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30.1 Respiratory and Circulatory Functions
TEKS 4B, 10A, 10C
KEY CONCEPT
The respiratory and circulatory systems bring oxygen
and nutrients to the cells.
30.1 Respiratory and Circulatory Functions
TEKS 4B, 10A, 10C
The respiratory and circulatory systems work together to
maintain homeostasis.
• The circulatory system transports
blood and other materials.
– brings supplies to cells
– carries away wastes
– separates oxygen-poor and
oxygen-rich blood
Oxygen-rich blood
Oxygen-poor blood
30.1 Respiratory and Circulatory Functions
TEKS 4B, 10A, 10C
• The respiratory system is where gas exchange occurs.
– picks up oxygen from inhaled air
– expels carbon dioxide and water
sinus
nose
mouth
epiglottis
trachea
lungs
30.1 Respiratory and Circulatory Functions
TEKS 4B, 10A, 10C
The respiratory system moves gases into and out of the
blood.
• The lungs contain the bronchi, bronchioles, and alveoli.
• Millions of alveoli give the lungs a huge surface area.
• The alveoli absorb oxygen from the air you inhale.
alveoli
bronchiole
30.1 Respiratory and Circulatory Functions
TEKS 4B, 10A, 10C
• Breathing involves the diaphragm and muscles of the rib
cage.
• Air flows from areas of high pressure to low pressure.
Air inhaled.
Air exhaled.
Muscles and
rib cage relax.
Muscles contract and
rib cage expands.
Diaphragm flattens
and moves downward.
Diaphragm relaxes
and rises.
30.1 Respiratory and Circulatory Functions
TEKS 4B, 10A, 10C
The circulatory system moves blood to all parts of the
body.
• The system includes the heart,
arteries, veins, and capillaries.
– heart pumps blood throughout body
– arteries move blood away from
heart
– veins move blood back to heart
– capillaries get blood to and from
cells
arteries
veins
30.1 Respiratory and Circulatory Functions
TEKS 4B, 10A, 10C
• There are three major functions of the circulatory system.
– transporting blood, gases, nutrients
– collecting waste materials
– maintaining body temperature
30.2 Respiration and Gas Exchange
TEKS 4B, 10A, 10C, 11A
KEY CONCEPT
The respiratory system exchanges oxygen and carbon
dioxide.
Nasal Cavity:
filters air
Pharynx: passage of
food and air Larynx:
voicebox
Trachea: passage of air,
filters foreign bodies
Lungs: organ for breathing
Diaphragm:
Muscle that
controls the size
of the chest cavity
Alveoli: air sac for gas
exchange (CO2 and O2)
30.2 Respiration and Gas Exchange
TEKS 4B, 10A, 10C, 11A
Gas exchange occurs in the alveoli of the lungs.
• Oxygen and carbon dioxide are carried by the blood to and
from the alveoli.
– oxygen diffuses from alveoli into capillary
– oxygen binds to hemoglobin in red blood cells
– carbon dioxide difuses from capillary into alveoli
GAS EXCHANGES
ALVEOLI
capillary
alveolus
Co2 diffuses
into alveolus.
co2
o2
capillaries
O2 diffuses
into blood.
30.2 Respiration and Gas Exchange
TEKS 4B, 10A, 10C, 11A
Respiratory diseases interfere with gas exchange.
• Lung diseases reduce airflow and oxygen absorption.
– Emphysema destroys alveoli.
– Asthma constricts airways.
– Cystic fibrosis produces sticky mucus.
30.2 Respiration and Gas Exchange
TEKS 4B, 10A, 10C, 11A
• Smoking is the leading cause of lung diseases.
30.3 The Heart and Circulation
TEKS 11A
KEY CONCEPT
The heart is a muscular pump that moves the blood
through two pathways.
30.3 The Heart and Circulation
TEKS 11A
The tissues and structures of the heart make it an
efficient pump.
• Cardiac muscle tissue works continuously without tiring.
NORMAL HUMAN HEART
30.3 The Heart and Circulation
TEKS 11A
• The heart has four chambers: two atria, two ventricles.
• Valves in each chamber prevent backflow of blood.
pulmonary valve
aortic valve
left atrium
right atrium
mitral valve
left ventricle
tricuspid
right ventricle
septum
• Muscles squeeze the chambers in a powerful pumping
action.
30.3 The Heart and Circulation
TEKS 11A
• The heartbeat consists of two contractions.
– SA node, or pacemaker, stimulates atria to contract
– AV node stimulates ventricles to contract
SA node
VA node
30.3 The Heart and Circulation
TEKS 11A
• Blood flows through the heart in a specific pathway.
1
3
2
4
30.3 The Heart and Circulation
TEKS 11A
• Blood flows through the heart in a specific pathway.
