[4] PRELIMS | PROCESS OF CONCEPTION AND EARLY FETAL DEVELOPMENT Flashcards
Mitosis results in the production of ___ or ___, which are exact copies of the original cells
diploid body; somatic cells
In mature individuals, this is the process by which our body cells continue to divide and replace themselves
mitosis
Meiosis is a process of cell division leading to the development of ___ and ___ needed to produce a new organism
eggs and sperm
The gametes must have a haploid number (___) of chromosomes so that when the female gamete (___) and the male gamete (___) unite to form the ___ or a fertilized ovum.
23; egg or ovum; sperm or spermatozoon; zygote
Meiosis occur during ___, the process by which germ cells, or ___, are produced.
gametogenesis; gametes
The normal human diploid number of chromosomes (___) is re-established
46
Time Period: from ovulation to fertilization
Ovum
Time Period: from fertilization to implantation
Zygote
Time Period: from implantation to 5-8 weeks
Embryo
Time Period: from 5-8 weeks until term
Fetus
Time Period: developing embryo or fetus and placental structures
Conceptus
Steps of Conception:
1. ___ transport
2. ___ transport
3. ___ and ___ development
4. ___ and ___ development
- Sperm Transport
- Egg Transport
- Fertilization and Zygote Development
- Implantation and Embryo Development
The sperm must be ___ and transported to the ___
deposited; site of fertilization
The sperm consists of a ___, ___ or mid-section/midpiece, and a ___.
head; body; tail
Each of these parts is equipped with ___ and ___ that allow the sperm as a whole to function properly
various molecules; smaller structure
A normal sperm head has a ___ and ___ shape
smooth; oval
This is the most important part of the cell given that it contains the nucleus
Sperm Head
This is a thin, elongated structure of the sperm
Tail
This is the central part of the sperm cell between the head and the tail
Mid-section/Midpiece
The mid-section makes up about ___ percent of the total sperm length
10%
The tail makes up about ___ of the entire sperm length
80%
The first step in egg transport is ___ by the uterine tube
capture of the ovulated egg
Ovulation must occur and the egg must be ___ by the ___
“picked up”; uterine tube
When inside the uterine tube, the egg is transported towards the ___, mainly as the result of contractions of the ___ of the tubal wall
uterus; smooth musculature
Egg transport occurs in two phases:
- Slow transport in the ___ for approximately ___
- More rapid phase for 8 hours during which the egg or embryo passes through the isthmus and into the uterus
Slow transport in the ampulla for approximately 72 hours
Tubal transport of the egg usually takes ___, whether or not fertilization occurs
3-4 days
Site of fertlization: ____ poriton of the ____
Ampullar portion of the fallopian tube
The union between the sperm and egg must result in the process of ___
Conception
Egg transport occurs in two phases:
- Slow transport in the ampulla for approximately 72 hours
- More rapid phase for ____ which the egg or embryo passes through the ____ and into the ____
More rapid phase for 8 hours during which the egg or embryo passes through the isthmus and into the uterus
This is the process by which a sperm fuses with an ovum to form a diploid cell or zygote
Fertilization
Other terms used to include: (3)
Conception, impregnation, fecundation
Preparation for Fertilization - High levels of estrogen cause:
- ____ within ____ helping ovum
- ____ of ____ facilitating movement of the sperm
- Peristalsis within fallopian tubes helping ovum
- Thinning of cervical mucus facilitating movement of the sperm
Preparation for Fertilization - Two layers of tissue surrounding the ovum’s cell membrane:
- cell membrane called ____
- gaseous corona called ____
Preparation for Fertilization - Two layers of tissue surrounding the ovum’s cell membrane:
- cell membrane called Zona Pellucida
- gaseous corona called Corona Radiata
Preparation for Fertilization - Ova considered fertile for about ____ after ovulation
Ova considered fertile for about 12-24 hours after ovulation
Preparation for Fertilization - Sperm can survive in female reproductive tract for ____ but are believed to be healthy for about ____
Sperm can survive in female reproductive tract for 48-72 hours but are believed to be healthy for about 24 hours
Sperm must undergo two processes before fertilization can occur: ____ and ____
Capacitation and Acrosomal Reaction
Capacitation is the removal of ____ and loss of ____
Plasma membrane; Seminal plasma CHON
Capacitation occurs in ____ and is thought to take about ____
Female reproductive tract; 7 hours
Acrosomal Reaction follows capacitation and is the process of ____ their enzymes to break down the ____ of the ovum
releasing; corona radiate
The Moment of Fertilization - occurs as ____
Nuclei unite
The Moment of Fertilization - ____ contains new combination of genetic material resulting in ____ from either parent and from anyone else
zygote; individual different
The Moment of Fertilization: ____ is determined
Sex of Zygote
Cellular Multiplication
Cleavage ➡️ Morula ➡️ Blastocyst