BIOL 320 1st EditionLecture 4 Outline of Last Lecture I. Adrenal GlandsA. Adrenal CorticosteroidsB. Homeostatic ImbalancesC. Stress ResponseD. DisordersII. PancreasA. Cell Typesi. Targetii. EffectsB. Diabetes MellitusOutline of Current Lecture III. Female GonadsIV. Male GonadsV. Pineal GlandVI. ThymusVII. Other Hormone-Producing StructuresVIII. Developmental ConsiderationsIX. Aging EffectsI. BloodII. Composition of BloodIII. ErythrocytesA. ProductionB. Life CycleC. DisordersCurrent LectureFemale Gonads- Ovaries:o Produce estrogen and progesteroneMale Gonads- Testes:o Produce testosteronePineal Gland- Pinealocytes:o Produce melatonin (important for sleep)- Suprachiasmatic Nucleus of the Hypothalamus:o Biological clock…important for circadian rhythms- Light signal detected by photoreceptors in retina of eye and send info to suprachiasmatic nucleus of thehypothalamus, which sends info to the pineal gland. The pineal gland then secretes melatonin back to the suprachiasmatic nucleus.- Melatonin:o Kids have higher levels of melatonin since they need more sleep for growtho Use: plays a big role in shift work (shift from night activity to day activity and vice versa)- Seasonal Affective Disorder (SAD):o Not enough light…o Cause: results from overproduction of melatonino Treatment: full-spectrum phototherapyThymus- Produces thymosin (important for white blood cells…especially T cells of immune system) and thymopoietin (maturation of T cells)- Governs production of white blood cells (WBC)- Most active in childhood- Atrophies with age- Immune response declines with ageOther Hormone-Producing Structures- Adipose cells:o Leptin: released when satiatedo Resistin: antagonizes insulin (promotes glucose in blood)- Skin:o Cholecalciferol: converted to calcitriol (uptake of calcium…active form of vitamin D)- GI Tract:o Enteroendocrine cells: release several peptide hormones that help regulate a variety of digestive functions (also have paracrine type functions)- Kidney:o Erythropoietin (EPO): maturation of RBC- Heart:o Atrial Natriuretic Peptide (ANP): reverse of ADH…promotes urination- Placenta:o Human chorionic gonadotropino Human placental lactogeno Human chorionic somatomammotropinDevelopmental Consideration- Endocrine cells come from all three germ layers- Germ layers:o Endoderm: endocrine glands derived form this layer produce amine, peptides, or protein hormoneso Mesoderm: endocrine glands derived form this layer produce steroid hormoneso Ectoderm: endocrine glands derived form this layer produce amine, peptides, or protein hormones- Growth Hormone:o Ethical issues with trying to give or use this but also for safety of individual- Substances that disrupt endocrine function:o Pesticideso Industrial chemicalso Arsenico Dioxino Pollutants: tree frogs are the canary of results these have on developmentAging Effects- Structural changes do occur over time- General endocrine functions decline with age- Ovaries function but then decline with age- Testosterone gradually declines with age- Growth Hormone decline more abruptly with age- Thyroid Hormone declines with age- Parathyroid Hormone does NOT decline with age…increases blood calcium levels leading to osteoporosis- Adrenals:o Medulla: epinephrine and norepinephrine are not affected with ageo Cortex: cortisol and aldosterone decline with age- Insulin release declines with age and receptor sensitivity declines with ageBlood- Connective tissue- Non-living- Characteristics:o Tissue type: connectiveo Taste: metallic/saltyo Color: scarlet red…depending on the presence of oxygeno pH: 7.35 – 7.45o Temperature: slightly warmer than body temperatureo Functions: Protection: route that defensive cells travel against infection and blood loss Regulatory: body temperature, pH, water/fluid balance Transport: gases, enzymes, hormones, waste, nutrients moved aroundComposition of Blood- Plasma (55% of whole blood):o 90% watero 10% solutes- Formed Elements (~45% of whole blood)o Buffy Coat (<1% of whole blood) Leukocytes and platelets (clotting factors)o Erythrocytes (45% of whole blood)Erythrocytes- Characteristicso Anucleate: do not have a nucleuso Biconcave: increases surface area to carry multiple units of hemoglobin for oxygen gas exchangeo Essentially no organelleso Normal values: Males tend to have higher count (higher muscle mass) than femaleso Hemoglobin: pigment that plays a role in gas exchange 2 alpha chains each with a heme group 2 beta chains each with a heme group Binds four molecules of oxygen 33% mass of RBC Will aslo bind to carbon monoxide (stronger affinity) and carbon dioxide (~20% of waste gass…for cycling process) Oxygen loading in the lungs- Produces oxyhemoglobin (ruby red) Oxygen unloading in the tissues- Produces deoxyhemoglobin or reduced hemoglobin (dark red) Carbon dioxide loading in the tissues- Produces carbaminohemoglobin (carries 20% of carbon dioxide in the blood)o Primary function: gas transporto Spectrin: flexible protein in walls of RBCs…allows it to bend, twist, torque in changing diameter/shape for travel through blood vesselso RBCs perfectly suited for job (gas transport) because: Large surface area High hemoglobin content Anaerobic: don’t steal from oxygen cargo- Productiono All three types of blood cells start from same hematopoietic stem cellso Erythropoiesis: production of RBC Made in bone marrow of flat bones and irregular bones in adults…almost all bones inchildren Hormonal Control of Erythropoiesis- EPO: stimulates blood productiono Effects of EPO More rapid maturation of committed bone marrow cells Increased circulating reticulocyte count in 1-2 days- Testosterone also enhances EPO production, resulting in higher RBC counts inmales Dietary requirements:- Fat, Protein, and Carbohydrates: for structural proteins- Iron needed for hemoglobin structure…lost regularly in fecal material- Vitamin B12 and Folic Acid: needed for normal DNA synthesis Formation of RBCs:- Hemocytoblasto Stem cell: going to be some type of blood cell- Proerythroblasto Committed cell: know what type of blood cell…definitely will become a RBC- Developmental Pathway:o Phase 1: ribosome synthesis Early erythroblasto Phase 2: hemoglobin accumulation Late erythroblast Normoblast (with nucleus)o Phase 3: ejection of nucleus Normoblast (without