Unit 1 Key Terms

Aerobic Metabolism - Energy production in cells using oxygen. When cells use oxygen, they produce more energy (ATP), which is essential for cell functions.

Anaerobic Metabolism - Energy production in cells without oxygen. It’s less efficient and results in the production of lactic acid, which can cause muscle fatigue or injury.

Autolysis - The process where a cell breaks itself down, usually when it is dying, using its own enzymes.

Cellular Dehydration - When a cell loses too much water, which can make it shrink and affect its function.

Cellular Edema - When a cell swells because it takes in too much water, which can cause it to malfunction or burst.

Cellular Hypoxia - When a cell does not get enough oxygen, leading to impaired function and possible cell death.

Codon - A sequence of three DNA or RNA bases that codes for a specific amino acid in protein synthesis.

Deoxyribonucleic Acid (DNA) - The molecule that carries genetic information needed for cell growth, function, and reproduction.

Free Radicals - Unstable molecules that can damage cells, proteins, and DNA, often leading to aging or disease.

Glycoproteins - Proteins that have sugar molecules attached to them. They help in cell signaling and immune responses.

Heterolysis - The process of breaking down foreign materials or pathogens (like bacteria) by the immune system.

Lysosomes - Cell structures that contain digestive enzymes to break down waste or damaged cell parts.

Mitochondria - Organelles in the cell that generate energy (ATP) and help control cell death.

Na+/K+ Pump (Sodium-Potassium Pump) - A protein in the cell membrane that moves sodium out of the cell and potassium into the cell, maintaining the cell’s balance of fluids and ions.

Nucleotide - The building blocks of DNA and RNA. Each nucleotide consists of a sugar, a phosphate, and a nitrogen base.

Plasma Membrane - The outer boundary of the cell that controls what enters and leaves the cell.

Purine Base - A type of nitrogenous base found in DNA and RNA (adenine and guanine are examples).

Pyrimidine Base - Another type of nitrogenous base found in DNA and RNA (cytosine, thymine, and uracil are examples).

Ribosomes - Tiny structures in the cell that make proteins by reading mRNA and assembling amino acids.

Transcription - The process where a cell makes an RNA copy of a segment of DNA, which is used to make proteins.

Translation - The process of building a protein by reading the RNA code (from transcription) at the ribosome.

Chapter 2

Aneurysm - An abnormal bulge or ballooning in the wall of a blood vessel, often due to weakness or damage to the vessel wall.

Angiogenesis - The process of forming new blood vessels from existing ones, crucial for tissue growth and healing.

Apoptosis - Programmed cell death that occurs in a controlled, regulated manner to remove damaged or unnecessary cells.

Atherogenesis - The formation of atherosclerotic plaques within the arteries, leading to narrowing and hardening of blood vessels.

Atrophy - The decrease in size or function of a cell, tissue, or organ, often due to lack of use, aging, or disease.

Benign - A term describing a non-cancerous growth or tumor that is usually slow-growing and does not spread to other parts of the body.

Biopsy - The removal and examination of tissue from the body to diagnose disease, often to detect cancer or other abnormalities.

Dysplasia - Abnormal development or growth of cells or tissues, often seen as precancerous changes.

Etiology - The study of the cause or origin of a disease or condition.

Gangrene - Tissue death caused by a lack of blood supply or infection, often leading to decay or rotting of the affected tissue.

Histology - The study of the microscopic structure of tissues and cells.

Hyperplasia - The increase in the number of cells in a tissue or organ, often due to a stimulus like hormonal changes or injury.

Hypertrophy - The enlargement of an organ or tissue through the increase in the size of its cells, often in response to increased workload.

Infarction - Tissue death caused by a lack of blood flow, typically due to blockage in blood vessels (e.g., heart attack, stroke).

Ischemia - Reduced blood flow to a tissue or organ, leading to a lack of oxygen and nutrients and potentially causing cell damage or death.

Malignant - Describes a cancerous tumor or growth that is aggressive, can invade nearby tissues, and has the potential to spread (metastasize) to other parts of the body.

