Note:  The following is only an outline of the lecture material.  It is not "all you need" to prepare for the second exam.
 
 

Chapter 18 Endocrine System How Cells Communicate • Direct Communication – Adjacent cells transfer ions, solutes, & lipid soluble materials • Synaptic Communication – Use of neurotransmitters (Nervous System) • Endocrine Communication – Use of hormones via the circulatory system • Panacrine Communication – Hormone-like products of the pancreas via extracellular fluid Endocrine System • Second major controlling system of the body • Some interaction with the nervous system • Influences metabolic activity with hormones • Actions take seconds to days • Responses are prolonged • Endocrine glands are ductless – Organs are small and scattered in the body Hormone Chemistry • Amino acid derivatives – Amino acid chains – Includes peptide hormones • Steroid hormones – Lipids – Bound to transport proteins in blood – Long lived – Must be broken down by liver • Eicosanoids – Smaller molecule lipids – In extracellular fluid Hormone Target Specificity • Special protein receptors on target cells • Extent of target cell activation – Levels of hormone in blood – Relative number of receptors for that hormone – Strength of union between hormone and receptor Mechanisms of Hormone Activity • Change rates of normal cellular processes • Changes caused by hormone stimulus – Change in plasma membrane permeability – Regulates molecules within the cell – Enzyme activation or deactivation – Induction of secretory activity – Stimulation of mitosis Second Messenger Systems • Effects caused by substances whose entrance into the cell is mediated by hormones – Hormones usually help proteins and peptides Direct Gene Activation • Some hormones diffuse into target cells • Hormone binds to DNA receptor protein • This turns on a gene • Products are enzymes that promote metabolic activity Duration of Hormone Acitvity • Cause of concentration at any time – Rate of release – Speed of  deactivation • Duration of hormone action is 20 min. to several hours Removal of Hormones • Removed by one of three methods – Degraded by enzymes – Kidney – Liver  • Break-down products are excreted • Each hormone type has a half-life Control of Hormone Release  • Most are regulated by negative feedback • Stimuli – Humoral  • Response to ions & nutrients in blood – Neural  • Sympathetic activation – Hormonal  • Started by other hormones – Some respond to multiple stimuli Major Endocrine Glands Pituitary Gland • = hypophysis • Rests within sella turcica – Depression of sphenoid bone • Attached to brain by infundibulum • Encircled by dural sheath Pituitary Gland Lobes • Posterior lobe • Neural tissue • Releases 2 hormones • Antidiuretic hormone • Targets kidney • Increases water in plasma • Oxytocin – Causes contractions of uterus – Contracts ductus defrens in prostate • Anterior lobe – True endocrine gland – Growth hormone • Targets all cells – Thyroid stimulating hormone • Causes thyroid to release hormones – Adrenocorticotropic hormone • Release of hormones from adrenal cortex – Gonadotropins  • Folicle stimulating hormone – Sperm production – Stimulates follicle cells of ovaries for development & estrogen secretion • Luteinizing hormone – Ovulation – Formation of corpus luteum – Prolactin  • Milk production Thyroid Gland • Located in anterior neck – Anterior surface of trachea • Two lateral lobes connected by median tissue (isthmus) • Largest pure endocrine gland • Internally composed of spherical follicles – Follicle cells • Surround follicles • Usually cuboidal • Produce thyroid hormone • Produce protein thyroglobulin – Parafollicular cells • Produce calcitonin Effects of Thyroid Hormones • Thyroid Hormone – Stimulates enzymes concerned with glucose oxidation – Increases metabolic rate – Plays role in maintaining blood pressure – Regulates tissue growth and development – No effect on brain, spleen, testes, uterus, & thyroid gland • Calcitonin – Lowers blood Calcium levels – Antagonist to parathyroid hormone – Inhibits osteoclast activity – Stimulates calcium uptake by bones – Most important during childhood Thyroid Problems • Hypothyroid – = myxedema – Low metabolic rate • Chills • Constipation • Dry skin • Edema • Lethargy  • Mental sluggishness • Cretinism – Hypothyroidism in infants • Short disproportionate body • Mental retardation • Hyperthyroid – Grave’s disease – Elevated metabolism – Sweating – Rapid heart rate • Goiter – Abnormal enlargement of thyroid – Often from lack of iodine • Needed for proper formation of thyroid hormone Formation of Thyroid