Key Vocabulary – Respiratory, Circulatory & Genetics Lecture

A comprehensive set of vocabulary flashcards covering respiratory anatomy and disorders, circulatory components, and fundamental genetics concepts presented in the lecture.

Breathing

The cyclic process of inhalation (drawing oxygen into the lungs) and exhalation (expelling carbon dioxide).

Inhalation

Phase of breathing during which air rich in oxygen enters the lungs.

Exhalation

Phase of breathing during which carbon dioxide-laden air leaves the lungs.

Nose

Gateway of the respiratory system containing cilia and mucous membranes that filter and moisten incoming air.

Cilia (nasal)

Microscopic hairs in the nasal passages that trap dust and other foreign particles.

Mucous Membranes

Moist tissue lining the nasal cavity that humidifies incoming air.

Pharynx

Throat; common passageway for air and food located after the mouth and nose.

Nasopharynx

Upper section of the pharynx associated with respiration.

Oropharynx

Middle portion of the pharynx behind the oral cavity.

Hypopharynx

Lower section of the pharynx leading to the esophagus and larynx.

Larynx

Voice box; connects pharynx to trachea and houses the vocal cords.

Vocal Cords

Folds of tissue in the larynx that vibrate to produce sound.

Epiglottis

Flap of tissue that closes over the trachea during swallowing to prevent food entry.

Trachea

Five-inch cylindrical windpipe carrying air to and from the lungs.

Bronchi

Two primary tubes formed by the tracheal split that enter each lung.

Bronchial Tree

Branching network of bronchi and smaller tubes within the lungs.

Bronchioles

Smallest air passages that lead directly to the alveoli.

Lungs

Pair of cone-shaped organs responsible for gas exchange with the blood.

Pleura

Double-layered membrane surrounding each lung.

Hilum

Slit-like opening on the lung surface where bronchi, blood vessels and nerves enter.

Alveoli

Microscopic air sacs where oxygen diffuses into capillaries and carbon dioxide diffuses out.

Diaphragm

Sheet of smooth muscle beneath the lungs that contracts and relaxes to drive ventilation.

Common Cold

Viral infection (often rhinovirus) of the upper respiratory tract causing sneezing, runny nose and congestion.

Influenza

Contagious illness by influenza viruses producing fever, chills, muscle aches and respiratory irritation.

Asthma

Chronic, reversible airway obstruction involving inflammation, excess mucus and bronchial muscle tightening.

Laryngitis

Inflammation of the larynx leading to hoarseness or loss of voice.

Bronchitis

Inflammation of the bronchial tubes often following an upper respiratory infection.

Pneumonia

Infection or inflammation of alveoli causing them to fill with fluid or pus and impair gas exchange.

Emphysema

Chronic disease that destroys alveolar walls, decreasing respiratory surface area and trapping air.

Chronic Obstructive Pulmonary Disease (COPD)

Group of progressive lung diseases—mainly emphysema, chronic bronchitis and asthma—that obstruct airflow.

Tuberculosis (TB)

Infectious disease caused by Mycobacterium tuberculosis, usually affecting the lungs.

Mantoux Test

Tuberculin skin test used to detect TB infection.

Lung Cancer

Malignant tumor of lung tissue; leading cause linked primarily to smoking.

Cigarette Smoke

Primary preventable risk factor for emphysema, COPD and lung cancer that damages lung tissue and cilia.

Heart

Muscular organ that pumps blood throughout the circulatory system.

Arteries

Blood vessels that carry blood away from the heart.

Veins

Blood vessels that return blood toward the heart.

Capillaries

Microscopic vessels where exchanges between blood and tissues occur.

Plasma

Pale yellow liquid component of blood (≈92 % water) that transports nutrients, hormones and waste.

Red Blood Cells (Erythrocytes)

Cells containing hemoglobin that transport oxygen and carbon dioxide.

Hemoglobin

Iron-containing protein in red blood cells that binds oxygen.

White Blood Cells (Leukocytes)

Immune cells that protect the body against pathogens.

Atherosclerosis

Arterial disease characterized by plaque buildup of cholesterol within artery walls.

Stroke

Loss of brain function due to interrupted blood flow—often from arterial blockage.

Coronary Heart Disease

Condition where narrowed coronary arteries reduce blood supply to the heart muscle.

Hypertensive Heart Disease

Cardiac disorder resulting from chronic high blood pressure narrowing small arteries.

Rheumatic Heart Disease

Heart valve damage following untreated Streptococcus pyogenes infection.

Hemophilia

Inherited disorder in which blood fails to clot properly.

Anemia

Condition of persistently low red blood cell count or hemoglobin leading to reduced oxygen transport.

Leukemia

Cancer characterized by abnormal overproduction of white blood cells.

Heredity

Transmission of traits from parents to offspring.

Genetics

Biology field that studies heredity and variation; term coined by William Bateson (1906).

Gene

Segment of DNA that codes for a specific trait.

Allele

Alternative form of a gene governing a particular trait.

Dominant Allele

Allele that masks the expression of a recessive allele in heterozygotes.

Recessive Allele

Allele whose effect is masked in the presence of a dominant allele.

Homozygous

Having two identical alleles for a trait (e.g., SS or ss).

Heterozygous

Having two different alleles for a trait (e.g., Ss).

Genotype

Genetic makeup (allele combination) of an organism for a specific trait.

Phenotype

Observable expression of a trait determined by genotype.

Punnett Square

Diagram predicting genotype probabilities of offspring from parental crosses.

Law of Segregation

Mendelian principle that allele pairs separate during gamete formation and reunite at fertilization.

Law of Independent Assortment

Mendelian principle that different allele pairs separate independently during gamete formation.

Monohybrid Cross

Genetic cross examining inheritance of one trait between heterozygous parents.

Dihybrid Cross

Cross tracking inheritance of two traits simultaneously (e.g., GgWw × GgWw).

Codominance

Inheritance pattern where two different alleles are both fully expressed in a heterozygote.

Histones

Proteins around which DNA is wrapped to form chromatin.

Chargaff’s Rule

Observation that DNA has equal amounts of adenine–thymine and guanine–cytosine.