FIRST TERM EXAM REVIEWER Flashcards
The study of the changes in cells, tissues, organs, and the body that occur throughout life.
DEVELOPMENTAL ANATOMY
The study of the ontogenic development of
organisms,i.e. from the time of fertilization of the egg to the organism’s resemblance of its mature
form.
EMBRYOLOGY
The development of an organism from fertilization up
to the time till death.
ONTOGENY
The study of the evolutionary development of
groups of organisms based on shared genetic and
anatomical characteristics.
PHYLOGENY
The early developmental form of an individual,
without a definite recognizable head, body or limbs.
EMBRYO
An organism on its advanced development
wherein a recognizable bodily form is clearly
visible.
FETUS
NEONATE
A newborn of less than four weeks old.
• Embryonic stage
• Fertilization
• Cleavage
• Gastrulation
• Organogenesis
• Postembryonic stage
• Adulthood
STAGES IN LIFE CYCLE
• Gametogenesis
• Fertilization
• Cleavage
• Gastrulation
• Organogenesis
• Growth and Histological Differentiation
PHASES OF ONTOGENIC DEVELOPMENT
• Observed that the embryo develops its organ
systems gradually.
• Described the fetal membranes and umbilical cord in cattle.
• Described the concepts of oviparity
(OVIPAROUS), viviparity (VIVIPAROUS) and
ovoviviparity (OVOVIVIPAROUS).
• Noted the two major patterns of cell division in
early development: meroblastic and holoblastic.
ARISTOTLE
• De Formato Foetu
• Described and illustrated gross anatomy of
embryos and their membranes.
HIERONYMUS FABRICIUS
• Published illustrations of dog and sheep embryos.
BARTOLOMEO EUSTACHIUS
• Published the first microscopic account of chick
development, identifying the neural groove, somites
and blood flow to the yolk sac.
MARCELLO MALPIGHI
• First to observe the blastoderm of the chick
embryo and to indicate that blood islands form
before the heart does.
WILLIAM HARVEY
• Performed detailed studies of the female
reproductive organs, especially the ovary.
• Considered mammalian antral follicles to be the
eggs.
REGNIER DE GRAAF
• The ‘most distinguished and influential of the early nineteenth century embryologists’.
• Proposed that all vertebrate embryos pass a stage
wherein they are anatomically similar.
• Seen in 18 day dog, 24 day cow and 48-60 hour chick
embryos.
KARL ERNST VON BAER
• First scientist to actually see the mammalian egg.
• Showed that the three layers were not merely a
feature of the chick but were universal in
vertebrates.
• Discovered the notochord.
KARL ERNST VON BAER
• First to report having seen moving spermatozoa.
ANTON VAN LEEUWENHOEK
• Demonstrated how the gut arises from the folding
of an originally indifferent flat tissue.
CASPAR FRIEDRICH WOLFF
• Made the first description of the germ layers
(ectoderm, mesoderm and endoderm) in the chick.
• Organs were not formed from a single germ layer.
CHRISTIAN PANDER
• First to describe the pharyngeal arches.
• Studied the comparative embryology in frogs,
salamanders, fish, birds and mammals.
MARTIN HEINRICH RATHKE
• Detailed observation on the initial cleavage stages
in rabbit.
THEODOR LUDWIG WILHELM VON
BISCHOFF
• Detailed observation on the initial cleavage stages
in man.
• Published the first textbook on embryology in man
and higher animals.
RUDOLPH ALBERT VON KOLLIKER
• Proposed germ cell plasm theory.
AUGUST WEISMANN
• The most influential of the late nineteenth century
embryologists.
• Often called the ‘Father of Experimental
Embryology.
WILHELM ROUX
• Conducted the first nuclear transfer experiment.
• Awarded the Nobel Prize for Physiology of
Medicine for his discovery of embryonic induction.
HANS SPEMANN
• Demonstrated the relationship between
chromosomes and sex.
EDMUND BEECHER WILSON & NETTIE
MARIA STEVENS
• Tested the totipotency of the nucleus.
• Produced the first blastocyst from nuclear transfer.
ROBERT BRIGGS & THOMAS KING
• His work resulted in the first mammal to be born
after cloning by nuclear transfer.
