Upgrade to remove ads
Terms in this set (33)
What is a zygote?
stage of early development in mammals that consists of a hollow ball of cells
What is implantation?
process in which the blastocyst attaches to the wall of the uterus
What is gastrulation?
process of cell migration that results in the formation of the three cell layers- the ectoderm, the mesoderm and the endoderm
What is neurulation?
the first step in the development of the nervous system
What is a placenta?
specialized organs in placental mammals through which respiratory gases, nutrients, and waters are exchanged between the mother and her developing young.
What is a fetus?
a human embryo after eight weeks of development
What is the fusion of a sperm and egg cell called?
What happens during the traveling of sperm?
They go through the penis to the vagina, just below the cervix they go into the uterus and get into the fallopian tubes towards fertilization. They attach to the egg and their protective layer dissolves whole the haploids combine into a zygote.
What prevents more than one sperm from fertilizing an egg?
Ernest Everett Just discovered that once a single sperm enters the egg, a barrier made of the content of granules just below the surface stop others
How are fraternal twin embryos made versus identical?
two eggs are released and fertilized versus one egg splitting in half once fertilized
What happens before implantation?
the zygote undergoes mitosis and a blastocyst occurs and then it attaches to the uterus wall and implantation begins
What is differentiation?
it is when the cells in the blastocyst begin to specialize and differentiate into the some of the different types of tissues that support and protect the embryo.
Key events in early development include ______, which produces the three cell layers of the embryo, and ______, which leads to the formation of the nervous system.
In what order do the three layers created by gastrulation occur?
ectoderm and endoderm first, followed by the mesoderm which is produced by the process of cell migration
What does ectoderm develop into?
skin and nervous system
What does endoderm develop into?
lining or organs (like stomach and intestines) of the digestive system and the respiratory and excretory sytems
What does mesoderm develop into?
cells differentiate and form internal structures like muscle blood cells and gonads
What happens in neurulation?
a block of mesodermal tissue begin to differentiate into notochord and then a neural plate is formed and forms a neural tube that forms the spinal cord and brain and then the neural clls go into nerve cells, skin pigment and structures like lower jaws
What is spina bifida?
a serious birth defect caused by a lack of folic acid given to the fetus by the mother, it manifests itself in an unclosed neural tube
What is the embryo surrounded by?
amnion a sac filled with amniotic fluid
What is chorion? What does it do to help create the placenta?
a sac outside amnion that makes direct contact with the tissue of the uterus and has chorionic villi come from its outer surface and latch onto the uterine lining to form the placenta.
What connection is the placenta?
It is the chain between mother and child that acts as the embryo's organ of respiration, nourishment and exercition and oxygen and nutrients flow through while carbon dioxide flows out.
Does the blood of the mother and embryo mix?
What is the embryo called after 8 weeks?
What is a fetus like after three months
the major organs and tissues are fully formed and the fetus is 8 cm long
What happens month 4-6?
the cells become more complex adn specialized, the heart beats to hearing level and the hair and skin grow.
What happens month 7-9?
the organ system matures and the fetus expands
What are babies born at 8 months like?
Premature babies that have severe breathing trouble due to lung issues
What are the steps of childbirth?
- labour begins and contraction of the cervix happen
- water breaks
- baby is pushed out screaming and begins to breath
- placenta blood supply dries up and umbilical cord is cut to form the navel
- placenta is expelled
- breast milk starts
Can aids and rubella (german measles) effect the fetus?
yes, since they are iruses
What can hurt fetuses besides viruses?
drugs and alcohol
What is oxytocin, and what is its role in childbirth?
A hormone is used in child birth to strengthen uterine contractions.
THIS SET IS OFTEN IN FOLDERS WITH...
Chapter 31 Nervous System
Health Adolescence Test
YOU MIGHT ALSO LIKE...
Mastering Biology 2
Chapter 47 Homework
Unit 33: Human Development and Heredity
Fertilization and Embryonic Development
OTHER SETS BY THIS CREATOR
**Этажи. Глава 6. Часть 1: Работа
Этажи. Глава 6. Часть 1: Работа
**Этажи. Глава 6. Часть 1: Учёба