– oxygen-poor blood enters right atrium, then right
ventricle
– right ventricle pumps blood to lungs
– oxygen-rich blood from lungs enters left atrium, then left
ventricle
– left ventricle pumps blood to body
30.3 The Heart and Circulation
TEKS 11A
The heart pumps blood through two main pathways.
• Pulmonary circulation occurs between the heart and the
lungs.
– oxygen-poor blood enters lungs
– excess carbon dioxide and water
expelled
– blood picks up oxygen
– oxygen-rich blood returns to heart
30.3 The Heart and Circulation
TEKS 11A
• Systemic circulation occurs between the heart and the rest
of the body.
– oxygen-rich blood goes to organs,
extremities
– oxygen-poor blood returns to
heart
• The two pathways help maintain a
stable body temperature.
Body
Right Atrium
Left Atrium
Right Ventricle
Left Ventricle
Lungs
30.4 Blood Vessels and Transport
Arteries, veins, and capillaries transport blood to all parts
of the body.
• Arteries carry blood away from the heart.
– blood under great pressure
– thicker, more muscular walls
endothelium
smooth muscle
valve
connective tissue
ARTERY
VEIN
CAPILLARIES
arteriole
venule
30.4 Blood Vessels and Transport
• Veins carry blood back to the heart.
– blood under less pressure
– thinner walls, larger diameter
– valves prevent backflow
endothelium
smooth muscle
valve
connective tissue
ARTERY
VEIN
CAPILLARIES
arteriole
venule
30.4 Blood Vessels and Transport
• Capillaries move blood between veins, arteries, and cells.
endothelium
smooth muscle
valve
connective tissue
ARTERY
VEIN
CAPILLARIES
arteriole
venule
30.4 Blood Vessels and Transport
• Blood pressure is a measure of the force of blood pushing
against artery walls.
– systolic pressure:
left ventricle
contracts
– diastolic pressure:
left ventricle
relaxes
• High blood pressure can precede a heart attack or stroke.
What might happen if a blood clot forms inside the
circulatory system and lodges in a major blood vessel?

Heart attack
• lack of oxygen to the heart

Stroke
• lack of oxygen to the brain

Tissue damage
• due to lack of oxygen
30.5
Blood
TEKS 4B, 5B, 11A
KEY CONCEPT
Blood is a complex tissue that transports materials.
30.5
Blood
TEKS 4B, 5B, 11A
Blood is composed mainly of cells, cell fragments, and
plasma.
• Whole blood is made up of different materials.
– plasma
– red blood cells
– white blood cells
– platelets
plasma
red blood cells,
white blood cells,
and platelets
30.5
Blood
TEKS 4B, 5B, 11A
• Plasma is a key factor in maintaining homeostasis.
– molecules diffuse into and out of plasma
– contains proteins that stabilize blood volume
– contains clotting factors
– contains immune proteins
30.5
Blood
TEKS 4B, 5B, 11A
Platelets and different types of blood cells have different
functions.
• The bone marrow manufactures most of the blood
components.
red blood cell
platelet
white blood cell
30.5
Blood
TEKS 4B, 5B, 11A
• Red blood cells make up 40-45 % of all blood cells.
– transport oxygen to cells and carry away carbon dioxide
– have no nuclei and contain hemoglobin
30.5
Blood
TEKS 4B, 5B, 11A
• White blood cells fight pathogens and destroy foreign
matter.
red blood cell
platelet
white blood cell
30.5
Blood
TEKS 4B, 5B, 11A
• Platelets help form clots that control bleeding.
platelets
fibrin
white
blood cell
red blood cell
30.6 Lymphatic System
TEKS 4B, 10A, 10C
KEY CONCEPT
The lymphatic system provides another type of
circulation in the body.
30.6 Lymphatic System
TEKS 4B, 10A, 10C
The lymphatic system is a major part of the immune
system.
• Structures in the lymphatic
system help fight disease.
– tonsils filter bacteria
and viruses
– thymus develops white
blood cells
– spleen filters lymph,
contains immune cells
tonsils
thymus
spleen
• Lymphocytes help destroy pathogens, parasites,
and foreign matter.
31.2 Immune System
TEKS 10A, 10C
Cells and proteins fight the body’s infections.
• White blood cells attack infections inside the body.
– Phagocytes engulf and destroy pathogens.
– T cells destroy infected cells.
– B cells produce antibodies.
30.6 Lymphatic System
Functions of the Immune System
• 1.
• 2.
Recognize self vs. non-self
Destroy non-self
TEKS 4B, 10A, 10C
30.6 Lymphatic System
TEKS 4B, 10A, 10C
How does your body know when
a substance is an invader?
