The Circulatory System

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The Circulatory System
Notes

• Chapter 37
• Section 1

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Lecture Outline Circulatory System
PowerPoint Notes
textbook questions
Keys
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(No Transcript)
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Functions of the Circulatory System

• Brings blood containing oxygen, nutrients, and
  hormones to cells
• Transports CO2 and other wastes away from cells

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Functions Continued

• Fights infection
• Regulates body temperature
• Helps stabilize pH and ionic concentration of
  body fluids.

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Circulatory System

• Components
• Heart
• Blood
• Vessels
• Arteries
• Veins
• Capillaries

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The Heart

• A muscular pump
• Moves blood through the body
• Is suspended in the pericardial sac

• Composed of four chambers
• Divided into right and left halves
• Made up of cardiac muscle cells

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Pericardium

• Protective sac of connective tissue
• Surrounds the heart

• Filled with
• fluid

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Myocardium

• The muscle of the heart
• Strong and thick
• Composed of spontaneously contracting cardiac
  muscle fibers

• Can conduct electricity like nerves
• Its blood supply comes from the coronary arteries

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Structures of the Heart

• Chambers
• Atria- (2) upper chambers
• Thin walled
• Receive blood from veins
• Send blood to ventricles
• Ventricles- (2) lower chambers
• Thick walled
• Receive blood from atria
• Pump blood out through arteries

• Septum
• Wall that divides heart into right and left
  halves

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Structures of the Heart

• Valves
• Prevent backflow of blood
• Keep blood moving in one direction

• Between the chambers
• At junctions of artery and chamber

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Structures of the Heart

• Chordae tendinease
• Heart strings
• Cord-like tendons
• Connect papillary muscles to tricuspid and
  mitral valves
• Prevent inversionof valve
• Papillary muscles
• Small muscles that anchor the cords

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Structures of the Heart
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Cardiac Cycle

• Refers to all of the events from the beginning of
  one heart beat to the beginning of the next heart
  beat
• When cardiac muscle contracts it does so as a
  single unit, creating a heart beat
• One heartbeat - a cardiac cycle - consists of two
  parts called systole and diastole

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Cardiac Cycle

• Diastole is the period of time when the heart
  relaxes after contraction

• Oxygenated blood from the lungs fills the left
  atrium
• Deoxygenated blood from other parts of the body
  fills the right atrium.

• At the end of the diastole, the atria contract,
  starting the Systole

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Cardiac Cycle
The term systole is synonymous with contraction
of a muscle.

• Atrial systole is the contraction of the heart
  muscle of the left and right atria. Both atria
  contract at the same time, sending blood into the
  corresponding ventricle

• Ventricular systole is the contraction of the
  muscles of the left and right ventricles, which
  contract at the same time.

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Cardiac Cycle

• During systole the ventricles contract, forcing
  the blood into the pulmonary artery to be
  re-oxygenated in the lungs, and into the aorta
  for systemic distribution of oxygenated blood

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Cardiac Cycle

• Heart Sounds

• Lub- sound- due to closure of the
  atrioventricular valves (mitral and tricuspid)
• Dub- sound- due to closure of the aortic valve
  and pulmonary valve

• Two normal heart sounds with each heart beat
• described as a..

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Cardiac Cycle

• Heart Rate - count of each heart beat
• On average, a heart beats 72 times a minute when
  at rest
• Usually it is calculated as number of
  contractions of heart (heart beats)in one minute
  and expressed as "beats per minute" (bpm).
• The pulse is the most straightforward way of
  measuring the heart rate
• Heart rate is controlled by nervous system

Hearse on an emergency
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Cardiac Cycle

• Sympathetic division increases heart rate
• Parasympathetic division decreases heart rate
• Heart rate increases when more food and oxygen
  are needed by the cells, or when under stress

• Resting heart rate can be significantly lower in
  athletes

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Cardiac Cycle
An electrocardiogram abbreviated as EKG or ECG
is a test that measures the electrical activity
of the heartbeat or one cardiac cycle.
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Cardiac Conduction System

• Why dont the atria and ventricles contract at
  the same time?
• Inefficient.Blood would not be moved in one
  direction,some would flow backwards

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Cardiac Conduction System

• Includes
• SA node
• AV node
• Bundle of His
• Purkinje fibers

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Cardiac Conduction System

• Sinoatrial Node (SA node)
• Located high on the right atrium.
• Pacemaker of the heart.
• Causes the wave of
  contractions in the
  atria.