STEEN MALTE WILLADSEN
• Birth of the transgenic sheep, Dolly.
KEITH CAMBELL &
IAN WILMUT
• Outermost or upper layer of cells.
• Gives rise to the epidermis, nervous tissue and
some skeletal and connective tissue of the head.
ECTODERM
• Deepest or innermost layer of cells that lines the
digestive, respiratory tract and those organs
associated to digestion.
ENDODERM
• The middle layer of cells.
• Forms most of the muscles and skeletal tissues,
urogenital system and the heart and blood vessels.
MESODERM
• Precursor of all connective and muscle tissues and
is component of all organs except the CNS.
MESENCHYME
• Segmented mesoderm located beneath the neural
tube and on either side of the notochord.
• Each segment is called somite which gives rise to
the axial skeleton and voluntary muscles.
PARAXIAL MESODERM
• Mesoderm located lateral to the paraxial
mesoderm which will give rise to the urogenital
structures.
INTERMEDIATE MESODERM
• Mesoderm that extends around the gut and
beneath the surface ectoderm to the ventral midline.
• Splits to divide into outer parietal and inner
splanchnic layer to form a cavity called coelom.
LATERAL MESODERM
• Hollow tube located in the dorsal midline beneath
the ectoderm.
NEURAL TUBE
• Longitudinal rod immediately ventral to the neural
tube.
• Extends from the level of the midbrain
(mesencephalon) to the tail.
• Indicates the future location of the vertebral
column.
NOTOCHORD
• Development and maturation of sex cells called
gametes.
• Includes meiosis and cytodifferentiation.
• GAMETES - matured sex cells of male and
female.
• Specifically termed: spermatogenesis for male &
oogenesis for female.
GAMETOGENESIS
• The lineage of cells from which gametes arise.
GERM LINE
• The cells which produce the gametes.
PRIMORDIAL GERM CELLS (PGCs)
• In mammals, primordialgerm cells arise from yolk
sac endoderm. The cells migrate around the gut to
the mesentery into the gonad.
• In birds and reptiles, they travel through the blood
stream and into the gonads.
• Two successive meiosis occur during
gametogenesis to reduce the diploid number of chromosomes of germ cells into haploid.
• Stages of meiosis is similar with the stages of
mitosis, i.e. P I,II ; M I,II ; A I,II and T I,II.
• Timing of meiosis differs in males and females.
• In males, meiosis starts from the onset of puberty
throughout the entire reproductive life.
• In females, meiosis starts before birth and completion of meiosis is upon fertilization.
PGC MIGRATION
• A process where a single cell divides
into two identical daughter cells (cell division) with
same diploid number of chromosomes.
• When you say diploid number it refers to the 2N
number of chromosomes of the cell in contrast to the
N ,a haploid number, ex. in humans 2N=46 and
N=23chromosomes.
• The major purpose of mitosis is for growth and to
replace worn out cells.
MITOSIS
• A process where a single cell divides
twice to produce four cells containing half the
original amount of genetic information.
MEIOSIS
What part or cell organelles are involved in
mitosis?
Cell membrane, nucleus, nuclear
membrane and centriole.
What cells in the body are diploid, which are
haploid?
The diploid cells are the somatic cells and
the haploid cells are the sex cells (gametes).
How do the cells become haploid?
During meiosis the sex cells become
haploid.
Why the sex cells ( gametes: sperm & egg) are
haploid?
During fertilization where the egg and
sperm cell unite will not result to polyploidy (more
than 2 sets of chromosomes).
• Cell cycle is a repeating series of events that
include growth, DNA synthesis, and cell division.
• In prokaryotes is quite simple: the cell grows, its
DNA replicates, and the cell divides (asexual
reproduction).
• In eukaryotes, the cell cycle is more complicated,
has several phases.
• The mitotic phase (M) actually includes both
mitosis and cytokinesis. This is when the nucleus
and then the cytoplasm divide.
• The other three phases (G1, S, and G2) are
generally grouped together as interphase. During
interphase, the cell grows, performs routine life
processes, and prepares to divide.
CELL CYCLE AND CELL DIVISION
• Cell undergoes rapid growth.
• Synthesize amino acids needed for DNA
replication.
