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Blood Vessels & Blood Transport
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Arteries Large hose-like vessels that carry blood away from the heart.
Have thick, multi- layered muscular walls. Walls are capable of stretching to accommodate the “pulse” of blood when the heart beats. Walls of arteries are thicker and stronger than the walls of veins and capillaries. Artery walls contain large amounts of muscle and elastic tissue. Muscle and elastic tissue allows an artery to change its diameter. Elastic tissue allows the artery to expand when the heart pumps blood into it. The blood exerts pressure against the vessel walls as it moves through the vessel, this is referred to as blood pressure. When an artery widens, more blood can flow through it, blood pressure decreases. When an artery contracts, less blood can flow through it, blood pressure increases. By changing diameter, an artery helps regulate blood flow and pressure.
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Arteries Capable of expanding and contracting to change and maintain the blood pressure. NO valves Blood spurts Blood inside them is high in oxygen & low in carbon dioxide except in pulmonary artery.
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Arteries Blood inside is bright red
Blood inside is under High pressure Examples: Coronary (heart), Brachial (arms), Carotid (head), Femoral (legs), Renal (kidney). Hepatic (liver)
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Arterioles Tiny branches off of the arteries.
Cannot be seen with unaided eye - microscopic Thinner, less muscular walls (compared to arteries) Feed blood into the capillaries. Narrower than arteries, but wider than capillaries.
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Capillaries Flow and pressure of blood is controlled by sphincters that are outside of the capillaries. Microscopic vessels ~ 8 µm in diameter. Erythrocytes (rbc’s) pass through in single file. Walls are only one cell thick (to facilitate diffusion of materials/exchange).
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Capillaries Thinness allows for easy diffusion outward or inward through the single cell layer. Form capillary beds - networks of vessels linking arterial and venous blood.
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Capillaries Oxygen , nutrients and other materials move out of the capillaries and into the extra-cellular fluid and then into cells. Carbon dioxide, wastes and other materials are picked up and move into the capillaries: (both involve diffusion for the movement).
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Venules Vessels larger than capillaries but smaller (i.e. narrower and thinner walls) than veins.
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Veins Larger inside diameter compared to arteries
Take blood towards the heart Thinner, less muscular walls than arteries, but still 3 layers No stretching or contracting of walls except by external muscles. Contain valves to help return the blood to the heart (compensate for lower venous pressure, less muscle in walls, and large diameter).
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Veins - Valves
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Veins Blood: Moves smoothly.
Low in oxygen except pulmonary circulation. Dull red. Low pressure. Examples: cardiac (heart) brachial (arms), jugular (head), femoral (legs), renal (kidney).
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Varicose Veins ADD THIS TO THE BOTTOM OF YOUR PAGE When the valves don’t function properly, blood leaks backwards and pools in veins Veins sag, stretch and swell, creating bulging knarled vessels
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Complete the Compare & Contrast On Page 2 (Point Form)
READ & Highlight The Blood Vessels Information on Page 3 of the booklet. Complete the Compare & Contrast On Page 2 (Point Form) Complete Questions 1-7 on the Back page DUE: Next Class
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Thin Endo Thin Endo Thin layer Thick layer Thin layer Thick layer
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The Circulatory System
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The Circulatory System
The circulatory system maintains Homeostasis (balance) by… 1. Facilitating gas exchange (O2 & CO2) 2. Delivering nutrients (from digestion) to cells 3. Picking up cellular waste 4. Facilitating temperature regulation 5. Assisting in an immune response 6. Delivering hormones 7. Closing wounds by clotting
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Coronary Circulation is the circulation of blood in the blood vessels of the heart muscle. The vessels that carry oxygen- rich blood to the myocardium (heart tissue) = coronary arteries. The vessels that remove deoxygenated blood from the heart muscle = cardiac veins.
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The Circulatory System
Pulmonary Circulation: carries deoxygenated blood away from the heart, to the lungs, and returns oxygenated (oxygen-rich) blood back to the heart. Systemic Circulation: carries oxygenated blood away from the heart to the body, and returns deoxygenated blood back to the heart.
