NU 545 Unit 7 Pathophysiology 79
completely answered questions and well
elaborated.
NU 545 Unit 7 Pathophysiology 79
completely answered questions and well
elaborated.
Describe the specific chromosomal abnormality responsible for Down Syndrome -
ANSWER-The most well known aneuploidy (those that do not contain a multiple of 23
chromosomes) in an autosome is trisomy of the 21st chromosome. J. Langdon Down
1st described the the disease in 1866. Down syndrome is seen in 1 in 800 births. IQ's
between 25 and 70. Facial features: low nasal bridge, epicentral folds, protruding
tongue, and flat low set ears. Congenital heart defects in 1/3 to 1/2 of live born children.
Decreased ability to fight respiratory conditions and an increased susceptibility to
leukemia. By age 40 symptoms resembling Alzheimer develop. 97% of Down
Syndrome's cases are caused by nondisjunction during the formation of one of the
parent's gametes or during early embryonic development. 3% from translocations. Risk
increases with maternal age.
Causes of mental retardation. - ANSWER-Chromosomal abnormalities.
What gene abnormality causes cystic fibrosis? - ANSWER-Like autosomal dominant
diseases, those caused by autosomal recessive alleles are rare in populations, although
the number of carriers for recessive diseases can be high. The most common lethal
recessive disease in white children, cystic fibrosis, occurs in about 1 in 2500 births.
Approximately 1 in 25 whites carries one copy of an allele that can cause cystic fibrosis
(see Chapter 36). Because an individual must be homozygous for a recessive allele to
express thedisease, the carriers are phenotypically normal. Because most recessive
alleles are maintained innormal carriers, they are able to survive in the population from
one generation to the next. As with many autosomal dominant diseases, many
autosomal recessive diseases are characterized by delayed age of onset, incomplete
penetrance, and variable expressivity.
How is a recessive gene inherited? - ANSWER-Autosomal recessive diseases occur
when both parents are carriers of the same disease and their child inherits an altered
gene from each of them. Children of carrier parents have:A 25% chance of inheriting
two altered genes and developing the disease.
Inheritance of Hemophilia A? - ANSWER-Hemophilia A and hemophilia B are inherited
in an X-linked recessive pattern. The genes associated with these conditions are
located on the X chromosome, which is one of the two sex chromosomes. In males
(who have only one X chromosome), one altered copy of the gene in each cell is
,NU 545 Unit 7 Pathophysiology 79
completely answered questions and well
elaborated.
sufficient to cause the condition. In females (who have two X chromosomes), a mutation
would have to occur in both copies of the gene to cause the disorder. Because it is
unlikely that females will have two altered copies of this gene, it is very rare for females
to have hemophilia. A characteristic of X-linked inheritance is that fathers cannot pass
X-linked traits to their sons.
Inheritance of Hemophilia A? - ANSWER-In X-linked recessive inheritance, a female
with one altered copy of the gene in each cell is called a carrier. Carrier females have
about half the usual amount of coagulation factor VIII or coagulation factor IX, which is
generally enough for normal blood clotting. However, about 10 percent of carrier
females have less than half the normal amount of one of these coagulation factors;
these individuals are at risk for abnormal bleeding, particularly after an injury, surgery,
or tooth extraction.
Risk factors for DM II; why is obesity an important risk factor for DM II? - ANSWER-An
important risk factor is TCF7L2 which encodes a transcription factor involved in the
secretion of insulin. Another association has been found between a common allele of
the gene that incomes peroxisome proliferator-activated receptor gamma (PPAR-y), a
nuclear receptor that is involved in adipocyte differentiation and glucose metabolism.
This receptor is the target of thiazolidinediones (TZD's) a class of drugs commonly used
to increase insulin sensitivity in those with type 2 diabetes. The 2 most important risk
factors for DM II are positive family history and obesity; the latter increases insulin
resistance.
Definition of carcinoma - ANSWER-Cancer arising from in epithelial cells
How do cancer cells gain access to the circulation? - ANSWER-cells gain access to
circulation through new tumor-associated blood vessels or angiongesis
Mobile tumor cells are able to enter circulation (leakly newsly made blood vessels)
once in circulation, cells must be able to withstand the physiological stress of travel in
the blood and lymphatic circulation
Sometimes they bind to blood platelets=protect themselves
What is adjuvant chemotherapy? - ANSWER-Adjuvant chemotherapy is an approach to
fighting cancer that combines different forms of healing. Chemotherapy and radiation, or
chemotherapy and surgery are used together. Usually the chemotherapy will be used
after all of the known and visible cancer has been removed surgically or with radiation.
Adjuvant chemotherapy aims to destroy hidden cancer cells that remain but are
undetectable.
Adjuvant means additional. Adjuvant chemotherapy is given to patients after primary
treatment, when the doctor thinks there is a high risk the cancer will return. After a
primary treatment of surgery or radiation, adjuvant chemotherapy reduces the risk of
, NU 545 Unit 7 Pathophysiology 79
completely answered questions and well
elaborated.
recurrence. The elimination of undetectable microscopic cancer cells that may have
traveled to other parts of the body is the goal of adjuvant chemotherapy.
When adjuvant chemotherapy doesn't result in a full cure it does make the intervals
between a cancer relapse longer. Adjuvant chemotherapy typically begins within three
to five weeks of the surgical removal of the cancer and has different treatment lengths
depending on the cancer. For breast cancer, the adjuvant chemotherapy is
administered for three to nine months. In the case of colon cancer, treatment rarely last
more than six months.
Most common time childhood cancers are diagnosed? - ANSWER-Childhood and
adolescent cancers are often associated with specific peak times of physical growth and
may occur as a consequence altered cellular regulatory mechanisms at a given time in
the child or adolescents development. Embryonal tumors most often develop before the
age of 5 years, acute lymphoblastic leukemia occurs most often in younger children,
and bone tumors occur most often in adolescents.
DES exposure prenatally - ANSWER-Diethylstibestrol (DES) which was prescribed by
physicians to treat spontaneous miscarriage. Identified as a transplacental chemical
carcinogen because a small percentage of the daughters of the women who took DES
developed adenocarcinomas or the vagina and cervix.
Where do most childhood cancers arise from? - ANSWER-Most childhood and
adolescent cancers arise from the mesodermal germ layer that gives rise to the
connective tissue, bone, cartilage, muscle, blood, blood vessels, gonads, kidney, and
the lymphatic system. Leukemia and brain tumors account for 61% of childhood
cancers.
Pediatric cancers and the N-myc oncogene. - ANSWER-Oncogenes and tumor
suppressor genes are associated with the development of childhood cancer. Proto-
oncogenes code for proteins that help regulate normal cell growth and differentiation. If
mutated, proto-oncogenes become oncogenes that help to turn normal cells into cancer
cells. Changes produced by specific oncogenes cause the cell cycle to become
dysregulated. An example of an oncogene identified in pediatric cancer is N-myc,which
is involved in neuroblastoma and glioblastoma. Tumor-suppressor genes arise from
genes that normally suppress cancer cell proliferation but have lost their suppressor
function, thus leading to uncontrolled growth. Some childhood cancers identified with
tumor-suppressor genes include osteosarcoma, leukemia, rhabdomyosarcoma,
retinoblastoma, and Wilms tumor.
Gland responsible for thermoregulation and cooling? - ANSWER-The eccrine sweat
glands are distributed over the body, with the greatest numbers in the palms of the
