Download Circulatory System - Wappingers Central School District

Circulatory
System
The heart
pumps about
3,600 gallons
of blood each
day
720
Circulatory
– Every organism must exchange materials with
its environment.
•
The purpose of the circulatory system is to
facilitate this exchange.
– All but the simplest animals have circulatory
systems with three main components:
•
•
•
A central pump
A vascular system
The circulating fluid
Blue Blood & Red Blood
Which one is his left arm?
Which one is his
Which is the right side
and which is the left?
• Video
Open and closed circulatory
system
The Role of the Cardiovascular
System in Homeostasis
– The cardiovascular system performs several
homeostatic functions:
•
•
•
•
•
Controlling chemical balance
Controlling the composition of the blood
Regulating body temperature
Distributing hormones
Defending against foreign invaders
The Heart
• The human heart is located near the center
of your chest.
• The heart is enclosed in a protective sac of
tissue called the pericardium.
• The heart has two sides and four chambers.
– The two sides are divided by a septum (wall).
– Prevents mixing of oxygen-poor blood and oxygen
rich blood.
• The upper chamber which receives blood is
the atrium.
• The lower chamber that pumps blood out of
the heart is the ventricle
Pericardium
Atrium and Ventricle
Pulmonary valve
Left atrium
Aortic valve
Right atrium
Mitral valve
Left ventricle
Tricuspid valve
Septum
Right ventricle
Myocardium
• The muscle of the heart
• Strong and thick
• Composed of
spontaneously contracting
cardiac muscle fibers
Myocardium
(heart muscle)
shown in red
Epicardium
(Outer surface
of myocardium)
Endocardium
(Inner surface of myocardium)
• Can conduct electricity
like nerves
• It’s blood supply comes
from the coronary
arteries
The Human Cardiovascular
System
– In the human cardiovascular system,
•
•
•
The central pump is the heart.
The vascular system is the blood vessels.
The circulating fluid is the blood.
– In humans and other vertebrates, the three
components of the cardiovascular system are
organized into a double circulation system.
•
There are two distinct circuits of blood flow.
• The pulmonary circuit.
• The systemic circuit.
• The pulmonary
circuit carries
blood between the
heart and the
lungs.
• The systemic
circuit carries
blood between the
heart and the rest
of the body.
Structures of the Heart
• Valves
Valves seen from above
Pulmonary
valve
– Prevents backflow of blood
– Keep blood moving in one
direction
Pulmonary veins
Tricuspid valve
Right atrium
Chordea tendinea
– Between the chambers
– At junctions of artery
and chamber
Mitral valve
Aortic valve
Left atrium
Pulmonary valve
Superior Vena Cava
Large vein that brings oxygen-poor blood from the
upper part of the body to the right atrium
Pulmonary Veins
Bring oxygen-rich blood from each
of the lungs to the left atrium
Pulmonary Valve
Prevents blood from flowing
back into the right ventricle
after it has entered the
pulmonary artery
Tricuspid Valve
Prevents blood from flowing
back into the right atrium after it
has entered the right ventricle
Inferior Vena Cava
Vein that brings oxygen-poor
blood from the lower part of
the body to the right atrium
Aorta
Brings oxygen-rich blood from the left
ventricle to the rest of the body
Pulmonary Arteries
Bring oxygen-poor blood
to the lungs
Aortic Valve
Prevents blood from flowing
back into the left ventricle
after it has entered the aorta
Mitral Valve
Prevents blood from flowing back
into the left atrium after it has
entered the left ventricle
Heartbeat
– The pacemaker, or SA (sinoatrial) node,
sets the tempo of the heartbeat.
– The pacemaker is composed of specialized
muscle tissue in the wall of the right
atrium.
Blood Vessels
 If the heart is the body’s “pump,” then the
“plumbing” is the system of arteries, veins,
and capillaries.
• Arteries carry blood AWAY from the heart.
– Aorta large blood vessel carries through the body
back to the heart.
• Veins carry blood toward the heart.
• Capillaries allow for exchange between the
bloodstream and tissue cells.
Aorta
• Video clip
• Blood still moves
through the veins
against the force
of gravity.
• As skeletal
muscles contract,
they help squeeze
the blood along.
Blood Pressure
 The force that blood exerts against the
walls of your blood vessels is called blood
pressure.
• Blood pressure is the main force driving the
blood from the heart to the capillary beds.
• A pulse is the rhythmic stretching of the
arteries caused by the pressure of blood forced
into the arteries during systole.
• Blood pressure decreases when the heart
relaxes
• Systolic (arteries and ventricles contract)
and diastolic (arties and ventricles relax)
– 120/80 is a normal adult
Disorders of the circulatory
system
• Atherosclerosis- fatty deposits (plaque)
build up on the walls of the arteries.
