The Cardiovascular System Chapter 10, 11 The Heart, Blood Vessels, Blood Types

Blood

PLASMA Liquid portion of the blood. 90% WATER Carries nutrients & other substances Salts (Na+, K+, Ca++, …) Proteins (fibrinogen, …) Contains clotting factors, hormones, antibodies, dissolved gases, nutrients and wastes

RED BLOOD CELLS Erythrocytes Carry hemoglobin and oxygen. Do not have a nucleus Do not have mitochondria (anaerobic respiration) Live only about 120 days. Cannot repair themselves Determine blood type

WHITE BLOOD CELLS Leukocytes Fight infection Formed in the bone marrow Five types: Neutrophils Lymphocytes Eosinophils Basophils Monocytes

PLATELETS Thrombocytes Clot blood by sticking together – via protein fibers called fibrin. These are cell fragment that are formed in the bone marrow

ABO BLOOD TYPES Blood type is determines by the presence or absence of blood proteins called ANTIGENS located on the surface of the erythrocytes. There are also ANTIBODIES on the surface of erythrocytes. When incompatible blood proteins mix, agglutination (blood clumping) results.

BLOOD TYPES There are 3 alleles that determine 4 blood types: A (dominant) B (dominant) O (recessive) Type A = AA, Ao Type B = BB, Bo Type AB = AB Type O = oo

ABO blood groups A Anti-B A, O B Anti-A B, O AB None A, B, AB, O O Blood Type Antigens Agglutinogen Antibodies Agglutinins Can receive from… A Anti-B A, O B Anti-A B, O AB None A, B, AB, O Universal recipient O none Universal donor https://www.youtube.com/watch?v=ttjn1jVACk8

Rh factor: + or - ? Open textbook to pp. 350-351. Read the paragraph that begins “The Rh blood groups…” Read the following 2 paragraphs. Stop at heading “Blood Typing.”

When Things Go Wrong: BLOOD Complete handout. Then cut & paste into NB.

The Closed Circulatory System Humans have a closed circulatory system, typical of all vertebrates, in which blood is confined to vessels and is distinct from the interstitial fluid. The heart pumps blood into large vessels that branch into smaller ones leading into the organs. Materials are exchanged by diffusion between the blood and the interstitial fluid bathing the cells.

Blood vessels

BLOOD VESSELS 3 TYPES Arteriesarterioles Take blood away from the heart 3 layers thick VeinsVenules Returns blood to the heart Contain VALVES to prevent backflow of blood Capillaries One cell layer thick Form “capillary beds” Where gas exchange occurs O2 leaves capillaries and enters body cells CO2, a waste product of cellular respiration, enters capillaries

BLOOD VESSELS Three layers of blood vessels: Tunica intima (all types of BV) Innermost layer Single thin layer of endothelium Provides a smooth surface to decrease resistance to blood flow The only tunic of capillaries

BLOOD VESSELS 2)Tunica media (arteries & veins) Bulky middle coat Contains smooth muscle and elastin The only tunic that plays an active role in blood pressure regulation Tunica externa (arteries & veins) Outermost layer Supporting, protective coat Also called the adventitia

THREE LAYERS OF BLOOD VESSELS

*Yellow = must know for quiz VEINS p. 759 vertebral brachiocephalic superior vena cava brachial inferior vena cava renal radial common iliac internal iliac CROSS OUT posterior tibial 12. internal jugular 13. subclavian 14. axillary 15. cephalic 16. hepatic 17. median cubital 18. ulnar 19. femoral 20. popliteal 21. CROSS OUT 22. anterior tibial

ARTERIES p. 747 external carotid vertebral brachiocephalic brachial renal aorta radial common iliac internal iliac popliteal anterior tibial 12. internal carotid 13. common carotid 14. subclavian 15. axillary 16. celiac trunk 17. superior mesenteric 18. ulnar 19. external iliac 20. femoral 21. posterior tibial

When Things Go Wrong: BLOOD VESSELS Complete handout. Then cut & paste into NB.

