third test lectures

* Please note: these notes are not "all you need" to prepare for the test, but will give an outline of the material that was covered
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Chapter 17 Blood Blood Functions • Distribution • O2 from lungs to body cells • Nutrients from digestive system • Metabolic waste from cells • Transport hormones to target organs • Regulation • Maintain body temperature • Maintain normal Ph • Maintain fluid volume • Protection • Prevent infection • Protect fluid and blood loss Composition of Blood • Only fluid tissue – Cells within a matrix • Composition – Erythrocytes – Leukocytes – Platelets  • Blood cell fragments – Plasma  Blood Plasma • 90% water • Over 100 dissolved solids – Proteins  • Enzymes  • Clotting proteins • Hormones  – Nutrients – Gases  – Electrolytes – Others  Erythrocytes • No nucleus or organelles in humans • Bag of hemoglobin bound by plasma membrane – 97% hemoglobin • Erythrocytes consume no oxygen • Functions – Mostly O2 transport • Hemoglobin binds easily and reversibly • Single erythrocyte has 250 million hemoglobin molecules • Each has 4 heme groups • 1 erythrocyte binds 1 billion O2 molecules – Small amount of CO2 • Destruction of erythrocytes – Useful lifespan  =  100-120 days – Most are destroyed by macrophages in the spleen – Some components are recycled, others excreted Erythrocytes • Disorders – Anemias • Blood has low oxygen carrying capacity – Not enough red blood cells – Decrease in hemoglobin – Abnormal hemoglobin » Ex: Sickle cells – Polycythemia • Abnormal excess of erythrocytes Leukocytes • Complete cells • Less than 1% of all blood cells • Defense against disease • Can leave capillaries and move through tissue with amoeboid motion • Two categories – Granulocytes – Cytoplasmic granules – Agranulocytes  • Granulocytes – Neutrophils • > 50% of leukocytes • Multilobed nucleus • Chemically attracted to sites of inflammation • Active phagocytes of bacteria and some fungi – Eosinophils • 1-4% of leukocytes • Bilobed with large granules in cytoplasm • Kill parasitic worms with enzymes in lysosomes – Basophils • 0.5% (rarest)  • Large s-shaped nucleus • Binds to antibodies and releases histamine • Agranulocytes – Monocytes  • Largest leukocyte • U-shaped nucleus • Acts as a macrophage of viruses and bacteria – Lymphocytes • Second most common leukocyte • About the size of an erythrocyte • Nucleus spherical or indented • Responsible for immunity • Leukocyte formation – Formed by hematocytoblast – Stem cells develop into types of leukocytes in 3-10 days – Live for hours to a lifetime • Leukocyte disorders – Leukopenia • Abnormal low white blood cell count – Leukemia • Cancer of a white blood cell type • Renegade leukocytes are from a single clone – Named for cell type » Lymphocytic leukemia • Bone marrow becomes occupied by cancer cells Platelets • Cell fragments • Contain chemicals that aid in clotting • Degenerate in about 10 days • Megakaryoblast ruptures to form platelets Transfusion & Blood Replacement • Loss of over 30% can be fatal • Transfusion = infusion of packed red cells • Heparin is used as an anticoagulant • Transfusion must be of compatible blood Developmental Aspects of Blood • Before birth – Fetal yolk sac – Liver  • Beginning in 3rd month – Spleen – Red bone marrow • Beginning in 7th month

Chapter 18 Heart Heart Trivia • Your heart is the size of your fist • Your heart weighs about 1 pound • About 2/3 of the heart is left of the mid-sternal line Coverings of the Heart • Pericardium – double walled sac – Fibrous pericardium • Superficial  • Connective tissue • Anchors heart to surrounding structures • Prevents overfilling of heart • Protects heart – Serous pericardium • Inside layer  • Serous membrane – Parietal layer » Lines internal fibrous pericardium » Attaches to large arteries – Visceral layer » Epicardium » Part of heart wall – Pericardial cavity is between layers of serous membrane • Gives a friction free environment Problems of the Pericardium • Pericarditis  – Inflamation of the pericardium • Painful • Can impede heart  • Cardiac tamponade – Compression of heart by fluid Layers of Heart