1. Circulation
Unit 11 – Body Systems

2. Circulation
 Blood travels to
every cell in the
body
– Delivers O2,
nutrients, energy
– Removes wastes
j
Capillaries
of head and
arms
Pulmonary
arteryAorta
Superior
vena cava
Inferior
vena cava
Pulmonary
veinCapillaries
of right lung
Capillaries of
left lung
Capillaries of
lower body

3. Circulation in Humans
j
Capillaries
of head and
arms
Pulmonary
arteryAorta
Superior
vena cava
Inferior
vena cava
Pulmonary
veinCapillaries
of right lung
Capillaries of
left lung
Capillaries of
lower body
 4 chambered heart
 Double –loop
 Pulmonary
Circulation: blood is
pumped from the
right side of the
heart to the lungs
 Systemic
Circulation: blood is
pumped to the body

4. Human Heart
 Hollow muscular organ
 Surrounded by a protective sac called
pericardium
 Myocardium - muscle in the heart walls
 A septum divides the heart in half
 Each side has 2 chambers
– Atrium (upper) receives blood
– Ventricles (lower) pump blood OUT of the heart
 Valves keep blood flowing in the right
direction

5. Human Heart
Mitral (Bicuspid) Valve
• Prevents backflow from the
left ventricle into the atrium
Septum
Right Ventricle
Tricuspid Valve
• Prevents backflow between
the right atrium and ventricle
Right Atrium
Pulmonary Artery
• Carries deoxygenated blood
from heart to the lungs
Pulmonary Valve
• Prevents backflow between the
right ventricle and pulmonary
artery
Pulmonary Veins
• Carries oxygenated blood from
lungs BACK to the heart
Aortic Valve
• Prevents backflow into the
left ventricle from the aorta
Left Atrium
Left Ventricle
Superior Vena Cava
• Large vein which brings
O2 poor blood from upper
body to the right atrium
Inferior Vena Cava
• Large vein which brings
O2 poor blood from upper
body to the right atrium
Aorta
• Brings oxygenated blood from
the heart to the rest of the body

6. Blood Vessels

7. Blood Vessels -Veins
 Veins have valves
 Return blood to the heart

8. Blood Vessels - Arteries
 Carry blood Away from the heart
 Blood is under the highest pressure in
the arteries
– Thick muscular walls
– Elastic
 Artery disease may lead to heart
attack or stroke

9. Blood Vessels - Capillaries
 Smallest vessels, only one cell thick
 Diffusion occurs between capillaries and all
cells
 Gas exchange

10. What is Blood Pressure?
 Pressure exerted by
blood against artery
walls
 Systolic – force
when ventricles
contract
 Diastolic – force felt
when ventricles relax
 Normal 120/80

11. What is Heartbeat?
 Controlled by the SA Node or “Pacemaker”

12. How is Heartbeat Measured?

13. Lymphatic System
 Collects fluid that leaks from the blood, and
returns it to the circulatory system
 Lymph flows through vessels
 Lymph nodes trap bacteria

14. Lymphatic System
 Two Organs
– Spleen removes old
RBCs
– Thymus - site where
T-cells mature
Superior
vena cava
Lymph
nodes
Thymus
Heart
Thoracic
duct
Spleen
Lymph
vessels

15. Components of Blood
 55% Plasma
 45% cellular
components
– Red Blood Cells
(RBC)
– White Blood Cells
(WBC)
– Platelets

16. Components of Blood
 What does each component look like?
What is the structure?
 What is the function of each component?
(plasma, RBC, WBC, platelets)
 How does structure determine function?
 Which cells are the most numerous?
 What is the scientific name for each cell
type?

17. Components of Blood
 Red Blood Cells (Erythrocytes)
– Iron containing hemoglobin binds O2
– Disc shape increases surface area
– Most numerous cell type
 White Blood Cells (Leukocytes)
– Fight infection
– Largest blood cell, least numerous
 Platelets (Thrombocytes)
– Release chemicals to clot blood
– Small cellular fragments

18. Blood Cells
Red Blood Cells White Blood Cells Platelets

19. Blood Types
 Incompatible blood types will result in
agglutination (clumping)

20. Blood Types
A, B, AB,
and O
OAnti-A &
Anti-B
NoneO
ABA, B, AB
and O
NoneABAB
B and ABO and BAnti-ABB
A and ABO and AAnti-BAA
Can Donate
To…
Can Receive
Blood
From…
Antibodies
in Plasma
Antigens on
RBC’s
Blood Type