BI 231 Pathophysiology Unit 1 Study Guide

Deoxyribonucleic acid (DNA)

Large, DS, always in nucleus, nucleotides ATCG

Ribonucleic acid (RNA)

Small, SS, in nucleus and cytoplasm, nucleotides AUCG

Replication

Using DNA as a template to make DNA; occurs in nucleus

Transcription

Using DNA as a template to make mRNA; occurs in nucleus

Translation

Using mRNA to make proteins at the ribosome; occurs in cytoplasm

Chromosomes

DNA that is condensed for cell division

Genes

Pieces of chromosomes that code for proteins, basic units of inheritance

Genotype

Composition of genes at a particular site

Phenotype

Physical characteristics resulting from the genotype

Karyotype

Ordered display of all chromosomes

Autosomes

Non-sex chromosomes (numbered 1 through 22), homologous pairs

Sex chromosomes

Determine genetic sex of individual, 23rd pair, X/Y, nonhomologous

Pedigree

Chart that tracks trait expression/inheritance within a family

Locus

Site on a chromosome where a certain gene is located

Alleles

The different genes that can be found at a specific locus

Euploid

Cells with a multiple of normal/expected number of chromosomes

Haploid

23 total chromosomes (mature gametes only)

Diploid

23 pairs of chromosomes (all human cells)

Polyploid

Abnormal number of chromosomes by a factor of 23

Triploid

Three copies of each chromosome, 69 total chromosomes

Tetraploid

Four copies of each chromosome, 92 total chromosomes

Aneuploid

Abnormal number of chromosomes but not by a factor of 23

Monosomy

Only one copy of a chromosome in a diploid cell

Trisomy

Three copies of one chromosome

Homologous chromosomes

Numbered pairs in diploid cells (one from each parent)

Homozygous

Loci of homologous chromosomes have same allele

Heterozygous

Loci of homologous chromosomes have different alleles

Dominant trait

Only one copy of gene needed for expression

Recessive trait

Two copies of gene needed for expression

Sex-linked trait

Mutation in gene on sex chromosome

Carrier

Individual who has a disease gene but is phenotypically normal

Nondisjunction

Error in which homologous chromosomes or sister chromatids fail to separate normally during meiosis or mitosis

Translocation

Exchange of genetic material between non-homologous chromosomes

Punnett square

Diagram of outcomes when genotype of parents is known; 2x2

Barr bodies

Condensed, inactive X chromosomes in female cells

Mutation

Change in DNA base sequence during replication

Polygenic traits

Traits that are a result of several genes acting together

Multifactorial inheritance

When environmental factors influence the expression of a trait

Down syndrome

Etiology: 47 total chromosomes due to trisomy of chromosome 21; CM: Distinctive faces, ID (intellectual disability); Prognosis: individuals have an increased risk for congenital heart disease and leukemia

Trisomy X

Etiology: 47 total chromosomes due to trisomy of X chromosome; CM: Most are phenotypically normal but can be associated with sterility or ID

Turner syndrome

Etiology: 45 total chromosomes due to monosomy of X chromosome; CM: Mild mental impairment without ID, webbing of neck, coarctation (narrowing) of aorta, sterility, short stature

Klinefelter syndrome

Etiology: 47 total chromosomes due to trisomy of sex chromosomes, XXY; CM: ID (usually mild or manifests as social anxiety), gynecomastia, infertility or sterility, sparse body hair, small firm testes, less muscular than other adult men

Autosomal dominant (AD) inheritance

Characteristics: Rare, most common in fewer than 1 in 500 individuals; Males and females affected equally; No skipped generations; Affected heterozygotes pass trait on to half of their children; Example: Huntington disease (chromosome 4)

Autosomal recessive (AR) inheritance

Characteristics: Rare with numerous carriers, most common in fewer than 1 in 2500 individuals; Males and females affected equally; Consanguinity and skipped generations are seen; Affected persons may have affected siblings but rarely affected parents; Offspring of carrier parents have 25% chance of having disease; Example: Cystic fibrosis (chromosome 7)

