2Cardiac Muscle Smooth Muscle Skeletal Muscle Essential Question 1What types of muscles help move blood around the body?Cardiac MuscleSmooth MuscleSkeletal Muscle
3Layers of the Heart Wall The wall of the heart consists of three layers: the epicardium (external layer), the myocardium (middle layer) and the endocardium (inner layer). The epicardium is the thin, transparent outer layer of the wall and is composed of delicate connective tissue. The myocardium, comprised of cardiac muscle tissue, makes up the majority of the cardiac wall and is responsible for its pumping action. The thickness of the myocardium mirrors the load to which each specific region of the heart is subjected. The endocardium is a thin layer of endothelium overlying a thin layer of connective tissue. It provides a smooth lining for the chambers of the heart and covers the valves. The endocardium is continuous with the endothelial lining of the large blood vessels attachedCardiac MuscleCardiac muscle fibers are shorter in length and larger in diameter than skeletal muscle fibers.Cardiac muscle fibers have actin and myosin filaments arranged in the same way as skeletal muscle, but usually only one nuclei.In contrast to skeletal muscle, cardiac muscle does not fatigue, cannot be repaired when damaged and is regulated by the autonomic nervous system.Gap junctions between the fibers allow ions to travel between cells to permit the rapid fire of action potentials.Excitement of a single fiber results in stimulation of all the other fibers in the network (ALL OR NONE) . As a result, each network contracts as a functional unit.
5Smooth MuscleArteries have smooth muscle that functions to regulate the flow of blood through the artery.Contraction of the smooth muscle decreases the internal diameter of the vessel in a process called vasoconstriction.Relaxation of the smooth muscle increases the internal diameter in a process called vasodilation.
7Where else can you find Smooth Muscles Walls of stomachUterusIntestinesIris of the eyeGI TractRespiratory TractKidneysBladderUretersCiliary muscleSphincterTracheaBile duct.
8Skeletal Muscle.Veins pass between skeletal muscles. The contraction of skeletal muscle squeezes the vein.Repeated cycles of contraction and relaxation of skeletal muscle, as occurs in the leg muscles while walking, helps facility blood back to the heart.
10What do you remember from PBS about the heart?” 1_______________2____________3___________4___________5___________6___________7___________8___________9__________Pump, 4 chambers, 4 valves, pericardial sack, electrical system, its own blood supply,
11Position and Shape of the Heart. The heart is located in the thoracic cavity in between the lungs, 60% of it lying to the left of the median plane.The heart is cone-shaped, with a broad base at the top from which the large blood vessels enter and exit.The tip, known as the apex, points downwards and lies close to the sternum.
12PericardiumA membrane that surrounds and protects the heart. It is composed of two layers containing a small volume of fluid which serves as a lubricant, facilitating the movement of the heart by minimizing friction.The inner layer is firmly attached to the heart wall and is known as the visceral layer or epicardium.The outer layer is composed of relatively inelastic connective tissue and is termed the parietal layer.
13Layers of the Heart Wall The wall of the heart consists of three layers:epicardium (external layer), is the thin, transparent outer layer of the wall and is composed of delicate connective tissue.myocardium (middle layer), comprised of cardiac muscle tissue, makes up the majority of the cardiac wall and is responsible for its pumping action. The specific regions dictates the thickness of the myocardium.endocardium (inner layer). is a thin layer of endothelium. It provides a smooth lining for the chambers of the heart and covers the valves. It is continuous with the endothelial lining of the large blood vessels attached to the heart
14Fibrous SkeletonIn addition to cardiac muscle tissue, the heart wall also contains dense connective tissues that:forms the fibrous skeleton of the heart.forms rings that surround the four heart orifices.The skeleton performs several functions:It serves as a point of attachment for the heart valves.It prevents the valves from overstretching as blood passes through them.It acts as an electrical insulator thereby preventing the direct spread of action potentials from the atria to the ventricles.
15Chambers of the HeartThe heart contains four chambers where the thickness of the myocardium of the chambers varies according to its function.The two upper chambers are the atria. The atria are thin-walled because they deliver blood into the adjacent ventricles. On the upper surface of each atrium is a pouch-like appendage which is thought to increase the capacity of the atrium slightly.The two lower chambers are the ventricles. The ventricles are equipped with thick muscular walls because they pump blood over greater distances.