• If a cell is not dividing, the cell enters the G0
phase from this phase.
Growth Phase 1 (G1): Longest phase
• Forms two genetically identical daughter cells.
• During this phase, the amount of DNA in the cell is
doubled, though the cell remains in a diploid state.
Synthesis Phase (S)
• A shortened
growth period in which many organelles are
reproduced or formed. Parts necessary for mitosis
and cell division are made during G2, including
microtubules used in the mitotic spindle.
Growth Phase 2 (G2)
• The resting phase where the cell has left the cycle
and has stopped dividing.
• These cells may remain in G0 for a long period of
time, even indefinitely, such as with neurons.
• Cells that are completely differentiated may also
enter G0.
• Some cells stop dividing when issues of
sustainability or viability of their daughter cells
arise, such as with DNA damage or degradation, a
process called cellular senescence.
• Cellular senescence occurs when normal diploid
cells lose the ability to divide, normally after about
50 cell divisions.
G0 phase
• The entire process involved in the transformation
of germinal epithelial cells (stem cells) to
spermatozoa.
• Occur in the seminiferous tubules of the testis.
• Can be divided into two phases:
spermatocytogenesis & spermiogenesis.
SPERMATOGENESIS
• Proliferative phase whereby spermatogonial cells
multiply by a series of mitotic divisions followed by
the meiotic divisions which produce the haploid (n)
number of chromosomes.
SPERMATOCYTOGENESIS
• Maturation of the spermatids while they are still in
the adluminal compartment.
SPERMIOGENESIS
• The release of matured spermatids into the lumen
of the seminiferous tubules where they stay for a
while then migrate in the epididymis for further
maturation.
SPERMIATION
• Oval structure which includes the nucleus
containing the haploid number of chromosomes.
• Also has a cap called the acrosome, which
contains enzymes to permit penetration into the
ovum.
• These are the acrosin and hyaluronidase.
HEAD
• The power plant of the sperm.
• Within it are numerous mitochondria that carry out
the metabolism that provides adenosine
triphosphate(ATP) for the sperm’s locomotion.
MIDPIECE
• Consists of a flagellum for propulsion.
TAIL
A. Coiled Tail with Droplet
B. Coiled Double Tail
C. “DAG” defect
D. Folded tail
E. Filamentous
F. Double Tail
G. Corkscrew Midpiece with Droplet
H. Corkscrew Midpiece
SPERM ABNORMALITIES
• The process by which oocytes are formed.
• The oogonia follow the same pattern in the sperm
cell.
• i. e. from oogonia to primary oocyte to secondary
oocyte to ootid to egg or ovum.
OOGENESIS
• A follicle containing the primary oocyte enveloped by a single layer of flat, follicular
epithelial cells.
PRIMORDIAL FOLLICLE
• A follicle little larger than the primordial follicle.
• A primary oocyte surrounded by a single layer
of cuboidal follicular cells.
PRIMARY FOLLICLE
• An oocyte with two or more layers of cuboidal
follicular cells having a small or no antrum.
SECONDARY FOLLICLE
• A very large follicle bulging from the surface of
the ovary with a fluid-filled cavity as identifying
characteristic.
MATURE FOLLICLE (Graafian follicle/ Vesicular
follicle/ Tertiary follicle)
• Cell membrane of the oocyte.
VITELLINE MEMBRANE
• A prominent translucent acellular layer located
between the vitelline membrane of the oocyte
and the follicular cells.
ZONA PELLUCIDA
• Squamous follicular cells which become cuboidal.
GRANULOSA CELLS
• Follicular cells directly adjacent to the zona
pellucida of the oocyte.
CORONA RADIATA
• Mound of granulosa cells on which the oocyte sits.
CUMULUS OOPHORUS
• A fluid-filled cavity containing the liquor folliculi.
ANTRUM
• Release of ovum from the follicle.
• Prior to ovulation, the oocyte and corona radiate
detach from the cumulus oophorus and float in the
follicular fluid.
• Pressure inside the follicle and hormone, LH are
the complementing
factors.
• Left ovary ovulates more frequently in the mare.
• Right ovary in the cow
OVULATION
• Ova is released without the need for copulation.