Wall • Epicardium – superficial – Viscerous serous membrane • Myocardium – middle – Mostly cardiac muscle – Most of heart – Fibrous skeleton of heart • Endocardium – Sheet of squamous epithelium – Continuous with blood vessels – Lines heart chambers Heart Chambers • Two atria – Superior • Two ventricles – Inferior • Partition divides the heart internally = septum Atria • Receiving chambers • Only push blood to ventricles • Blood enters right atrium from 3 veins – Superior vena cava – Inferior vena cava – Coronary sinus • Blood enters left atrium from 4 pulmonary veins Ventricles • Right ventricle is mostly anterior – Blood to lungs • Left ventricle is mostly posterior – Massive walls – Pumps blood to aorta Pathway of Blood through Heart • Heart is 2 sided pump – Right, pulmonary circuit  is low pressure • Low O2, high COs – Left, systemic circulation is high pressure • High O2, Low CO2 • Blood flows from atrium to ventricle Heart Valves • Blood flows in one direction – Backflow is prevented by valves • Two types of valves – Atrioventricular valves – Semilunar valves Atrioventricular Valves (AV) • Valves pulled closed as ventricle contracts • Tricuspid valve – Right AV valve – 3 flexible cusps • Bicuspid valve = mitral valve – Left AV valve – 2 cusps • Valves are attached with cordae tendinaea – Collagen cords – Anchor to ventricle walls – Called heart strings Semilunar Valves • Prevents backflow into ventricles • Pressure forces valves open, which then close again • Two valves – Aortic semilunar valve – Pulmonary semilunar valve Coronary Circulation • Blood inside the heart does not nourish the heart • Coronary arteries come off of Aorta – Divide into smaller arteries – Not everyone has the same branches • Heart gets 5% of all blood • Venous blood collected by cardiac veins – Empties into coronary sinus Heart Problems • Angina pectoris – Thoracic pain – Caused by deficiency in blood to heart – Can cause muscle spasms – Myocardial cells are weakened, but do not die • Myocardial infarction – Heart attack – Caused by coronary blockage – Tissue dies • Myocardial tissue is not replaced – Some areas are more serious than others Microscopic Anatomy of Cardiac Muscle • Striated • Plasma membrane of adjacent cells interlock – Intercalated discs • Large mitochondria • Wide T-tubules • Cells contract as one unit Heart Stimulation • Heart does not need nerve impulse to start contractions • Nerve impulses can alter rhythm • Action potential is initiated by autorhythmic cells Autorhythmic Cells • Sinoatrial node • Atrioventricular node • Atrioventricular bundle • Bundle branches • Perkinje fibers Sinoatrial Node • Pacemaker • Generates impulses about 75 times/minute • Determines heart rate • Atrioventricular node fires about 0.1 sec. after sinoatrial node Problems with Heart Rate • Arrhythmias – Irregular heart rhythm – Uncoordinated atrial & ventricular contractions • Fibrillation – Rapid & irregular or out-of-phase contractions – Defibrillation by electric shock Autonomic Influences • Sympathetic can increase speed and force • Parasympathetic slows • Cardiac centers are in medulla oblongata Electrocardiography • Elecrocardiograph monitors electrical currents of heart • EKG = elecrocardiogram – P wave (sinoatrial node) – QRS complex (ventricular polarization) – T wave (ventricular repolarization) – PR interval (time from atrial excitation to ventricular) – QT interval (ventricular contractions) Heart Sounds • Normal heart sounds caused by closing of valves – Pause is resting period • Murmurs are abnormal sounds – Usually signifies valve problems Regulation of Heart Rate • Other factors – Age • Slower as you age – Gender • Females are faster – Exercise • Increases rate – High body temperature • Increases rate

