Happy One Week before Spring Break! Essential Question Today How does the structure of the heart ensure its functions? Objectives Identify the major parts of the heart. Describe the pathway of circulation, systemic and pulmonary.
The Heart - Transplants Without our hearts, we wouldn t function too well (duh) 50,000 people a year need a heart (cardiac) transplant Only 5,000 of those people receive one (http://www.uptodate.com/contents/heart-transplantation-beyond-the-basics)
The Heart - Transplants Read through the article and consider the following questions: How might surgeons replace a heart? What structures would they connect the heart with? What are the functions of the heart? What other structures make up the cardiovascular system?
Coversheet Your Objectives
Chapter 13 Cardiovascular System
Overview to the circulatory system A two-way irrigation system. A pump (heart) cycles nutrients and oxygen out to the fields (tissues and organs). Depleted fluids return from the fields, dump their waste gas (CO2) in the lungs, pick up fresh oxygen, then cycle nutrients and O2 out to the fields again. The cycle repeats itself 60-80 times each minute.
Irrigation System Pipes (blood vessels) Away from the heart: arteries (except Toward the heart: veins pulmonary system) arteries-- (aorta is largest) arterioles-- capillaries-- venules-- veins (vena cava is largest)
I. Functions of the Heart A.Generate blood pressure B. Assist in transport of blood pulmonary circuit systemic circuit C. Guarantee one-way flow of blood D. Regulates blood supply
II. Structure of the Heart A. Size and location 1. Triangular organ, about the size of an adult fist (5.5 x 3.5 ) 2. Located within the mediastinum (space btwn the lungs), with apex ( point ) located between the 5th and 6th intercostal space.
B. Coverings of the heart 1. Layered fibrous sac ( pericardium ) or tissue baggie surrounds the heart 2. Pericardial cavity: space between the parietal (outer layer) and visceral (adheres to organ) layers of the pericardium
C. Wall of the heart Consists of three (3) layers: i epicardium: thin, outermost layer ii myocardium: cardiac muscle tissue iii endocardium: smooth tissue lining each room or chamber
D. Heart Chambers and valves 1. Has two smaller upper chambers (atria) and two larger lower chambers (ventricles) 2. Atria receive blood whereas ventricles send or pump blood 3. Every time blood enters or leaves a room it must pass through a door ( valve )
Comparison of Right and Left Ventricles
E. Skeleton of the heart 1. Heart does not have bones, but does have tough, fibrous rings that enclose the bases of the pulmonary artery and aorta
F. Path of blood through the heart (The Voyage of the Mighty RBC) 1. Vena cava (superior and inferior) 2. Right atrium 3. Pass through right atrio-ventricular valve (tricuspid valve) 4. Right ventricle 5. Pulmonary semi-lunar valve 6. Pulmonary artery (O 2 -poor blood) 7. Lungs (dump waste products CO 2 )
8. Lungs (pick up oxygen) 9. Enter left atrium via pulmonary vein (via four entrances) 10. Pass through left atrioventricular valve (bicuspid or mitral valve) 11. Left ventricle 12. Leave through aortic semilunar valve 13. Travel throughout body, delivering O 2 and nutrients, gathering waste produces such as CO 2
Fetal Pig Lab! Focus on dissecting into the hind legs to uncover the renal, genital, and iliac arteries. Cut gently into the lateral sides of the fetal heart to uncover the atria, ventricles, and foramen ovale
Fetal Pig Lab! When you are done, have me come and check your dissection to sign you off! Remember to clean up thoroughly!
Parts of the Heart Worksheet Turn to the worksheet in your notes over the heart To help complete this, use your textbook, pages 343, 345, 371 (331 and 334 in the Bicycle Book)
WELCOME BACK!
Build a Circulatory System o To help you learn the different major vessels that make up the circulatory system, you will be drawing a lifesize example of the arteries, veins, and heart.
Build a Circulatory System o Use the venous and arterial diagrams to create your life-size example o Work in a group of 2-3 people o Choose someone to be your model o Color the veins in blue o Color the arteries in red o The vessels will typically go side by side
Build a Circulatory System o Draw arrows to show which direction the blood is flowing through the vessels o Label the major vessels o Remember to put all your group member s names on the poster! o This will be your first quiz score over 13.2
Next Class o Quiz over blood flow and heart structures o Notes over blood supply to the heart and heart sounds o Heart Sounds Lab
Welcome! o Quiz #1 - Parts of the Heart and Blood flow
Creating a Circulatory System o Get into your groups to finish up your circulatory system o Make sure to color the blood vessels, and add arrows to show the direction of blood flow o Label the major veins and arteries from the diagrams passed out last class
Next Class o Notes over blood supply to the heart and heart sounds o Heart Sounds Lab o No Quiz
Exit Ticket o What are three major veins you need to know? What are three major arteries you need to know?
Warm-up - Article o Stiff: The Curious Lives of Human Cadavers by Mary Roach o Excerpt from pages 167-170 in the chapter, How to Know if You re Dead
Objectives o Describe the pathway of circulation to the heart. o Describe the normal heart sounds and what they mean. o Describe how the cardiac cycle is regulated.
Agenda o Notes o Heart Beat and Blood Pressure Lab
G. Blood Supply to the Heart 1. Coronary arteries supply blood to the heart muscle or myocardium 2. Blood returns to the right atrium through the cardiac veins and coronary sinus
Arterial Circulation: Heart
III. Structure of the Heart A. Characteristics of cardiac muscle cells 1. Striated with intercalated discs 2. Involuntary 3. Fibers connect to form a functional syncytium 4. If any part of syncytium is stimulated the entire structure contracts as a unit
IV. Heart Actions A. Cardiac cycle 1. Atria contract---ventricles relax Ventricles contract--atria relax 2. Pressure within the chambers of the heart rises and falls in repeated cycles.
