Download Circulatory System

Circulatory System
Circulatory System Overview
• Most of the cells in the human body are
not in direct contact with the external
environment. The circulatory system
acts as a transport service for these cells.
Two fluids move through the circulatory
system: blood and lymph. The blood,
heart, and blood vessels form the
cardiovascular system. The lymph,
lymph nodes, and lymph vessels form the
lymphatic system. The cardiovascular
system and lymphatic system collectively
make up the circulatory system.
The Heart
a.
b.
c.
d.
central organ of the cardiovascular system
pumps blood through an intricate network of blood vessels
beats more than 2.5 billion times in a life span
pericardium- saclike structure that surrounds the heart and
reduces friction as the
heart beats
e. septum- divides the heart vertically into 2 parts
1. right side- pumps to the lungs
2. left side- pumps to other parts of the body
f. atrium- upper chambers of the heart
g. ventricle- lower chambers of the heart
Circulation
1. Blood returning to the heart from parts of the body other than the
lungs has a high concentration of CO2.
2. This deoxygenated blood enters the right atrium.
3. Right atrium pumps blood to right ventricle.
4. Right ventricle force blood into the pulmonary arteries which lead to
the lungs.
5. In the lungs, CO2 diffuses out and O2 fuses into the blood.
6. Oxygenated blood returns to the left atrium.
7. Left atrium pumps blood to the left ventricle, which forces blood into a
large blood vessel called the aorta.
8. From the aorta blood is transferred to all parts of the body except for
the lungs.
Blood Pressure
a. The force that blood exerts against the walls of a blood vessel.
b. Highest in the 2 main arteries that leave the heart.
c. systolic pressure- pressure of the blood when ventricles contract.
1. 120 mm of Hg for males (normal)
2. 110 mm of Hg for females (normal)
d. diastolic pressure- when ventricles relax
1. 80 mm of Hg for males (normal)
2. 70 mm of Hg for females (normal)
e. hypertension- high blood pressure
1. strains walls of arteries
2. leading cause of death in many countries
Lymphatic system
a. returns fluids (lymph) that have collected in
the tissues to the blood stream
b. lymph nodes- filter lymph, trapping foreign
particles, microorganisms, and tissue
debris
c. lymph nodes also store white blood cells
(lymphocytes) that fight disease.
The human heart creates
enough pressure when
it pumps out to the body
to squirt blood 30 feet.
The circulatory system of
arteries, veins, and
capillaries is about
60,000 miles long.
It takes about 20 seconds
for a red blood cell to
circle the whole body.
An individual is born with a hole in the septum of his
heart between the two atria. Which statement
best explains why this condition may be harmful?
A.
B.
C.
D.
The person will have high blood pressure.
The person will have low blood pressure.
The cells of the body may not get enough oxygen.
The blood will not flow to the lungs for gas
exchange.
An individual is born with a hole in the septum of his
heart between the two atria. Which statement
best explains why this condition may be harmful?
A.
B.
C.
D.
The person will have high blood pressure.
The person will have low blood pressure.
The cells of the body may not get enough oxygen.
The blood will not flow to the lungs for gas
exchange.