16VentriclesThe right and left ventricles act as two separate pumps that simultaneously eject equal volumes of blood. The right ventricle only pumps blood into the lungs, which are close by and present little resistance to blood flow so work load is less.On the other hand, the left ventricle pumps blood to the rest of the body, where the resistance to blood flow is considerably higher. Therefore, the left ventricle works harder than the right ventricle to maintain the same blood flow rate. Consequently, the left ventricle is significantly thicker than that of the right.
17Right Atrium (RA)The right atrium forms the section of the base of the heart and receives blood from the superior vena cava, inferior vena cava and coronary sinus.Blood flows from the right atrium to the right ventricle through the tricuspid valve (also know as the right atrioventricular valve).The right atrium also houses the sinoatrial node.
18Right Ventricle (RV)The right ventricle forms most of the anterior surface of the heart and is crescent-shaped in cross-section.The tricuspid valve provides the means for blood to leave the RA and move into the RVThe right ventricle is separated from the left by a partition called the interventricular septum.Deoxygenated blood passes from the right ventricle through the pulmonary semi-lunar valve to the pulmonary trunk, which conveys the blood to the lungs.
19Left Atrium (LA)The left atrium forms the section of the base of the heart and is similar to the right atrium in structure and shape.It receives oxygenated blood from the lungs via the pulmonary veins.Blood passes from the left atrium to the left ventricle through the bicuspid or mitral valve.The left atrium lies under the tracheal bifurcation and enlargement of this area of the heart can cause breathing difficulties.
20Left Ventricle (LV)The left ventricle forms the apex of the heart and is conical in shape.Blood passes from the left ventricle to the ascending aorta through the aortic valve.From here some of the blood flows into the coronary arteries, which branch from the ascending aorta and carry blood to the heart wall.The remainder of the blood travels throughout the body.
28Varicose VeinsNormally, one-way valves in the veins keep blood flowing from your legs up toward your heart.Varicose veins are caused by weakened valves in the veins in your legs.When these valves do not work as they should, blood collects in your legs, and pressure builds up.
29Varicose Veins www.sirweb.org/news/videoClips.shtml As pressure builds in the veins, the walls of the veins become weak, dilated, and twisted.Venous return is slowed, causing blood to become sluggish.
30Causes of Varicose Veins Varicose veins often run in families.Aging increases your risk.Increased pressure on leg veins fromBeing overweightPregnancyOr having a job where you must stand for long periods of time.
31The structure of blood vessels is in direct relationship to the function it performs ArteryVeinCapillary
32Cross section of an artery Why don’t we get varicose arteries.
33Essential Question4. How do the structure of arteries, veins and capillaries relate to their function in the body?5. What unique features of veins help move blood back to the heart?6. What are varicose veins?7. Why don’t we ever hear about varicose arteries?
34View Vessel Slides Draw in your journal what you saw in the slides With team of 4 devise a way to explain how varicose veins form and why we done get varicose arteries.Final product could be drawing, diagram, information brochure, clay model, or a letter to your grandmother to answer her questions about varicose veins.Present your findings to the class
36The FlowBlood vessels move blood from the heart to the lungs to pick up oxygen and deliver this oxygen to all of the tissues of the body.Arteries flow away from the heart and branch into smaller vessels called arterioles.Arterioles lead into the capillary beds, thin nets of vessels where gas exchange occurs.Blood then converges back into small veins called venules and eventually back into the major veins to be returned to the heart.Vessel size varies dramatically along this path.
37Make paper Flag for these vessels Ascending Aorta Renal artery/vein Descending Aorta Iliac artery/vein Brachiocephalic artery Femoral artery/vein Subclavian artery/vein Popliteal artery/vein Carotid artery vein Posterior Tibial artery/vein Radial artery/vein Superior Vena Cave Ulnar artery/vein Inferior Vena Cava Common Iliac Vein Internal Jugular vein Superficial palmar arch
40The aorta is the largest artery in the body about the diameter of a garden hose. The capillaries, on the other hand, are so tiny that about ten of them would be as thick as one of the hairs on our head.The structure of blood vessels relates directly to their particular function and to the amount of pressure exerted on the vessel walls.
47Cardiac OutputCardiac Output is a measure of how much blood the heart can pump in one minute by the ventricles.Cardiac Output (ml/min) = Stroke Volume (75ml/beat) X Heart Rate (BPM)
48What are some diseases that affect CO if dependent on SV & HR hypertensionheart failureinfection and sepsiscardiomyopathyrhythm disturbancescoronary artery disease
49Essential Question9. What is cardiac output? 10. How does cardiac output help assess overall heart health? 11. How does an increased or decreased cardiac output impact the body?