Chapter 19 Blood Vessels Types of Blood Vessels • Arteries and Arterioles – Away from heart • Capillaries – Within the tissues – Site of  exchange with cells • Veins and veinules – Toward the heart Structure of Blood Vessel Walls • Opening = lumen • Three layers – Tunica interna • = tunica intima • Innermost layer  • Endothelium • Slick surface minimizes friction • Supported by connective tissue in large vessels – Tunica Media • Middle layer • Smooth muscle with sheets of elastin • Influences blood flow and blood pressure – Tunica Externa • = tunica adventia • Connective tissue • Anchors and protects blood vessels Blood Vessel Accessory Structures • In tunica externa – Nerve fibers – Lymph vessels • Large blood vessels have their own blood vessels – Vasa vasorum Blood Vessel Types • Arteries  – Elastic arteries • Thick walled • Elastin in all 3 tunics • From heart to medium sized arteries • Inactive in vasoconstriction • Arteries – Muscular arteries • Distal to elastic arteries • Includes most named arteries • Thick tunica media • Active in vasoconstriction – Arterioles • Smallest arteries • Single layer of smooth muscle around endothelium • Capillaries – Smallest blood vessels – Average length = 1mm – Red blood cells pass single file – Exchange materials – Capillary beds are interweaving networks of capillaries • Capillary types – Continuous • Common in skin and muscles • Endothelium is not interrupted • Cells have junctions to allow passage of fluids – Except in brain – Fenestrated  • Has pores = fenestrations – Usually covered by a delicate membrane • Active in absorption – Sinusoidal  • Leaky capillaries • Fenestrated with irregular lumens • Allow large molecules to pass • Lined with macrophages • Found in some organs like liver, bone marrow, spleen • Venules – Formed where capillaries unite – Almost entirely endothelium – Porous • Veins – All tunics distinct – Low blood pressure – Valves prevent backflow  – Hold 65% of body’s blood • Venous sinuses – Specialized flattened veins – Only in brain and heart – Thin walls supported by surrounding tissue Blood Movement • Arteries – Pressure from heart – Vasoconstriction • Capillaries  – Mostly blood pressure (although low) • Veins – Mostly by milking action of muscles Vessel Problems • Varicose veins – Pooling of blood due to incompetent valves – Downward pressure restricts blood • Arteriosclerosis – Thickening of arterial walls from within – Often associated with plaque deposits • Usually lipids Vascular Anastomoses • Unions of vascular channels • Vessels separate and then come together Provides blood even if one source is blocked

Chapter 20 The Lymphatic System • Network of lymphatic vessels – Collect fluids (lymph) • Unabsorbed blood • Plasma protein • Antigens  • Lymphoid organs and tissues – Filter lymph Distribution of Lymphatic Vessels • One way system toward heart • Begins in lymph capillaries – Between tissue cells • Except in bone, teeth, and nervous tissue – Excess drains into cerebrospinal fluid Lymph Capillaries • Materials entering – Large proteins – Cell debris – Pathogens – Microorganisms – Cancer cells – Blood cells – Fluids • Lacteals – Specialized lymph capillaries – Found around intestine – Collect fat from intestine and delivers it to the bloodstream Lymph Vessels • Formed by merging lymph capillaries • Same tunics as veins, but with thinner walls – Also more internal valves Lymph Transport • Pumpless system – Low pressure – Aided by movement of muscles – Also aided by pulsing veins – Empties into veins prior to vena cava Lymphoid Cells • Lymphocytes – Main part of immune system • Macrophages  – Phagocytize foreign substances – Activate t-lymphocytes • Dendritic dells – Spiney-looking phagocytes • Reticular cells  – Provide support network Lymphoid Tissue • Mostly reticular connective tissue • Macrophages on outside • Lymphocytes on inside Lymphoid Tissue Packaging  • Diffuse lymphatic tissue – Scattered reticular tissue elements – Found in almost all organs • Lymphoid follicles – Solid bodies of reticular elements and cells – Not encapsulated – Often part of lymph nodes Lymph Nodes • Structure – Bean-shaped capsule • Dense fibrous connective tissue – Trabeculae  • Extensions of capsule inward – Two regions of tissue • Cortex = outer • Medulla = inner • Circulation – Lymph enters convex side – Moves through cortex to medulla – Flow stagnates • Allows lymphocytes & macrophages to work • Bubo – Infected lymph node – Become inflamed when overwhelmed by antigens • Common symptom in bubonic plague • Can become secondary cancer