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(1 st, 2 nd, 3 rd ) (Below: Fetus at 16 weeks) (Conception)
Growth and Development During Each Trimester TrimesterLength of TimeGrowth and Development First TrimesterConception through third month Development of major organ systems Second TrimesterFourth through sixth month Refinement of organ systems Third TrimesterSeventh through ninth month Weight gain and maturation
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
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 1 st 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 1 st trimester – baby peeing in womb baby peeing in womb Fetus at 10 weeks
The 2 nd Trimester 12 weeks: begins the 2 nd 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 Hearing fetus heartbeat Fetus at 14 weeks Fetal doppler
2nd Trimester (cont.) 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
3rd Trimester 28 Weeks: 14” and 2.5 lbs – Viable with an increased threat from infection & immaturity Major developments in 3 rd 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
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