Embryology Review Notes

Flashcards created from embryology lecture notes to aid in study and recall of key terms and concepts.

Embryology

Study of the embryo and its development.

Embryon

Greek term meaning something that swells in the body.

Epigenetic Development

Process by which a single cell develops into a complex organism.

Prenatal Period

Time from conception to birth, subdivided into embryonic (0-8 weeks) and fetal (8 weeks to birth) stages.

Postnatal Period

Period after birth, including stages such as infancy, childhood, puberty, adolescence, and adulthood.

Ventral

Term indicating the belly side.

Dorsal

Term indicating the back side.

Cranial

Term indicating toward the head.

Caudal

Term indicating toward the tail.

Rostral

Term indicating toward the nose.

Median Plane

Divides the body into equal right and left sections.

Sagittal Plane

Divides the body into right and left sections.

Transverse Plane

Divides the body into top and bottom sections.

Frontal Plane

Divides the body into front and back sections.

Oblique Plane

Any section not aligned with the primary planes.

Gross Anatomy

Study of body structures visible to the naked eye.

Microscopic Anatomy

Study of structures that require magnification.

Sex Cell

Reproductive cells (sperm or egg) involved in fertilization.

Testis

Primary male reproductive organ that produces sperm and hormones.

Sperm Maturation

Process of sperm cell development, taking about 14 days.

Hormonal Control

Regulation of reproductive processes through hormones.

Ovulation

Release of an egg from the ovary.

Ectopic Pregnancy

Pregnancy occurring outside the uterus.

Implantation

Process by which the embryo attaches to the uterine wall.

HCG

Human Chorionic Gonadotropin, hormone produced in pregnancy.

Cleavage Division

First cell divisions after fertilization leading to smaller cells.

Blastocyst

Stage of development where the embryo forms a hollow sphere.

Amniotic Sac

Fluid-filled cavity that protects the developing fetus.

Mesoderm

Middle layer of embryonic cells that forms various systems.

Notochord

Structure that defines the axis of the embryo and develops into the spine.

Primitive Streak

Structure that indicates the future development axis during gastrulation.

Fertilization

Union of male and female gametes to form a zygote.

Capacitation

Process that sperm undergo to become capable of fertilizing an egg.

Acrosome Reaction

Changes in sperm that facilitate penetration of the egg.

Polyspermy

Fertilization of an egg by multiple sperm.

Zona Pellucida

Protective layer surrounding the egg that must be penetrated for fertilization.

Cortex (of Egg)

Outer layer of the egg cell that facilitates sperm entry.

Cortical Reaction

Response of the egg after fertilization preventing multiple sperm entry.

Cleavage

Cell divisions that occur after fertilization to increase cell number.

Morula

Solid ball of cells that forms before the blastocyst stage.

Gastrulation

Process of cell movement and differentiation that forms the three germ layers.

Nervous System Development

Formation of the nervous system during embryonic development.

Villi

Projections from the chorion that increase surface area for nutrient and gas exchange.

Umbilical Cord

Structure that connects the fetus to the placenta for nutrient exchange.

Placenta

Organ that develops during pregnancy to facilitate nutrient and waste exchange.

Epithelial Cells

Cells that line surfaces and cavities of organs.

Syncytiotrophoblast

Outer layer of trophoblast that invades the uterine lining.

Cytotrophoblast

Inner layer of trophoblast that contributes to the placenta.

Epiblast

Layer of the bilaminar disk that forms the embryo proper.

Hypoblast

Layer of cells beneath the epiblast in the bilaminar disk.

Day 7 Development

Stage when the bilaminar disk begins to form.

Gestation Period

Duration of pregnancy.

Amniotic Fluid

Fluid that surrounds and protects the embryo.

Zygote

Fertilized egg cell resulting from the union of sperm and egg.

Fertilization Site

Location in the ampulla of the uterine tube where fertilization occurs.

Somatopleuric Mesoderm

Part of mesoderm that contributes to the body wall.

Splanchnopleuric Mesoderm

Part of mesoderm that contributes to the internal organs.

Ant. Pituitary Gland

Gland that releases hormones affecting reproductive processes.

Follicle Stimulating Hormone (FSH)

Hormone involved in regulating reproductive processes.

Luteinizing Hormone (LH)

Hormone that triggers ovulation and development of corpus luteum.

Proliferative Phase

Phase of the menstrual cycle characterized by rebuilding the endometrial lining.

Secretory Phase

Phase of the menstrual cycle after ovulation when the uterine lining is prepared for implantation.

Menstrual Phase

Phase marking the start of the menstrual cycle when the functional layer is shed.

Ischemic Phase

Phase at the end of the menstrual cycle when hormone levels drop, leading to tissue death.

Basal Layer

Base layer of the endometrium that remains after the menstrual phase.

Menopause

Time in a woman's life when menstrual cycles cease.

Gastrulation

Process following cleavage where cells differentiate into three primary germ layers.

Embryonic Layers

Three layers (ectoderm, mesoderm, endoderm) formed during gastrulation.

Fertilization Outcomes

Results of fertilization including restoration of chromosome number and initiation of cleavage.

Zygotic Cleavage

Initial divisions that occur after fertilization, forming a multicellular structure.

Trophoblast

Outer cells of the blastocyst that help in implantation and placentation.

Amnioblasts

Cells that form the amnion.

Fetal Development Stages

Stages that the human fetus undergoes from conception to birth.

Bilateral Symmetry

Symmetry that is mirrored on either side of the body.

Embryonic Development

Process by which the embryo forms and develops.

Negative Feedback Mechanism

Regulatory mechanism where the output reduces the process.

Spermatogenesis

Process of sperm cell development.

Oogenesis

Process of egg development.

Spermatic Cord

Structure containing blood vessels, nerves, and the ductus deferens.

Acrosome

Cap-like structure on the sperm that contains enzymes necessary for penetrating the egg.

Scrotum

Pouch of skin containing the testes.

Maternal Circulation

Blood flow from the mother to the fetus through the placenta.

Extra-embryonic Mesoderm

Layer that forms connective tissues and blood vessels of placenta.

Chorionic Villi

Finger-like projections of the chorion that extend into the endometrium.

Human Proteins

Proteins produced by the human body during various processes.

Mitochondria

Organelles that produce energy for sperm movement.

Electrolyte Balance

Maintaining appropriate levels of ions in body fluids.

Fetal Membranes

Protective layers that surround the developing fetus.

Umbilical Vein

Vessel that carries oxygenated blood from the placenta to the fetus.

Embryo Development Timeline

Key weeks and changes in embryo development.

Chronic Disease Impact

Effects of maternal diseases on fetal development.

Environmental Factors

External influences that can affect embryonic development.

Developmental Anomalies

Abnormalities that occur during fetal development.

Genetic Factors

Inherited traits that can influence development.

Cross-sectional View

Image or representation that depicts a slice through an object.

Intersticial Implantation

Type of implantation where the embryo embeds within the uterine wall.

Eccentric Implantation

Implantation where embryo is positioned off-center within the uterus.

Central Implantation

Implantation where embryo is located in the center of the uterus.

Infundibulum

Funnel-shaped end of the uterine tube that catches the egg after ovulation.

Hatsan Implantation

Checkpoint in implantation process.