulmonary arteries, carry deoxygenated blood from the heart to
the lungs. They are the only arteries that carry deoxygenated blood.
Blood
 Blood is composed of blood cells suspended in a liquid called
blood plasma. Plasma, which constitutes 55% of blood fluid,
is mostly water (92% by volume).
 The blood cells present in blood are mainly red blood cells
and white blood cells.
 The most common of the two are red blood cells contain
hemoglobin, an iron-containing protein, which facilitates
transportation of oxygen by reversibly binding to this
respiratory gas and greatly increasing its solubility in blood.
 Get more into white blood cells when we get back into the
immune system.
Today/next class:
 Today we are going to start working on finishing the respiratory
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system and then continue on and remove the cardiovascular
system on the turtles!
You need to take out the ventricle, and both atriums, both aortas
(largest artery in the body), and the right/left subclavical arteries.
Then remove all veins that are attached including the ventral
abdominal veins!
When you are working on removing the system you need to focus
on not disrupting the over systems and work out the veins,
arteries and hearts attached together.
You will have a quiz at the beginning of the period over the
cardiovascular system, if your group gets finished early I want to
see you studying the information that will be on the quiz.
Clean up last 10 minutes of class