Download The Cardiovascular System)

Ch. 13 Notes (The Cardiovascular System)
Functions of the Cardiovascular System
 Brings blood containing _______________, __________________, and ___________________ to cells
 Transports _______ and other wastes away from cells
 Fights infection
 Regulates body temperature
 Helps stabilize ______ and ______________________________ of body fluids.
Components
 Heart
 Blood
 Vessels: __________________________________________________
The Heart
 Is a muscular pump that moves blood through the body
 Is suspended in the _______________________
 Composed of four chambers
 Divided into right and left halves
 Made up of __________________ muscle cells
Layers of the Heart
 _____________________ – protective sac of connective tissue that surrounds the heart and filled with fluid
 _____________________ (outer) – (visceral pericardium) connective tissue that protects the heart from friction
 _____________________ (middle)
o The muscle of the heart
o Strong and thick
o Composed of spontaneously contracting cardiac muscle fibers
o Can conduct electricity like nerves
o It’s blood supply comes from the _____________________
 _____________________ (inner) – consists of epithelium and connective tissue that contains many elastic and
collagenous fibers
Structures of the Heart
Chambers
 ___________ – (2) upper chambers
o Thin walled
o Receive blood from veins
o Send blood to ventricles
 _____________________ – (2) lower chambers
o Thick walled
o Receive blood from atria
o Pump blood out through arteries
 __________________ – a wall that divides heart into right and left halves
 Valves
o Prevent backflow of blood
o Keep blood moving in one direction
o Located between the chambers
 ___________________________
o “Heart strings”
o Cord-like tendons
o Connect papillary muscles to tricuspid and mitral valves
o Prevent inversion of valve
 _____________________ – small muscles that anchor the cords
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 ___________________and ___________________
Diastole is the period of time when the heart relaxes after contraction
Oxygenated blood from the lungs fills the _____________________________
Deoxygenated blood from other parts of the body fills the _______________________________
At the end of the diastole, the atria contract, starting the Systole
Heart Sounds
o Two normal heart sounds with each heart beat described as a…..
o “_________”- sound- due to closure of the atrioventricular valves (____________and______________)
o “_________”- sound- due to closure of the aortic valve and pulmonary valve
 Heart Rate - count of each heart beat
 On average, a heart beats _______ 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 _____________________________
 An ____________________________ abbreviated as EKG or ECG is a test that measures the electrical activity
of the heartbeat or one cardiac cycle.
Cardiac Conduction System
 Includes:
 _____________________ , _____________________ , _____________________ , _____________________
 Sinoatrial Node (SA node)
o Located high on the right atrium.
o _____________________ of the heart.
o Causes the wave of contractions in the atria to send blood into the ventricles
 Atrioventricular Node (AV node)
o Located in the interatrial septum close to the tricuspid valve
o Carries the electrical impulse from the SA node to fiber bundles in the ventricles.
o This causes the ventricles to contract from the apex (bottom) up squeezing blood up and out
Cardiovascular Circuits
 _____________________ Circulation
o Pumps blood low in oxygen to the lungs to pick up oxygen and return to heart
 _____________________ Circulation
o Oxygenated blood is pumped to the body cells thru the aorta and other arteries
o Blood low in oxygen returns to the heart
 _____________________ Circulation
o The coronary circulation consists of the blood vessels that supply blood to, and remove blood from the
heart muscle itself.
o The vessels that supply blood high in oxygen to the myocardium are known as coronary arteries.
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 miles……2.5
times around the earth
 _____________________
o Receive blood from ventricles
o Take blood away from the heart
o Usually carry _____________________ blood
o Thickest vessel walls
o Withstand greater blood pressure
o Are very elastic
o Connect to capillaries
o _____________________ is the largest artery

________________________
o Transport blood away from capillaries
o Carry blood toward heart
o
o
o
o
o
o
o
o
Take blood to atria
Have valves
Thinner vessel walls with less smooth muscles than arteries
Can stretch a great deal
Have larger diameters
Usually carry _____________________ blood
_____________________ is the largest vein
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
 ___________________________
o Smallest of blood vessels
o Only one cell thick (epithelial cell)
o Connect ___________________ to _____________________
o Bring oxygen and nutrients to cells
o Removes CO2, urea, and other wastes from cells
o Where blood is under low pressure and moving slowly
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
 Blood pressure is most commonly measured via a _______________________________ (blood pressure cuff)
 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
 Pulse is usually measured in _________________________________________.
 In most people, the pulse is an accurate measure of heart rate.
Circulatory System Disorders
Heart Disease
 Risk factors
 Older age
 Male gender
 Cigarette smoking
 High cholesterol
 Diabetes
Atherosclerosis
 Starts with damage or injury to the inner layer of an artery
 Fatty deposits called plaque build up in the arteries
 This causes:
 Blockage in artery
 Less flexible vessels
 High Blood Pressure
Hypertension (High Blood Pressure)
 Makes the heart and blood vessels work harder
 Increases the chance of heart disease, heart attack or stroke
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
 Symptoms
 Chest pain
 Squeezing or heavy pressure on chest
 Pain that radiates down left shoulder and arm
 Shortness of breath





Stress
Obesity
Heredity
Physical inactivity
High blood pressure
 Nausea or vomiting
 Anxiety or Fainting
 Lightheadedness - dizziness
 Palpitations (feeling like your heart is beating too fast)
 Sweating, which may be extreme
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 deprived of oxygen and die
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
Hemorrhage
 Hemorrhage is the medical term for bleeding - the loss of blood from the body
 Hemorrhage generally becomes dangerous, or even fatal, when it causes hypovolemia (low blood volume) or
hypotension (low blood pressure).
Hemophilia
 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 bleeding even with minor injuries
 Bleeding can occur internally, in joints and muscles, which causes swelling and pain
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 million Americans
 There are different kinds of anemia
 Iron Deficiency
 Vitamin D eficiency
 Hemolytic Anemias
 Sickle Cell 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
Sickle Cell Disease
 Sickle cell trait- The person is carrying the defective gene, but also has some normal hemoglobin
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.
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
 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
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 of the brain and in the aorta
 Can burst and lead to death at any time