PLTW Biomedical Science Spring Semester Comprehensive Review

Patient Assessment and Physical Examination Fundamentals

  • Visual Acuity and Eye Examination:

    • Visual Acuity Testing: A patient may be required to read a standardized eye chart to measure the clarity or sharpness of their vision.

    • External vs. Internal Anatomy: Medical professionals examine the external structures of the eye during a routine physical. To view the internal structures, such as the retina and blood vessels, they use a handheld device called an ophthalmoscope.

  • Ear Anatomy and Examination:

    • Otoscope: A handheld instrument used by medical professionals to examine the ear canal and the tympanic membrane (eardrum).

    • Ear Structures: The human ear is divided into three primary regions: the external, middle, and inner ear.

    • Sound Transmission: The ossicles (a set of three small bones in the middle ear) are responsible for transmitting sound vibrations from the tympanic membrane to the inner ear.

    • Acute Otitis Media (AOM): This is the medical term for a middle ear infection. It typically causes symptoms such as pain and diminished hearing.

    • Secondary Functions: Beyond hearing, the ear is a complex organ responsible for maintaining balance.

  • Lung Sounds and Respiratory Assessment:

    • Wheezing: Described as a high-pitched whistling sound heard during breathing, often associated with narrowed airways.

    • Rhonchi: An irregular lung sound that occurs when the bronchi or bronchioles are narrowed.

    • Cyanosis: A medical condition characterized by a bluish discoloration of the skin, indicating that the patient's blood is low in oxygen.

  • Skin and Throat Assessment:

    • Dermatology: The skin is the body's largest organ.

    • Melanoma: This is identified as the most serious and dangerous form of skin cancer.

    • Strep Throat: A common infection of the throat. Signs and symptoms include fever, painful swallowing, and body aches. Redness in the eyes is notably not a standard symptom of strep throat.

    • Palpation: The medical term for the act of touching or feeling a patient's body (such as checking lymph nodes or organs) to evaluate function or physical condition during an exam.

Cardiovascular Anatomy and Physiology

  • Heart Structures and Chambers:

    • Atria: The top chambers of the heart (not to be confused with ventricles, which are the bottom chambers).

    • Ventricles: The lower, more muscular chambers of the heart.

    • Apex: The bottom, pointed tip of the heart.

    • Blood Flow Specialization:

      • The right side of the heart contains deoxygenated blood.

      • The left side of the heart contains oxygenated blood.

  • Valves and Circulation:

    • Function of Valves: The primary purpose of heart valves is to prevent the backward flow of blood, ensuring unidirectional circulation.

    • Tricuspid Valve: Located between the right atrium and right ventricle.

    • Mitral Valve Regurgitation: A condition characterized by the backflow of blood from the left ventricle into the left atrium.

    • Heart Murmur: An abnormal heart sound typically described as a whooshing noise.

  • Vessels and Blood Collection:

    • Arteries: Vessels that carry oxygen-rich blood away from the heart to the rest of the body.

    • Superior Vena Cava: A major vein that returns deoxygenated blood from the upper body to the right atrium.

    • Pulmonary Artery: Carries deoxygenated blood from the right ventricle to the lungs.

    • Venipuncture: The median cubital vein in the arm is the most frequently used site for drawing blood.

Vital Signs and Homeostasis

  • Homeostasis: Defined as the maintenance of stable internal physiological conditions within the body, regardless of external changes.

  • Vital Signs: These serve as signals of the body's ability to maintain homeostasis.

    • Oxygen Saturation: Measured as a percentage (%) of hemoglobin that is bound to oxygen.

    • Body Mass Index (BMI): A measurement calculated as a ratio of an individual's weight relative to their height. BMI=weightheight2BMI = \frac{\text{weight}}{\text{height}^2}.

    • Blood Pressure: Typically measured in units of millimeters of mercury (mmHg\text{mmHg}).

Medical History and Professionalism

  • Medical History Components: Approximately two-thirds of medical diagnoses can be made using only a patient's medical history. Components include:

    • Chief Complaint: The patient's primary reason for the visit and current symptoms.

    • Social History: Aspects of the patient's life including living situation, occupation, school, travel, and lifestyle habits.

    • Past Medical History: Previous health issues, procedures, medications, vaccinations, and hospital stays.

    • Family History: Medical information regarding the patient's close relatives.

  • Professional Conduct:

    • Empathy: The ability to understand and share the feelings of another person.

    • Demeanor: A healthcare provider's outward behavior or bearing toward a patient.

    • Tact: Discretion and sensitivity when dealing with others.

  • Healthcare Roles:

    • Primary Care Physician (PCP): A specialist physician trained to work on the front line of the healthcare system, providing care for any general health problems a patient may have.

    • Triage: The process of determining which patients are most in need of urgent care during an emergency situation.

Clinical Laboratory Testing and Hematology

  • Complete Blood Count (CBC):

    • Erythrocytes: Red blood cells (RBCs).

    • Leukocytes: White blood cells (WBCs); these play a critical role in the immune system.

    • Thrombocytes: Platelets, responsible for blood clotting.

    • Hematocrit: The proportion or percentage of red blood cells in the total volume of blood.

    • Hemoglobin: The iron-containing protein in RBCs that transports oxygen.

    • Anemia: A condition indicated by a low RBC count and low Hematocrit, occurring when hemoglobin levels drop below the normal range.

  • Basic Metabolic Panel (BMP):

    • Measures substances such as glucose, sodium, creatine, and calcium.

    • Hemoglobin is not typically measured in a BMP; it is part of a CBC.

    • Creatine Levels: Abnormal levels of creatine in a metabolic panel often lead doctors to investigate the structure and function of the urinary system (kidneys).

  • Cholesterol and Heart Health:

    • HDL (High-Density Lipoprotein): Known as "good" cholesterol.

    • LDL (Low-Density Lipoprotein): Known as "bad" cholesterol.

    • Healthy Profile: Ideal heart health is associated with low LDL levels and high HDL levels.

Biology and Metabolism

  • Cellular Processes:

    • Mitosis: An orderly series of steps in which DNA in the cell nucleus is equally distributed to two daughter nuclei.

    • Cellular Respiration: The process by which cells use glucose to produce Adenosine triphosphate (ATP). This process occurs within the mitochondria.

    • Diabetes and Glucose: If glucose cannot enter the cells, it remains in the bloodstream. High blood glucose is termed hyperglycemia, while low blood glucose is hypoglycemia.

  • Digestion:

    • Mechanical Digestion: The physical act of breaking down food into smaller parts.

    • Chemical Digestion: The breakdown of food via enzymes and acids.

  • Biological Hierarchy: The correct order of human organization is:

    1. Cells

    2. Tissues

    3. Organs

    4. Organ Systems

    5. Human (Organism)

  • Tissue Types: There are four basic types of tissues in the human body:

    1. Nervous

    2. Epithelial

    3. Connective

    4. Muscle

Forensic Science and Pathology

  • Postmortem Changes:

    • Algor Mortis: The change in body temperature after death as it equilibrates with the environment.

    • Livor Mortis (Lividity): The pooling of blood in the body following death.

    • Rigor Mortis: The stiffening of joints and muscles after death.

  • Entomology: In the Blue Bottle Fly Life Cycle, the stage where eggs hatch and larvae emerge is the first instar.