Transcript Cardiovascular System

CARDIOVASCULAR SYSTEM
CARDIOVASCULAR SYSTEM
 Often referred to as the transportation system
 Consists of the: Heart, Blood Vessels and the Blood
 It carries oxygen and nutrients to the cells and metabolic material and carbon
dioxide away from the cells
THE HEART
THE HEART
 Muscular hollow organ that pumps blood throughout the body
 Weighs less than a pound and about the size of your fist
 It contracts about 100,000 times a day and pumps the equivalent of 2000 gallons
of blood through the body
 Located in the mediastinal cavity which is located between the lungs, behind the
sternum and above the diaphragm
TISSUE OF THE HEART
 Endocardium-smooth layer of tissue
that lines the inside of the heart and is
continuous in the vessels. It allows for
smooth flow of blood.
 Myocardium-muscular middle layer of
the heart that allows for contraction
and movement of blood flow.
 Pericardium-Double layered
membrane or sac that covers that
outside of the heart. Filled with
pericardial fluid that diminishes
friction and damage to the
membranes as the heart beats
PARTS OF THE HEART
 Septum-muscular wall that separates
the heart into right and left sides
 Prevents blood flow between right
and left sides
 Two parts:
 Interatrial Septum
 Interventricular Septum
PARTS OF THE HEART
 The Right Atrium
 Receives blood as it returns from the
body cells
 Blood enters from the Superior and
Inferior Vena Cava
 Blood is deoxygenated
PARTS OF THE HEART
 The Right Ventricle
 Receives blood from right atrium
 Pumps blood to the lungs for oxygen
via the Pulmonary Artery
PARTS OF THE HEART
 Left Atrium
 Receives oxygenated blood from the
lungs via Pulmonary Veins
PARTS OF THE HEART
 Left Ventricle
 Receives blood from the left atrium
 Pumps oxygenated blood to the body
 Uses the Aorta to transport blood
PARTS OF THE HEART
 Valves
 Tricuspid Valve-Located between the
right ventricle and right atrium, it
closes when the right ventricle
contracts, allowing blood to flow to the
lungs and preventing blood from
following back into the right atrium.
PARTS OF THE HEART
 Pulmonary Valve
 Located between the right ventricle
and pulmonary artery
 Closes when the right ventricle finishes
contraction
 Prevents blood flow back into the right
ventricle
PARTS OF THE HEART
 Mitral Valve
 Located between left atrium and left
ventricle
 Closes when left ventricle contracts
 Prevents blood flow back into left
atrium
PARTS OF THE HEART
 Aortic Valve
 Located between the left ventricle and
aorta
 Closes when the left ventricle finishes
contracting
 Prevents blood flow back into the left
ventricle from the aorta
CARDIAC CYCLE (HEART BEAT)
 Though the heart is separated into
two halves it does work in unison
when the heart beats.
 The cycle consist of a brief rest period
called Diastole
 The contraction that follows Diastole
comes from the ventricles and is
known as systole
 Two contractions in one beat, first the
atriums contract then relax then the
ventricles contract then relax. That
gives us the “lub-dub” sound we here
CONDUCTIVE PATHWAY
 Electrical impulses originating in the
heart cause cyclic contraction of the
muscle fibers of the heart.
 Bundle of His branches into a right
bundle branch and a left bundle
branch.
 Group of nerves located in the right
atrium called the Sinoatrial Node
 These carry the impulse throughout
the ventricles into the Purkinje Fibers
 Sends out electrical signal over both
atria, which forces contraction.
 These fibers are another bundle of
nerve fibers that insure the impulse
reaches all fibers of the heart causing
ventricular contraction
 Once impulse passes through atria it
reaches the Atrioventricular node
which then send impulse to the
Bundle of His
CONDUCTIVE PATHWAY
CONDUCTIVE PATHWAY OF THE HEART
 Electrical Pathway occurs
approximately every .8 seconds
 Treatment is dependent on type and
severity
 We can record this via (ECG) or
electro-cardiogram to detect
abnormal rhythm or disease
 Defibrillators, pacemakers and
medicines are common treatments
 Abnormal rhythms are called
Arrhythmias
 May be mild or life threating
depending on location and severity
CONDUCTIVE PATHWAYS
 Pace Makers
 Small battery powered device with
electrodes
 Electrodes are threaded through a vein
into the right atrium and the apex of
the right ventricle
 Device monitors heart rhythm and
delivers shocks based on the rhythm
 Either deliver predetermined shocks
(fixed) or shocks when it senses heart is
out of rhythm (demand)
BLOOD VESSELS
 Arteries- carry blood away from the heart
 Aorta is the largest artery
 Aorta branches into all other arteries of the body that supply blood
 1st branch of the aorta is the coronary artery which divides into right and left
branches which supply blood to the myocardium of the heart
 Smallest branches of arteries are called arterioles and they join with the capillaries
 Arteries are more muscular and elastic than other blood vessels because they
receive blood pumped from the heart
BLOOD VESSELS
BLOOD VESSELS
 Capillaries connect arterioles with venules (smallest veins)
 Capillaries are located within close proximity to almost every cell in the body
 Have very thin walls and only have one layer of cells