• Sending bloodinto the ventricles

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Cardiac Conduction System

• Atrioventricular Node (AV node)
• Located in the interatrial septum close to the
  tricuspid valve
• Carries the electrical impulse from the SA node
  to fiber bundles in the ventricles.
• This causes the ventricles to
  contract

• The location of nerve fiber bundles cause the
  ventricles to contract from the apex (bottom)
  upsqueezing blood up and out

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Pathway of Circulation

• Oxygen-poor blood draining from the body through
  veins into the superior and inferior vena cava
  flows to the right atrium, through the tricuspid
  valve, and into the right ventricle.
• As the right ventricle contracts, oxygen-poor
  blood passes through the pulmonary valve into the
  pulmonary arteries and on to the lungs to receive
  oxygen.

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Pathway of Circulation

• Oxygen-rich blood from the lungs enters the heart
  through the pulmonary veins, passing into the
  left atrium.
• Then through the mitral valve to the left
  ventricle. Contraction of the left ventricle
  forces blood through the aortic valve into the
  aorta.
• Various arteries branch off from the aorta to
  supply blood to all parts of the body.

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Pathway of Circulation

• Arteries branch into smaller and smaller vessels
  (arterioles)
• They eventually become capillaries, which supply
  blood to all body parts
• Capillaries merge into (venuoles) which join into
  veins and carry blood back to the heart.

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Pathway of Circulation
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Pathway of Circulation
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It takes about 1 min. for blood to make 1
complete cycle
And so on
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CardiovascularCircuits
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Pulmonary Circulation

• Takes place on the right side of the heart.
• Pumps blood low in oxygento the lungs to
  pick up oxygen and return to heart

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Systemic Circulation

• Takes place on left side of heart
• Oxygenated blood is pumped tothe body cells
  thruthe aortaand otherarteries
• Blood lowin oxygenreturns to the heart

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Coronary Circulation

• The coronary circulation consists of the blood
  vessels that supply blood to, and remove blood
  from the heart muscle itself.

• Although blood fills the chambersof the heart,
  the muscle tissue of the heart is so thick
  that it requires coronary blood vessels to
  deliver blood deepinto the myocardium.

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Coronary Circulation

• The vessels that supply blood high in oxygen to
  the myocardium are known as coronary arteries.

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Blood Vessels

• Form a closed circuit of tubes that carry blood
  throughout the body
• Laid end to end, the blood vessels in an average
  human body will stretch approximately 62,000
  miles2.5 times around the earth

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Blood Vessels

• Have characteristic features
• Are distinguished by size, tissue layers and
  direction of blood flow

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Blood Vessels

• Arteries
• Receive blood from ventricles
• Take blood away from the heart
• Usually carry oxygenated blood
• Thickest vessel walls
• Withstand greater blood pressure
• Are very elastic
• Connect to capillaries
• Aorta is the largest artery

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Blood Vessels

• Veins
• Transport blood away from capillaries
• Carry blood toward heart
• Take blood to atria
• Have valves
• Thinner vessel walls with lesssmooth muscles
• than arteries
• Can stretch a great deal
• Have larger diameters
• Usually carry de-oxygenated blood
• Vena cava is the largest vein

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Blood Vessels

• The contraction of muscles compressing veins
  helps push blood up through the leg veins back to
  the heart. The valves allow the blood to flow
  towards the heart only.

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Blood Vessels

• Capillaries
• Smallest of blood vessels
• Only one cell thick (epithelial cell)
• Connect arteries to veins
• Bring oxygen and nutrients to cells
• Removes CO2, urea, and other wastes from cells
• Where blood is under low pressure and moving
  slowly

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Blood Vessels

• A network of capillaries runs close to the cells
  in every part of the body. The capillaries have
  very thin walls which allows nutrients to diffuse
  through into the tissues and waste products to
  filter back into the capillaries.

