BIOL 320 1st EditionLecture 10Outline of Last Lecture I. Capillary ModificationsII. Venules & VeinsIII. HemodynamicsIV. Blood Flow- Long-Term Auto-regulation of Blood Flow- Blood Flow: Skeletal Muscles- Blood Flow: BrainV. Blood PressureVI. Venous ReturnVII. Blood Pressure Regulation- Cardiac Output Regulation by BP- Short-Term BP Controls- VMC Regulation: Baroreceptor Reflex- Long-Term BP Regulation: RenalOutline of Current Lecture VIII. Regulation of MAPIX. Extrinsic Factors Affecting BPX. Homeostatic Imbalances for BP- Hypotension- HypertensionXI. Circulatory Shock- Definition- Result- TypesXII. Vascular Disorders- Atherosclerosis- ArteriosclerosisXIII. Developmental Aspects- Formed from?- Fetal Shunts- Umbilical Veins & Arteries- Vessel Formation- AgingI. Lymphatic Systema. Functionsb. Lymph Fluid Formation?c. VolumeII. Lymphatic Vesselsa. Lymph Capillariesb. Endothelial Liningc. Collectsd. Collecting VesselsIII. Lymphatic Drainagea. Pathwayb. TransportIV. Lymphatic Collecting Vesselsa. Characteristicsb. Transportc. Acquire Nutrients?V. Lymph Transport (REVIEW)VI. Lymphoid Cellsa. Macrophagesb. Lymphocytesi. Functionsii. TypesVII. Lymphoid Tissuesa. Lymph Nodesi. Regional Concentrationsii. Functioniii. Primary Cell Typeiv. CharacteristicsCurrent LectureRegulation of MAPExtrinsic Factors Affecting BP- Age- Sex- Weight- Race- Mood- Posture- Socioeconomic status (maybe due to diet?)- Physical ActivityHomeostatic Imbalances for BP- Hypotension:o Orthostatic: temporary decline in BPo Chronic: consistently low BP; usually related to poor nutrition; sign possibly of Addison’s Disease(low production of mineralocorticoids and glucocorticoids) and Hyperthyroidismo Acute: rapid change/decrease in BP; sign of circulatory shock!- Hypertension:o Transient: normal; caused by fever, physical exertion and emotional upseto Chronic: damage to vessels, baroreceptors, heart muscle, vascular organs Primary (essential): risk factors include those above, heredity, stress, & smoking- Major cause of heart failure, vascular disease, renal failure, stroke Secondary: due to other disordersCirculatory Shock- Definition: blood volume is low, so can’t circulate normally- Result: inadequate blood flow and can’t meet tissue needs- Types:o Hypovolemic shock: large blood loss; sever vomiting; severe diarrheao Vascular shock: extreme vasodilation…WHY?...not enough blood to circulate evenly to tissueso Cardiogenic shock: poor heart function (heart caused); heart cannot sustain circulationo Obstructive shock: blockage of blood flowo Anaphylactic shock: due to massive histamine release (due to severe allergic reactions)…histamine causes vasodilation  causes vascular shockVascular Disorders- Atherosclerosis:o Deposit: lipid plaques on wallso Result: increased peripheral resistance, increases BP, harder for heart to circulate, dramatic increased turbulence & BPo Increased risk: heart attack, stroke, thrombi, emboli- Arteriosclerosis:o Family of degenerative diseases/disorders where arteries/arteriole become calcified resulting in decreased elasticityDevelopmental Aspects- Endothelial lining develops from the mesoderm germ layer- Fetal Shuntso Foramen ovale: pulmonary circulation bypass during development in the womb; becomes fossa ovaleo Ductus arteriosus: bypasses fluid-filled non-functioning lungs during development in the wombo Ductus venosus: liver bypass during development in the womb- Umbilical Veins and Arterieso Functions: gas exchange for developing baby in the womb- Vessel Formationo Occurs: As needed Wound healing Uterine…every month of menstrual cycle- Agingo High blood pressureo Atherosclerosiso Varicose veinsLymphatic System- Functionso Fat absorptiono Immunity (lymphocytes travel within it)o Fluid balance (recapture…bruising for example)- Lymph Fluid Formation?o Fluid that has leaked out of the bloodstream (fenestrated capillaries especially)- Volumeo ~1.5 ml/min or 2.1 L/dayo ~43% of circulating blood volumeo Circulates at low pressureLymphatic Vessels- Lymph Capillaries: collect lymph in all tissues; one-way path to heart- Endothelial Lining: very loose & leaky; increased tissue pressure opens flaps to allow lymph to enter [if pressure is equal between tissue space and lymph capillary  flaps remain closed]- Collects:o Fluid (plasma)o Cellso Waste materialo Proteins- Collecting Vessels (similar to veins) = convergence of lymph capillariesLymphatic Drainage- Pathwayo Lymph capillaries  Collecting vessels  Lymph nodes  Trunks  Ducts  Subclavian veins- Transporto No central pumpo Pressure changes due to: Activity of smooth muscle Activity of skeletal muscle BreathingLymphatic Collecting Vessels- Characteristicso Similar to veins, except: Thinner walls, more internal valves Anastomose more frequently- Transporto In skin, collecting vessels travel with superficial veinso Deep vessels travel with arteries- Acquire Nutrients?o Nutrients supplied from branching vas vasorumLymph Transport (REVIEW)- No central pump- Lymph pressurized by:o Tissue pressureo Smooth muscle activityo Skeletal muscle activityo Breathingo Arteries- Lymph flow matches tissue activity- Valves ensure one-way flowLymphoid Cells- Macrophages (“big eaters”): different from monocytes; engulf trash/debris/microbes/damaged cells- Lymphocytes:o Functions Protect body from foreign antigens Some mature into attack cellso Types T Lymphocytes: activated in thymus gland; direct immune response B Lymphocytes: activated in bone marrow; produce plasma cells that secrete anti-bodiesLymphoid Tissues- Lymph Nodeso Regional Concentrations Axillary Inguinal Cervicalo Function: Filter lympho Primary Cell Type: Macrophageo Characteristics: More afferent than efferent vessels Become enlarged during infection Cancer spreads/metastasizes via lymphatic