Biomedical Science Course Exam Review Notes

Lesson 1.1: Investigating the Scene\n\n* Principles of Biomedical Science (PBS): The application of the principles of the natural sciences, especially biology and physiology, to clinical medicine. It can be used to investigate mysterious deaths and design experiments for testable questions.\n* Crime Scene Processing: Involves purposeful documentation of the conditions at the scene and the collection of physical evidence (blood, hair, fingerprints, shoeprints). This helps investigators identify or exonerate suspects and establish the sequence of events.\n* Bloodstain Patterns: Analysis of patterns left at a scene helps establish the events that took place. Specific data can be gathered through experiments to determine the height from which blood fell.\n* Key Career Roles in Death Investigation:\n * Forensic Pathologist (Medical Examiner): A medical doctor who primarily performs autopsies to determine the cause of death.\n * Toxicologist: Usually a PhD who tests body fluids (blood, vitreous humor, urine) for toxins and medications.\n * Coroner: An elected official who works with police to decide whether an autopsy is needed and if a crime has been committed.\n* Experimental Design Definitions:\n * Control Group: The group where the independent variable is NOT applied; serves as a standard for comparison.\n * Independent Variable: The variable manipulated or varied by the researcher.\n * Dependent Variable: The measurable effect, outcome, or response.\n * Positive Control: Expected to have a positive result to show the experimental setup works.\n * Negative Control: Conditions produce a negative outcome to identify outside influences.\n * Hypothesis: A clear prediction of anticipated results.\n * Personal Protective Equipment (PPE): Specialized clothing or equipment worn to protect against infectious materials, as defined by OSHA.\n\n# Human Body Systems and Organs\n\n* System: A collection of parts (cells, tissues, and organs) working together to perform a job.\n* Urinary System (“Place for pee”): Filters waste from the blood. Organs include Kidneys, Ureters, Bladder, and Urethra.\n* Nervous System (“Full of nerves”): Sends electrical signals to control other systems. Organs include Brain, Spinal Cord, Peripheral Nerves, and Sense Organs.\n* Endocrine System (“Secrete within”): Secretes hormones (e.g., hunger signals). Organs include Pancreas, Thymus, Thyroid, Pituitary, Pineal Gland, Adrenal Glands (“after kidneys”), and Ovaries/Testes.\n* Digestive System: Absorbs nutrients. Organs include Teeth, Tongue, Salivary Glands, Pharynx, Esophagus, Stomach, Small/Large Intestines, Rectum, Liver, and Gall Bladder.\n* Respiratory System: Brings in $O_2$ and removes $CO_2$. Organs include Nasal Cavity, Pharynx, Larynx, Trachea, Bronchus, Bronchioles, and Alveoli (“Hollow”).\n* Cardiovascular System (“Heart and small vessels”): A transportation system for nutrients and gases. Components include Heart (Atria/Ventricles), Veins/Venules, Arteries/Arterioles, Capillaries, and Erythrocytes (“red cells”).\n* Immune System: Kills pathogens (“disease starters”). Organs include Bone Marrow, Thymus, Spleen, Lymph Nodes, Tonsils, Leukocytes (“white cells”), and Appendix.\n* Skeletal System: Provides structural support and makes blood cells.\n\n# Lesson 1.2: DNA Analysis and Structure\n\n* The DNA Blueprint: Human DNA consists of over 3 billion base pairs. It is packaged as chromosomes containing numerous genes (segments of DNA coding for traits).\n* Nucleotide Structure: The building block of DNA consisting of a five-carbon sugar (deoxyribose), a phosphate group, and a nitrogenous base.\n* Complementary Base Pairing:\n * Adenine (A): A purine base; pairs with Thymine (T).\n * Thymine (T): A pyrimidine base; pairs with Adenine (A).\n * Cytosine (C): A pyrimidine base; pairs with Guanine (G).\n * Guanine (G): A purine base; pairs with Cytosine (C).\n* DNA Isolation Process (Lysis):\n 1. Break open cells (lysis) using a buffer to maintain pH.\n 2. Remove membrane lipids using detergent.\n 3. Remove proteins using the enzyme protease (optional).\n 4. Precipitate DNA using ice-cold alcohol.\n* Gel Electrophoresis: Separates DNA fragments based on size and electrical charge. DNA is negatively charged and moves toward the positive electrode. Smaller fragments move faster and further.\n* Restriction Fragment Length Polymorphisms (RFLPs): Differences in DNA sequences that result in different patterns of fragment lengths when treated with restriction enzymes.\n* DNA Quantities: A human genome has 46 chromosomes. Total length is calculated as:\n$3 \times 10^9 \text{ bp} \times 3.4 \times 10^{-10} \text{ meters/bp} = 1 \text{ m of DNA}$\n(Estimates range up to 3 meters).\n\n# Lesson 1.3: The Findings and Autopsy\n\n* Autopsy (“self-eyes”): An examination of the body after death (post-mortem) to determine the cause and manner of death. It involves weighing and examining organs and toxicology analysis of fluids.\n* Health Insurance Portability and Accountability Act (HIPAA): A set of standards designed to protect patient privacy and rights regarding health information (name, condition, insurance, etc.).