Metaplasia - The reversible change of one type of mature cell into another type, often in response to stress or injury (e.g., lung tissue in smokers).

Neoplasia - The abnormal and uncontrolled growth of cells, leading to the formation of a neoplasm (tumor), which may be benign or malignant.

Oxidative Stress - A condition where there is an imbalance between free radicals and antioxidants in the body, leading to potential damage to cells and tissues.

Pathognomonic Changes - Specific changes in cells, tissues, or organs that are characteristic of a particular disease or condition and can aid in diagnosis.

Pathological Hypertrophy - Enlargement of an organ or tissue due to disease or abnormal stress, such as heart muscle enlargement due to hypertension.

Physiological Hypertrophy - Normal enlargement of an organ or tissue due to a healthy, natural process, such as muscle growth from exercise.

Pluripotent Stem Cells - Stem cells that have the ability to differentiate into any cell type of the body, except for extra-embryonic tissues like the placenta.

Chapter 3

Allele - A variant form of a gene that can occupy a specific position (locus) on a chromosome. Each individual has two alleles for each gene, one inherited from each parent.

Aneuploidy - The presence of an abnormal number of chromosomes in a cell, either too many or too few, which can lead to genetic disorders.

Autosomal - Refers to the chromosomes that are not sex chromosomes (X or Y). Humans have 22 pairs of autosomal chromosomes.

Carrier - An individual who has one copy of a recessive allele for a genetic disorder but does not exhibit symptoms of the disorder because the other allele is dominant or normal.

Dominant - A type of allele that expresses its effect even if only one copy is present (heterozygous), overpowering the effect of a recessive allele.

Gene Locus - The specific location or position of a gene on a chromosome.

Genomics - The study of the entirety of an organism's genes, including their structure, function, and interactions.

Genotype - The genetic makeup of an individual, referring to the specific alleles they carry for a particular gene or set of genes.

Heterozygous - Having two different alleles for a particular gene (one inherited from each parent).

Homozygous - Having two identical alleles for a particular gene (either both dominant or both recessive).

Karyotype - The complete set of chromosomes in a cell, arranged and paired according to their size, shape, and number, often used to identify chromosomal abnormalities.

Mutation - A change in the DNA sequence that can alter gene function, potentially leading to disease or new traits. Mutations can be inherited or acquired.

Oncogene - A mutated or overexpressed gene that has the potential to cause cancer by promoting uncontrolled cell growth and division.

Oncoproteins - Proteins produced by oncogenes that contribute to cancer by interfering with normal cell regulatory pathways, leading to unchecked cell growth.

Pharmacogenomics - The study of how a person's genetic makeup affects their response to drugs, helping to tailor personalized medical treatments.

Phenotype - The observable characteristics or traits of an individual, such as eye color or height, resulting from the interaction of the genotype with the environment.

Recessive - A type of allele whose effect is only expressed when two copies are present (homozygous). The trait it codes for will not appear in the presence of a dominant allele.

Single Nucleotide Polymorphisms (SNPs) - Variations in a single nucleotide base pair in the DNA sequence among individuals, which can influence traits and disease susceptibility.

Translocation - A chromosomal abnormality where a segment of one chromosome is transferred to another chromosome, often linked to cancer and other genetic disorders.

Tumor Suppressor Gene - A gene that helps regulate cell growth and division. When these genes are mutated or inactivated, they may fail to prevent tumor formation, leading to cancer.

Leukocytosis - An increase in the number of white blood cells (leukocytes) in the blood, often due to infection or inflammation.

Leukopenia - A decrease in the number of white blood cells (leukocytes) in the blood, which can make the body more susceptible to infections.

Lymph Node - Small, bean-shaped structures that are part of the lymphatic system and act as filters, trapping bacteria, viruses, and other foreign substances.

Phagocytosis - The process by which certain cells (such as macrophages and neutrophils) engulf and digest foreign particles, pathogens, or dead cells.

Pyrogen - A substance that induces fever by triggering the body’s temperature-regulating mechanism in the hypothalamus, often released by bacteria or inflammatory cells.

Vector - An organism, such as an insect, that transmits a pathogen from one host to another (e.g., mosquitoes transmitting malaria).