site Spleen • Largest lymphoid organ • Left side of abdominal cavity • Filters blood – Extracts old & defective blood cells – Stores platelets & breakdown products from blood cells – Removes bacteria & foreign matter • Structure  – Surrounded by thin fibrous capsule – Trabeculae  – White pulp • Mostly lymphocytes – Red pulp • Connective tissue • Red blood cells • Liver can take over the spleens functions Thymus • Cause t-lymphocytes to become immunocompetant – Hormones thymosin and thymopotien • Does not directly fight antigens • Has epithelial cells, not reticular fibers Tonsils • Simplest lymphoid organ • Ring of lymphoid tissue around pharynx • Appear as swellings of mucosa • Not fully encapsulated • Remove pathogens entering mouth – Trap bacteria & other particles • Naming of tonsils – Palatine • Largest • Posterior end of oral cavity • Most commonly infected – Lingual • At base of tongue – Pharyngeal • Posterior wall of nasopharynx – Tubal  • Around opening of auditory tubes into pharynx Peyer’s Patches • Distal portion of small intestine • Isolated clusters of lymph nodes similar to tonsils Appendix • Tubular offshoot of first part of large intestine • Heavily concentrated lymph nodes Lymphatic Problems • Elephantiasis – Lymphatics become clogged with parasitic worms – Swelling reaches enormous proportions • Hodgkin’s disease – Malignancy of lymph nodes – High cure rate Body Defenses Nonspecific Body Defenses • Surface membrane barriers  – Keratin  • Resistant to chemicals, microorganisms, bacterial enzymes, toxins – Mucous membranes line all body cavities • Protective chemicals – Acid skin secretions • Inhibit bacteria – Sebum • Bacterialcides  – Mucous • Traps microorganisms – Saliva & lacrimal fluid • Lysozimes – Hydrocloric acid • Produced by stomach • Phagocytes – Eat pathogens that get through skin & mucosae • Macrophages – Wander through tissues – Kills more than once • Neutrophils – Produce defensins – Kills antigen & neutrophil • Eosinophils • Natural Killer Cells – Lyse and kill cancer cells • Tissue response to injury = inflammation – Prevents spread of damaging agents – Gets rid of cell debris and pathogens – Starts repair process • Antimicrobial proteins – Complement system – About 20 proteins – Become fixed to foreign cell membrane – Lyse cell • Interferon  – Protein released by cell infected by virus – Immobilizes immune system • Fever – Abnormally high body temperature • Heat can denature enzymes of bacteria Specific Body Defenses • Immune System – Recognizes specific antigens (foreign substances) – Aspects of immune system • Systemic (not isolated) • Has memory • Is antigen specific Cells of the Immune System • Lymphocytes – Differentiate into T- or B-lymphocytes • Lymphocytes – Must become immunocompetent • Able to recognize an antigen • Have unique receptors • Become antigen specific before antigen encounter • T-cells in thymus • B-cells in bone marrow • Macrophages – Arise from monocytes – Secrete proteins to activate T-cells – T-cells in turn release chemicals that excite macrophages to become extremely active Autoimmune diseases • Body does not distinguish self from antigen – Multiple sclerosis • Destroys white mater of central nervous system – Myasthenia gravis • Impairs communication between nerve & skeletal muscle – Juvenile diabetes – Lupus – Rheumatoid arthritis

Chapter 21 Respiratory System Purpose of the Respiratory System • Supply oxygen • Dispose of CO2 Organs of Respiratory System • Nose • Nasal cavity • Pharynx • Larynx • Trachea • Bronchi • Lungs  • Alveoli Nose  • Functions  – Provides airway – Warms & humidifies air – Filters air – Resonating chamber for speech – Houses olfactory receptors • Framework  – Nasal & frontal bones – Maxillary bones – Hyaline cartilage – Dense fibrous connective tissue – Ethmoid & sphenoid – Palate  • Nasal septum – Divides nasal cavity • Vestibule  – Superior to nares – Sebaceous glands, sweat glands, hair follicles • Hairs = vibrissae – Filter coarse particles • Conchae = projecitons – Cause air turbulence  – Increase surface area • Mucosa – Lines nasal cavity – Olfactory mucosa • Roof of nasal cavity • Smell receptors – Respiratory mucosa • Pseudostratified columnar • Goblet cells – Mucous with lysozyme – Quart of mucous a day Paranasal Sinuses • Parts of bones around nasal cavity • Lighten skull • Warm & humidify air Pharynx • Connects mouth to larynx • Three regions – Nasopharynx  – Oropharynx – Laryngopharynx  • Nasopharynx – Posterior to nasal cavity – Only air passage – Closed by uvula during swallowing – Ciliated pseudostratified epithelium – Pharyngeal tonsils = adnoids – Auditory tubes drain into nasopharynx • Oropharynx – Posterior to oral cavity – Passage for food & air – Stratified squamous epithelium – Tonsils • 2 palatine • 1 lingual • Laryngopharynx – Extends to larynx – Common passageway • Links pharynx to trachea • Functions  – Maintains airway – Switches food and air  – Voice production Larynx • 9 cartilages connected to membranes & ligaments – Largest = thyroid • Adams apple in males • Growth caused by hormones at puberty • Epiglottis – 9th cartilage – Elastic cartilage – Covered by taste bud-containing mucosa – Guardian of airways • Voice box – Ligaments attached to thyroid cartilage – Mostly elastic fibers • Vocal cords • Voice box – Glottis = medial opening – Stratified squamous above, pseudostratified below • Voice production – Releases of air + opening & closing of glottis – Tense cords = high pitch – Loudness depends on force of air – Other structures necessary for voice • Pharynx • Sinuses • Tongue • Soft palate • Lips  Trachea • Windpipe  • Extends from larynx to bronchi • Nerves sensitive to blockage – Causes caughing • Only an air passage • Wall of trachea – Mucosa • Pseudostratified • Goblet cells • Smokers cough from destroyed cilia – Submucosa  • Connective tissue • Contains seromucous glands – mucous sheets – Adventia • Outer rings of hyaline cartilage Bronchi • Trachea divides to form 2 primary bronchi – Right is shorter than left • Inside lungs, bronchi divide – 23 orders of branching • Secondary, tertiary, …. • As branches become smaller – Cartilage rings replaced by irregular plates – Epithelium changes • Pseudostratified • Columnar • Cuboidal – Smooth muscle increases • Respiratory zone – Bronchioles = tiny bronchi – Terminal bronchioles end in alveoli – Alveoli • Alveolar ducts • Alveolar sacs Respiratory Membrane • Alveolar squamous epithelium & pulmonary capillaries – Gas on one side, blood on the other – Surfactant secreted to reduce tension – Macrophages move freely – Pores occur between adjacent alveoli • Equalize pressure Lungs • Occupy most of thorax • Rest on diaphragm • Blood veins enter & leave through medial hilus • Left lung is smaller than right – Cardiac notch accommodates heart – Left lung with 2 lobes, right with 3 • Ling support tissue is mostly elastic connective Pleura • Double layered serosa – Parietal pleura • Lines thoracic wall – Visceral pleura • Covers lungs • Pleural fluid fills cavity – Allows gliding movement Problems of Respiratory Center • Chronic Obstructive Pulmonary Diseases – Chronic bronchitis – Emphysema – Features  • Labored breathing  • Coughing • Frequent infections • Ends in respiratory failure • Most involve history of smoking • Emphysema – Permanent enlargement of alveoli – Lung fibrosis ®loss of elasticity – Airways collapse during expiration – Air is trapped in alveoli – Leads to barrel chest from forced expiration • Chronic bronchitis – Inhaled irritants lead to excessive mucus production in lower passageways – Inflammation & fibrosis of mucosa • Tuberculosis – Caused by bacterium • Mycobacterium tuberculosis – Bacterium is airborne – 1/3 of world is infected • Most do not develop symptoms – Destroys respiratory membrane – Connective tissue seals off infected & damaged area – Cure takes 12 months of antibiotic treatment – Resistant strains are common • Lung Cancer – 1/3 of U.S. cancer deaths – 90% are smokers – Cure rate is about 7% • Metastisizes rapidly Developmental Aspects • Premature infants have problems keeping lungs inflated  – Surfactant producing cells form late in development • Cystic fibrosis – Often fatal hereditary disorder • Excess mucous production • Respiratory rate – Infants = 40-80/min. – 5 years = 25 Adult = 12-18