 These walls allow from transmission of oxygen and nutrients and receiving of
metabolic waste and carbon dioxide
BLOOD VESSELS
BLOOD VESSELS
 Veins carry blood back to the heart
 Venules are the smallest veins and connect to capillaries
 Two largest veins are the Superior Vena Cava and Inferior Vena Cava
 Veins are thinner and less musclur
 Contain valves that prohibit blood flow backwards
BLOOD VESSELS
BLOOD VESSELS
BLOOD VESSELS
BLOOD VESSELS
BLOOD COMPOSITION
 Approximately 4-6 quarts of blood within the average adult
 Transports oxygen and nutrients to the body systems and removes waste and
carbon dioxide from the systems
 Also transports hormones, heat and metabolic wastes
 Composed of two parts: Plasma and Blood Cells
BLOOD PLASMA
 90% water
 Contains blood proteins as well: Fibrinogen and Prothromin, both needed for
clotting
 Also contains: nutrients, carbon dioxide and oxygen, metabolic and waste
products, hormones and enzymes
BLOOD CELLS
 Erythrocytres
 Red Blood Cells
 Produced in red bone marrow at a rate
of one million per minute
 Live about 120 days
 About 4.5 to 5.5 million per millimeter
of blood (one drop)
 Contain Hemoglobin which is part
protein (globin) part iron (heme)
 Carries both oxygen and carbon dioxide
BLOOD CELLS
 Leukocytes
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White Blood cells
Formed in yellow bone marrow
Not as numerous
Live 3-9 days
5000-9000 per millimeter of blood
Can pass through capillary walls and
enter tissue
 Main function is to fight infection
 Most do this through phagocytosis
BLOOD CELLS
 Leukocytes
 5 types
 Neutrophils-phagocytize bacteria by
secreting an enzyme called lysozyme
 Eosinophils-remove toxins and defend
the body from allergic reaction by
producing antihistamines
 Basophils-participate in the bodies
inflammatory response; produce
histamine (vasodilator) and heparin
(anticoagulant)
 Monocytes-phagocytize bacteria and
foreign materials
 Lymphocytes-provide immunity for the
body by developing antibodies
BLOOD CELLS
 Thrombocytes
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AKA Platelets
Form in red bone marrow
Live 5-9 days
250,000-400,000 per millimeter of
blood
 Important for clotting purposes
STEPS TO BLOOD CLOTTING
PROBLEMS IN THE SYSTEM
 Anemia
 Lack of red blood cells or hemoglobin or
both
 Symptoms include: pallor (paleness),
fatigue, dyspnea (difficulty breathing),
and rapid heart rate
 Types:
 Acute-Blood-Loss-hemorrhage that results
in rapid blood loss
 Iron Deficiency-Inadequate amount of iron
in the system
 Aplastic-Injury to the bone marrow leads to
lack of formation of blood cells
 Pernicious-abnormally large blood cells but
not as many
 Sickle Cell-inherited anemia that results in
abnormally shaped red blood celss
PROBLEMS OF THE SYSTEM
 Aneurysm
 Ballooning out of the artery wall
 Disease, congenital defect or injury
leads to weakened wall
 Can cause pain or pressure or could
result in no symptoms at all
 Potential for ruptures can lead to
hemorrhage and possible death
 Surgical removal is best treatment with
replacement of wall with plastic or
another vessel
PROBLEMS OF THE SYSTEM
 Arteriosclerosis
 Hardening or thickening of the artery
walls, resulting in loss of elasticity and
contractility
 Results from ageing
 Can cause hypertension-aneurysmcerebral hemorrhage
 Treatment is lower blood pressure
through diet, medications or both
PROBLEMS OF THE SYSTEM
 Atherosclerosis
 Occurs when fatty plaques are
deposited on the walls of the arteries
 This narrows the opening which can
reduce or eliminate blood flow
 Have the potential to break loose
causing embolisms
 Treatment includes: diet, exercise,
reduction of stress, avoidance of
tobacco products, angioplasty, bypass
surgery
PROBLEMS OF THE SYSTEM
 Embolus
 A foreign substance circulating in the
bloodstream. It can be air, a blood clot,
bacterial clots, or a fat globule
 Enters a passage too small can result in
blockage of the vessel
PROBLEMS OF THE SYSTEM
 Hemophilia
 Inherited disease that occurs almost
exclusively in males
 Lack of a blood protein leads to
inability to clot
 Hypertension
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High blood pressure
Systolic over 140
Diastolic over 90
Risk factors include: family history,
race, obesity, smoking, stress and age
 Treatment is diet, exercise and
medication
PROBLEMS OF THE SYSTEM
 Myocardial Infarction
 Heart Attack
 Blockage of coronary artery cuts off the
supply of blood to the heart
 The affected heart tissue dies this is
known as an infarct
 Death can occur immediately
 Symptoms include: crushing chest pain,
radiates to the neck and down left side
of the body, cold sweats, dyspnea, and
blood pressure change
 Treatment if caught: medications, diet,
exercise and surgery if needed
PROBLEMS OF THE SYSTEM
 Phlebitis
 Inflammation of a vein
 Usually occurs in the leg
 Symptoms include: pain, edema,
redness, and discoloration
PROBLEMS OF THE SYSTEM
 Varicose Veins
 Dilated swollen veins that have lost
elasticity and causes stasis
 Occur in the leg
 Result from: pregnancy, prolonged
sitting or standing, and heredity factors
 Treatment: exercise, support garments,
avoidance of prolonged sitting or
standing and tight fitting clothing,
possible surgery