Vetan Topic 1 Flashcards
study of the prenatal development of an organism; study of the growth and differentiation of an organism from zygote into a highly complex and independent living being like its parents
embryology
increase in the number of cells as a result of cell growth and cell division
cell proliferation
result of cells expressing some genes and suppressing others within a common genome
cell differentiation
branch of embryology that deals with the causes and results of abnormal development or congenital malformation
teratology
an abnormality that arises during prenatal
development due to hereditary or environmental factors
congenital malformation or congenital defect
a developmental disturbance that involves an organ or a portion of an organ
anomaly
developmental disturbance that involves several organs and causes great distortion of the individual
monstrosity
cell division that results in two daughter cells having diploid number of chromosomes
that are identical to the parent cell
mitosis
cell division that results in four daughter cells having haploid number of chromosomes
meiosis
sheet of cells which gives rise to all tissues and organs of the body
germ layer
the outermost germ layer; gives rise to the epidermis of the skin, nervous
tissues and some skeletal and connective tissues of the head
ectoderm
the middle germ layer; gives rise to most of the skeletal and muscular tissues, the heart and blood vessels and the urogenital system (kidney, ovary and testis)
mesoderm
innermost germ layer; form the lining of the digestive (stomach, intestine)
and respiratory (trachea, bronchus) tracts
endoderm
single layer or several layer of cells that rest on a basal lamina and are closely
joined together at their lateral surfaces
epithelium
type of epithelium which lines the blood vessels
endothelium
lines body cavities and covers the surfaces of visceral organs contained in these cavities
mesothelium
a group of loosely and irregularly arranged cells separated by a large amount of extracellular matrix
mesenchyme
tissue which connects and support other tissues of the body
connective tissue
What are the five events of early embryogenesis?
Gametogenesis
Fertilization
Cleavage
Gastrulation
Neurulation
process of development and maturation of sex cells called gametes
gametogenesis
mature reproductive cells capable of fertilization
gametes
The structure and physiology of gametes must accommodate three functions. What are these?
- to survive in environment quite different from that of the gonad;
- to recognize homologous cells of the other gender and participate in events
related to fertilization; and - to provide sufficient genetic and cytoplasmic materials to support.
development of a new organism
refers to the development and
maturation of female gamete
oogenesis
refers to the maturation and development of male gametes (spermatozoa)
spermatogenesis
gonads in males are known as?
testes
Inside the testes are specialized tubules known?
seminiferous tubules
During sexual differentiation, the primordial germ cells differentiate into _______ that undergo mitosis many times to produce many
daughter spermatogonia.
spermatogonia (diploid cells)
Increased production of the hormone _______
stimulates spermatogonia to enter Meiosis I and become primary spermatocytes
testosterone
Spermatids become spermatozoa in a process called?
spermiogenesis or morphogenesis
primary spermatocytes complete Meiosis I to give rise to?
two secondary spermatocytes
Meiosis II of secondary spermatocytes results to?
four spermatids
sperm cells are stored inside the _______ where they complete their maturation before they are released to the outside environment through ejaculation
epididymis
becomes compact to form the head of the sperm
nucleus
the axial filament of the sperm
centrosome
is reduced greatly in bulk giving envelop surrounding the head, rise to middle piece and tail
cytoplasm
during spermiogenesis, golgi apparatus becomes the?
acrosome
it becomes the spiral filament in the middle piece
mitochondria
female gonads are known as the ______ and inside an important process known as oogenesis takes place
ovaries
these are special stem cells found in the
female individual which eventually differentiate to form the female gametes or the
egg cells
oogonia
hormone that initiates ovulation where the mature follicle ruptures releasing the secondary oocyte into the oviduct (fallopian tube)
luteinizing hormone
Meiosis I begins shortly before birth but arrests at
prophase I where all primary oocytes stay dormant in the ovaries until it reaches?
puberty
marks the beginning of the monthly
menstrual cycle in female individuals
puberty
At sexual maturity, the primary oocytes complete the ______ to give rise to
secondary oocytes and the 1st polar body which later degenerate
1st meiotic division
At ovulation, the nucleus of the secondary oocyte begins Meiosis II progressing only to
_________, then division arrests.
metaphase II
Meiosis II only resumes when?
sperm penetration becomes successful
zygote that will travel along
the fallopian tube and into the uterus and will implant itself into the
endometrium of uterus
this hormone ensures that the endometrium is just the right layer and thickness for the
developing embryo
estrogen
union of a haploid female gamete (oocyte) with a haploid male gamete (spermatozoon) to form a diploid zygote
fertilization
Where does fertilization takes place?
fallopian tube (oviduct)
it cover the sperm and impede making contact with the oocyte takes place and these changes increases sperm motility
sperm capacitation
a series of cell divisions that occurs in the zygote following fertilization
cleavage
cleavage that occurs in birds and
amphibians contains a large amount of yolk
meroblastic or discoid cleavage
what are the two types of cleavage?
- Holoblastic cleavage or equal cleavage
- Meroblastic or discoid cleavage.
cleavage that occursin mammals contains a small amount of yolk (isolecithal egg)
holoblastic cleavage or equal cleavage
a series of mitotic divisions by which a large zygote
is fractionated into numerous ”normal size” cells called
blastomeres
Cleavage begins with a zygote, progresses through compaction to a solid ball of cells called as?
a morula
cleavage terminates at the start of?
blastocyst or blastula stage
When does blastocyst develops?
during the 2nd week following the rupture of the zona pellucida
blastomeres divide once every?
12 hours
How many cell division does a morula have when it leaves the uterine tube and enters the uterus (uterine horn)?
16-cell stage
During rapid transitional changes of morula, outer blastomeres become TROPHOBLAST which forms these two extraembryonic membranes?
chorion and amnion
While inner blastomeres become the INNER CELL MASS OR EMBRYONIC DISC, which forms? (3)
embryo
yolk sac and allantois
What are the four extraembryonic membranes?
chorion
amnion
yolk sac
allantois
What are the three rapid transitional changes of morula?
- increased number and compaction of blastomeres
- transformation and rearrangement of blastomeres (which later give rise to 4 extraembryonic membranes)
- Rearrangement of blastomeres results in the formation of blastocyst and the embryo enters the blastula stage of cleavage.
It is the surface cell of the blastocyst.
trophoblast
Surface cells of blastocyst are designated as trophoblast, while the fluid-filled cavity is called?
blastocoele
This indicates the location of the nucleus and cytoplasm of the zygote during meroblastic or discoid cleavage.
embryonic disc or blastodisk
What is a very young avian embryo (a multinucleated cell)?
syncytium
a portion of the ovum cytoplasm that bulges out as a result of contact of the sperm with the vitelline membrane
fertilization cone
Sperm penetrates the corona radiata and zona pellucida of the ovum to reach the?
perivitelline space
It is the partial disintegration of the acrosomal membrane to release lytic enzymes which denature zona pellucida proteins which facilitate penetration by the reactive sperm.
acrosomal reaction