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LA RA LV RV
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The Heart Is a muscle. Made of cardiac muscle (myocardium) tissue.
Contractions are innate and will continue without nervous stimulation in some circumstances. (Myogenic) 2 Separate pumps (oxygenated & deoxygenated blood). Size of a fist. Located in the thoracic cavity or chest. Located in the pericardial cavity.
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The Heart Covered by a protective membrane called the pericardium.
4 valves stop the backflow of blood: tricuspid, bicuspid, aortic semilunar, & pulmonary semilunar. Valves are controlled by tendons: the chordae tendonae (which are anchored by papillary muscles) ADD TO NOTES!
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Complete the Labels on THE HUMAN CIRCULATORY SYSTEM DIAGRAM Highlight & Make Note of the Main Arteries and Veins
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ATRIOVENTRICULAR VALVES
Tricuspid between the Right Atrium & the Right Ventricle Bicuspid between the Left Atrium, & the Left Ventricle SEMILUNAR VALVES Aortic Semilunar between the Left Atrium and the Aorta Pulmonary Semilunar between the Right Atrium and the Pulmonary Artery Papillary Muscles
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HEART Valves: LABEL IN NOTES
Tricuspid & Bicuspid are Atrioventricular (AV) Valves Tricuspid Valve Bicuspid (Mitral) Valve Aortic Semilunar Valve Pulmonary Semilunar Valve
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The Right Side of the Heart
Collects blood from around the body and pumps it to the lungs. 2 Collection tubes: Superior Vena Cava: collects blood from the head, arms, & upper trunk. Inferior Vena Cava: collects blood from lower trunk, & legs. Pumps blood to the lungs: Pulmonary circulation (heart ↔ lungs ↔ heart) RIGHT SIDE OF THE HEART = DEOXYGENATED BLOOD
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The Left Side Has thicker, more muscular walls than the right side.
Collects the blood from the lungs and pumps it to all the parts of the body: Systemic Circulation (heart ↔ body ↔ heart). Blood enters the left side through the pulmonary veins: 2 from each lung. LEFT SIDE OF THE HEART = OXYGENATED BLOOD
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The Circulatory System
Blood Flow Start and end at the Left Atrium, name each structure of the circulatory system that you come into contact with (including valves). The structures must be listed in order & color coordinated properly. Don't forget the mystery box as a prize.
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Left Atrium ← ↓ Bicuspid Valve Left Ventricle Aortic Semilunar Valve Aorta Arteries Arterioles Capillaries (capillaries→cells→capillaries) Venules → Pulmonary Veins ↑ Lungs (capillaries) Pulmonary Artery Pulmonary Semilunar Valve Right Ventricle Tricuspid Valve Right Atrium Superior & Inferior Vena Cava Veins
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Pulmonary Trunk Pulmonary SL Valve Chordae Tendinae
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Video – How the heart works
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T/F About Blood Pressure
Blood pressure begins with a heartbeat. Blood pressure stays the same all day, every day. Blood pressure helps the blood flow to all parts of the body. A blood pressure reading has two numbers. You can tell what your blood pressure is by the way you feel. A healthy person could have a blood pressure of around 120/80. Blood pressure should be checked every five years. You can only tell what your blood pressure is by having it measured. Being overweight can lower blood pressure. Eating large amounts of food high in salt (sodium) can cause blood pressure to rise. Regular exercise will help keep your blood pressure healthy. Only a relaxed and easygoing person can have normal blood pressure.
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Blood Pressure Blood pressure is the force the blood exerts on the body tissue Remember blood pressure is controlled by the pumping of the heart Pressure is highest near the heart and decreases as it gets to the capillaries Baroreceptors measure pressure in the blood, just as chemoreceptors measure the chemicals in the blood (CO2 mainly) A Sphygmomanometer is used to measure Blood Pressure externally
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Blood Pressure Systole = Contractions of the ventricles; systolic pressure High blood pressure created by the emptying of the left ventricle. Diastole = is the relaxation phase of the ventricles when they are filling with blood. Low Pressure maintained by the arteries between contractions Normal Adult 120/80mmHg Normal Child = 115/70 mmHg
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Factors that Affect Blood Pressure
The amount of blood: blood can be lost as a result of injury or increased as a result of a disorder such as cancer. The less blood there is, the less pressure. The heart rate: the faster the heart pumps blood, the greater the pressure which is built up. The pressure falls as the heart rate decreases, especially during rest or sleep. The size of the arteries: when the arteries vasodilate the volume of the vessel increases and the pressure falls. If the arteries vasoconstrict the pressure is higher because of the extra resistance to blood flow.
