Exam 1 Flashcards
Euploid Cells
Cells with a multiple of the normal # of chromosomes.
Haploid cells
Euploid cells- Gametes- Sperm/Egg-23 chromosomes
Diploid Cells
Euploid cells- normal body cells- 46 chromosomes
Aneuploid Cells
A cell that doesn’t contain a multiple of 23 chromosomes. Includes trisomy/monosomy
Down’s Syndrome
Trisomy of Chromosome 21
1:800-3 copies of 21st chromosome.
Risks: maturity of mother
Trisomy
A cell containing three copies of one chromosome
Nondisjunction
When chromosomes don’t split correctly
Locus
the position of a gene or mutation on a chromosome
Turner’s Syndrome
Monosomy of X chromosome
Occurs in females.
Klienfelter Syndrome
Duplicates X chromosomes along with one Y
chromosome
Female characteristics on a male
3 Modes of inheritance
- Autosomal dominant
- Autosomal recessive
- X-linked recessive
Autosomal dominant inheritance
- Both mother and father exhibit the trait and are equally likely to transmit
- No generations are skipped
- Affected heterozygus individuals transmit the trait to approx. 50% of offspring
Example: Huntington’s Disease
Autosomal recessive
- Both sexes affected in equal proportions
- Diseases seen in siblings, but not parents
- Aprox 25% offspring affected
Example: cystic fibrosis
X-linked recessive
- Trait seen much more in males
- Never transmitted from father to son
- Can be transmitted through many carrier females
- Affected father —– all daughters affected
Example: muscular dystrophy
Recurrance Risk
The probability an individual will develop a genetic disease (Autosomal dominant inheritance: 50%/Autosomal recessive 25%)
Penetrance
Percentage of individuals with a specific genotype who also exhibit the expected phenotype.
Incomplete penetrance
Individuals with the disease causing genotype may not exhibit the disease. —- carriers
Expressivity
Extent of variation in phenotype associated with a particular genotype
Phenotype
Outward appearance of an individual—result of both genotype and environment
Genotype
Composition of genes at a given locus
Alleles
Different forms of a gene: homozygus (AA or aa) or heterozygus (Aa)
Expressivity
The extent of variation in phenotype associated with a particular genotype
Multifactorial Inheritance
When environmental factors influence the expression of a trait
Single gene trait
Traits caused by a single gene
Polymorphic
A locus that has two or more alleles that each occur with a significant frequency in a population
Sex-limited traits
Can only occur in one sex.
Example: uterine/testicular cancer
Sex-influenced trait
Occurs more often in one sex over the other.
Example: male pattern baldness
Polygenic inheritance
Traits resulting from several genes acting together
Epigenetics
Same gene sequence cause different phenotypes due to chemical modification, which alters expression of genes
Genomic imprinting
One parent inactivattes the gene during transmission to offspring—during fertilization
Threshold of liability
Stacking risk factors to reach a point where you definitely have the disease.
Example: diabetes—Eventually this person gets diabetes
Atrophy
Decrease/shrinkage in cellular size.
Most common in skeletal muscle, the heart, secondary sex organs, and the brain.
Physiologic (adaptive) cell adaptations
Normal or natural adaptations
Pathogenic cell adaptations
Result of a problem
Physiologic atrophy
Shrinkage of the thymus
Pathogenic atrophy
Occurs from decreased:
- workload
- use
- blood supply
- nutrition
- hormonal stimulation
- nervous stimulation
Hypertrophy
Increase in size of cells—> size of affected organ
Particularly in heart and kidneys
Hypertrophy is triggered by
-Mechanical signals (stretch) Trophic signals (growth factors, hormones, vasoactive agents)
Hyperplasia
Increased # of cells resulting from an increased rate of cell division. (epidermis/liver)
Hyperpasia occurs when:
- Cells can synthesize DNA
- Cells can divide
Dysplasia
Abnormal change in size, shape, and organization of mature cells. Found adjacent to cancer, but doesn’t necessarily mean the pt has cancer.
Metaplasia
Reversible replacement of one mature cell type by another, less differentiated cell. Loss of specialized function due to the cell’s environment.
Cellular injury
Most diseases begin with cell injury. (reversible/irreversible injury)
Hypoxia
partial depletion of O2
Hypoxia causes (5)
- Reduced amount of O2 in air
- Loss of hemoglobin/decreased efficiency of hemoglobin (anemia)
- Under production of RBC
- Disease of cardio/respiratory system
- Poisoning of oxidating enzymes in cells
- Ischemia
Cellular responses to hypoxia
ATP decreases»>failure of sodium-potassium pump and sodium-calcium exchange draws water into cell with high Na concentration»>swelling
Reperfusion injury
Reintroduction of O2 to oxygen startved cells causes oxygen starved cells causes oxygen intermediates (radicals) to enter the cell and cause cell damage or cell death
Ischemia
Most common cause of hypoxia. Reduced blood supply. Caused by narrowing of arteries/decreased circulation due to blood clots
Anoxia
total lack of O2
Oxidative stress
Injury induced by free radicals, especially by reactive oxygen species (ROS)
Free radical
electrically uncharged atom or group of atoms with an unpaired electron: unstable atoms-bond strongly>leads to chain reactions
Free radicals damage cells by (4)
- antioxidants neutrilize lipid peroxidation-destruction of polyunsaturated lipids
- alteration of protiens
- alteration of DNA (fragmentation)
- Mitochondrial damage
Chemical injury
toxic, mutagenic, and carcenogenic materials
Cellular injury mechanisms
- Hypoxic
- Free radicals/reactive oxygen species
- Chemical injury
- unintentional and intentional injury
- Infectious
- Immunologic/Inflammatory injury
Cellular damage from lead
Harms unborn fetuses/children
Affects:
- nervous system
- Production of blood cells (hematologic)
- kidneys
Effects:
- High calcium concentrations
- Anemia
- Convulsions/delerium
- Wrist/finger/foot paralysis
- Glucose in urine
- GI problems
Cellular damage from Carbon monoxide
Interferes with cellular respiration. Causes O2 deprivation (hypoxic injury)
Effects:
- Headache
- Giddiness
- tennitus
- nausea
- weakness
- vomiting
Cellular damage from Alcohol
Affects nutritional status & deficiencies. Acetaldehyde is toxic
Effects:
- liver disease
- heart disease/hypertension
- CNS
Asphyzial injuries
Caused by a failure of cells to receive or use oxygen. (ie. strangulation/suffocation/drowning/chemical suffocation like CO)
cells react like hypoxia
Blunt force injuries
Trauma to the body resulting in tearing, shearing, or crushing of tissues
- contusions
- hematoma
- abrasion
- laceration
- fractures
Hematoma
collection of blood in soft tissue
Contusion
Typical bruise
Abrasion
Skinning skin
Laceration
ripping/tearing of skin
Fractures
broken bones
Sharp injuries
- incised
- stab
- puncture
- chopping
Incised
Longer than deep wound
Infectuous injury
Disease producing potential depends on:
- ability to invade and destroy
- produce toxins
- hypersensitivity reactions
Immunologic and inflammatory injury
Membranes injured by direct contact to chemicals of immune response
Manifestations of cellular injury:Accumulations (7)
Accumulation of
- water
- lipids and carbs
- glycogen
- protiens
- Pigment changes
- electrolytes
- Urate
Water accumulation
Due to ATP loss (hypoxia)
Cellular swelling due to solute irregularity. Reversible.