30.6 Lymphatic System
Foreign Invaders
• Antigen: Marker used
to identify cells
• Pathogen:
– Any non-self
substance capable of
triggering an immune
response
– A pathogen can be a
whole non-self cell, a
bacterium, or a virus.
- Even allergens and
cancerous cells
TEKS 4B, 10A, 10C
30.6 Lymphatic System
Foreign Invaders
• Antibody:
– Protein that recognize
and bind to pathogens.
– Once the body has
been exposed to a
pathogen, the body
creates memory B
cells, reducing the
chance of being
infected again!
TEKS 4B, 10A, 10C
ANATOMY OF THE IMMUNE SYSTEM
• The immune system is
localized in several
parts of the body
– immune cells
develop in the
bone marrow and
thymus
– immune responses
occur in the
secondary organs
ANATOMY OF THE IMMUNE SYSTEM:
The immune system is localized in several parts of the body
– Spleen: filters and
removes old and
damaged red blood
cells
• removes infectious
agents and uses them
to activate cells called
lymphocytes
– Bone marrow: tissue
insides bones that
produces blood cells
• B cells and T cells are
types of white blood
cells
ANATOMY OF THE IMMUNE SYSTEM:
The immune system is localized in several parts of the body
– Thymus: T cells
mature here (learn
their job)
– Lymph nodes: small
organs that filter out
dead cells, antigens,
and other “stuff” to
present to
lymphocytes
ANATOMY OF THE IMMUNE SYSTEM:
The immune system is localized in several parts of the body
– Lymphatic Vessels:
collects fluid (lymph)
“leaked” from blood into
the tissues and returns
it to circulation
– Tonsils: 3 pairs masses
of lymphoid tissuehelps protect against
bacteria around the
throat
– Appendix: “safe house”
for the beneficial
bacteria living in the
human gut
• Non-specific defense mechanisms:
– The body’s attempt to destroy all types of foreign
invaders
– General, not targeted to a specific pathogen (virus
or bacteria)
• Specific defense mechanisms:
– Immune response specific for a pathogen
There are three lines of defense
against infection
The Immune System is the Third Line
of Defense Against Infection
First Line of Defense:
The outer layer of the body
• Goal:
prevent organisms from
gaining access to the body
• Details:
– Physical barriers: skin,
hair
– Chemical barriers: sweat,
tears, saliva, mucus, skin
• These contain
enzymes that break
down cell walls of
many bacteria
Second line of defense:
Cells and proteins in our blood stream
• Goal: recognize, neutralize and destroy invaders inside the body
• Details: inflammation and fever (swelling, redness, warmth, pain)
– Increased blood flow brings cells to fight infection
• Macrophage, phagocytes, and neutrophils
Third Line of Defense:
The Immune Response
• Two types of cells are involved:
– B cells: provide immunity against antigens and
pathogens in the body fluids by making
antibodies
• This is called humoral immunity
• Vaccines cause B cells to produce antibodies
– T cells: provide defense against abnormal
cells and pathogens inside living cells
• This is called cell-mediated immunity
Putting it all Together
• 1. Virus infects body
Putting it all Together
2.Macrophage (WBC) eat virus and display viral
antigen
Putting it all Together
• 3. White blood cell activates Helper T cell
Putting it all Together
• 4. Helper T Cells activate B cells and killer T
cells
Putting it all Together
5. Some B cells become memory cells for future
immune response, some become plasma cells
Putting it all Together
6. Plasma cells make antibodies which bind to
viral
antigen
Putting it all Together
7. Antibodies attach to the virus and infected body
cells, signals for their destruction
– Antibodies protect against foreign invaders
Putting it all Together
• 8. Killer T cells destroy infected body cells
31.6
Diseases that Weaken the Immune
System
TEKS 4C
HIV targets the immune system.
• The human immunodeficiency virus
(HIV) is a retrovirus.
– attacks and weakens the
immune system
– is transmitted by mixing
infected blood with a bodily
fluid
31.6
Diseases that Weaken the Immune
System
TEKS 4C
• HIV infection leads to AIDS.
dead
T cell
T cell
activated
B cell
antibody
HIV
– HIV reproduces in and destroys T cells.
– The body cannot replace T cells fast enough.
– T cells cannot help in immune responses.
31.6
Diseases that Weaken the Immune
System
TEKS 4C
• AIDS is acquired immune deficiency syndrome.
– several opportunistic infections
– very low amount of T cells
31.5 Overreactions of the Immune System
In autoimmune diseases, white blood cells attack the
body’s healthy cells.
• Autoimmune diseases are failures of the immune system.
– White blood cells cannot recognize healthy cells.
– White blood cells attack healthy body cells.
– Tissues fail because of attack.
31.5 Overreactions of the Immune System
• There are over 60 autoimmune diseases.