Hormone • Iodide ions from diet • Iodide ions diffuse to apical surface of follicle cell – Forms colloid • Iodide + thyroglobulin • The product is paired to form thyroid hormone Parathyroid Glands • Usually 2 pair of glands – Can be up to 8 • On posterior of thyroid gland • Made of 2 cell types – Oxyphil cells • Function unknwon – Chief cells • Secrete parathyroid hormone Parathyroid Hormone • Protein hormone • Most important controller of Ca++ balance – Increases Ca++ in blood • From digestive tract • Bones • Kidneys via calcitrol – Inhibits osteoblasts – Stimulates osteoclasts – Increases absorption from intesting • Vitamin D must be present Thymus • Deep to sternum • Large in children – Diminishes in size • Produces thymosins – Develop and mature the immune response Adrenal Glands • = suprarenal glands • Pyramid glands on top of kidney • Actually 2 glands – Adrenal Cortex • Outer – Adrenal medulla • Inner  Adrenal Cortex • Yellow color due to stored lipids • Produces over 2 dozen steroid hormones • Cells are in 3 distinct zones • Zona glomerulosa – Outer – Mineralocorticosteroids • Control balance of minerals & H2O in blood • Zona fasiculata – Glucosteroids • Metabolic hormones • Zona reticularis – Produces androgens • Some contribute to the onset of puberty Adrenal Medulla • Spherical chromaffin cells – Secrete epinephrine and norepinephrine Kidneys • Small amounts of endocrine tissue • Release several hormones and renin Hormones of Kidneys • Calcitrol – Steroid hormone – Stimulates calcium & phosphate absorption • Erythropoietin – Peptide hormone – Stimulates production of red blood cells Renin • Not a hormone • Associated with hormone activity • Helps regulate blood pressure Heart • Contains endocrine cells – Atrial natriuretic peptide • Helps control blood pressure & volume Pancreas • Behind stomach • Mixed gland – Endocrine & exocrine • Mostly made of acinar cells – Exocrine – Produce alkaline enzyme • Digestive enzymes • Islets of Langerhans – Endocrine pancreas – Produce pancreatic hormones • Insulin • Glucagon – Regulates blood sugar level Insulin • Peptide hormone • Released by b cells • Lowers blood sugar levels • Allows glucose to enter cells Glucagon • Releases glucose into blood • Major target is liver • Prompted by declining blood sugar level • 1 molecule can release 1 million glucose molecules Diabetes mellitus • Hyposecretion or hypoactivity of insulin • Glucose is unable to enter cells • More fats are mobalized • Blood sugar level increases • Two types – Type I = juvenile diabetes • No insulin activity • Insulin dependent – Type II  • Insulin is produced • Receptors do not respond • Occurs mostly after age 40 Hypoglycemia • Hyperinsulinsim • Low blood sugar • Symptoms – Anxiety – Nervousness – Tremors – weakness Pancreas • Somatostatin – Produced by delta cells – Inhibits insulin & glucagon secretion – Slows nutrient absorption • Pancreatic polypeptide – Produced by F cells – Inhibits gall bladder contraction – Regulates production of pancreatic enzymes Testes • Male gonads • Secrete androgens – Steroid hormones – Produced in interstitial cells – Sperm maturation – Protein synthesis in muscles – Male secondary characters Ovaries • Steroid sex hormones – Estrogen • Produced by follicular cells • Female secondary characteristics • Follicle stimulation – Inhibin • Produced by follicular cells • Inhibits FHS production by pituitary Ovary – Progestins • Produced by corpus luteum • Prepares uterus for implantation • Prepares mammary glands for secretion – Relaxins • Produced by corpus luteum • Relaxes uterine muscles • Stimulates mammary development Pineal Gland • Hangs from 3rd ventricle of diencephalon • Part of epithalamus • Pinealocytes – Secretory cells – Prodoce many peptides & amines – Produces melatonin • Sets biological clock • Mostly released at night Stomach • Some endrocrine cells – Gastrin • Stimulates HCl release – Serotonin • Contractions of stomach muscles Duodenum • Intestinal gastrin • Secretin – Increases bile release – Inhibits secretions of stomach Placenta • Produces steroid & protein hormones • Influence the course of pregnancy Skin • Produces cholecalciferol – Inactive form of vitamin D – Activated by kidney

