Chapter 1 - Historical Aspect of Embryology Flashcards
What is the major subdivision of Anatomy?
Microscopic and Macroscopic (Gross) Anatomy
Study of structure and function of cells
Cytology
studies the forms and structures of cells, tissues and organs of the body with the aid of a microscope.
Histology
This is the study of morphogenesis of the single cell after the union of two cells.
Developmental Anatomy
Study of growth and development of fertilized egg inside the reproductive tract.
Embryology
This is the formation of body structures and organs. It requires cell division and cell differentiation
Embryogenesis
Is used for the development of new individuals by means of asexual reproduction.
Blastogenesis
Is the study of the structures big enough to be seen by unaided eye.
Gross Anatomy
Deals with the similarity and dissimilarity of structures of
various species of animal.
Comparative Anatomy
Focuses on the structures of the organ systems, example digestive, urinary, nervous system.
Systemic Anatomy
Branch of anatomy dealing the different regions of the body.
Regional Anatomy
Is the early developmental form of an organism, without a definite
recognizable head, body or limbs.
embryo
An organism on its advanced development wherein a recognizable bodily form is clearly visible that distinguishes its adult species.
fetus
The most critical period during pregnancy or gestation.
1st trimester
This is the individual’s entire lifespan (starting as a zygote then the following stages: embryo, fetus, postpartum life as an individual and ends at death)
Ontogeny
Defined as the time from fertilization to the earliest
(primordial) stages of organ development (about 30 days in dog, cat, sheep, pig; almost 60 days in horse, cattle, human). It ends when various organs are formed.
Embryonic period
The time between the embryonic period and parturition (the end of
gestation), during which organs grow and begin to function.
Fetal period
Embryonic stage
Fertilization- union of male and female gametes (mature sex cells)
Cleavage- segmentation division
Gastrulation- differentiation of the 3 germ layer
Organogenesis- establishment of the organs
Postembryonic stage- fetal stage
Adulthood
Stages in the Life Cycle
Gametogenesis-
Fertilization
Cleavage
Gastrulation
Organogenesis
Growth and Histogenesis
Phases of Ontogenic Development
Theories of Generation
Preformism: Ovism and Spermism
Epigenesis
Phylogenesis
the prevailing view of many scientists and scholars
interested in embryology that organisms develop from miniatures of themselves.
Preformism
Proposed that the structure of an animal emerges gradually from a relatively formless egg. First proposed by the Greek philosopher Aristotle.
Epigenesis
the theory states that origin and evolution of a species is a continuing process that is measured in several years. Example, the evolution of man
from monkey.
Phylogenesis
- Father of Embryology
Proposed that all vertebrate embryos pass a stage wherein they are anatomically similar seen in 18 dy dog, 24 dy cow and 48-60 hr chick embryos
KARL ERNST VON BAER
The most influential of the late nineteenth century embryologists
Often called the ‘Father of Experimental Embryology’
WILHELM ROUX
Observed that the embryo develops its organ systems gradually. Foetu described and illustrated gross anatomy of embryos and their membranes
ARISTOTLE
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
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
cells that give rise to all tissues and organs of the body.
Germ layer
Gives rise to the epidermis, nervous tissue and some skeletal and connective tissue of the head. Outermost or upper layer of cells
ECTODERM
The middle layer of cells. Forms most of the muscles and skeletal tissues, urogenital system and the heart and
blood vessels.
MESODERM
Deepest or innermost layer of cells that lines the digestive, respiratory tract and those organs associated to digestion
ENDODERM
Precursor of all connective and muscle tissues and is component of all organs except the CNS
MESENCHYME
Branch of embryology that deals with the causes and results of abnormal
development or congenital malformation. a group of loosely and irregularly arranged cells separated by a large amount of extracellular matrix.
Teratology
abnormality that arises during prenatal development due to hereditary or environmental factors.
Congenital malformation or congenital defect
congenital defect caused by disturbance of development of an organ
or portion of an organ.
Anomaly
congenital defect caused by disturbance of development of several organs and causes great distortion of the individual.
Monstrosity
single layer or several layers of cells that rest on a basal lamina; cells are closely joined together at their lateral surfaces.
Epithelium
a tissue which connects and supports other tissues of the body, such as adipose tissue, tendons, ligaments, cartilage and bone.
Connective Tissue
pertains to the back
Dorsal
the belly
Ventral
the head
Cephalic
the tail
Caudal
the middle part
Medial
the side of the embryonic body
Lateral
is used to refer to the extreme anterior
portion of the head or the relative location of
intracephalic structures such as the various parts of
the brain
Rostral
Toward the
back
dorsad
toward the head
cephalad
which is covered by a layer of ectodermal epithelium which will become the
epidermis of the skin
Body
an elongated hollow structure derived from ectoderm and located
beneath the ectodermal epithelium which runs along the dorsal midline of the
body
Neural tube
forebrain
prosencephalon
midbrain
mesencephalon
hindbrain
rhombencephalon
another hollow tube that run the length of the embryo near the ventral midline and gives rise to the digestive tract.
Gut tube
a segmented portion of the mesoderm located on either side of the neural tube.
Paraxial mesoderm
a longitudinal rod of mesodermal cells located beneath the neural tube
that extends from the midbrain to the tail. It will not give rise to any adult structure in vertebrate embryos although in lower forms of fishes, it gives rise to the axial
skeleton.
Notochord
a small cluster of mesodermal cells located lateral to the paraxial mesoderm it gives rise to the embryonic kidneys, and the gonads
Intermediate mesoderm
a layer of mesodermal cells located lateral to the intermediate mesoderm.
Lateral mesoderm
first seen as a slightly curved tube located in the ventral midline of the
embryo beneath the caudal part of the pharynx.
Heart
include the ventral aorta, aortic arches, dorsal aortae, vitelline (or omphalomesenteric) arteries and allantoic (or umbilical) arteries.
Arteries
include the cranial and caudal cardinal veins,
the common cardinal veins, vitelline veins and
allantoic veins.
Veins
