Embryology and Development

Flashcards covering key vocabulary and concepts from a lecture on embryology and development, including stages of development, genetic factors, potential complications, and birth processes.

Somites

Repeating patterns in the embryo that eventually turn into bones (like ribs and vertebrae), muscles (like intercostal muscles), and blood vessels.

Limb Buds

Structures that develop into the arms and legs. They are larger versions of somites and are made of cells from the mesoderm. They eventually form bones and muscle tissues.

Chemical Gradients and Induction

Processes involving signals from neighboring cells and environments with varying chemical concentrations that instruct stem cells to differentiate into specific cell types, allowing for the formation of different muscles, bones, and connective tissues.

Apoptosis

Programmed cell death critical for development. Without it, structures like the fingers wouldn't form correctly.

Teratogens

Chemicals that disrupt the development of the embryo. An example is a morning sickness pill that caused babies to be born without limbs.

Branchial Arches

Embryonic structures that, in fish, turn into gills. In humans, they develop into the middle ear (auditory ossicles), hyoid bone, and mandible (lower jaw).

Ontogeny Recapitulates Phylogeny

The idea that an embryonic structure used for one purpose in an ancestor is repurposed for a different structure in the descendant. The branchial arches exemplify this.

Induction (Chicken Wing Example)

Stem cells (mesoderm) placed on the anterior side of a developing chicken wing can cause extra digits to grow due to communication with neighboring cells.

Endoderm

One of the primary germ layers in the embryo. It forms a tube-like structure that eventually develops into the respiratory system, the digestive tract, and other structures like the lungs, stomach, liver, and intestines.

SOX2, FOXA8, FOXA38, FOXA4, NKX2.1

Combination of chemicals needed to turn the endoderm into lungs

Lung development

Apoptosis is key to the development of the lung. It assists in making left and right lungs.

Embryo vs. Fetus

Embryo is a general term used in early development. Once the organism distinctly resembles a human, it is referred to as a fetus.

Organogenesis

The development of organs, which mainly occurs by week four and is completed by week ten of development.

Facial Development

Morphological movements include mouth getting smaller, nostrils migrating towards the anterior, and eyes moving closer to the center of the face.

Cleft Lip/Palate

Developmental issue caused by alcohol consumption because the mouth didn't fully finish its development. This requires reconstructive surgery and is a gap found in the philtrum.

Fetal Alcohol Syndrome

Condition is caused by alcohol consumption. It occurs when the eyes are farther apart, and nostrils are also farther apart, and is associated with mental slowness, which may cause behavior issues.

Bipotential Stage

The stage (around six weeks) where the embryo's genitalia is neither distinctly male nor female. The structures will develop into male structures with testosterone or female structure with no hormone.

Labial Scrotal Folds

Structure turns into the scrotum in males and the labia majora in females.

Urethral Folds

Structure turns into the seam that connects the scrotum and penis in males but turns into the urethral opening in females.

Genital Tubercle

Structure turns into the glans penis in males and the glans clitoris in females.

Hypospadias

Condition where the urethra does not develop correctly in males, and the urethral opening is found on the shaft of the penis rather than at the glans penis.

Placenta

Structure built from the embryo that provides nutrients to the embryo from the mother. Once out, there will be a significant release of blood.

Oxytocin

A hormone released to cause the myometrium to contract, pushing the baby towards the cervix, released from the hypothalamus. This also fastens the process of blood clotting.

Episiotomy

A surgical procedure to cut the urogenital diaphragm in order to prevent the rupturing of the peritoneal tendon.

Cesarean Section

A surgical procedure is performed by cutting through the rectus abdominis and uterus to remove the baby. There are different pros and cons to vaginal and C-Section.

Placenta Previa

Condition where the placenta blocks the vaginal canal and is a medical indication to conduct a cesarean section.

Placenta Abruptio

Condition where the placenta abruptly detaches from the uterus, causing bleeding. This is a medical indication to conduct a cesarean section.

Breech Presentation

Medical reason for C-section because it is a poor position for the baby to be delivered.

Situs Inversus

Rare anatomical variation where the orientation of the organs is inversed. This alone does not cause harm.