Chapter 19 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 erythrocytyes – Useful lifespan  =  100-120 days – Most are destroyed by macrophages in the spleen – Some components are recycled, others excreted • 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 Leukocytes • 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 Leukocytes • Leukocyte formation – Formed by hematocytoblast – Stem cells develop into types of leukocytes in 3-10 days – Live for hours to a lifetime Leukocytes • 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 20 Heart 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 ventrical 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 Requirements of Heart • Great dependence on O2 – Only aerobic respiration • Can switch metabolic pathways easily – Glucose – Fatty acids – Even lactic acid Mechanism of Contraction • Sequence of electrical events – Influx of sodium ions – Sarcoplasmic reticulum releases Ca++ – Ca++ triggers contraction • Cardiac muscle is self excitable = autorhythmic • Long refractory period prevents tetanic contractions 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 • Autonomic Regulation – Release of norepinephrine • Heart beats faster • Threshold reached more quickly – Acetylcholine slows heart – At rest both systems work somewhat • Called vagal tone • Other chemical regulation – Hormonses • Epinephrine enhances heart rate • Thyroxine slows heart – Ions – Lack of Ca++ depresses heart • Other factors – Age • Slower as you age – Gender • Females are faster – Exercise • Increases rate – High body temperature • Increases rate

Chapter 21 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 vesels 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 – 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 Cardiovascular physiology • Bloodflow functions – Pressure • Force pre unit area • Ave. = 120/80 mm Hg. in major arteries • 35-18 in capillaries • Almost 0 in veins – Resistance  • Opposition to flow – Blood vessel diameter – Blood vessel length – Blood viscosity Maintaining Blood Pressure • Neural controls • Vasomotor center reflex arcs • Chemical controls that reduce blood pressure by promoting vasoconstriciton • Epinephrine and norepinephrine • Nocotine • Antiduretic hormone • Angiotensisn II (resopnse to renin) • Chemical Controls that reduce blood pressure • Atrial natriuretic peptide • From atria  – Nitric oxide • Secreted by endothelial cells – Inflammatory chemicals – Alcohol • Renal regulation  • Kidneys regulate blood pressure by regulating blood volume • Rising blood pressure enhances fluid loss by urine • Falling blood pressure to retain water • When blood pressure falls, the kidney releases renin Extremes in Blood Pressure • Hypotension – Low blood pressure – Systolic < 100 – Usually no cause for concern – Orthostatic hypertension • Temporary due to rising suddenly – Chronic causes  • Poor nutrition • Disease • Circulatory shock • Good health in well conditioned people • Hypertension – High blood pressure – Risk factors • High fat or salt diet • Obesity • Advanced age • Stress • Heredity race • Smoking

Chapter 22 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

Chapter 23  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 Stages of Inflammation • Release of inflammatory chemicals • Histamine • From basophils • Promotes vasodilation  • Kinins • From plasma, urine, saliva & some cells • Aids leukocyte activity • Prostoglandins • From cell membranes • Cause infammation • Hyperemia • Congestion with blood • Exudate seeps into tissue space • Clotting factor proteins • Antibodies  • Causes local swelling • Isolates injured area • Phagocyte mobilization • Neutrophils enter • Monocytes develop into macrophages after developing lysozymes • Replace neutrophils • Disposers of cell debris • Occasional results – Pus  • Dead & dying neutrophils • Living & dead pathogens • Cell debris – Abscess • Puss walled off by collagen fibers Nonspecific Body Defenses • 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 – Caused by pyrogens • Released by leukocytes & macrophages • Resets hypothalamus • Liver & spleen do not release iron & zinc needed by bacteria Specific Body Defenses • Immune System – Recognizes specific antigens (foreign substances) – Aspects of immune system • Systemic (not isolated) • Has memory • Is antigen specific Types of Immunity • Humoral – Antibody mediated – Attack freely circulating antigens • Cellular – Cell mediated – Attack infected cells Cells of the Immune System • Lymphocytes – Differentiate into T- or B-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 Humoral Immune Response • B-lymphocytes are activated when antigens bind to receptors • B-cells grow and multiply rapidly – Two clone types form • Plasma cells – Secrete antibodies » 2000 molecules /sec. • Memory cells – Long lived  – Do not secrete antibodies – Starts future immune response very quickly Antibodies • Soluble proteins • Antibody recognizes appropriate