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• C B
• O L
• M O
• P O
• A D
• R
• I V
• S E
• O S
• N S
• E
• O L
• F S

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Blood Pressure

• Blood pressure refers to the force exerted by
  circulating blood on the walls of blood vessels

The pressure of the circulating blood decreases
as blood moves through arteries, arterioles,
capillaries, venules, and veins
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Blood Pressure

• Blood pressure is most commonly measured via a
  sphygmomanometer(blood pressure cuff)
• It uses the height of a column of mercury to
  reflect the circulating
  pressure

• Average blood pressure for an adult is 120/80

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Blood Pressure

• Systolic pressure is defined as the maximum
  pressure in the arteries exerted during
  ventricular contraction (which occurs near the
  beginning of the cardiac cycle)
• Diastolic pressure is the minimum pressure
  exerted when ventricles relax and fill (at the
  resting phase or end of the cardiac cycle)
• Blood pressure readings S/D

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Blood Pressure

• Pressure waves move through the blood vessels
• A person's pulse is the throbbing of their
  arteries as an effect of the pressure waves
  (heart beat)
• Pulse is used to denote the frequency of the
  heart beat

• It can be felt at neck, wrist, and other places
• Pulse is usually measured in beats per minute.
• In most people, the pulse is an accurate measure
  of heart rate.

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Blood Pressure
vasodialation
Vasoconstricion
and

• Vasoconstriction is narrowing of a blood vessel.
• When a blood vessel constricts, the flow ofblood
  is restricted or slowed.
• Blood pressure will increase

• Vasodilatation is where blood vessels in the
  body become
  wider
  following relaxation
  of smooth muscle
  in vessel wall. This
  will reduce
  blood
  pressure - since
  there is more room
  for the blood.

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Blood

• The life stream of the body, affecting every cell
  and system we have.

• The blood is an accumulation of many different
  elements, each working in a specific way to keep
  us alive.

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Blood

• A circulating connective tissue consisting of
  several types of cells suspended in a fluid
  medium known as plasma.

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Blood

• Functions of blood
• Supply oxygen to tissues
• Supply nutrients such as glucose, amino acids and
  fatty acids to tissues

• Removal of wastes such as CO2 , urea and lactic
  acid from tissues
• Immunological functions, including circulation of
  white cells, and detection of foreign material by
  antibodies

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Blood

• Functions of blood continued
• Messenger functions, including transport of
  hormones and signaling of tissue
• Coagulation, part of body's self-repair
  mechanism
• Regulation ofcore body temperature
• Regulation of body pH and ion concentrations

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Blood
8

• What percent of your body is blood?
• How much blood do we contain?
• On average 4-6 liters
• We contain about a pint of blood for every 15
  pounds of body weight
• Composition of Blood
• What percent of your blood is cellular?
• What percent of your blood is plasma?

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Blood

• What is plasma?
• A clear, straw colored fluid
• What percent of plasma is water?
• Whats in plasma?

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• Dissolved gasses
• Vitamins
• Minerals
• Salts
• Nutrients

• Enzymes
• Hormones
• Waste products
• Plasma proteins

Layering of blood components in a centrifuged
blood sample
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Blood

• The cellular components are
• red blood cells (erythrocytes)
• white blood cells (leukocytes)
• platelets (thrombocytes)
• Blood cells are formed in bonemarrow

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Blood

• B
• L
• O
• O
• D
• C
• E
• L
• L

F O R M A T I O N
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Blood

• Red Blood Cell Characteristics
• (RBC)- Erythrocyte
• Biconcave disks
• No nucleus
• Contain the iron based pigment hemoglobinwhich
  binds with oxygen to transport it
• Life span about 120 days
• 5 billion/1mL of blood most numerous
• Are very small

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Blood

• To the right is a Wright's stained peripheral
  blood smear under 1000 X magnification.

• The average size of a red blood cell is 7.2
  micrometers in diameter.

• To the right is an artist's drawing showing the
  biconcave shape of the red blood cell.

