Embryology 1

concerns the study of structure and function of cells

studies the forms and structures of cell, tissues and organ of the body with the aid of a microscope

studies the morphogenesis of the single cell, after the union of two cells (male and female sex cells) and occur throughout life

the study of growth and development of fertilized egg inside the reproductive tract of the female animal prior to birth/hatching (embryonic or fetal stage) that resembles its mature species

is the study of structures big enough to be seen by unaided eye

deals with the similarity and dissimilarity of structures of various species of animals

focuses on the structures of organs systems, example digestive, urinary, nervous system

branch of anatomy dealing the different regions of the body, example of which is the head, chest or abdomen, etc., it is also called topographic anatomy used for clinical studies

is the early developmental form of organism, without a definite recognizable head, body or limbs. Usually begins from fertilization to 8 weeks

is an organism on its advanced development wherein recognizable bodily form is clearly visible that distiguishesits adult species. It usually begins on the 9th wk of gestation

the most critical period during pregnancy or gestation wherein bodily organ system is establishing.

Embryonic stage

Organogenesis

Postembryonic stage

Adulthood

Fertilization

Cleavage

Gastrulation

union of male and female gametes (mature sex cells)

segmentation division

differentiation of the 3 germ layers

establishment of the organs

Fetal stage

Phases of Ontogenic Development

development and maturation of gametes

Theories of generation

the development of the embryo is from the existence of preformed embryo which is contained in the sperm(spermism) or in the egg(ovism)

the development of an organism originates from the fertilized egg to its mature form

the theory states that origin and evolution of a species is a continuing process that is measured in several years - man to monkey

Father of embryology, "most distiguished and influential of the early 19th century microbiologist"

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 embryo

The most influencial of the late 19th century embryologist and often called the "Father of Experimental Embryology"

observed that the embryo develops its organ system gradually

described the concepts of oviparity, viviparity and ovoviviparity

egg laying

eggs hatched inside the body

ex. some shark, snake(anacondas)

organism developed inside the body

noted also the two major patterns of cell division in early development: meroblastic and holoblastic

De Formato Foetu described and all illustrated gross anatomy of embryos and their membranes

published the first microscopic account of chick development, identifying the neural groove, somites and blood flow to the yolk sac

first to observe the blastoderm of the chick embryo and to indicate that blood islands form before the heart does.

Made first description of the germ layers(ectoderm, mesoderm and ectoderm) in the chick; Organs were not formed from a single germ layer

First to describe the pharyngeal arches

Studied the comparative embryology in frogs, salamander, fish, birds and mammals

Detailed the observation on the initial cleavage stages in man

published the first textbook on embryology in man and higher animals

Conducted the first nuclear transfer experiment

Awarded the nobel prize for physiology of medicine for his discovery of embryonic induction

Tested the totipotency of the nucleus and Produce the first blastocyst from nuclear transfer

Their work resulted to the birth of transgenic sheep, Dolly

Outermost or upper layer of cells

Give rise to the epidermis, nervous system and some skeletal and connective tissues of the head

The middle layer

Forms most of the muscle and skeletal tissues, urogenital system and the heart and blood vessels

Deepest or innermost layer of cells that lines the digestive, respiratory tract and those organs associated to digestion

Precursor of all connective and muscle tissues and is component of all organs except the CNS

hollow tube located in the dorsal midline beneath the ectoderm

Longitudinal rod immediately ventral to the neural tube

Extenda from the level of the midbrain(mesencephalon) to the tail

Indicates the future location of the vertebral column

Segmented mesoderm located beneath the neural tube and on the either side of the notochord

Each segment is called somite which gives rise to the axial skeleton and voluntary muscles

Mesoderm located lateral to the paraxial mesoderm which will give rise to the urogenital structures

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 is called ________