– Leads to high blood pressure
(hypertension)
– Can cause blood clots
– Can cause heart attack
– Can cause a stroke
Cardiovascular disease accounts for 40%
of all deaths in the United States.
The leading cause of death in the United
States is heart attack.
Blood
&
The Lymphatic System
Components of blood
• Plasma- 90% water 10% dissolved gases,
salts, nutrients, enzymes, hormones, waste
products and proteins.
– Allows blood to clot
• Red blood cells (erthrocytes)-Transport
oxygen
– Contains protein hemoglobin
• Contains iron which gives it the red-ish color
• Made in red bone marrow
• Circulate for about 120 days destroyed in liver and
spleen
Components of blood
• White blood cells- (Leukocytes)
Attack foreign substances or
organisms. (Army)
– Also made in red bone marrow
– Phagocytes “eating cells” are a type
of white blood cells that engulf and
digest foreign cells
• Platelets- (thrombocytes) are bits
of cytoplasm pinched off from
larger cells in the bone marrow
– Fibrinogen is a membrane-wrapped
protein found in plasma.
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..
Lymphatic system
• The lymphatic system has two main
functions:
• Return tissue fluid to the circulatory system
• Fight infection
• The fluid is known as lymph.
• The organs of the lymphatic system are
lymph nodes, packed with white blood cells
that fight infection.
– The lymphatic
system
Figure 24.7
Respiratory System
• What is Respiration?
• At the cellular level- The release of
energy from the breakdown of
molecules in food in the presence of
oxygen. Blood carries oxygen and carbon
dioxide between the lungs and trillions
of cells throughout the body.
Video Clip
Figure 23.UN1
Human Respiratory System
• Purpose- To bring about the exchange
of oxygen and carbon dioxide.
• With each breath air enters the body
fills the lungs, where gas exchange
takes place.
• The respiratory system consists of the
nose, pharynx, larynx, trachea, bronchi,
and lungs.
Figure 23.17
• Air moves through the nose to a tube at
the back of the mouth called the
pharynx (throat).
• Pharynx serves as a passageway for
both air and food.
• From the pharynx air moves into the
trachea (windpipe).
• A piece of cartilage called the epiglottis
covers the entrance to the trachea
when you swallow
Video Clip
The Larynx
• The larynx contains two highly elastic
folds of tissue known as the vocal cords.
• From the larynx, air passes through the
trachea into two large passageways in
the chest cavity called bronchi.
• Each bronchus leads into one of the
lungs.
• Inside the lung the large bronchus
subdivide into even smaller bronchi,
which lead to even smaller passageways
called bronchioles. Video Clip
Lungs must be kept clean
• In order to keep the lung healthy, the air
must be warmed, moistened and filtered.
• Large dust particles get trapped by little
hairs lining the entrance to the nasal cavity.
• A mucus moistens the air and traps inhaled
particles of dust and smoke.
• Cilia sweep the trapped particles and mucus
away from the lungs towards the pharynx.
Bronchioles
• The bronchioles
continue to
subdivide until
they reach a
series of dead
ends, these are
millions of tiny air
sacs called alveoli.
Figure 23.18
Alveoli
• There are about 350 million alveoli in a
healthy lung, providing an enormous
surface area for gas exchange.
• Alveoli carry out the process of gas
exchange in the lungs.
• Grouped in clusters like grapes
Video Clip
The Air that you Inhale &
Exhale
Inhale:
• 21% oxygen
• 0.04% carbon dioxide
Exhale:
• Less than 15% oxygen
• 4% Carbon dioxide
How is breathing Controlled?
• Medulla Oblongata
• Cells in its breathing center monitor the
amount of carbon dioxide in the blood.
• As the Carbon dioxide levels rise, nerve
impulses from the breathing center
cause the diaphragm to contract,
bringing air into the lungs.
• The higher the carbon dioxide levels
the stronger the impulse.
– The breathing control centers increase or decrease
breathing rate in response to CO2 levels in the blood.
Taking a Breath
– Breathing is the alternating process of
inhalation and exhalation.
Tobacco and The Respiratory
System
• Smoking tobacco damages and
eventually destroys the lungs.
• Tobacco contains 3 harmful substances:
– Nicotine: stimulant
– Carbon monoxide: poisonous gas that blocks
the transportation of oxygen by hemoglobin
in the blood.
– Tar: is a cancer causing substance.
Video clip
Statistics
• Only 30% of male smokers live to the
age of 80.
• 55% of nonsmokers live to 80
• 160,000 people in the US are diagnosed
with lung cancer each year.
• Smoking causes:
– Bronchitis (acute, chronic)
– Emphysema
– Lung cancer