Blood Pressure

Pulse Points

Blood Flow, Blood Pressure, and Resistance Use pages 721-723 to complete handout. Blood flow Blood pressure (BP) Resistance Blood Viscosity Total Blood Vessel Length Blood vessel diameter

Blood Pressure VOCABULARY

Mean Arterial Pressure (MAP) Average blood pressure in aorta MAP=CO x PR Cardiac Output (CO) is amount of blood pumped by heart per minute CO=SV x HR SV: Stroke volume of blood pumped during each heart beat HR: Heart rate or number of times heart beats per minute Cardiac reserve: Difference between CO at rest and maximum CO Peripheral Resistance (PR) is total resistance against which blood must be pumped

Factors Affecting MAP

THE HEART

The HEART Cardiac muscle tissue Highly interconnected cells FOUR chambers Right atrium Right ventricle Left atrium Left ventricle

Size, Shape, Location of the Heart Size of a closed fist Shape Apex: Blunt rounded point of cone Base: Flat part at opposite of end of cone Located in thoracic cavity in mediastinum

EXTERNAL

Internal

Function of the Heart Valves

pulmonary http://www.youtube.com/watch?v=q0s-1MC1hcE

Blood Flow Through Heart

Conducting System of Heart http://www.youtube.com/watch?feature=endscreen&NR=1&v=II5RPs1hlGI

Circuits Pulmonary Circulation Systemic Circulation The blood pathway between the right side of the heart, to the lungs, and back to the left side of the heart. Systemic Circulation The pathway between the heart and the rest of the body

Coronary Circulation From RIGHT side of heart To outer muscle of heart Back to LEFT side of heart

Pericardium

Heart Wall Three layers of tissue Epicardium: This serous membrane of smooth outer surface of heart Myocardium: Middle layer composed of cardiac muscle cell and responsibility for heart contracting Endocardium: Smooth inner surface of heart chambers

Heart Wall

Systemic and Pulmonary Circulation

Heart Skeleton Consists of plate of fibrous connective tissue between atria and ventricles Fibrous rings around valves to support Serves as electrical insulation between atria and ventricles Provides site for muscle attachment

Cardiac Muscle Elongated, branching cells containing 1-2 centrally located nuclei Contains actin and myosin myofilaments Intercalated disks: Specialized cell-cell contacts Desmosomes hold cells together and gap junctions allow action potentials Electrically, cardiac muscle behaves as single unit

Electrical Properties Resting membrane potential (RMP) present Action potentials Rapid depolarization followed by rapid, partial early repolarization. Prolonged period of slow repolarization which is plateau phase and a rapid final repolarization phase Voltage-gated channels

Action Potentials in Skeletal and Cardiac Muscle

SA Node Action Potential

Refractory Period Absolute: Cardiac muscle cell completely insensitive to further stimulation Relative: Cell exhibits reduced sensitivity to additional stimulation Long refractory period prevents tetanic contractions

Electrocardiogram Action potentials through myocardium during cardiac cycle produces electric currents than can be measured Pattern P wave Atria depolarization QRS complex Ventricle depolarization Atria repolarization T wave: Ventricle repolarization

Cardiac Arrhythmias Tachycardia: Heart rate in excess of 100bpm Bradycardia: Heart rate less than 60 bpm Sinus arrhythmia: Heart rate varies 5% during respiratory cycle and up to 30% during deep respiration Premature atrial contractions: Occasional shortened intervals between one contraction and succeeding, frequently occurs in healthy people

Alterations in Electrocardiogram

Cardiac Cycle Heart is two pumps that work together, right and left half Repetitive contraction (systole) and relaxation (diastole) of heart chambers Blood moves through circulatory system from areas of higher to lower pressure. Contraction of heart produces the pressure

Cardiac Cycle

Events during Cardiac Cycle

Heart Sounds First heart sound or “lubb” Second heart sound or “dupp” Atrioventricular valves and surrounding fluid vibrations as valves close at beginning of ventricular systole Second heart sound or “dupp” Results from closure of aortic and pulmonary semilunar valves at beginning of ventricular diastole, lasts longer Third heart sound (occasional) Caused by turbulent blood flow into ventricles and detected near end of first one-third of diastole

Location of Heart Valves

When Things Go Wrong: HEART Complete handout. Then cut & paste into NB.

Effects of Aging on the Heart Gradual changes in heart function, minor under resting condition, more significant during exercise Hypertrophy of left ventricle Maximum heart rate decreases Increased tendency for valves to function abnormally and arrhythmias to occur Increased oxygen consumption required to pump same amount of blood