X-linked recessive inheritance

Characteristics: Rare, most common in fewer than 1 in 3500 males; Males much more commonly affected than females; Never transmitted father to son; Skipped generations common; Affected fathers pass gene to all daughters who then pass gene to half their sons; Example: Duchenne muscular dystrophy

Familial adenomatous polyposis (FAP)

Chromosome 5

Malignant melanoma

Chromosome 9

Sickle cell disease

Chromosome 11

Retinoblastoma

Chromosome 13

Neurofibromatosis

Chromosome 17

Breast Cancer

Chromosome 17

ALS

Chromosome 21

Hemophilia A, B

X chromosome

Atrophy

Decrease in cell size

Hypertrophy

Increase in cell size

Hyperplasia

Increase in cell number

Metaplasia

Reversible replacement of one mature cell type by another

Dysplasia

Deranged cell growth, often pre-cancerous, atypical hyperplasia

Necrosis

Type of cell death with severe swelling and breakdown of organelles

Apoptosis

Programmed cell death; cellular self-destruction for elimination of unwanted cell populations

Hypoxia

Lack of sufficient oxygen

Ischemia

Reduced blood supply

Anoxia

Total lack of oxygen

Reperfusion

Restoration of blood flow and oxygen to tissues

Blunt force injury

Tissue injury caused by application of mechanical energy

Contusion/bruise

Bleeding into the skin and underlying tissues

Hematoma

Collection of blood in soft tissues or closed spaces

Subdural

Between dura and arachnoid; torn bridging veins (whiplash or AHT)

Epidural

Between dura and skull; torn arteries (skull fractures)

Abrasion

Removal of superficial skin layers due to friction injury

Laceration

Tear caused by blunt force that exceeds tensile limits; typically irregular with tissue bridging; often internal

Sharp force injury

Tissue injury caused by sharp objects

Asphyxiation

Oxygen deprivation; suffocation, strangling, drowning, choking, paralysis

Cell death

Cessation of all metabolic activity; may be one cell or many

Somatic death

Death of the person, and thus all cells within; Cessation of all respiratory and circulatory activities

Autopsy

Post-mortem exam by certified medical professional

Cadaver

Dead body in a controlled environment.

Cellular adaptation

Cells adapt to their environment to avoid injury.

Reversible changes

Changes affecting size, number, phenotype, metabolic activity, or function of cells that can be reversed.

Physiologic adaptations

Adaptations that happen as a normal event with development.

Pathologic adaptations

Adaptations that occur as a result of disease or injury.

Types of adaptation

Atrophy, hypertrophy, hyperplasia, and metaplasia.

General mechanisms of cell injury

Cell injury occurs when changes in conditions cause cells to lose structure and function.

Reversible injury

Injury from which cells can recover, including cellular adaptations.

Irreversible injury

Injury that leads to cell death.

Ischemic Injury

Injury caused by a lack of blood flow, leading to tissue hypoxia.

Hypoxic Injury

Injury caused by a lack of oxygen.

Ischemia-Reperfusion Injury

Injury that occurs when blood flow is restored to ischemic tissues.

Oxidative Stress

Injury caused by reactive oxygen species (ROS) such as free radicals.

Chemical injury

Injury that occurs when cells are exposed to exogenous substances.

Heavy metals

Examples of injurious chemicals; lead is most harmful to kids affecting the nervous system, blood, kidneys, and GI.

Carbon monoxide (CO)

A chemical that displaces oxygen due to its higher affinity for hemoglobin.

Alcohol

A chemical that affects the liver, nervous system, nutrition, heart, GI, and has social consequences.

Unintentional injury

Leading cause of death among those age 1-34.

Intentional injury

Includes suicide and homicide, ranking 2nd-4th for the same age group.

Cellular Death

Occurs when there is sufficient structural or physiologic damage, leading to irreversible injury.

Coagulative necrosis

Type of necrosis where proteins solidify/clump, commonly seen in heart and kidneys.

Liquefactive necrosis

Type of necrosis where free enzymes degrade tissue, commonly seen in brain and nervous tissue.

Caseous necrosis

Type of necrosis associated with tuberculosis, characterized by a 'cheesy' appearance.

Fat necrosis

Type of necrosis caused by leakage of lipases, commonly seen in the pancreas.