\n* Confidentiality Exceptions: Information can be shared if the patient is under 18, has signed a release form, or in cases of suspected abuse.\n* System Malfunction Consequences:\n * Urinary Failure: Waste buildup leads to death without dialysis.\n * Nervous Failure: Causes paralysis, Parkinson's, or epilepsy.\n * Cardiovascular Failure: Blood circulation lack leads to vision loss or limb loss (common in diabetes).\n\n# Lesson 2.1 & 2.3: Diabetes and Feedback Loops\n\n* Diabetes: A disorder of high blood glucose levels caused by insufficient insulin (Type 1) or insulin resistance (Type 2).\n* Hormones:\n * Insulin: Secreted by pancreatic beta cells; facilitates glucose entry into cells via GLUT4 transport.\n * Glucagon: Secreted by pancreatic alpha cells; raises blood glucose levels.\n* Feedback Mechanisms:\n * Negative Feedback: Counteracts fluctuations to maintain homeostasis (e.g., temperature, blood sugar, blood pressure).\n * Positive Feedback: Magnifies a process until completion (e.g., labor, blood clotting, growth).\n* Glucose Tolerance Test (GTT):\n * Normal: $< 140 \text{ mg/dL}$\n * Prediabetes: $140 \text{--} 199 \text{ mg/dL}$\n * Diabetes: $> 200 \text{ mg/dL}$\n* Osmosis and Diabetes: High blood sugar creates a hypertonic environment in the blood. Solvent (water) is drawn out of cells (hypotonic) into the bloodstream, leading to cell dehydration, thirst, and hunger.\n\n# Lesson 2.2: The Science of Food and Macromolecules\n\n* Macromolecules: Large molecules (polymers) built from smaller subunits (monomers).\n * Carbohydrates: Monosaccharides (e.g., glucose, fructose); used for quick energy. Detected with Benedict’s (simple sugars) or Iodine (starch).\n * Proteins: Amino acids; build tissues and hormones. Detected with Biuret solution (turns purple).\n * Lipids: Fatty acid chains; long-term energy storage. Detected by the brown paper test (greasy smear).\n* Chemical Reactions:\n * Dehydration Synthesis: Joining two molecules by removing a water molecule; requires ATP.\n * Hydrolysis: Splitting a molecule by adding water; releases ATP.\n* Calorimetry: Measuring energy in food by burning it to heat water. One Calorie (kilocalorie) is the heat required to raise $1 \text{ g}$ of water by $1^{\circ}\text{C}$.\n\n# Lesson 3.1 & 4.1: Sickle Cell Disease and Blood\n\n* Blood Composition:\n * Erythrocytes (RBCs): Contain hemoglobin to carry $O_2$; 7-8 µm wide; live ~4 months.\n * Leukocytes (WBCs): Immune system cells; 12-25 µm wide.\n * Thrombocytes (Platelets): Minute bodies for blood clotting.\n * Plasma: Yellow fluid carrying nutrients, hormones, and waste.\n* Sickle Cell Anemia: A recessive genetic trait where a mutation in the beta-globin protein (substitution of Valine for Glutamic Acid) causes hemoglobin to polymerize into long chains, distorting RBCs into a crescent shape. This blocks blood flow, causing pain and organ damage.\n* Hematocrit: The percentage of whole blood volume composed of RBCs, used to diagnose anemia.\n* Genetics: Both parents must pass the recessive allele for a child to have the disease. Having only one allele is ‘Sickle Cell Trait’ and provides protection against malaria.\n\n# Lesson 4.2 & 4.3: Heart Anatomy and Function\n\n* Heart Path: Right Atrium → Tricuspid Valve → Right Ventricle → Pulmonary Valve → Lungs → Pulmonary Veins → Left Atrium → Bicuspid (Mitral) Valve → Left Ventricle → Aortic Valve → Aorta → Body.\n* Cardiac Tissue: Myocardium (muscle), Endocardium (inner lining), Pericardium (outer sac).\n* Blood Pressure (BP): Measured in mmHg using a sphygmomanometer. Normal is $120/80$. Hypertension is consistently $140/90$.\n * Systole: Contraction phase (top number).\n * Diastole: Relaxation phase (bottom number).\n* Electrocardiogram (EKG/ECG):\n * P Wave: Signal from SA node to AV node (atria contract).\n * QRS Interval: Ventricles contract.\n * T Wave: Ventricles repolarize (relax).\n* Cholesterol: A lipid produced in the liver for cell membranes.\n * LDL (Low Density Lipoprotein): “Bad”; carries cholesterol to tissues; high levels lead to plaque.\n * HDL (High Density Lipoprotein): “Good”; takes cholesterol back to the liver for removal.\n\n# Lesson 5.1 & 6.2: Infection and Microbiology\n\n* Infectious Agents: Including Bacteria, Viruses, Fungi, Protozoans, Helminths, and Prions.\n* Bacteria vs. Viruses:\n * Bacteria: Living, single-celled, reproduce via binary fission, treated with antibiotics. Shapes: Coccus (sphere), Bacillus (rod), Spirillum (spiral).\n * Viruses: Non-living, require a host cell (replication), prevented with vaccines but not treated with antibiotics.\n* Gram Staining:\n * Gram Positive: Retain crystal violet (purple) due to thick peptidoglycan.\n * Gram Negative: Take up safranin counterstain (red/pink).\n* Immune Defense Layers:\n 1. Nonspecific External: Skin, mucus, antibacterial enzymes.\n 2. Nonspecific Internal: Phagocytes, inflammation, histamine.\n 3. Specific: B cells (produce antibodies) and T cells (kill infected cells).\n* PCR (Polymerase Chain Reaction): Used to amplify DNA. Steps: 1) Denature, 2) Anneal primers, 3) Extension by Taq polymerase. Billions of copies can be made from a single drop of blood or saliva.", "title": "Biomedical Science Course Exam Review Notes"} post_process() result: {