50Changes in cardiac output often signal diseases of the heart and these changes can impact the function of other body systems.Increased blood pressure in vessels can indicate possible blockages, and these blockages can interrupt blood flow to an organ or limbIncreased BP decreases Cardiac Output in a diseased heart
51Smoking Can Cost You an Arm and a Leg! Activity 4.3.5Smoking Can Cost You an Arm and a Leg!
52Essential Question 12. What is blood pressure? 13. How can the measurement of blood pressure in the legs be used to assess circulation?
53Blood PressureWhen your heart beats, the contraction forces blood through the arteries to the rest of your body. This pressure created on the arteries is called systolic blood pressure, and measured in (mm Hg)A normal systolic blood pressure is below 120.The diastolic blood pressure number or the bottom number indicates the pressure in the arteries when the heart rests between beats.A normal diastolic blood pressure number is less than 80.
55Part III- Take ABI measurements Complete Part I and share your findings with class before receiving part II Part II-Draw a feedback loop to show the body responds to an increase in BPPart III- Take ABI measurements
56Example of BP feedback loop In the example to the right blood pressure has increased. Receptors in the carotid arteries detect the change in blood pressure and send a message to the brain. The brain will cause the heart to beat slower and thus decrease the blood pressure. Decreasing heart rate has a negative effect on blood pressure.
57FYI Renin-Angiotensin-Aldosterone System Decreased blood volume or blood pressure stimulates the release of Renin that starts the processThe glomulerus, a bundle of capillary blood vessels found in the kidney, senses a drop in blood flow or a drop in sodium and secretes an enzyme called renin into the bloodstream.Renin moves to the liver where it converts the inactive peptide angiotensiongen to angiotensin I.Angiotensin I travels to the lungs where another enzyme converts it to angiotensin II.Angiotensin II makes its way to the adrenal glands at the top of the kidneys where it stimulates the production of aldosterone.Aldosterone helps the kidneys conserve sodium and water, leading to increased fluid volume and sodium levels.NOTE: If blood flow to the kidneys or the amount of sodium increases, less renin is produced in an attempt to normalize blood pressure.Animation:
58Ankle Brachial Index (ABI) A test done by measuring blood pressure at the ankle and in the arm while a person is at rest.Measurements are usually repeated at both sites after 5 minutes of walking on a treadmill.A slight drop in the ABI with exercise, even if you have a normal ABI at rest, means that you probably have PAD.
59Part IV Activity 4.3.5 Doppler ultrasound device Activity Student Resource Sheet – ABI Worksheet.
60The Body’s Response to Exercise Project 4.4.1The Body’s Response to Exercise
61Essential Question1. What is the connection between power and movement in the body?ATP
62Recall how the body generates ATP. Food (primarily glucose) and oxygen are both vital to the assembly of ATPATP is always stored in the body but the amount in the body can only last 2 or 3 seconds. When it is used it is broken down from one adenozine and three phosphate molecules into adenzine diphosphate (2 phosphate molecules) and a separate phosphate molecule. This reaction is exothermic and produces energy.There are three main ways it can be resynthesised and these are by using the phospho-creatine system, the lactic system and the aerobic system.Aerobic resipration is much more complicated as oxygen is present. It starts the same way as lactic respiration but as oxygen is present, there is no lactic acid formed, instead pyruvic acid is converted into acetyle CoA by the enzyme coenzyme A. The acetyle CoA is then converted into citric acid by oxaloacetic acid. The citric acid then goes through something called the Krebs cycle where everything produced in respiration except the energy is removed. This leaves 2 ATP molecules. The hydrogen removed from the reaction then is converted using something called an electron transfer chain into 34 ATP molecules and water.
63Essential Question2. How does the body maintain a supply a ATP during exercise?Exercise requires the coordinated effort of many human body systems includingnervous system,muscular system,skeletal system,cardiovascular system,respiratory system.