Acquired Immune Deficiency Syndrome (AIDS) - A disease caused by the human immunodeficiency virus (HIV) that weakens the immune system by attacking and destroying CD4+ T cells, making the body more vulnerable to infections and certain cancers.

Active Immunity - Immunity that results from the body’s own production of antibodies or T cells after exposure to a pathogen or vaccination.

Adaptive Immunity - A type of immunity that develops throughout life, involving the immune system's ability to recognize and specifically target foreign invaders like bacteria or viruses.

Antigen - A substance (usually a protein or polysaccharide) that the immune system recognizes as foreign and responds to by producing antibodies.

Autoimmune Disease - A condition where the immune system mistakenly attacks the body's own cells and tissues, thinking they are foreign (e.g., rheumatoid arthritis, lupus).

Human Immunodeficiency Virus (HIV) - The virus that causes AIDS by attacking and weakening the immune system, specifically targeting CD4+ T cells.

Immunodeficiency - A condition in which the immune system’s ability to fight infections is weakened, either due to genetic factors or as a result of illness or treatment (e.g., HIV/AIDS).

Immunoglobins - Antibodies produced by B cells that help defend the body against foreign pathogens (e.g., IgG, IgM, IgA, IgE, IgD).

Innate Immunity - The body’s first line of defense against pathogens, consisting of physical barriers (e.g., skin), immune cells (e.g., macrophages), and nonspecific defenses.

Passive Immunity - Immunity acquired by receiving antibodies from another individual or source (e.g., through breast milk or from an antibody injection), offering temporary protection.

Bands - Immature neutrophils (a type of white blood cell) that are typically released into the bloodstream during infection or inflammation.

Blast Cells - Immature or undifferentiated cells, often referring to early forms of white blood cells, which can be abnormal in conditions like leukemia.

Leukemia - A type of cancer affecting the bone marrow and blood, characterized by the uncontrolled production of abnormal white blood cells.

Lymphoma - A type of cancer that originates in the lymphatic system, primarily affecting lymph nodes and lymphoid tissues. There are two main types: Hodgkin lymphoma and non-Hodgkin lymphoma.

Anemia - A condition characterized by a decrease in the number of red blood cells or hemoglobin in the blood, leading to insufficient oxygen delivery to tissues.

Aplastic Anemia - A rare condition in which the bone marrow fails to produce enough blood cells, including red blood cells, white blood cells, and platelets, leading to pancytopenia.

Erythropoiesis - The process of producing red blood cells (erythrocytes) in the bone marrow, regulated by erythropoietin in response to oxygen levels in the blood.

Hemolysis - The destruction or breakdown of red blood cells, which releases hemoglobin into the bloodstream, often causing anemia and other complications.

Pernicious Anemia - A type of anemia caused by vitamin B12 deficiency, often due to the lack of intrinsic factor, a protein needed for vitamin B12 absorption in the intestines.

Pica - The craving and consumption of non-nutritive substances such as dirt, clay, or starch, often associated with iron deficiency anemia.

Polycythemia - An abnormal increase in the number of red blood cells in the blood, which increases blood viscosity and can lead to complications like clotting.

Reticulocyte - An immature red blood cell that still contains ribosomal RNA. Reticulocytes are typically released from the bone marrow into the bloodstream, where they mature into erythrocytes.

Disseminated Intravascular Coagulation (DIC) - A serious condition characterized by widespread clotting in the blood vessels, leading to the consumption of clotting factors and platelets, which causes excessive bleeding.

Extrinsic Pathway - The clotting pathway that is triggered by external trauma to blood vessels, involving tissue factor (TF) and factor VII, which leads to the activation of the common coagulation pathway.

Fibrinolysis - The process of breaking down fibrin in blood clots, which helps to dissolve the clot once it is no longer needed, preventing excessive clotting.

Plasmin - An enzyme that is responsible for breaking down fibrin in blood clots during fibrinolysis, helping to prevent excessive clot formation.

Thrombocytopenia - A condition in which there is a low number of platelets in the blood, leading to increased risk of bleeding and difficulty forming blood clots.