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Blood

• How RBCs transport oxygen....Hemoglobin
  .the iron containing pigment

Hemoglobin makes red blood cells red
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Blood

• White Blood Cell Characteristics
• (WBC)- Leukocyte
• No definite shape
• Have nucleus
• Protect body against infection
• Life span varies (3 days-a few months)

• 7,000/1mL of blood
• Numbers increase ifinfection is present
• Larger than RBCs

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Blood

• Types of white blood cells
• Monocytes are the largest
• Neutrophils are the most numerous
• Lymphocytes are produced by the lymph tissue
• Basophils releasehistamines

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Blood

• Types of white blood cells

When a cell undergoes apoptosis, programmed cell
death, white blood cells called macrophages
consume cell debris.
The role of a macrophage is to phagocytize
(engulf and then digest) cellular debris and
pathogens.
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Blood

• Platelet Characteristics
• Thrombocyte
• RBC fragments
• Irregularly shaped
• No nucleus
• 150,000-400,000/1mL
• Life span about 7-11 days
• Have a sticky surface
• Responsible for blood clotting (injury
  healing)

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Blood

• This is an actual picture of White Blood Cells,
  in with some red blood cells. The platelets are
  stained purple, a T-Lymphocyte white cell is
  stained green, and a Monocyte white cell is
  stained gold as seen through a scanning
  electronmicroscope.

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Blood

• Red blood cells and platelets are the most
  numerous.
• Of the leukocytes, neutrophils are the most
  numerous
• Lymphocytes are the predominant cell type
  responsible for immune responses.

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Blood Clotting

• Steps in Blood Clotting
• platelets clump
• platelets release thromboblastin
• thromboblastin produces thrombin
• thrombin converts fibrinogen into fibrin
• fibrin causes a clot

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Blood Clotting

• Blood vessel is injured.
• Platelets clump at the site and produce a
  substance that produces strands of fibrin.
• Fibrin strands help to clog the opening or hole
  in the vessel.

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Blood Clotting
Needed to stop bleeding(hemorrhage)
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Blood Types

• ABO Blood Groups
• Red blood cell membranes may contain antigens
  a substancethat triggers an immune response in
  blood that does not contain the same antigen.
• Blood plasma may contain antibodies, specialized
  proteins that bind to non-self antigens to
  destroy them.
• It is important to prevent the mixing of red
  cells that contain an antigen with plasma that
  contains the corresponding antibody.

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Blood Types
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Blood Types
Anti- Body
Receive From
Donate To
Type
Antigen
A
A
A or O
A or AB
Anti - B
B
Anti - A
B
B or AB
B or O
UniversalReceiver
Neither
AB
A B
AB,A,B,O
AB
UniversalDonor
O
None
Both
O
O,A,B,AB
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Blood Types
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Blood Types

• Blood Transfusion
• The process of transferring blood or blood-based
  products from one person into the circulatory
  system of another
• For blood loss due to trauma, surgery, or severe
  anemia
• Can be life-saving

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Blood Types

• What Happens When Mixing Wrong Blood Type?

• Antibodies in blood will attack the foreign
  blood.
• They will cause the blood cells to clump.
  agglutination.
• Will stop the blood from moving.
• Circulatorysystem shuts down

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Blood Types Rh Factor

• An additional antigen found on the surface of red
  blood cells.
• Rh Means that the person carries the
  antigen.
• Rh - Means that the person
  DOES NOT carry the
  antigen.

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Blood Types Rh Factor
Percentage of the Population With Each Blood Type
The Rh, or rhesus, factor wasdiscovered
in1940 when testing bloodwith a rhesus monkey.
The Rh system was named after rhesus monkeys,
since they were initially used in the research to
make the antiserum for typing blood samples. 
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Blood Types Rh Factor
Rh-negative Woman withRh-positivefetus
In the nextRh-positivepregnancy,maternalantibo
diesattack fetalred bloodcells
Cells fromRh-positivefetus enterwomansbloodst
ream
Rh-negative Woman and Rh-positive manconceive a
child
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Circulatory System Disorders
Heart Disease

• Risk factors
• Older age
• Male gender
• Cigarette smoking
• High cholesterol
• Diabetes
• Stress
• Obesity
• Heredity
• Physical inactivity 
• High blood pressure  

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Circulatory System Disorders
Atherosclerosis

• Starts with damage or injury to the inner layer
  of an artery
• Fatty deposits called plaquebuild up in the
  arteries
• This causes
• Blockage in artery
• Less flexible vessels
• High BloodPressure

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Circulatory System Disorders
Hypertension

• High Blood Pressure

Makes the heart and blood vessels work
harder Increases the chance of heart disease,
heart attack or stroke
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Circulatory System Disorders
Heart Attack

