The increase in the size of cells and consequently in the size of the affected organ. caused by specific hormone stimulation or by increased functional demand. ü ü Pregnancy: an adaptive response muscular enlargement occurs in the striated muscle cells of both the heart and skeletal muscles. After removal of one kidney, the other kidney adapts to an increased demand for work with an increase in both the size and the number of cells.
Hypertrophy of cardiac muscle in the left ventricular chamber.
HYPERPLASIA
is an increase in the number of cells resulting from an increased rate of cellular division. Two types of normal hyperplasia or Pathologic hyperplasia are: compensatory hyperplasia is an adaptive mechanism that enables certain organs to regenerate. For example, removal of part of the liver leads to hyperplasia of the remaining liver cells (hepatocytes) to compensate for the loss. hormonal hyperplasia occurs chiefly in estrogen-dependent organs, such as the uterus and breast. After ovulation, for example, estrogen stimulates the endometrium to grow and thicken for reception of the fertilized ovum.
Pathologic hyperplasia is the abnormal proliferation of normal cells and can occur as a response to excessive hormonal stimulation or the effects of growth factors on target cells. Example: endometrium (which is caused by an imbalance between estrogen and progesterone secretion, with over secretion of estrogen)
METAPLASIA
reversible replacement of one mature cell by another, sometimes less differentiated, cell type. Example: replacement of normal columnar ciliated epithelial cells of the bronchial (airway) lining by stratified squamous epithelial cells. The newly formed squamous epithelial cells do not secrete mucus or have cilia, causing loss of a vital protective mechanism. Bronchial metaplasia can be reversed if the inducing stimulus, usually cigarette smoking, is removed.
CELLULAR INJURY
What is Cellular Injury? Most diseases begin with cell injury, and all forms of loss of function derive from cell injury and cell death. Cellular injury occurs if the cell is unable to maintain homeostasis a normal or adaptive steady state in the face of injurious stimuli. Injured cells may recover (reversible injury) or die (irreversible injury).
What is Cellular Injury? Injurious stimuli include: chemical agents, lack of sufficient oxygen (hypoxia) free radicals infectious agents physical and mechanical factors immunologic reactions genetic factors nutritional imbalances.
Oncology 101: Genetic
Genetic Information
Genetics: General Information Genetic information organized, stored, and retrieved from chromosomes made of DNA. Genes are individual units of hereditary information located at a specific position on chromosome. 59
Genetics: General Information
Gene Expression
Genetics: Gene Expression Genotype ( what they have ) The genetic makeup of an organism Phenotype ( what they demonstrate ) The observable, detectable, or outward appearance of the genetics of an organism Example A person with the A blood type could be AA or AO. A is the phenotype AA or AO is the genotype. 62
Genetics: Gene Expression If two alleles are found together, the allele that is observable is dominant, and the one whose effects are hidden is recessive 63
Genetics: Gene Expression In genetics, the dominant allele is represented by a capital letter, and the recessive by a lowercase letter 64
65 Genetics: Gene Expression
Genetics: Gene Expression Carrier A carrier is one that has a disease gene but is phenotypically normal For a person to demonstrate a recessive disease, the pair of recessive genes must be inherited 66
Genetics: Gene Expression Carrier Example Ss = sickle cell anemia carrier ss = demonstrates sickle cell disease 67
Deoxyribonucleic Acid (DNA)
DNA: Structure DNA consists of two parallel nucleotide chains running in opposite directions and held together by hydrogen bonds. The parallel structure twists to form a double helix. Most genetic information of a cell is organized, stored, and retrieved in structures called chromosomes that are made up of densely coiled DNA. 69
DNA: Structure the backbone of the DNA strand is made from alternating phosphate and sugar residues. The DNA double helix is stabilized primarily by two forces: ü hydrogen bonds between nucleotides ü base-stacking interactions among nucleobases. 70
DNA: Base Pair Classification The nucleobases are classified into two types: ü Purines (Adenine and guanine) ü pyrimidines (cytosine and Thymine) Purines Adenine and guanine Double-ring structures Pyrimidines Cytosine and thymine Single-ring structures 71
72 DNA: Base Pair Classification
DNA Replication
DNA: Replication Untwisting and unzipping of the DNA strand Single strand acts as a template Complementary base pairing by DNA polymerase Adenine-thymine; cytosineguanine 74
DNA: Replication
DNA: Replication
Ribonucleic Acid (RNA)
RNA Ribonucleic acid (RNA) A polymeric molecule essential in various biological roles in coding, decoding, regulation, and expression of genes. Cellular organisms use messenger RNA (mrna) to convey genetic information (using the nitrogenous bases guanine, uracil, adenine, and cytosine) that directs synthesis of specific proteins. 78
Transcrip tion
80 Transcriptions
DNA: Transcription Abnormalities of Chromosomal Structure Chromosomal mutations
Genetic and Cancer: Basic Mechanisms Cancer has a multifactorial etiology: genetic environmental personal factors interacting to produce a malignancy. Genetic mutations and genetic instability are at the very core of cancer development. Most cancer is not the result of an inherited mutation. 82
Genetic and Cancer: Basic Mechanisms Most cancer is associated with genetic mutations. occur in single cells sometime during the life of an individual. A malignant tumor arises after a series of genetic mutations have accumulated. Genetic mutations that are acquired are associated with exogenous or indigenous factors. 83
Oncology 101: Immunity
The Immune System Human immune system begins to develop in the embryo. Starts with hematopoietic (from Greek, "blood-making") stem cells. Stem cells differentiate into major cells in the immune system granulocytes, monocytes, and lymphocytes Stem cells continue to be produced and differentiate throughout ones lifetime.
Immune System: anatomy and structure
Immune System: anatomy and structure 87