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Factors that Affect Blood Pressure
4. The elasticity of the vessels: the walls of the arteries must be flexible as a surge of blood is forced out of the heart, and then relax after the surge has passed. If they cannot stretch in this way, they are described as being “hardened”. Hardening of the arteries is called “arteriosclerosis” The viscosity of the blood: Blood which has a high viscosity is thick and sticky and does not flow as easily as thin watery liquids and the pressure will be higher due to the resistance of the blood to flow easily through the vessels.
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Regulation of Blood Pressure
As blood is pumped from the heart to the various blood vessels, enough pressure is generated in order to send blood to all parts of the body. HYPERTENSION: CHRONIC HIGH BLOOD PRESSURE Small blood vessels in vital organs are most often affected Blood vessels can be scarred, hardened and inelastic which will be blocked or possibly rupture. Can lead to organ damage and failure if blood pressure is no regulated. HYPOTENSION: CHRONIC LOW BLOOD PRESSURE Blood is not pumped effectively through the systemic circuit of the body. Body lacks blood supply to vital organs which means cells do not have enough oxygen Reduces the amount of ATP a cell can generate which leads to fainting, dizziness and seizures.
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T/F About Blood Pressure
Blood pressure begins with a heartbeat. TRUE Blood pressure stays the same all day, every day. FALSE Blood pressure helps the blood flow to all parts of the body. TRUE A blood pressure reading has two numbers. TRUE You can tell what your blood pressure is by the way you feel. FALSE A healthy person could have a blood pressure of around 120/80. TRUE Blood pressure should be checked every five years. FALSE You can only tell what your blood pressure is by having it measured. TRUE Being overweight can lower blood pressure. FALSE Eating large amounts of food high in salt (sodium) can cause blood pressure to rise. TRUE Regular exercise will help keep your blood pressure healthy. TRUE Only a relaxed and easygoing person can have normal blood pressure. FALSE
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Nervous Control of the Heart
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Internal Control of Heart Rate
The heart or cardiac muscle beats involuntarily. The beat of each cell of heart muscle is in synchrony or in pace with the beat of every other heart muscle cell. Nervous impulses from a specialized bundle of nervous tissue called the Sinoatrial (SA) Node control the rate of the heart beat and also synchronize the beating of all cardiac cells.
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Internal Control of Heart Rate
The sinoatrial or SA node is known as the pacemaker. The SA node causes a wave of contraction to start in both the right and left atrium This wave of contraction causes the Atrioventricular (AV) node to initiate contractions of the ventricles.
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Internal Control of Heart Rate
The bundle of HIS carries the nervous stimuli to all parts of the ventricle via Purkinje Fibres which brings the impulse to each cardiac cell. The SA node paces the heart at 72 beats/min which can be considered a “normal” resting heart rate.
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External Control of Heart Rate
The Medulla Oblangata in the brain controls the nerves that influence heart rate. O2 and CO2 concentration levels in the blood are measured by chemoreceptors that stimulate one of two nerves to the heart in order to maintain homeostasis. Increased or accelerated heart rate is caused by stimulation of the sympathetic nerve. Decreased or slowing of the heart rate is caused by the stimulation of the parasympathetic nerve. Pressure sensitive baroreceptors in the arteries respond to changes in the blood pressure. Increased heart rate will cause increase O2 delivery and increase CO2 pick up/ removal
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Heartbeat Sounds If you listen to your heartbeat through a stethoscope you hear 2 characteristic sounds that repeat over and over as the heart continues to beat: Lub-dub, lub-dub… Lub The sound which is a result of the closing of both atrio-ventricular valves (tricuspid/bicuspid) Occurs during Systole, or ventricular contraction (i.e. atricular relaxation) Is louder and longer of the 2 sounds
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Heartbeat Sounds Dub The sound which is the result of the closing of both semi-lunar valves (pulmonary/aortic) Occurs during Diastole, or Ventricular relaxation (or atrial contraction) Is the softer and shorter of the 2 sounds.