antigen • Causes destruction of antigen Secondary Immune Response • Re-exposure to antigen • Antibodies produced so fast the antigen does not cause disease • Usually lasts a lifetime Types of Immunity • Active – Naturally acquired – Artificially acquired  • Vaccines – Dead or attenuated  – Produce memory cells without full symptoms • Passive – Borrowed immunity – Degenerate  – Usually from mother to fetus Cell Mediated Immune Response  • Antibodies are ineffective if antigen gets into a cell • T-cells provide cellular immunity • Recognize and respond to fragments of protein antigens, not shaped • Types of T-cells – Cytotoxic T-cells • Cell killing cells – Helper T-cells • Start cloning of T-cells  • Activate response – Suppressor T-cells • Stop immune response • Keeps body from attacking self  • Antigen recognition – Must have double recognition • The antigen • Protein of infected cells – Found on surface of cell after infection • Once activated, T-cells go through clonal process Allergies • Hypersensitivity – Abnormally strong immune response – Causes damage of healthy tissue – Can be immediate or delayed 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 24 Respiratory System Purpose of the Respiratory System • Supply oxygen • Dispose of CO2 • Processes – Pulmonary ventilation • Air in & out of lungs – External respiration • Between blood & air – Transport of respiratory gasses in blood – Internal respiration • Between blood & cells 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  Pharynx • 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 parrageway Larynx • Links pharynx to trachea • Functions  – Maintains airway – Switches food and air  – Voice production • 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 – 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 • Air is now saturated with water vapor • 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 Breathing Mechanisms • Two phases  – Inspiration – Expiration • Pressure relationships – Pressure in alveoli = atmospheric pressure – Intrapleural pressure is 4 mm Hg less than alveoli • Keeps lung from collapsing – Called pneumothorax Inspiration • Action of several muscles – Brings in about ½ liter of air – Mostly diaphram • Contraction = larger thoracic cavity • Fills lungs – Intercostal muscles • Lifts rib cage • Expands thorax a little Expiration • Mostly a passive process • Depends mostly on natural elasticity  • Forces expiration is an active process Non-Respiratory Air Movements • Most result from reflex activity – Coughing – Sneezing – Crying – Laughing – Hiccups – Yawn  Alveolar Gas • Different than atmosphere – Less N & O2 – More CO2 & H2O • O2 & CO2 are being exchanged • Air has been humidified • Alveolar air is a mixture of atmospheric & previous alveolar air – All of the air is not exchanged with each breath Gas Exchange • External Respiration – Exchange across pulmonary membrane – O2 in CO2 out – Blood becomes redder – Process of diffusion • Respiratory membrane is 0.5 - 1ìm thick – Pneumonia thickens membrane • Healthy lung has 140 m2 of surface area for gas exchange • Internal gas exchange • Exchange in body tissues – Mostly by diffusion – Pressure gradient is reduced Transport of Respiratory Gas • Oxygen – 98.5% is bound to hemoglobin • Binding is rapid & reversible – 1.5% is dissolved in plasma – Hypoxia = inadequate O2 delivery to body tissues Types of Hypoxia • Anemic – Too few erythrocytes – Inadequate amounts of hemoglobin • Ischemic – Blood circulation impaired • Ex: congestive heart failure • Histotoxic – Cells unable to use O2 – Usually from poisons like cyanide • Hypoxemic – More attractive gasses like Carbon monoxide Transport of Respiratory Gas • CO2 transport – As bicarbonate ion • 60-70% • HCO3 buffers pH – Bound to hemoglobin • 20-30% • Binds to globin, not heme group – Dissolved in plasma • 7-10% Control of Respiration  • Medullary respiratory group – Pacesetting center – Inspiratory center • Impulses excite diaphram – One part may be important in forced respiration • Pons respiratory center – Influence & modify medullary neurons – Some inhibitory effect on medulla Factors Influencing Breathing • Pulmonary irritant reflexes • Some irritants cause cough reflex or sneeze • Receptors • Trachea  • Bronchi • Nasal cavity • Hering-Breuer reflex • Stretch receptors terminate inspiration • Prevents excessive lung stretching • Influence of higher brain centers • Hypothalamus • Strong emotions cause rate & depth change • Cortical controls • Conscious control • Chemical factors • Chemoreceptors respond to CO2, O2, & H+ • CO2 pressure • High CO2 can cause breathing increase • Hyperventilation • Flushes system • Can cause breathing to stop • Breathing starts again as CO2 increases • Breathing into paper bag increases CO2 • O2 pressure • Low O2 causes increased breathing • Usually not a factor before CO2 • Atrial pH influence • When pH decreases, ventilation increases Respiratory Adjustments • Exercise causes breathing to be deeper & faster • Psychic stimuli – Anticipation of needs causes increase • Propriocenters in muscles tendons & joints send message to respiratory center, even before CO2 causes changes 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

