PSYB32H3 Lecture Notes - Gonorrhea, Lanugo, Toxoplasmosis

40 views2 pages
Published on 11 Oct 2012
School
Department
Course
PSYB20
Chapter 3 Prenatal Development and birth
The Stages of Prenatal development
- Prenatal development: 38 weeks (9 months)
- The 9 months are characterized in two ways
1. Trimsters: periods of 3 months
2. Zygote, embryo, and fetus
- Proximal-distal: growths first occurs in central
areas (internal organs) then in more distal areas
(such as arms and legs)
- Cephalo-caudal: downward from head to trunk
The zygote: (first 2 weeks)
- The sperm fertilizes the ovum = zygote
- Zygote proceeds down fallopian tubes
- Tendrils of zygote penetrate the blood vessels
in the wall of the uterus
- Zygote forms physiological dependence with
the mother
The embryo: (beg of 3rd week to end of 8th week)
- Most important physiological systems and
structures become differentiated
- Amniotic sac: thin membrane around embryo
for protection from temp, PH...
- Placenta: a fleshy, disk-like structure formed by
cells from the lining of the uterus and from the
zygote, protects and sustains embryo’s life
- Umbilical cord: a tube that contains the blood
vessels that carry blood back and forth b/w the
infant and placenta
- Most miscarriages (natural end of a pregnancy
before the infant is capable of survival outside
the womb) 1/4 pregnancies occur at this stage
The fetus: (beg. Of 3rd month to delivery)
- End of 3rd month: fetus has ALL body parts
- Month 4: starts moving
- Month 5: reflexes such as sucking, swallowing...
- Lanugo soft hair covers the body
- Month 6: eyes open and close
- Fetus can still not create enough surfactant so
birth at this point = respiratory distress
syndrome
- Age of viability: 22-26 weeks.
RISKS IN THE PRENATAL ENVIRONMENT
- Teratogens: an environmental agent that may
cause developmental deviations in a growing
human organism
- Teratogens can exert their effects on prenatal
development in specific ways:
1. It effects only during critical periods
2. Each has their own effects
3. Either maternal or fetal genotypes may
counteract its effects
4. The effect of one may intensify the
effect of another
5. Different ones may produce same
defects
6. The longer the exposure, the more
detrimental the effect
- Environmental dangers:
1. Legal and illegal drugs
2. Nicotine(smoking) and alcohol
Fetal alcohol syndrome
Fetal alcohol spectrum disorder
3. Heroin, Cocaine, and other drugs
- Environmental Toxins: Lead, PCBs,
- Medical Interventions in Pregnancy and
childbirth can have negative effects:
1. DES (Diethylstilbestrol) for
miscarriages, but had serious effects
2. Thalidomide for morning sickness
3. Epidural or spinal blocks
- Maternal factors: Age and Parity (# of children
she has already), Diet, Emotional State
- Disease and Disorders in mother may affect the
infant: (ex. RH factor incompatibility: if the
mother is RH+ and child is RH-, the mothers
blood could attack fetal blood cells!)
1. Parasitic infections (Ex. Toxoplasmosis =
from raw meat or contact with feces
can cause eye and brain damage)
2. Bacterial infections (Gonorrhea,
Syphilis, Chalmydia: all STDs)
3. Viral infections (genital herpes = STD,
HIV /AIDS)
BIRTH
Stage 1: fetus moves towards cervix
Stage 2: fetus moves through vaginal opening
Stage 3: placenta detaches from the uterine wall
Unlock document

This preview shows half of the first page of the document.
Unlock all 2 pages and 3 million more documents.

Already have an account? Log in

Document Summary

The 9 months are characterized in two ways: trimsters: periods of 3 months, zygote, embryo, and fetus. Proximal-distal: growths first occurs in central areas (internal organs) then in more distal areas (such as arms and legs) Teratogens: an environmental agent that may cause developmental deviations in a growing human organism. Teratogens can exert their effects on prenatal development in specific ways: It effects only during critical periods: each has their own effects, either maternal or fetal genotypes may counteract its effects, the effect of one may intensify the. Cephalo-caudal: downward from head to trunk effect of another. Tendrils of zygote penetrate the blood vessels in the wall of the uterus. The embryo: (beg of 3rd week to end of 8th week) Most important physiological systems and structures become differentiated. Amniotic sac: thin membrane around embryo for protection from temp, ph

Get OneClass Grade+

Unlimited access to all notes and study guides.

YearlyMost Popular
75% OFF
$9.98/m
Monthly
$39.98/m
Single doc
$39.98

or

You will be charged $119.76 upfront and auto renewed at the end of each cycle. You may cancel anytime under Payment Settings. For more information, see our Terms and Privacy.
Payments are encrypted using 256-bit SSL. Powered by Stripe.