• Most species
Spontaneous ovulation
• The physical act of coitus or mechanical stimulation.
• Cats, rabbits, camels, ferrets.
• Induced-female animal ovulates due to an
externally-derived stimulus during, or just prior to,
mating, rather than ovulating cyclically or
spontaneously. Stimuli causing induced ovulation
include the physical act of coitus or mechanical
stimulation simulating this, sperm and Pheromones.
Induced ovulation
• Union of male female gametes/ sex cells.
FERTILIZATION
▪ Mating can be natural, artificial or in vitro.
▪ Mating–sexual intercourse of a male and female
with the deposition of semen in the female
reproductive tract.
MATING
• Can be the classic AI and observing the occurrence
of estrus or Fixed Time AI (FTAI) via hormonal
intervention. Monitoring/observation of estrus is no
longer done/problem because AI is at a fixed time.
ARTIFICIAL INSEMINATION (AI)
▪ Ovum are picked up (OPU) via guided
Ultrasonography.
▪ Ovum aspirated from the collected ovaries from
abbatoir/slaughterhouse.
▪ Fertilized in the laboratory.
▪ Transferred into a recipient animal.
IN IN-VITRO FERTILIZATION
SPERM DEPOSITION
Cat - Vagina
Dog- Uterus
Cattle - Vagina
Horse - Uterus
Sheep - Vagina
Pig - Cervix/Uterus
• Takes place in the ampullary region of the oviduct.
• Sperm cells travel the female reproductive tract to meet the egg cell. However , only one lucky sperm
wins the ovum.
• Sperm cells as they travel the segments of female
tract decrease in number due to environmental
conditions in each specific segments of the tract.
FERTILIZATION
• Delivers spermatozoa to the fertilization site very
shortly after copulation (15-30 mins).
RAPID TRANSPORT PHASE
▪ Delivers spermatozoa to the ampulla in a more
uniform manner over a sustained period of time (6-
12 hrs).
SLOW/ SUSTAINED TRANSPORT PHASE
▪ Movement of sperm cells from one horn to
another ( usually during AI).
INTERCORNUAL TRANSPORT
▪ Cervix produces mucus rich in: Sialomucin &
Sulfomucin.
• Less viscous mucus favors sperm transport as they
can easily
swim.
DURING THE SPERM TRANSPORT
• Low in viscosity.
• Produced by cells in the basal areas of the cervical
crypts.
SIALOMUCIN
• Viscous
• Produced in the apical portions of the cervical
epithelium.
• Sperm cells swim up the ovum while the ovum
moves down and meet the sperm cells in the
ampulla of the oviduct.
SULFOMUCIN
• A biochemical process that occur in the female
tract whereby spermatozoa acquire the capacity to
fertilize the egg.
• If spermatozoa are deposited in the vagina, cervix
or uterus ( semen deposition varies among species), it apacitation may begin through the cervix,
uterus and isthmus respectively.
CAPACITATION
• Hyperactive motility
• Binding to zona pellucida
• Acrosomal reaction
• Penetration of zona pellucida
• Sperm-oocyte membrane fusion
• Sperm engulfed
• Decondensation of sperm nucleus
• Formation of male pronucleus
POST-CAPACITATION
• Primary zona binding region
• Acrosome reaction promoting ligand
Two zona binding sites
• Proposed model for zona binding and the
initiation of the acroso- mal reaction in mammalian
spermatozoa. The sperm plasma membrane
overlying the acrosome contains two receptor-like
regions. The first, called the zona binding region
(ZBR), reacts with ZP3 to cause physical
attachment of the sperm to the zona pellucida. A
second membrane region, the acrosome reaction
promoting region (ARPR), also binds to ZP3 and
initiates the acrosome reaction by causing the sperm
plasma membrane to fuse (arrows) to the outer acrosomal membrane.
ZONA BINDING
• Calcium-triggered reaction of the oocyte cell
membrane.
• Small, dense granules called cortical granules
undergo exocytosis and their contents are released
into the perivitelline space.
CORTICAL REACTION
• A process whereby the zona pellucida undergoes
biochemical changes so that no further sperm can
penetrate the zona.
ZONA BLOCK
• The fusion of the male and female pronuclei,
fertilization is done.
SYNGAMY