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THE CARDIAC CYCLE = 1 Full Heart Beat
THE PULSE – Results from the rhythmic expansion of the arteries as blood spurts from the left ventricle. Pulse corresponds to Heart Rate STEP 1: Atrial Systole and Ventricular Filling The Ventricles relax & blood flows into them from the atria. 70% flows passively, 30% moved when atria contract STEP 2: Ventricular Systole The atria relax and blood is pumped from the ventricles into the aorta and pulmonary artery. (1st heart sound: Lub) STEP 3: There is a short period of atrial & ventricular relaxation. Semilunar valves prevent backflow of blood & the cardiac cycle starts again.
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ECG/EKG: Electrocardiograms
Heart rate is monitored by the brain – it monitors the level of CO2 in the blood and alters the heart rate accordingly The tiny electrical current produced each time the heart contracts can be recorded on a machine that produces an electrocardiogram or ECG/EKG An ECG machine records the changing currents produced by contractions of the heart and helps to detect any abnormalities
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ECG STAGES POLARIZATION: Anything that has two poles, one positive and one negative is polarized Example a battery, the Earth, Elements, Magnet DEPOLARIZATION: When the poles switch positions When you body is sending out an electrical signal to get your heart pumping REPOLARAIZATION: When the poles are switched back to the original positions When your body is recharging or getting ready to fire another electrical signal to tell your heart to beat
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P Wave Passing of electrical impulse or signal from the SA node
Depolarization of the Atria Causes the atria to contract Contraction is mechanical the signal is electrical Contraction happens after the P wave, but before the Q wave Known as the PQ interval
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QRS Wave Form the QRS Complex
This is the big spike in your graph Electrical impulse from your AV node through your ventricles Causes your ventricles to contract After Q wave but stops at the T wave Called QT interval Depolarization of ventricles
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T Wave Repolarization of the ventricles
This is when the AV node is getting refueled to fire again What about Repolarization of the Atria? Does happen during the EKG but is covered by the QRS complex This interval is known as the QS interval
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http://www. youtube. com/watch
beL2h84&safety_mode=true&persist_saf ety_mode=1&safe=active
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Factors Affecting Heart Rate
Activity: the heart increases its rate to provide oxygen to all the parts of the body that require it Emotions: Such as fear or shock and tension will all affect the heart rate Chemicals: such as carbon monoxide, nicotine, alcohol and adrenaline, all affect the rate of the heart
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TACHYCARDIA: When your heart beats more than 72 beats per minute, such as during exercise or from the consumption of caffeine or nicotine. BRADYCARDIA: When the heart beats very slowly, less than 72 beats per minute, such as athletes who have an elevated cardiac output even during rest. ARRYTHMIA: abnormal heart rhythm
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Chemical Control of the Heart
Chemicals (hormones) are released by your body tissue in response to stimulus from specific situations. Hormones are received by the brain, which sends the nervous signal to cause the heart rate to speed up or down PHYSICAL ACTIVITY: increase in activity level causes an increase in CO2 in the blood brain detects the increase of CO2 brain sends impulses along the nervous system to release noradrenaline
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Chemical Control of the Heart
Noradrenaline reaches the heart and makes the SA node fire more rapidly, causing the blood to be oxygenated more quickly EMOTIONS: Body experiences a sudden shock, sharp pain, gets excited, angry or nervous Adrenaline is released by the adrenal glands on the kidneys Which causes heart rate to increase and blood flow to increase to muscles Noradrenaline: a hormone that is released to slow the heart rate Adrenaline: a hormone that is released to speed up the heart rate
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