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Human Growth. & Development. List a developmental milestone in human growth & development. What is the relevance?. Medical professionals need to understand stages of growth of development. Growth ~ refers to the measurable physical changes that occur throughout a person’s life.
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Human Growth & Development
List a developmental milestone in human growth & development
What is the relevance? • Medical professionals need to understand stages of growth of development. Growth ~ refers to the measurable physical changes that occur throughout a person’s life. Development ~ refers to the changes in intellectual, mental emotional, social and functional skills that occur over time
What is the relevance? • Different periods of life present unique challenges, changes, and problems. • How one handles those challenges influences their health and the next stage in their lives.
Growth and Development • Each phase of growth and development contains four major parameters • Physical development • Intellectual-cognitive development • Psycho-emotional development • Social development
Physical Development • Bodily changes • Often times measurable • Height / weight • Muscle development • Changes in body organs
Intellectual-Cognitive Development • Thinking skills • Learning how to solve problems • Make judgments • Deal with situations
Psycho-Emotional Development • Changes in feelings • Love • Hate • Joy • Fear • Excitement
Social Development • Interactions and relationships with other people • Family • Friends • Business associates
Growth and Development Each of these parameters contain numerous developmental milestones. Developmental Milestones ~ significant points in the growth process
Developmental Milestones • Progress from the simple to the more complex • Person learns to sit, then crawl, then stand , then walk, and then run • Children learn “gross” motor skills such as walking first then learn “fine” motor skills such as using a crayon
Principles of Growth and Development • Each stage establishes the foundation for the next stage. • Stages proceed in an orderly pattern • ****However, the rate of progress varies among individuals.***** • Health care providers must understand that each life stage creates certain needs in individuals.
Principles of Growth & Development - Development is influenced by genetics • Genes ~ units of hereditary material contained in human cells • Each person’s set of genes is unique • Environment also influences an individual • Do you believe we are more a product of our environment, our heredity, or both? Why? • Discuss your stance with your neighbor
At what point do you believe that a fertilized egg becomes a “person”?
Conception through Teenage Years • Pregnancy lasts 10 lunar months (40 weeks/ 9 calendar months/ 266-280 days) • Consists of 3 trimesters of 3 months each(1st, 2nd, 3rd) (Below: Fetus at 16 weeks) (Conception)
The First Trimester First Trimester
Key Terms (First Trimester) • Ovum ~ human egg of the female • About the size of a pencil dot on paper • Sperm ~ male reproductive cell • Too small to see with the human eye • Conception = Fertilization • Union of the nuclei of the egg and the sperm • Fallopian tube ~ tube that extends from the uterus to the ovary
What Happens the First Trimester? • Conception occurs when one sperm, traveling with millions of other sperm, penetrates the ovum. • Conception occurs in the first third of the fallopian tube
Timing is Everything • In the female ovulation occurs at midcycle , around day 14. • The egg lives for about 24 hours after ovulation. • Sperm usually live between 12 and 48 hours. • (some survive up to 72 hours) • Female sperm live longer *
Timing is Everything • For fertilization to occur, sexual intercourse must take place around the time of ovulation, generally no earlier than 72 hours before ovulation and no later than 24 hours after ovulation. • Reflex ovulators ~ women who ovulate in response to having intercourse • Rabbits are reflex ovulators
How Fertilization Occurs • During intercourse, about 200-600 million sperm are released. • Only about 100,000 survive the acidic environment of the vagina. • Sperm swim through the uterus and into the fallopian tube towards the egg. • Within 1-2 hours they are gathered around the egg.
How Fertilization Occurs • One (and only one) sperm penetrates the egg and unites with the nuclei of the egg. • Zygote ~ fertilized egg *
How Fertilization Occurs • The single-cell zygote has 46 chromosomes, 23 from the egg and 23 from the sperm. • The zygote begins to divide, forming clusters of cells that slowly makes its way through the fallopian tube toward the uterus. (3-5 days) • The cells (morula) look like a cluster of grapes with a root like structure on the back which will become the placenta.
How Fertilization Occurs • When this cluster of cells reaches the uterus, it implants itself into the plush lining, where it grows and develops into a human being with billions of cells. • Implantation ~ embryo adheres to uterus lining. • Implantation occurs when the cluster attaches itself into the upper rear wall of the uterus
How Fertilization Occurs Amniotic sac develops over this group of cells • A membrane that surrounds the fetus • The outer group of cells starts to develop into a shape that is the head and a tail • Embryo ~ human being growing in the uterus from the time of conception to about the eighth week.
How Fertilization Occurs http://www.webmd.com/baby/slideshow-conception
Pro life or Pro Choice? Why??? ****JUST AS YOU HAVE YOUR OWN OPINION, SO DO OTHERS! RESPECT THEIRS AS WELL!!****
The First Trimester • 21-25 days, a heart begins to beat and nervous system starts to develop! • 4 weeks: embryo is ¼“ long • Arm buds bulge • Consists of head, body, and tail • Eyes and ears can be detected • 5 weeks: a nose is visible • 6 weeks: almost ½”, floating in amniotic sac • Leg buds appear • 7 weeks:¾” and can move hands • Fingers are defined, organs are visible, skull bones are growing. Embryo at 3 wks Embryo at 7 wks
The End of the 1st Trimester • 8 weeks: almost 1”, liver is large, bones are forming, testes and ovaries are distinguishable • At 8 weeks, developing infant is called a fetus • 10 weeks: 1 ½”– 2”, kidneys produce urine, lower trunk muscles develop • About to end the 1st trimester • baby peeing in womb Fetus at 10 weeks
The 2nd Trimester • 12 weeks: begins the 2nd trimester; head is 1/3 of the entire length, ribs can be seen, hair begins to grow • 16 weeks: 4 ½” long, weighs 3-4 oz; human looking face, testicles of males position for descent. (can tell sex of fetus) • Mother feels fetal movements, known as “quickening” • Fetus blinks and begins sucking • Heartbeat can be heard with fetal instruments (fetal doppler) • Hearing fetus heartbeat Fetus at 14 weeks Fetal doppler
20-24 weeks: 12” long, major systems continue to develop, bones continue to form. Fetus may suck its thumb Eyes remain sealed closed Survival at this point of pregnancy is unlikely Fetus ~ end of 8th week till birth 2nd Trimester (cont.)
28 Weeks: 14” and 2.5 lbs Viable with an increased threat from infection & immaturity Major developments in 3rd tri: weight gain, growth in length, & maturation of organs Although viable, best place for growth & development is the uterus! 38-40 weeks = FULL TERM Fetal influences: whatever the mother consumes (alcohol, drugs, and tobacco can harm infant even in small amounts) fetus growth 3rd Trimester
The Placenta • Disc shaped structure about 7” in diameter and 1” thick. • Highly vascular • Site where nutrients and waste are exchanged between mother and baby. • Oxygen, food and other nutrients diffuse from the mother’s blood to the embryo’s • Carbon dioxide and other waste diffuse from the embryo’s blood into the mother’s blood to be excreted. • placenta images