Science Module
th
7
Grade
Body Systems
Circulatory System
7th Grade Science
TAKS 2
TEKS 7.9(A)
TAKS Objective 2
The student will demonstrate an
understanding of living systems and the
environment – Interdependence occurs
among living systems
TEKS Science Concept
• TEKS 7.9 (A) identify the systems of the
human organism and describe their
functions.
Student Prior Knowledge
• TEKS 6.10 (C) identify how structure
complements function at different levels of
organization including organ and organ
systems.
Background
Circulatory System
Structures
• Heart
• Blood Vessels
– Arteries
– Veins
– Capillaries
• Blood
Circulatory System
Function
• The overall function of the circulatory system is
to transport materials throughout the body
toward and away from particular target organs
and tissues.
Two Pathways
• Pulmonary Circulation
– Carries blood to lungs and back to the heart
• Systemic Circulation
– Carries blood to body and back to the heart
Capillaries of head and arms
Superior vena
cava
Aorta
Pulmonary artery
Pulmonary vein
Capillaries of right
lung
Capillaries of left
lung
Inferior vena cava
Capillaries of abdominal
organs and legs
Your Blood Vessels:
Pathway of Circulation

3 types of vessels
– Arteries
– Capillaries
– Veins
Artery vs. Vein
Arteries:
carries blood Away from heart
–
–
–
–
Large
Thick-walled, Muscular
Elastic
Oxygenated blood

Exception Pulmonary Artery
– Carried under great pressure
– Steady pulsating
Arterioles: smaller vessels, enter tissue
Capillaries
–
–
–
–
Smallest vessel
Microscopic
Walls one cell thick
Nutrients and gases diffuse here
Veins:
Carries blood to heart
–
Carries blood that contains
waste and CO2

–
–
Exception pulmonary vein
Blood not under much
pressure
Valves to prevent much
gravity pull
Venules: larger than capillaries
Varicose Veins
Damaged Valves in Veins
Your Heart: The Vital Pump
At REST, the heart
pumps about 5
QUARTS of blood a
minute.
 During EXTREME
EXERTION (exercise)
it can pump 40 quarts
a minute.

Heart:
Structure and Function
Keeps blood moving
 Large organ
composed of Cardiac
muscle

Structure of Heart

Four chambers
– Two upper (Atria)
 Right Atria
 Left Atria
– Two lower
(Ventricles)
 Right Ventricle
 Left Ventricle
Bloods Path Through the Heart

Both Atria fill at same time
– Rt atrium receives oxygen POOR blood from
body via the vena cavas
– Left atrium receives oxygen RICH blood from
lungs through four pulmonary veins

After filled with blood atria contract,
pushing blood into ventricle
Both ventricles contract
Right ventricle contracts and pushes
oxygen-poor blood toward lungs,
 against gravity,
 through pulmonary arteries
Bloods Path Through the Heart
(cont)
Left ventricle contracts and forces oxygen
rich blood
 out of heart through
 aorta (largest vessel)
The Blood
Body contains 4-6 L
 Consists of

–
–
–
–
Water
Red Blood Cells
Plasma
White blood cells and
platelets
Erythrocytes (RBC)

Transporters of
– Oxygen
– Carbon Dioxide

RBC are produced in red bone
marrow of
–
–
–
–
ribs,
humerus,
femur,
sternum, and other long bones
Leukocytes (WBC)

WBC fight infection
–


Attack foreign
substances
Less abundant
Large cells
Platelets
PLATELETS are for CLOTTING blood
 Cell fragments
 Produced in bone marrow
 Fibrin (sticky network of protein
fibers)

– Form a web trapping blood cells
Blood Clotting
Section 37-2
Break in Capillary Wall
Clumping of Platelets
Clot Forms
Blood vessels injured.
Platelets clump at the site
and release thromboplastin.
Thromboplastin converts
prothrombin into thrombin..
Thrombin converts
fibrinogen into fibrin, which
causes a clot. The clot
prevents further loss of
blood..
Blood Types
Massive loss of blood requires a transfusion
 Four Types

–A
–B
– AB
–O

Inherited from your parents
Blood Types
What happens when you mix blood
types?
 Plasma
contains proteins that
correspond to the shape of the
different antigens
 If you mix one type with the
wrong one, you get CLUMPING
Type O is the universal donor
 Type AB is the universal acceptor

What Makes Our Blood Type?
Blood Transfusions
Blood Type
of Donor
Blood Type of Recipient
A
B
AB
O
A
B
AB
O
Unsuccessful transfusion
Successful transfusion
Rh Factor

Rhesus factor (Rh), also inherited
– Rh+ (have antigen)
– Rh- (NO antigen)

Can cause complications in pregnancies
– mother Rh- 1st baby Rh+ : blood mixes with
mother; mother’s body makes anti-Rh+
antibodies
– 2nd Rh + body attacks baby
– Now have medicine to prevent antibody
formation
Getting to the Heart of the Matter
ENGAGE
1. Walt Disney’s 1957 “Hemo the Magnificent”
2. Play song from St. Joseph’s Aspirin Commercial
(originally in Happy Days episode) at:
http://www.stjosephaspirin.com/page.jhtml?id=/stjoseph/include/5_2.inc
Lyrics
• Pump, pump, pumps your Blood.
• The right atrium’s where the process begins, where the
CO2 Blood enters the heart.
• Through the tricuspid valve, to the right ventricle, the
pulmonary artery, and lungs.
• Once inside the lungs, it dumps its carbon dioxide and
picks up its oxygen supply.
• Then it’s back to the heart through the pulmonary vein,
through the atrium and left ventricle.
• Pump, pump, pumps your Blood.
EXPLORE
• Circulatory System
Simulation
Capillaries of head and arms
Superior vena
cava
Aorta
Pulmonary artery
Pulmonary vein
Capillaries of right
lung
Capillaries of left
lung
Inferior vena cava
Capillaries of abdominal
organs and legs
EXPLAIN
Circulation Coloring Activity
1. Color the path of oxygenated blood red.
2. Color the path of deoxygenated blood blue
3. Label the following structures on the above diagram:
Aorta
Left Atria
Right Atria
Left Ventricle
Right Ventricle
Lungs
Vena Cava
Tissues of the Body
Capillaries
4. Use arrows to indicate blood flow direction.
ELABORATE
Circulation Relay
What is Blood Made of?
What is Blood Made of?
• CANDY RED HOTS 44%: Red Blood
Cells (RBCs) - carry oxygen and
carbon dioxide around body, RBCs
only live for about 3 months but are
continuously produced in the bone
marrow.
CORN SYRUP 55%: Plasma/Water syrupy, thick, clear, yellowish liquid
that carries dissolved food and
wastes in water.
WHITE JELLY BEANS 1/2%: White
Blood Cells (WBCs) - bigger than
RBCs, oddly-shaped cells that 'eat'
bits of old blood cells and attack
germs.
CANDY SPRINKLES 1/2%: Platelets
- bits of cells and cytoplasm that help
your blood clot.
EVALUATE
• Given a drawing the student will label and describe the
functions of the four major parts of the circulatory system:
Heart, arteries, veins and capillaries.
• After participating the circulatory relay simulation, the
learner will travel the correct circulation pathway beginning
at the left ventricle and ending at the left atrium.
• After participating in the blood activity, the learner will list
the following four components of the blood: RBC, WBC,
Plasma and Platelets and describe the function of blood.