Transcript Circulatory System

You Gotta Have Heart
The Circulatory System
Circulatory System Consists of…
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Blood Vessels
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Blood
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
Heart
Functions to
transport oxygen,
nutrients and
wastes
throughout the
body.
Two Pathways: The heart functions
as two separate pumps
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Pulmonary Circulation
– The right side of the heart carries oxygen
poor blood from the heart to lungs and
oxygen rich blood back from the lungs
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Systemic Circulation
– The oxygen rich blood is carried from the left
side of the heart to body and oxygen poor
blood is carried 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
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3 types of vessels
– Arteries
– Capillaries
– Veins
Artery vs. Vein
Arteries:
carries blood Away from heart
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–
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Large
Thick-walled, Muscular
Elastic
Oxygenated blood
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Exception Pulmonary Artery
– Carried under great pressure
– Steady pulsating
Arterioles: smaller vessels, enter tissue
Capillaries
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–
–
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
Circulatory System
BLOOD
The Blood
Body contains 4-6 L
 Consists of
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–
–
–
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Water
Red Blood Cells
Plasma
White blood cells and
platelets
Plasma
Platelets
White blood
cells
Red blood
cells
Whole Blood Sample
Sample Placed in Centrifuge
Blood Sample That
Has Been Centrifuged
Plasma
Platelets
White blood
cells
Red blood
cells
Whole Blood Sample
Sample Placed in Centrifuge
Blood Sample That
Has Been Centrifuged
Plasma
Platelets
White blood
cells
Red blood
cells
Whole Blood Sample
Sample Placed in Centrifuge
Blood Sample That
Has Been Centrifuged
Parts of the Blood
Your Blood: Fluid Transport
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a connective tissue
55% plasma
45% cells
Liquid Portion Carries
 Blood cells
– Erythrocytes (RBC - red blood
cells)
– Leucocytes (WBC - white blood
cells)
 Platelets (non cellular particles)
 Proteins
– Enzymes
– Hormones – Endocrine System
 Nutrients - Digestive System
 Gases - Respiratory System
 Inorganic salts
Oxygen in the Blood
Hemoglobin, iron
containing molecule
 Loosely picks up
oxygen in the lungs
 Loses oxygen in areas
low in oxygen
(diffuses)
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Carbon Dioxide in the Blood
Hemoglobin carries CO2 also
 CO2 is a waste product of
cellular work
 70% of CO2 combines with
water
 The rest travels to the lungs
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What does blood contain?
45% Packed Cells consisting
of erythrocytes, leukocytes,
platelets
 55% Plasma which includes
plasma proteins, gases,
salts, nutrients, enzymes,
hormones, waste products
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Erythrocytes (RBC)
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Transporters of
– Oxygen
– Carbon Dioxide
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RBC
– Lack a nucleus
– Contain hemoglobin
– Disk-shaped
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RBC are produced in red bone
marrow of
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–
–
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ribs,
humerus,
femur,
sternum, and other long bones
Lives for 120 days
Old RBC are destroyed in liver
and spleen
Leukocytes (WBC)
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WBC fight infection
–
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Less abundant
Large cells
Some live for
months
–
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Attack foreign
substances
Most just a few days
Several types
ALL contain nuclei
Platelets
PLATELETS are for CLOTTING blood
 Cell fragments
 Produced in bone marrow
 Short life span (1 week)
 Fibrin (sticky network of protein
fibers)
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– Form a web trapping blood cells
3 Types of Plasma Proteins
Albumins-transport substances such as
fatty acids, hormones and vitamins. Also
help regulate osmotic pressure and blood
volume.
 Globulins-transport substances and fight
viral and bacterial infections.
 Fibrinogen-protein responsible for the
ability of blood to clot
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Plasma Protiens
Blood Clotting
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..
Circulatory System
HEART
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.
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Heart:
Structure and Function
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Keeps blood moving
Large organ composed of
– cardiac muscle,
– rich in mitochondria
– Enclosed by a protective
sac called the pericardium
 Myocardium-thick layer of
muscle surrounded by 2
thin layers of connective &
epithelial tissue
The Structures of the Heart
Superior Vena Cava
Large vein that brings oxygen-poor blood from the
upper 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
Pulmonary Veins
Bring oxygen-rich blood from each
of the lungs to the left atrium
Left Atrium
Pulmonary Valve
Prevents blood from flowing
back into the right ventricle
after it has entered the
pulmonary artery
Right Atrium
Tricuspid Valve
Prevents blood from flowing
back into the right atrium after it
has entered the right ventricle
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
Left Ventricle
Inferior Vena Cava
Vein that brings oxygen-poor
blood from the lower part of
the body to the right atrium
Septum
Right Ventricle
Structure of Heart (cont)
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Four chambers
– Two upper (Atria)
 Walls thinner
 Less muscular
– Two lower
(Ventricles)
 Walls thicker
 More muscular
 Do more work
Blood Flow Through the Heart
©COPY 1997 HeartPoint
Bloods Path Through the Heart
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Both Atria fill at same time
– Rt atrium receives oxygen POOR blood from
body from vena cava
– Left atrium receives oxygen RICH blood from
lungs through four pulmonary veins
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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)
Control of the Heart
(Nervous System)
Medulla oblongata regulates rate
 Sensory cells stretch when too fast
 Pressure drops when beat is too low
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Heartbeat Regulation
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Force of blood from left ventricle into arteries
(pulse)
Pacemaker (SA Node), group of cells at top of
right atrium
Electrical impulse, signals BOTH atria to contract
Triggers 2nd set of cells (AV Node)-base of the
right atrium to send message to ventricles, they
contract
EkG – record of electrical changes in the heart
The Sinoatrial Node
Contraction of Atria
Contraction of Ventricles
Sinoatrial
(SA) node
Conducting
fibers
Atrioventricular
(AV) node
Blood Pressure
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Blood against the blood vessel’s walls
– The systolic pressure refers to
 the pressure recorded while the ventricles pump
the blood.