64Cellular respiration is the process by which ATP is Produced ATP is the main energy source used by the cellsOrganic molecules such as glucose, lipids, and proteins are broken down to produce ATP3 stages of cellular respiration, Glycolysis, Krebs cycle, Electron Transport Chain (ETC)
65ATP A nucleotide used by cells as a form of energy. Cellular Respiration-Process that occurs in cells to produces ATP for cells in order to carry out all cell functions.-ATP is produced by the breaking down of organic molecules such as glucose, lipids and proteins3 Stages of Cellular Respiration-Glycolysis is the first stage-Krebs Cycle is the second stage-Electron Transport Chain is the third stageATP-ATP is a nucleotide with a ribose sugar, adenine base and 3 phosphate groups-Energy stored between 2nd and 3rd phosphate groupGlycolysis-1st step of cellular respiration-Occurs in cytoplasm of the cell-Glucose is broken down into a smaller molecule-Products of gylcolysis move into the next stepThe Krebs Cycle-2nd step of cellular respiration-Occurs in the mitochondria-The mitochondria is the “powerhouse” of the cellETC-3rd step of cellular respiration-1 molecule of glucose yields 36 molecules of ATP-Most of the ATP is being produced by the ETC-A minor amount of ATP is produced in glycolysis and the Krebs cycleSource: Amanda Soderlind, Author
68Essential Questions What is peripheral artery disease? Why can smoking lead to peripheral artery disease?
69Key TermsAorta -The large arterial trunk that carries blood from the heart to be distributed by branch arteries through the body.Arteriole- Any of the small terminal twigs of an artery that ends in capillariesArtery- Any of the tubular branching muscular- and elastic-walled vessels that carry blood from the heart through the body.Arteriosclerosis-A chronic disease characterized by abnormal thickening and hardening of the arterial walls with resulting loss of elasticityAtherosclerosis- A cardiovascular disease in which growths called plaques develop on the inner walls of the arteries, narrowing their inner diameters.Atrium- A chamber of the heart that receives blood from the veins and forces it into a ventricle or ventricles.
70Key TermsBlood pressure-The hydrostatic force that blood exerts against the wall of a vessel.Capillary-Any of the smallest blood vessels connecting arterioles with venules and forming networks throughout the body.Cardiac muscle-Striated muscle fibers (cells) that form the wall of the heart; stimulated by the intrinsic conduction system and autonomic motor neuronsCardiac output -The volume of blood ejected from the left side of the heart in one minute.Circulation-The movement of blood through the vessels of the body that is induced by the pumping action of the heart and serves to distribute nutrients and oxygen to and remove waste products from all parts of the body.Coronary Artery-Either of two arteries that arise one from the left and one from the right side of the aorta immediately above the semilunar valves and supply the tissues of the heart itself
71Key TermsHeart rate- A measure of cardiac activity usually expressed as number of beats per minutePeripheral artery disease- A form of peripheral vascular disease in which there is partial or total blockage of an artery, usually one leading to a leg or arm.Peripheral vascular disease- Vascular disease affecting blood vessels outside of the heart and especially those vessels supplying the extremities.Pulmonary Circulation- The passage of venous blood from the right atrium of the heart through the right ventricle and pulmonary arteries to the lungs where it is oxygenated and its return via the pulmonary veins to enter the left atrium and participate in the systemic circulationPulse - A regularly recurrent wave of distension in arteries that results from the progress through an artery of blood injected into the arterial system at each contraction of the ventricles of the heart.
72Key terms Smooth muscle A tissue specialized for contraction, composed of smooth muscle fibers (cells), located in the walls of hollow internal organs, and innervated by the autonomic motor neuronsStroke volumeThe volume of blood pumped from a ventricle of the heart in one beatSystemic CirculationThe passage of arterial blood from the left atrium of the heart through the left ventricle, the systemic arteries, and the capillaries to the organs and tissues that receive much of its oxygen in exchange for carbon dioxide and the return of the carbon-dioxide carrying blood via the systemic veins to enter the right atrium of the heart and to participate in the pulmonary circulation
73Key TermsValveA bodily structure (as the mitral valve) that closes temporarily a passage or orifice or permits movement of fluid in one direction only.Varicose veinAn abnormal swelling of a superficial vein of the legs.VeinAny of the tubular branching vessels that carry blood from the capillaries toward the heart and have thinner walls than the arteries and often valves at intervals to prevent reflux of the blood which flows in a steady stream and is in most cases dark-colored due to the presence of reduced hemoglobin.VentricleA chamber of the heart which receives blood from a corresponding atrium and from which blood is forced into the arteries.VenuleAny of the minute veins connecting the capillaries with the larger systemic veins