Aim: To describe the processes of birth and aging identifying the major factors, stages, and effects that result in the development from a baby in the womb to senescence in old age.
Objectives: To correctly describe and identify the process of human birth and the major biological components of the process.
To explain in your own words the early care a mother gives to her new born and the changes to the baby in growth to childhood.
To detail correctly the stages of childhood, adolescence, adulthood, and senescence, it’s hormonal interaction and the effect of degeneration.
Birthing in humans is named labour and can be divided into three major stages: first stage, delivery and afterbirth.
Birth begins when the mother feels her first contractions, the muscular wall of her uterus contracts approximately one every twenty minuets the contractions increase in frequency and intensity until birth.
Oxytocin a hormone secreted by the pituitary gland induces the contractions.
The mother's cervix dilates and the amnion is broken by pressure exerted by the baby’s head. This is called the breaking of the waters.
This first stage of labour ends with the baby’s head being pushed through the cervix. Typically 4-12 hours after the first contractions.
The second stage of labour begins when the baby’s head is pushed from the cervix into the vagina.
The uterus, cervix, vagina are referred to together as the birth canal.
Strong contractions continue to push the baby along the birth canal and within 10-60 minuets the baby’s head emerges form the birth canal.
The rest of the baby follows within minuets helped by a midwife or obstetrician.
Babies get short of oxygen as they pass through the birth canal and for this reason are often bluish in colour. After a few crying breaths the blood is reoxygenated and the baby losses the blue colour.
The umbilical cord is clamped in two places to prevent bleeding and is cut between the clamps severing the mother and child.
Contractions continue after the birth to expel the umbilical cord and placenta.
Complications of Pregnancy
Breech birth occurs if the baby does not turn to position its head toward the cervix before birth. The attendant professional may be able to turn the baby into the correct position if detected. If this is not done the birth is longer and much more dangerous for both mother and child.
Forceps Delivery
Forceps can be used to turn a baby, or aide in delivery if the contractions are weak. Forceps are not as popular these days as they can damage the baby’s head.
Caesarean
surgical procedure where the baby is born via a cut in the abdominal wall and uterus of the mother. Can be use if a long pregnancy risks the mother or child.
Induction
Labour is started artificially by cutting the amnion or by giving the mother an oxytocin injection.
Birth Defects.
97% of babies are born healthy but in 3% of births there are complications in the health of the newborn known as birth defects.
Downs Syndrome:
Occurs when the baby receives an extra copy of chromosome 21. They have 47 instead of 46 chromosomes. These people have a rounder face; almond shaped eyes and generally have severe learning difficulties, although many can hold jobs.
Sickle Cell Anemia
The individual’s blood has a reduced capacity to bind and carry oxygen. The blood cells have a characteristic sickle shape.
Cystic Fibrosis
Lungs produce sticky mucus. This condition is treated with a nasal spray these days.
Environmental stress can lead to birth defects in a baby.
Spina bifida where an exposed spinal cord can lead to various levels of paralysis.
Cleft Palate a problem with the bone structure of the upper mouth that is corrected
via surgery.
Cigarette smoking, alcohol consumption and drug taking on the part of a pregnant mother are environmental stresses that aversely effect a child.
Expectant mothers should visit an antenatal class regularly.
Milk Production
Within a couple of days before birth the mother begins to produce milk in her mammary glands.
Result of the hormone prolactin produced in the pituitary gland.
In the first few days after birth and before true milk production has started the mammary glands produce a yellowish water fluid named colostrum. This fluid contains antibodies that help protect the baby against infection.
Babies that are breast fed for the first 4-9 months grow better, suffer less disease, cry less, and develop better bonds with the mother.
Growth: Irreversible increase in the dry mass of an organism.
Development: Regular change in the structure and function of an organism as it ages. Three main aspects: 1) physical 2) mental 3) emotional 4) social
Childhood
Period of growth between birth and puberty.
Baby; birth to first birthday.
Newborns can recognize their mothers by smell.
Three-month-old babies can smile and react to people’s facial expressions; they act differently to different people.
Six-month-old babies can make a variety of sounds, sit up and play with objects.
By the age of one babies can say a few words, are beginning to walk, and can understand some of what they hear.
From one to two, toddlers, Learn to walk, begin to feed self, show handedness preference, start toilet training, temper tantrums, begin to string words together in sentences, and start to draw.
By five most children can go to the toilet on their own, enjoy playing with other children, know their own address, and start attending school.
Between five and puberty there is an increase in vocabulary, and power of expression, development of insight into what others think and feel, abstract thought begins, as does the understanding of concepts such as justice, truth and honesty.
Puberty is the time when secondary sexual characteristics develop, growth of genital hair, facial hair and deepen voice, in males, growth of genital hair, widening of hips, growth of breasts, start of menstruation in females.
In females these events are triggered by the production of the hormone oestrogen in the ovaries.
In males these events are triggered by the production of the hormone testosterone by the testes.
In males puberty occurs between 15-16 in females between 13-14 but this statistic has changed much in the last 100 years with the average age at which girls have their first period being reported to be 16 at the turn of the century and 13 today.
The time after our physical growth and development are complete. Humans take longer to reach maturity than any other animal.
The time when we can live independently of our guardians.
A factor that is changing in response to differing controls of wealth and resources
in society.
By adulthood our formal education has ended, also a social concept that is changing.
Human Brain
As we mentioned in our last classes the human brain is a complex organ that enforces certain requirements on our development.
Humans need much help in their early development.
As we grow up the brain still grows but it grows far less rapidly over time
than does the rest of our body and thus becomes a smaller portion of our entire
mass at adulthood.
Between 45-55 a woman reaches menopause and her menstrual cycle stops permanently.
Before that time it may stop due to pregnancy, breast-feeding or loss of weight (exercise of illness).
Senescence is the degeneration of our physical and mental faculties due to age.
It can begin soon after we reach thirty-five.
Is characterized by:
Loss of muscle strength
Decrease in lung capacity
Loss of nervous system performance (e.g. Slower reaction times, loss of hearing, eyesight, taste and smell).
Loss of sexual desire
Stiffening of joints and loss of flexibility.
Weakening of bones
Wrinkling of skin
Graying and loss of hair.
Loss of thermoregulation capacity, capacity to resist heat or cold.
Loss of mental faculties.
Death
Today most people live to reach 70.
Age increases our susceptibility to biological dangers and death can finally come from a common source: a disease that may not have been fatal when younger for example.
Problems such as heart disease, cancer, and strokes often lead to death and are problems that result for the body’s deteriation in function.
With increases in the ability of modern medicine to prolong life doctors and lawyers have begun to define different forms and stages of death.
It was reported recently that a quarter of death certificates are inaccurate.