B. Heart sounds [ lubb dupp ] Heart sounds are due to the vibrations that the valve movements produce. 1. lubb : vibration and closure of AV valves as ventricles contract (systole) 2. dupp :closing of semilunar valves when ventricles relax (diastole)
Measuring Blood Pressure and Heart Rate Lab Get into groups of 2-3 Each person needs a lab worksheet Only 4 sphygmomanometer and stethoscopes Only 4 groups will be able to do the first part of the lab at a time Work on Measuring Pulse and the rest of the lab while waiting for the first part
Measuring Blood Pressure and Heart Rate Lab
Measuring Blood Pressure and Heart Rate Lab When you are done, turn in your work up front Make sure to finish the questions and tables on the last page!
Next Class Quiz over Heart Sounds and what they mean. Study your notes to prepare for this quiz! Blood Vessels and Blood Pressure Notes
Warm-up = Checkpoint Quiz #2 Quiz over blood vessels, heart sounds and what they mean!
Objectives Describe how the cardiac cycle is regulated. Describe the structure of the veins and arteries.
Essential Question How do the structures of the blood vessels affect their function?
C. Cardiac conduction system ( Flow of electricity) 1. Cardiac muscle fibers can contract rhythmically on their own, but must be coordinated by electrical signals (impulses) for effective pumping. (orchestra conductor) 2. Heart has its own built-in conduction system for initiating ( starting ) and conducting ( sending) impulses through the myocardium. 3. SA node to AV node (slow travel); AV bundle to Purkinje fibers is rapid travel 4. Autonomic nerve signals: control heart rate
Four structures in heart wall generate impulses a. SA (sino-atrial) node: pacemaker fxn: impulse conduction thru atria atrial contraction b. AV (atrioventricular) node fxn: relays impulses to ventricles via: c. AV bundle or Bundle of His (between ventricles) d. Purkinje fiber (ventricular walls)
D. Electrocardiogram 1. Electrocardiograph: visible tracings of heart s electrical signals 2. Electrocardiogram: (ECG): graphic record of the heart s electrical activity
The QRS complex represents ventri cular depolarization and contraction. The PR interval indicates the transit time for the electrical signal to travel from the sinus node to the ventricles. T wave is normally a modest upwards waveform, representing ventricular repolarization.
E. Regulation of the cardiac cycle 1. Physical exercise, body temperature and concentrations of various ions affect heart beat 2. Fibers from the Autonomic Nervous system innervate ( connect to ) the S-A and A-V nodes. 3. Cardiac center (medulla oblongata) regulates autonomic impulses to the heart
V. Blood Vessels A. Arteries and arterioles 1. Adapted to carry blood away from heart under high pressure 2. Consist of three layers ( tunics ) a. endothelium ( tunica intima ) b. smooth muscle ( tunica media ) c. elastic/connective tissue ( tunica externa )
3. Autonomic nerve fibers innervate the smooth muscle in the vessel walls causing either vasoconstriction (lumen narrows) or vasodilation (lumen widens).
B. Capillaries 1. Connect the smallest arteries (arterioles) and the smallest veins (venules) 2. Capillary wall is a single layer of cells that forms a semi-permeable membrane 3. Opening in capillary walls, where endothelial cells overlap, vary in size from tissue to tissue 4. Precapillary sphincters regulate capillary blood flow.
C. Exchanges in capillaries 1. Capillary blood and tissue fluids exchange gases, nutrients and various waste products 2. Diffusion is most important means of transport 3. Filtration occurs at arteriolar end 4. Osmosis occurs at venous end
D. Venules and veins 1. Venules continue from capillaries and merge to form veins 2. Veins carry blood toward the heart 3. Venous walls have three (3) layers like arterial walls, but are thinner. They have less smooth muscle and elastic/connective tissue.
Cardiovascular System Worksheet 1. Fill in what you can on your own 2. Use a textbook or the internet to help you fill in the rest. 3. Ask me for help if you need it!
The QRS complex represents ventri cular depolarization and contraction. The PR interval indicates the transit time for the electrical signal to travel from the sinus node to the ventricles. T wave is normally a modest upwards waveform, representing ventricular repolarization.
Next Class Quiz over 13.3 and 13.5 (at end of class) Review on TUESDAY TEST on TUESDAY of next week
VI. Blood Pressure A. Arterial blood pressure 1. Rise and falls with the phases of the cardiac cycle 2. Systole: pressure produced when the ventricle contracts 3. Diastole: pressure produced when the ventricle relaxes systolic = 120 diastolic 80
B. Factors that influence arteries blood pressure 1. Cardiac output (volume of blood discharged from left ventricle/minute) 2. Blood volume (5 liters or 8% body weight) 3. Peripheral resistance (friction between blood and walls of blood vessels) 4. Blood viscosity increases ( thicker blood ) polycythemia vera
C. Control of blood pressure 1. Regulate cardiac output and regulate peripheral resistance 2. Baroreceptors (aorta and carotid walls) sense BP changes send message to medulla oblongata to decrease 3. Control (vasomotor) centers in medulla oblongata maintains tone of smooth muscles in arteriole walls
D. Venous Blood Flow 1. Influenced by skeletal muscle contractions breathing movements, and vasoconstriction. 2. Many veins contain flaps or valves that prevent blood from backing up 3. Venoconstriction can increase venous pressure and blood flow.
Some Interesting Cardiac Stuff
4. Fetal circulation a. Refers to circulation before birth b. Modifications required for fetus to efficiently get oxygen and nutrients from the maternal blood
c. Unique structures i. placenta, ii. umbilical arteries and vein iii. ductus venosus (passes through liver connecting umbelical vein with inferior vena cava) iv. foramen ovale (opening between right and left atria