Pathophysiology: Cellular Foundations, ECM, Organelles, Genetics, and DNA Replication

Vocabulary flashcards covering core pathophysiology concepts including cellular functions, tissue types, ECM components, organelles, chromosomal abnormalities, DNA replication enzymes, and epigenetics.

Epithelial Tissue

Tissue that covers exterior body surfaces and lines body cavities.

Connective Tissue

Tissue that connects and supports cells and organs, providing protection, insulation, and energy storage.

Muscle Tissue

Tissue involved in contraction and physical movement.

Nervous Tissue

Tissue responsible for the generation and propagation of nerve impulses.

Fibroblasts

Cell type responsible for producing extracellular matrix (ECM) in fibrous connective tissue.

Chondrocytes

Cell type responsible for producing extracellular matrix (ECM) in cartilage.

Osteoblasts

Cell type responsible for producing extracellular matrix (ECM) in bone.

Collagen

An extracellular matrix component that provides tissues with tensile strength.

Pulmonary Fibrosis

A disease state where chronic inflammation stimulates lung fibroblasts to produce excess collagen, making the lungs stiff, impairing lung expansion and gas exchange, and leading to progressive shortness of breath.

Glycosaminoglycans (GAGs)

Polar, often sulfated extracellular matrix molecules carrying a negative charge that attract water and allow tissues to resist compressive forces.

Osteoarthritis

A disease state caused by the loss of GAGs from the cartilage ECM, reducing its ability to resist compressive forces and causing joint pain, stiffness, and increased bone-on-bone contact.

Elastin

An extracellular matrix protein that provides tissues with the ability to recoil.

Conductivity

The chief function of nerve cells, manifested by a wave of excitation or electrical potential passing along the cell surface in response to a stimulus.

Metabolic Absorption

The cellular function in which cells take in and use nutrients and other substances from their surroundings.

Cytosol

The fluid region of the cell that acts as the site of many metabolic reactions and protein synthesis.

Nucleus

Organelle that stores DNA, controls gene expression, and serves as the site of DNA replication and RNA synthesis.

Endoplasmic Reticulum (ER)

Organelle that synthesizes proteins (rough ER) and lipids (smooth ER), and transports newly synthesized molecules.

Golgi Apparatus

Organelle that modifies, sorts, packages, and ships proteins and lipids for secretion or membrane targeting.

Lysosomes

Membrane-bound organelles containing enzymes that digest and recycle damaged organelles, cellular waste, and large molecules.

Mitochondria

Organelles that produce ATP through aerobic respiration.

Peroxisomes

Organelles that break down fatty acids, detoxify harmful substances, and protect cells from oxidative damage.

Microtubules

Cytoskeletal components essential for cell division, intracellular transport of vesicles, and the structure of cilia and flagella.

Actin Filaments

Cytoskeletal components involved in muscle contraction (thin filaments), cell movement across a surface, and cell shape.

Karyotype

An organized display of an individual's 46 chromosomes (23 pairs) arranged by size and chromosome number.

Aneuploidy

A condition resulting from nondisjunction or chromosome loss during cell division where one or more sets of chromosomes in a cell have an abnormal number of chromosomes.

Patau Syndrome (Trisomy 13)

An autosomal aneuploidy occurring in ~1 in 10,000–20,000 live births, characterized by severe intellectual disability, cleft lip/palate, congenital heart defects, brain abnormalities, polydactyly, and high infant mortality.

Edwards Syndrome (Trisomy 18)

An autosomal aneuploidy occurring in ~1 in 5,000–6,000 live births, characterized by severe developmental delay, clenched fists with overlapping fingers, congenital heart defects, rocker-bottom feet, and high infant mortality.

Down Syndrome (Trisomy 21)

An autosomal aneuploidy occurring in ~1 in 700–800 live births, characterized by mild to moderate intellectual disability, characteristic facial features, hypotonia, congenital heart defects, and an increased risk of leukemia and early-onset Alzheimer's disease.

Klinefelter Syndrome (XXY)

A sex chromosome aneuploidy occurring in ~1 in 600–1,000 males, characterized by tall stature, small testes, infertility, gynecomastia, and decreased testosterone.

Jacob Syndrome (XYY Syndrome)

A sex chromosome aneuploidy occurring in ~1 in 1,000 males, characterized by tall stature, normal sexual development, and possible learning or behavioral difficulties.

Triple X Syndrome (XXX)

A sex chromosome aneuploidy occurring in ~1 in 1,000 females, often asymptomatic, characterized by tall stature, possible learning difficulties, and normal fertility in most individuals.

Turner Syndrome (45,X)

A sex chromosome aneuploidy occurring in ~1 in 2,500 female live births, characterized by short stature, webbed neck, ovarian insufficiency, infertility, and congenital heart defects (especially coarctation of the aorta).

DNA Helicase

An enzyme that unwinds DNA during replication by breaking hydrogen bonds between parental strands.

Topoisomerase

An enzyme that relieves supercoiling ahead of the replication fork during DNA replication.

Single-Strand Binding Proteins

Proteins that stabilize separated single strands of parental DNA to keep them apart during replication.

Primase

An enzyme that synthesizes a short RNA primer required to initiate DNA replication.

DNA Polymerase III

An enzyme that synthesizes new DNA in the $5' \rightarrow 3'$ direction.

DNA Polymerase I

An enzyme that removes RNA primers and replaces them with DNA during replication.

DNA Ligase

An enzyme that seals nicks by joining Okazaki fragments on the lagging strand during DNA replication.

Epigenetics

The study of modifications to DNA—such as histone modifications and cytosine methylation in promoter regions—that do not alter the DNA sequence but alter gene expression levels and can be inherited.