Causes and Mechanisms of Disease Flashcards
what is the difference because intrinsic and extrinsic causes of disease
extrinsic: the cause lies outside the body
intrinsic: the cause lies within the body
what is the major intrinsic factor contributing to pathology?
genetics or inheritance
____ is the basic unit of heredity
gene
Genes are made up of _____, and are combined together in long strands called ______
DNA
chromosomes
do all cells have the same genetic information?
yes
how many chromosomes in a human contain all the genetic information?
46 chromosomes
what is meiosis?
division of genetic material by half during production of eggs and sperm
what is mitosis?
duplication of genetic material so each cell has 46 chromosomes
how many pair of autosomes and sex chromosomes?
22 autosomes and 1 pair of sex chromosomes
what is a homologous pair?
two chromosomes that have the same genetic info and look the same (identical)
what are the sex chromosomes for male and female
xx in women and xy in males
define allels
genes for the same trait, at the same point, on a homologous pair of chromosomes
when is dominant and recessive found?
when the pair of alleles is heterozygous for a trait
define genotype
refers to the genetic makeup of the person
define phenotype
how a person looks as a result of their genetic makeup
define karyotype
actual picture of the chromosomes
characteristics of down syndrome (another name for it, amount of chromosomes, what traits are found in the human)
- also known as 21 trisomy
- there are three 21 chromosomes
- total of 47 chromosomes
- have large tongues
what is down syndrome caused by?
non-dysjunction of 21st pair of chromosomes
what is macroglossia
enlarged tongue
what is klinfelters syndrome caused by? number of chromosomes? traits about the human with this syndrome
- caused by a non-dysjunction of sex chromosomes
- XXY sex chromosomes
- only found in males and they are tall, have reduced facial and body hair, enlarged breasts, atrophy of testes, sterile and slight retardation
what is turners syndrome? found in males/females? traits about human
- XO sex chromosomes
- always found only in females
- they have short, web-skinned at base of neck, don’t secrete female hormones, and mentally disable
When is one diagnosed with turners syndrome?
at puberty when they should be developing sex characteristics
what are sex-linked disorders?
gene for a disorder formed on one of the sex chromosomes
what are 3 common examples of sex-linked disorders?
- hemophilia ( bleeding disorder)
- color blindness
- baldness in men
T/F: women are considered carriers of sex-linked traits while men show the trait
true
what are the 2 type of mutations
- point mutations: only one gene affected
2. mutations that involve a whole chromosome
T/F: once mutated the chromosome cannot revert back to normal
false, it can reverse mutation
What are 4 agents that cause mutations
- chemicals
- thalidomide
- viruses
- x-rays (radiation
what cells are most affected by radiation
cells which are most actively growing and dividing (epithelial linings, blood forming tissues, gonads, embryos, children, and cancer cells)
what are some injuries on the body level from radiation
- burning to the skin: redness, swelling, loss of hair
- Can cause damage to blood vessels: poor healing in future, and less blood flow to the tissues
- excessive radiation to head and neck: destruction of salivary glands (causes xerostomia), burning of tissues,
