Intro Flashcards
What is embryology?
The study of human development from time of conception to birth
Why study embryology?
Helps us to understand:
Normal relationships of body structures Congenital anomalies Incomplete development of structures Gross anatomy Diseases
Who named ovaries and the graffiti follicle?
Reiner de Graaf
What is the theory of preformation
Miniature human in each sperm
Johan Ham van Arnhem & Anton van Leeuwenhoek
What is the theory of Epigenesis?
Embryonic development results from growth and differentiation of specialized cells
Opposite of preformation
(Caspar Friedrich Wolff)
What is the cell theory?
When was it developed?
Who created it?
The basic structure and basic unit of reproduction in all organisms
All living organisms have at least one cell
Cells arise only from cells (Rudolf Virchow)
Developed in 1838
Matthias Schneider and Theodor Schwann
Schwann cells make what?
The myelin sherif that surrounds your nerves
What is considered prenatal?
From conception to birth
What is considered postnatal?
Birth to adulthood
- infancy
- childhood
- puberty
- adolescence
- adulthood
How many weeks for embryonic?
Weeks 1-8
How many weeks for fetal?
Weeks 9-birth
Embryo refers to
The developing human during all of its early stages of development week 2-8
What structures begin to form in the embryo stage?
All major structures
Fetus refers to
Week 9 to birth
What occurs during the fetal stage?
Differentiation and growth of the tissues and organs formed during the embryonic period
Esp during the 3rd and 4th months
Less than 1 month old is considered
A newborn or neonate
Infancy 1-12 months what all occurs?
Rapid growth
Length increases by 1/2
Body weight triples
6-8 teeth
Childhood
13 months-puberty
What all occurs?
Primary teeth erupt (20 total) and are replaced by secondary teeth (32-36)
Active ossification - pre pubertal growth spurt
When does puberty occur?
12-15 in girls
13-16 in boys
What occurs during puberty?
Secondary sex characteristics develop
When does puberty end?
First menses in girls
Mature sperms in boys
What occurs during adolescence?
11-19 y/o
Rapid physical and sexual maturation
General growth rate slows down
Sexual structures growth rate accelerate (breast and male genitalia)
What occurs during adulthood?
18-21 y/o
Full physical growth and maturity
Ossification and completion between age 21-25
Conceptus-
Entire products of conception from fertilization onward (embryo) and the membranes (amnion, chorionic sac, placenta)
Oocyte-
Also called ovum/egg
Female germ cell produced by the ovaries
All primary oocytes are present at birth
When does the oocyte begin?
During the fetal stage of development when oogonia (primordial oocyte) mature to form primary oocytes
Primary oocytes mature into secondary oocytes at what rate?
1 per month beginning at puberty and ceasing at menopause
Sperm -
Male germ cell produced in the testes (testicles)
Spermatogonia -
Primordial sperm cells that are dormant in the seminiferous tumbles of the male testes until puberty
Spermatogenesis -
Production of mature sperm
Begins at puberty and continues throughout adulthood
How long does the spermatogeneisis (production of mature sperm) process take?
2 months
Zygote-
Formed by the union of an oocyte and a sperm
Beginning of a new human being!
Cleavage
Mitosis cell division of the zygote
Forms embryonic cells called blastomeres
Morula-
12 or more blastomeres from a ball of cells
3-4 days after fertilization
Primordial -
An aggregation of cells in the embryo indicating the first trace of an organ or structure
Gestation -
The amt of time between conception and birth
40 weeks avg
Divided into trimesters
Trimesters-
A period of consisting of three calendar months
9 month per trimester
When are the most critical stages of development?
First trimester
Parturition
The process of fetus, placenta, and fetal membranes are expelled from mothers reproductive tract
Labor
A series of involuntary uterine contractions which result in the dilation of the cervix
3 stages of labor
1) Cervix relaxes and is completely dilated
2) fetus descends through cervix and vagina
3) placental stage as soon as fetus is born and ends with expulsion of placenta and membranes
When does labor officially begin?
Cervix dilates 2 in
Regular contractions less than 10 min apart
12 hrs first pregnancy
7 hrs for second pregnancy
Primigravidas
Multigravidas
???
Abortion
All naturally occurring terminations of pregnancy before 20 weeks
Spontaneous abortion
Occur naturally during the first 12 weeks (roughly 15% end this way)
Miscarriage
Naturally occurring terminations that occur after 20 weeks
Missed abortion
The conceptus is retained in the uterus after the death of the fetus or embryo
Abortus
Aborted products of conception
Or non-viable birth weighing less than 500g w/ no chance of survival
Reproductive organs do what?
Reproductive or sex organs that produce and transport germ cells (gametes) from the gonads (testes or ovaries) to the site of fertilization
Female reproductive organs
Uterus
Ovaries
Uterine tubes
Vagina
Uterus
Thick walled, pear shaped organ
- body (2/3)
- cervix (1/3)
Cervix
Has a passage way (lumen) called cervical canal which connects the uterine body with the vagina
The openings in the cervix are referred to
Internal os - communicates with the cavity of the body of the uterus
External os - communicates with the vagina
Cervical canal -
Allows sperm/semen to enter the body of the uterus for fertilization
The passage way a child passes through to be born
Dilation of it is a predictor of impending childbirth
Uterine body
The walls of the body of the uterus consisting of 3 layers
3 layers of the uterine body
1) perimetrum - thin external
2) myometrium - thick smooth muscle layer
3) endometrium - thin internal mucous membrane
3 layers of the endometrium:
1) compact layer lines the uterine cavity
2) spongy layer contains spiral arteries and veins
3) basal layer
What in the compact layer aids in the implantation?
Glandular epithelium that secrete a glycogen-right material
What do the spiral arteries of the spongy layer do?
During literal phase they grow into the compact layer and contains bodies of the uterine glands
Sloughed off during menses
Ovaries
Almond shaped glands on each side of uterus that produce oocytes
Release secondary oocytes into the uterine tubes
Produce estrogen and progesterone