Chapter 25 Digestive System Digestive System Organs • Mouth  • Pharynx • Esophagus • Stomach • Small intestine • Large intestine • Anus • Accessory organs • Function – Breaks food into smaller parts – Absorption of nutrients into blood Digestive Process Activities • Ingestion  – Taking food into digestive system • Propulsion – Moving food along • Voluntary = swallowing • Involuntary = peristalsis • Mechanical digestion – Chewing  – Mixing food with saliva – Churning food in stomach • Chemical digestion – Enzymatic breakdown of  food • Absorption – Transfer of nutrients to circulatory system • Defecation – Elimination of indigestible materials Coverings of Digestive Organs • Visceral peritoneum – External surface • Parietal peritoneum – Lines walls of abdominal cavity • Peritoneal cavity – Filled with serous fluid • Messentary – Connects visceral & parietal peritoneum – Provides routes for blood vessels, nerves, lymphatics • Blood supply = splanchnic circulation – Holds organs in place Histology • Four tunics – Mucosa  • Lines lumen from mouth to anus • Secretes mucus, enzymes, hormones • Absorbs digestive products • Protects against disease • Layers  – Surface epithelium » Simple columnar – Lamina propria » Areolar connective » Capillaries » Lymphatics  – Muscularis mucosae » Smooth muscle – Submucosa • Dense connective tissue with elastic fibers – Muscularis externa • Responsible for peristalsis • Layers – Inner circular – Outer longitudinal – Serosa • Areolar connective • Outer layer of squamous epithelium Mouth • = oral cavity = buccal cavity • Slightly keratinized • Lips & cheeks – Skeletal muscles – Skin covering • Vestibule = area between cheek & gums • Lips – Extend from nose to chin – Red margin • Transition between karatinized & oral mucosae – Labial frenulum • Median fold that attaches lip to gum • Palate – Roof of mouth – Hard palate • Underlain by bone • Tongue forces food against it during chewing – Soft palate • Mostly skeletal muscle • Rises to nasopharynx during swallowing • Contains palatine tonsils • Tongue – Movements mix food with saliva – Initiates swallowing – Intrinsic muscles • At tip • Allows shape change – Extrinsic muscles • Alters tongue position – Lingual frenum  • Secures tongue to floor of mouth • Salivary glands – Many different glands • Parotid - anterior to ear – Infected in mumps • Submandibular  – Next to mandible • Sublingual – Anterior to mandible • Buccal glands – Small intrinsic salivary glands – Serous cells • Watery secretions (97-99.5%)containing enzymes – Mucous cells • Mucus – Some saliva is always produced – Increase caused by parasympathetic • Functions of saliva – Cleanses mouth – Dissolves food • Allows for taste – Aids compaction of food into bolus – Begins breakdown of food with enzymes • Teeth – Humans have 2 sets • Deciduous = milk teeth – Start at 6 months – Pairs at 1-2 month intervals – All 20 by 24 months • Permanent – Milk teeth roots are reabsorbed – Full set is 32, unless wisdom are absent • Types of teeth – Incisors • Chisel shaped • Cutting  – Canines  • Conical • Tear & pierce – Premolars (bicuspid) & molars (broad crowns) • Grinding & crushing • Tooth structure – Crown exposed part • Enamel layer – Mineralized calcium salts – No cellular repair • Gingiva = gum – Surrounds tooth – Root • Embeded in bone • Peridontal ligament – Anchors tooth to bone • Cementum – Calcified connective tissue – Attaches tooth to peridontal ligament – Dentin • Underlies enamel • Produced by odontoblast • Bone-like material – Pulp • Connective tissue • Blood vessels • Nerve fibers Pharynx • Digestive system uses two parts – Oropharynx  – Laryngopharynx  • Movement is mostly gravity Esophagus • Muscular tube • Collapsed when not in use • Straight route to the stomach • Mucosa changes from stratified squamous to simple columnar  • Muscularis externa is part skeletal muscle, part smooth muscle Digestion in Mouth, Pharynx, Esophagus • Mechanical breakdown – Mastication – Compacting by tongue • Mixing food with saliva • Heartburn  – Gastric juice regurgitates into esophagus Swallowing  • Coordinated movement – Tongue – Soft palate – Pharynx – Esophagus – Over 22 muscle groups • Voluntary = buccal phase • Involuntary = pharyngeal & esophogeal phase Stomach • Storage tank – Left side of abdomen – Can extend to 1 gallon – Collapses into rugae = longitudinal folds • Chemical breakdown of protein begins • Food is converted to chyme – Creamy paste • Regions of stomach – Cardiac – entry of food, near heart – Fundulus – Body  – Pyloric region • Ends in pyloric sphincter – Controls stomach emptying • Features  – Greater curvature – Lessur curvature – Omentum • Messentary • Greater omentum – From greater curvature over small intestine • Lesser omentum – From liver to lesser curvature • Modification of tunics – Muscularis external • Three muscle layers – Inner oblique – Middle circular – Outer longitudinal • Allows for churning of food – Mucosa • Simple columnar is entirely goblet cells • Gastric pits – Secretory cells that produce gastric juice • Secretory cells – Mucous neck cells • Different type of mucus – Parietal cells • Secrete HCl • Gives stomach pH 1.5-3.5 • Kills bacteria – Chief cells • Produces pepsin – Enteroendocrine cells • Release hormones • Mucosal barrier – Prevents stomach from digesting itself – Thick alkaline mucus – Epithelial cells with tight junctions – Epithelial cells replaced in 3-6 days – Gastric ulcers • Damage to tissue • Hypersecretion of HCl • Hyposecretion of mucus • Pain 1-3 hours after a meal • Gastric motility – Peristalsis at about 3/min. • Pacemaker cells in smooth muscle along greater curvature – Pyloric valve only allows liquid & small particles to pass – Empties completely in about 4 hours Small Intestine • Major digestive organ • Site of nutrient absorption • Site of most chemical digestion • Regions of small intestine – Duodenum – Jejunum – Ileum  • Villi – Finger-like projections of mucosa – Absorptive columnar cells – Lacteal capillaries – Pulsate using small amounts of smooth muscle • Increase contact with nutrient soup • Milks fat through lacteal • Microvilli  – Tiny projections of the plasma membrane – Have enzymes • Histology differences – Mucosa is simple columnar • Have goblet cells – Submucosa has Peyer’s patches • Lymphoid tissue • Digestive processes – Materials pass through in 3-6 hours – Depends on slow measured delivery of chyme – True peristalsis only after most nutrients are absorbed Accessory Organs • Liver – Largest gland in body – 4 primary lobes – Under diaphragm on right side – Falciform ligament • Mesentary that suspends liver from diaphragm – Round ligament • Fibrous remnant of fetal umbilical vein • Liver microscopic anatomy – Plates of liver cells  • Hepatocytes – Produce bile – Process blood borne nutrients » Glucose to glycogen – Store fat – Play role in detoxification • Radiate around central vein – Liver sinusoids • Leaky capillaries – Kupffer cells • Macrophages  – Bile canaliculi • Small canals for bile • Liver – Composition of bile • Bile salts – Emulsify fats • Bilirubin – Waste product of hemi portion of hemoglobin – Gives feces a brown color • Gallbladder  – Thin walled muscular green sack – At inferior margin of liver – Stores bile – Gallstones = crystallized cholesterol • Pancreas – Produces a broad spectrum of enzymes – Delivers to duodenum – Acini  • Secretory cells of pancreas – Islets of Langerhans • Endocrine gland Large Intestine • Frames small intestine on 3 sides • Major function – Absorption of water – Elimination of solid waste • Bacterial flora – Colonize colon – Ferment indigestible carbohydrates – Synthesize B vitamins & vitamin K (clotting proteins) • Anatomy – Muscularis is reduced, except at end • Teniae coli – 3 bands of smooth muscle – Forms haustra = sack like areas • Subdivisions  – Cecum • Sack-like first part – Vermiform appendix • Masses of lymphoid tissue – Colon  – Rectum  • 3 internal transverse folds = rectal valves – Separate feces from flatus – Anus • Has two sphincters – Internal anal sphincter » Involuntary » Smooth muscle – External anal sphincter » Skeletal muscle • Microscopic anatomy – Mucosa is simple columnar epithelium • Thicker than in other parts of digestive system • Tremendous numbers of goblet cells • Anus has stratified squamous epithelium • Mobility of large intestine – 12-24 hours for material to pass – Only food breakdown is by bacteria – Sluggish contractions every 30 minutes or so – Powerful contractions 3-4 times per day

Chapter 26 Included in notes from previous chapter