Structural Abnormalities and Birth Defects (Q2,P4,Ch.4)

Question 1

Chromosomes (and Genetics)

Answer 1

• Chromosomes
• Humans have 23 pairs of chromosomes (46 total)
• zygote (46)= 23 from ovum gamete, 23 from sperm gamete
• Pairs 1-22 are autosomes (identical/match)
• Pair 23 are the sex chromosomes (XX=Girl, XY=Boy)

Question 2

Chromosomes

Answer 2

• Made from DNA

Question 3

Genes

Answer 3

• The basic unit of heredity
• those traits/characteristics we inherit from our parents
• Consist of specific nucleotide sequence: adenosine, guanine, cytosine, thymine (uracil)
• 20,000 TO 30,000 in humans

Question 4

Genotype

Answer 4

The sum of all genes in an individual

Question 5

Phenotype

Answer 5

The expression of one’s genes

Question 6

Heterozygous

Answer 6

Genes of unequal influence for a particular trait

Question 7

Homozygous

Answer 7

Genes of equal influence

Question 8

Alleles

Answer 8

Matching genes: one from mother, one from the father

Question 9

Dominance

Answer 9

One genes dominates the other
(example: brown eye color)

Question 10

Recessive

Answer 10

The gene that is being dominated
(example:blue eye color)

Question 11

Mutation

Answer 11

Spontaneous changes in genetic information (DNA)
- Usually negative (may result in cancers)
- May be an adaptation to some environmental circumstance

Question 12

Congenital anomaly

Answer 12

Other than normal problem/disorder present at or before birth

Question 13

Malformation

Answer 13

Term used to describe any anomaly

Question 14

Hypoplasia

Answer 14

A part of the body is smaller than normal at birth

Question 15

Aplasia

Answer 15

Failure of a part to develop

Question 16

Polydactalism

Answer 16

More than normal number of digits (fingers or toes)

Question 17

Phocomelia

Answer 17

Proximal portion of limbs fail to develop

Question 18

Amelia

Answer 18

Absence of one or more limbs

Question 19

Spina Bifida

Answer 19

• Structural abnormality in which the spinal column fails to close around the spinal cord
• Usually results in death (stillbirth)
• Causes severe, crippling nerve damage
• Children with proper care/surgery/medicine/rehab can live into adulthood but will always be impaired

Question 20

List of Limb Deformities

Answer 20

Amelia
Hypoplasia
Aplasia
Phocomelia
Polydactalism

Question 21

Cleft Palate

Answer 21

The palate/roof of the mouth fails to join or close

Question 22

Cleft/Hare Lip

Answer 22

Failure of lips to join at the midline

Question 23

Cleft Palate and Cleft/Hare Lip

Answer 23

• May occur together or separately
• surgery, dental, orthodontics, and speech therapy may be needed

Question 24

Color Blindnes

Answer 24

• Inability to distinguish or identify various colors and shades
• Defect stems from specialized cells in the retina of the eye call cones
• Usually inherited but may be acquired

Question 25

Types of color blindness

Answer 25

Red/Green: It makes green look more red. Blue/Yellow: confuse blue with green and yellow with violet. Achromatopsia: can only see shades of black, white and grey

Question 26

Vascular Nevus

Answer 26

- Birthmark/strawberry mark - superficial blood vessels are enlarges - Vary in size, shape and position - Usually found on the head, neck, and arms

Question 27

Down's Syndrome

Answer 27

- Chromosomal abnormality - one extra chromosome at the 21 position of autosomes (trisomy 21) - Manifestations of down's syndrome are similar in all effected - Characterized by: mental retardation, short body, thick neck, almond shaped eyes - Often associated with children born from older mothers or first births

Question 28

Cystic Fibrosis

Answer 28

- Most common fatal inherited/genetic disease in the USA - Abnormal cells produce a thick, sticky mucous that clogs cells of the lungs, pancreas, etc - Terminal Disease: average age at death is early 20's - Abnormal gene is known and research to correct it is ongoing

Question 29

Turner's Syndrome

Answer 29

- Absence of one of the sex chromosomes in females - Produces a phenotypic female (XO; 45 chromosomes) - Causes web neck, short body, cardiac problems, gonadal risk of cancer, sterile

Question 30

Kleinfelter's Syndrome

Answer 30

- Affects males at birth - 47 chromosomes (XXY) - Causes hormonal abnormalities, sterile

Question 31

Sudden Infant Death Syndrome/ Cot death/ Crib Death

Answer 31

- Sudden, unexplained death of an infant under 1 year old - No structural abnormalities or birth defects present - Idiopathic (unknown cause) - Ongoing study - Risk factors: baby sleeps on stomach, smoking mothers, young mothers, drug abusing mothers, post GI or respiratory infections)

Question 32

Hernia

Answer 32

- Protrusion of an organ through a wall normally containing it/ protrusion of digestive system through a rip or tear in abdominal wall - may be congenital or appear later in life - Inguinal hernia: groin - Umbilical Hernia: umbilical area - Hiatal Hernia: Diaphragm