Childhood development

Conception
he process of becoming pregnant involving fertilization or implantation or both
fetoscopy
examination of the pregnant uterus by means of an endoscope

 

ovum
a female sex cell (gamete)
sperm
male sex cell
zygote
cell created when sperm and ovum combine
germinal period
earliest developmental stage
blastocyst
hollow fluid filled ball

(zygote is this four days after fertilization)

placenta
permits food and oxygen to reach the baby and wastes to be carried away
villi roots
one of the branching processes of the surface of the chorion of the developing embryo of most mammals that help to form the placenta
ultrasound

(sonogram)

image of baby produced by ultrasound
amniocentesis
the surgical insertion of a hollow needle through the abdominal wall and into the uterus to obtain amniotic fluid especially for the determination of fetal sex or chromosomal abnormality
Chorion biopsy
medical sample of the highly vascular outer embryonic membrane that is associated with the formation of the placenta
embryo
an animal in the early stages of growth
endoderm
 the innermost of the three primary germ layers of an embryo that is the source of the epithelium of the digestive tract and its derivatives and of the lower respiratory tract
amniotic sac
A two-layered membrane that surrounds the embryo or Fetus in the uterusThe amniotic sac is filled withfluid in which the embryoor fetus is suspended. 
embryonic sac
formed by a thin sac around the embryos and fetuses of reptiles, birds, and mammals and containing the amniotic fluid
embryonic period
(humans) fertilization until the end of the 10th week — precursors of all major organs are developed
Cephalocaudal
proceeding or occurring in the long axis of the body especially in the direction from head to tail
fetal period
Beginning of fetal period. Sexual differentiation continues, with male sexual organs showing more rapid development and the female remaining more neutral. buds for all 20 temporary teeth laid down. Vocal cords appear; digestive system shows activity. Stomach cells begin to secrete fluid; liver pours bile into intestine. Kidneys begin functioning, with urine gradually seeping into amniotic fluid. Other waste products passed through placenta into mother’s blood. Bones and muscles continue development, and by end of third month spontaneous movements of arms, legs, shoulders and fingers are possible.
fetus
 the young of an animal in the womb or egg, especially in the later stages of development whenthe body structures are in the recognizable form of its kind, inhumans after the end of the second month of gestation.
heredity
passing down qualities from ancestor to descendant through the genes
nature-nurture debate
debate among theorists about whether genetic  or environmental factors are more important influences on development
cell
 smallest unit of living matter capable of functioning independently

smallest structural unit of living matter capable of functioning independently

DNA
any of various nucleic acids that are usually the molecular basis of heredity
chromosomes
rod-shaped or threadlike DNA-containing structures of cellular organisms that are located in the nucleus

 

genes
segment of a DNA  molecule that contains instructions for production of various proteins that contribute to the body’s growth and function
mitosis
cell duplication, in which each new cell receives an exact copy of the original chromosomes

;

proximodistal
physical growth that proceeds from the center of the body outward
gametes
sex cells, sperm, and ova, which contain half as many chromosomes as regular body cells

 

a mature male or female germ cell ;capable of initiating formation of a new diploid individual by fusion with a gamete of the opposite sex

meiosis
the process of cell division through which gametes are formed

and in which the

chromosomes are divided in half

crossing-over
meiosis,

the exchange between chromosomes next to each other

XYY syndrome
– extra Y chromosome

– above average height, large teeth, and sometimes severe acne

-intelligence, male sexual development, and fertility are normal

– 1 in 1,000

hermaphrodite
an animal or plant having both male and female reproductive organs
Adrenogenital syndrome
gender identity held by individuals who score high on both traditionally masculine and feminine personality characterisitcs
dominant trait
has two dominant alleles= (homozygous) — DD–

or

only one allele affects the child’s characteristics (heterozygous)–Db

recessive trait
 traits like blond hair, red hair, and near-sightedness

bb–

result only from two recessive alleles

 

 

phenotype
 

 

an individual’s directly observable physical ; behavioral characteristic

(determined by genetic and environmental factors)

genotype
– an individual’s genetic makeup

– determines species and unique characteristics

genome
one haploid set of chromosomes with the genes they contain; broadly: the genetic material of an organism
genetic engineering

(gene therapy)

the insertion of usually genetically altered genes into cells especially to replace defective genes in the treatment of genetic disorders or to provide a specialized disease-fighting function
congenital defects
abnormalities

existing at or dating from birth

Down Syndrome
-mental retrdatio, memory & speech problems, limited vocab, and slow motor development

– failure of 21st pair of chromosomes to separate

-1 of 770 births

Turner’s Syndrome
-missing X chromosome

-short, webbed neck, incomplete  development of sex characteristics at puberty, sterility, impared spatial intelligence

-1 in 2,500 to 8,000

– hormone therapy and spec ed

Klienfelter’s Syndrome
Extra X chromosome. Tallness, body fat like female, sterility, impaired verbal intelligence, incomplete sex characteristics

-1 in 900

-hormone therapy

Sickle-cell anemia
Abnormal sickling of red blood cells

-osygen deprivation

susceptible to infection esp pneumonia

-recessive

-1 in 400 to 600    transfusions

Teratogenic
relating to, or causing developmental malformations
Fragile X Syndrome
most common inherited cause of mental retardation

– 25 to 30 percent have syptoms of autism

– impaired social interaction and delayed or absent language

Cystic Fibrosis
– recessive

– lungs, liver, & pancrea secrete large amounts of mucus leading to breathing difficulties

1 in 2,000 to 2,500 births

Genetic counseling
guidance relating to genetic disorders that is provided by a medical professional typically to individuals with an increased risk of having a child with such a disorder
fetal alcohol syndrome
 highly variable group of birth defects including mental retardation, deficient growth, and malformations of the skull and face that tend to occur in the offspring of women who consume large amounts of alcohol during pregnancy
fetal alcohol effects
slow physical growth

facial abnormalities

brain injury

 

rubella
German measles

– can cause miscarriage, physical malformations, mental retardation, and low birth weight

acquired immune deficiency syndrome

AIDS

a disease of the human immune system that is characterized cytologically especially by reduction in the numbers of CD4-bearing helper T cells to 20 percent caused by an infection with HIV blood

– causes metal retardation in fetus

RH factor
A condition that arises when the inherited blood types of mother and fetus differ

mother  (Rh-negative)

father (Rh-positive) then baby may inherit father’s blood type

Monozygotic twins
identical

– have the same genetic make up

– 1 in 330 births

-zygote separates into two

Dizygotic twins
fraternal

– most common type of multile births

– results from the release and fertiliztion of two ova

Phenylketonuria

PKU

inability to metabolize the amino acid phenylalanine, contained in many proteins

-causes severe central nervous system damage in the first year of life

-recessive

-1 in 8,000

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