• acute myocardial infarction
• Interruption of oxygen supply to the heart
• Causes death of the heart muscle
• Leading cause of death in both men and women

Coronary Blockage
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Circulatory System Disorders
Heart Attack

• Symptoms
• Chest pain
• Squeezing or heavy pressure on chest
• Pain that radiates down left shoulder and arm
• Shortness of breath
• Nausea or vomiting
• Anxiety or Fainting
• Lightheadedness - dizziness
• Palpitations (feeling like your heart is beating
  too fast)
• Sweating, which may be extreme

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Circulatory System Disorders
Stroke

• Interruption of oxygen supply to the brain
• Caused by
• A clot in an artery in the brain
• Breakage of an artery in the brain
• Causes brain cells to be deprivedof oxygen and
  die

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Circulatory System Disorders
Thrombosis/Embolism

• Thrombosis is the formation of a clot
  (thrombus) inside a blood vessel, obstructing the
  flow of blood

• Embolism occurs when an object (usually a blood
  clot) migrates from one part of the body
  (through circulation) and causes a blockage
  (occlusion) of a blood vessel in another part of
  the body

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Circulatory System Disorders
Hemorrhage

• Hemorrhage is the medical term for bleeding -
  the loss of blood from the body
• Hemorrhage generally becomesdangerous, or even
  fatal, when it causes hypovolemia (low blood
  volume) or hypotension (low blood pressure).

• Hematoma- a collection of blood due to internal
  bleeding (burse)

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Circulatory System Disorders
Hem philia

• A rare inherited bleeding disorder in which the
  blood does not clot normally
• The person is missing or has low levels of
  certain proteins in the blood called clotting
  factors
• Usually occurs only in males
• They suffer prolonged bleedingeven with minor
  injuries
• Bleeding can occur internally, in joints and
  muscles, which causes
  swelling and pain

Swelling in left knee joint due to spontaneous
bleeding
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Circulatory System Disorders
Anemia

• A condition where there is an abnormally low
  number of red blood cells circulating in the body
  or when the blood does not have enough hemoglobin
  
• The body's tissues are being starved of oxygen
• Most common disorder of the red blood cells,
  affecting () 3.5 millionAmericans
• There are different kinds of anemia
• Iron Deficiency
• Vitamin Deficiency
• Hemolytic Anemias
• Sickle Cell Anemia

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Circulatory System Disorders
Anemia
Iron Deficiency Anemia

• A person with anemia will feel tired, weak,
  breathless, and dizzy
• They may have a pale complexion, increased heart
  rate, low blood pressure, and difficulty
  concentrating
• The severity of the symptoms is related to the
  severity of anemia

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Circulatory System Disorders
Sickle Cell Disease

• Sickle cell trait- The person is carrying the
  defective gene, but also has some normal
  hemoglobin

• Sickle cell anemia-The person has most or all of
  the normal hemoglobin replaced with the sickle
  hemoglobin

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Circulatory System Disorders
Valve Disorders

• Valvular Regurgitation

• Valvular stenosis
• A condition in which there is a narrowing,
  stiffening, thickening, fusion
  or blockage of
  one or more valves of
  the heart.

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Circulatory System Disorders
Heart Murmur

• A whooshing sound between the heart beats
• The whoosh is an extra noise that blood makes as
  it flows through any of the heart's chambers or
  valves or even through a hole within the heart
• More than half of all children have a heart
  murmur at some time in their lives and most of
  these don't mean anything is wrong

Problems Opening
Problems Closing
Normal Heart Valve
Closed
Opened
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Circulatory System Disorders
Heart Murmur

• Innocent heart murmurs can occur when blood flows
  more rapidly through the heart - such as during
  physical activity or exercise, pregnancy, fever,
  anemia, from aging or even heart surgery
• Over time, innocent heart murmurs may disappear
• Abnormal heart murmurs are caused by structural
  defects in the heart. congenital heart defects,
  valve abnormalities, or holes in the heart
• Some abnormal defects can be treated with
  medicines while others require surgical repair

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Circulatory System Disorders
Aneurysm

• Localized, blood-filled dilation (bulge) of a
  blood vessel caused by disease or weakening of
  the vessel wall
• Most commonly occur in arteries at the base
  ofthe brain and in the aorta
• Can burst andlead to deathat any time

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Blood Vessel Microscope Slide
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