Thrombocytosis - An abnormal increase in the number of platelets in the blood, which can increase the risk of thrombosis (abnormal clotting).

Thrombopoietin - A hormone primarily produced by the liver and kidneys that stimulates the production of platelets (thrombocytes) in the bone marrow.
Bradypnea - Abnormally slow breathing, usually defined as a respiratory rate less than 12 breaths per minute in adults.

Bronchitis - Inflammation of the bronchial tubes, often caused by infection or irritation, leading to symptoms such as cough, mucus production, and difficulty breathing.

Diaphragm - A dome-shaped muscle that separates the thoracic and abdominal cavities, playing a key role in breathing by contracting to allow lung expansion during inspiration.

Expiration - The process of exhaling air from the lungs, which occurs when the diaphragm relaxes and the chest cavity decreases in size, forcing air out.

Hypercapnia - An excessive level of carbon dioxide (CO2) in the blood, usually caused by hypoventilation or impaired gas exchange in the lungs.

Hypoxia - A condition in which there is a deficiency of oxygen in the tissues, which can lead to cellular damage and organ dysfunction.

Inspiration - The process of inhaling air into the lungs, typically facilitated by the contraction of the diaphragm and other respiratory muscles.

Oxyhemoglobin - A compound formed when oxygen binds to hemoglobin in red blood cells, enabling oxygen transport in the bloodstream.

Perfusion - The flow of blood through the lungs or tissues, ensuring that oxygen is delivered to the tissues and waste products, such as carbon dioxide, are removed.

Pneumonia - An infection or inflammation of the lungs, often caused by bacteria, viruses, or fungi, leading to symptoms like cough, fever, chest pain, and difficulty breathing.

Pulmonary Aspiration - The inhalation of foreign substances, such as food, liquids, or vomit, into the lungs, which can lead to aspiration pneumonia or other complications.

Retractions - Visible sinking or pulling in of the skin between the ribs or around the neck during breathing, often indicating respiratory distress.

Tachypnea - Abnormally rapid breathing, typically defined as a respiratory rate greater than 20 breaths per minute in adults.

Ventilation - The process of moving air in and out of the lungs, ensuring adequate oxygen supply and the removal of carbon dioxide.

Ventilation-Perfusion Ratio (V-Q Ratio) - The ratio of ventilation (air reaching the alveoli) to perfusion (blood flow in the capillaries around the alveoli), which is essential for efficient gas exchange.

Asthma - A chronic respiratory condition characterized by inflammation and narrowing of the airways, leading to wheezing, shortness of breath, and coughing, often triggered by allergens or irritants.

Chronic Obstructive Pulmonary Disease (COPD) - A group of lung diseases, including emphysema and chronic bronchitis, characterized by airflow limitation and difficulty breathing, often caused by smoking.

Compliance - The ability of the lungs and chest wall to expand and contract with pressure changes during breathing. Low compliance indicates stiff lungs, while high compliance suggests overly flexible lungs.

Emphysema - A type of COPD in which the alveoli (air sacs in the lungs) become damaged and enlarged, impairing the lungs' ability to exchange gases and leading to shortness of breath.

Forced Expiratory Volume (FEV) - The volume of air that can be forcibly exhaled in a specified period, usually measured in one second (FEV1). It is commonly used to assess lung function.

Forced Vital Capacity (FVC) - The total amount of air that can be forcibly exhaled after taking a deep breath, measured during a spirometry test.

Obstructive Disease - A type of lung disease in which airflow is obstructed, making it difficult to exhale air from the lungs (e.g., asthma, COPD).

Pneumothorax - The presence of air or gas in the pleural space, causing the lung to collapse and impairing normal lung function.

Restrictive Disease - A category of lung diseases characterized by reduced lung expansion, leading to decreased total lung capacity and difficulty fully expanding the lungs (e.g., pulmonary fibrosis, scoliosis).

Total Lung Capacity (TLC) - The maximum amount of air the lungs can hold, which is the sum of the tidal volume, inspiratory reserve volume, expiratory reserve volume, and residual volume.