– The diastolic pressure refers to
 the pressure recorded as the ventricles fill with
blood.
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A normal blood pressure is 120/80
Disorders of Circulatory System
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ATHEROSCLEROSIS
– Fatty deposits called plaque
– Builds up in walls of arteries
– Obstructs flow
– Also a risk if clot breaks free and blocks flow
elsewhere
Disorders (cont)
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Hypertension
– High blood pressure
– Hearts works harder than necessary
– Increases risk of heart attack or stroke
Disorders (cont)
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Heart Attack
– Atherosclerosis in coronary artery
– Heart muscle begins to die
 Symptoms
– Nausea
– Shortness of breath
– Severe chest pain
IMMEDIATE MEDICAL ATTENTION NECESSARY
Disorders (cont)
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Stroke
– Blood clot gets stuck in blood vessels leading
to brain
– Brain cells die due to lack of oxygen
 Or blood vessel burst
– Can lead to paralysis,
 loss of ability to speak
 death
The Lymphatic System
A network of vessels, nodes and organs
 Collects the fluid that is lost by the blood
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– Up to 3 liters per day
Returns fluid back to circulatory system
 Fluid is known as lymph
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Lymph
Lymph collects in lymphatic capillaries
 Lymph vessels contain valves
 Ducts collect the lymph
 Lymph is returned to the circulatory
system through 2 openings in the superior
vena cava
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– Openings under the left and right clavicle
bones
Lymph
Lymph vessels are dotted with small bean
shaped enlargements called nodes
 Lymph nodes act as filters
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– Trapping bacteria and other microorganisms
– Can become enlarged “swollen glands”
Lymph System
Lymph vessels play an important role in
nutrient absorption
 Absorb fats and fat-soluble vitamins from
the digestive tract and carry them to the
blood
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Lymph System
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Lymph moves through the lymphatic
system
– under osmotic pressure from the blood
– is pushed along by the contractions of nearby
skeletal muscles
– Important to have a steady flow
– Edema, tissue swelling , can occur when
vessels are blocked due to injury or disease
Thymus Gland
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The thymus gland
– Located beneath the sternum
– Site of T cell maturation
Spleen
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The spleen
– helps to cleanse the blood and removes
damaged blood cells
– Harbors phagocytes that engulf and destroy
bacteria and other microorganisms
The Respiratory System
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The Respiratory System functions
– To bring about the exchange of oxygen and
carbon dioxide between the blood, the air,
and tissues
– Consists of the nose, pharynx, larynx,
trachea, bronchi, and lungs
Respiratory System
Pharynx-serves as passageway for both air and
food
 Trachea or windpipe carries the air, a flap of
tissue called the epiglottis covers the entrance to
the trachea when you swallow
 Entering air is warmed, moistened, and filtered
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– Dust is trapped by the hairs lining the nasal cavities
– Mucus moistens the air and traps inhaled particles of
dust or smoke.
– The mucus and trapped particles are either swallowed
or spit out
Respiratory
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Larynx-contains the vocal cords
– Muscles pull the cords together
– Air moving between cords cause them to
vibrate and produce sound
Respiratory
Bronchi branch from the trachea into each
lung
 Bronchi branch into smaller bronchioles
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– Both are surrounded by smooth muscle that
supports them and enables the ANS to
regulate the size of the air passageways
– Bronchioles dead end into the alveoli
Respiratory
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Alveoli are millions of tiny air sacs
– Are grouped in clusters, like grapes
– Are surrounded by a network of capillaries
– The real work of the respiratory system takes
place here, where blood and air are side by
side
– The Gas Exchange is carried out here
Gas Exchange
150 million alveoli in a healthy lung
 Enormous surface area for gas exchange
 The process is very efficient
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– Air you inhale is 21% oxygen and .04 CO2
– Exhaled air is > 15% oxygen and 4% CO2
– Hemoglobin increases the oxygen-carrying
capacity of blood more than 60 times
– Without hemoglobin you would need 300
liters of blood to get the same result
Breathing
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Breathing is the movement of air into and out of
the lungs.
– There are no muscles connected to the lungs
– The force that drives air into the lungs comes from
the air pressure
– Lungs are sealed in 2 sacs called the pleural
membranes
– A large, flat muscle known as the diaphragm
contracts and relaxes causing a vacuum
– The system works because the chest cavity is sealed.
– A puncture may allow air to leak into the chest cavity
and make breathing impossible
Breathing Control
By the medulla oblongata
 You may hold your breath but eventually
the body forces you to breathe
 Controlled by the amount of CO2 in the
breathing center
 More CO2 the stronger the impulses
 If CO2 reaches critical point you cannot
keep from breathing
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Disorders
Smoking can cause respiratory diseases
such as chronic bronchitis, emphysema
and lung cancer.
 Only 30% of male smokers live to be 80
while 55% of male nonsmokers live to be
80
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Disorders
Chronic Bronchitis-inflammation of the bronchi
 Can make even simple activities difficult
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Emphysema-loss of elasticity in the tissues of
the lungs
– Breathing is very difficult
– Cannot get enough O2 to the body or get rid of the
CO2
– Can use medicines or O2 to improve life
Lung Cancer
Lung cancer is very deadly because its
cells can spread to other locations
 By the time it is usually detected it has
spread to dozens of places
 160,000 people in US diagnosed each year
 Few will survive 5 years
 Passive or second hand smoke can be a
major issue for family members of a
smoker, can lead to asthma in children
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