Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
32 Cards in this Set
- Front
- Back
|
Embryology |
The study of the embryo |
|
|
Embryo |
A fetus in the first 8 weeks |
|
|
Fetus |
An unborn child from week 8 onward |
|
|
Zygote |
Haploid Egg + Haploid Sperm= Diploid Zygote |
|
|
What is conception? |
When an egg is fertilized by sperm |
|
|
When does embryonic development begin? |
At conception |
|
|
Ontogeny |
The succession of morphological changes during normal development |
|
|
Totipotent |
A cell that can become any of the cell types that will be present in the adult |
|
|
Differentiation |
The development of specialized cells |
|
|
What is cleavage? How are the cells affected? |
Cleavage is the early rapid division in a cell. Embryo does not enlarge, but divides into many smaller cells. |
|
|
What is a blastomere? |
The smaller cells that the embryo is divided into during cleavage |
|
|
What is a blastocyst? |
The embryo at the end of day 4 A fluid-filled, hollow ball of cells |
|
|
What are the two types of cells in a blastocyst? Which gives rise to the embryo? Which helps form the placenta? |
1. Trophoblast: Helps form placenta 2. Inner Cell Mass: Becomes the embryo |
|
|
What are the two layers that are formed by the inner cell mass? |
1. Epiblast 2. Hypoblast |
|
|
Where do the amniotic and yolk sacs come from? What are the roles of the yolk sac and amniotic sac? |
The bilaminar disk gives rise to the body of the fetus AND the extraembryonic membranes. Amniotic sac surrounds the embryo. Yolk sac gives rise to blood cells, vessels, and digestive tube. |
|
|
What is the name of the process that modifies a bilaminar disk to become a trilaminar disk? |
Gastrulation |
|
|
What stage in development is signified by the appearance of the primitive streak? What are cells doing at and around the primitive streak? |
Gastrulation Epiblast cells migrate inward at the primitive streak and become the endoderm |
|
|
What is the process of gastrulation? |
The bilaminar disk becomes trilaminar This produces the 3 germ layers that will become all the tissues of the body |
|
|
What are the primary germ layers? What are their adult derivitives? |
1. Endoderm (lining of the body tube) 2. Ectoderm (skin, nervous) 3. Mesoderm (bone, muscle, connective) |
|
|
What are the subdivisions of the mesoderm and what do they give rise to? |
Lateral Plate: Coelom Intermediate: Kidney/Urinary and Reproductive Paraxial: Neural Tube |
|
|
What is created when the lateral plate mesoderm subdivides into splanchnic and somatic mesoderm? |
The coelom |
|
|
Where do somites come from and where are they located? |
Cells in the mesoderm on both sides of the neural tube |
|
|
What gives rise to sclerotome, dermatome, and myotome? What does each of these produce? |
Somites Sclerotome- Vertebral Column and Occipital Region Myotome- Muscles of the body wall and appendages Dermatome- Dermis of the skin |
|
|
What is the notochord and where is it found? |
Defines the embryo's midline, provides structural support, stimulates development of neural tube Found in the mesoderm on the dorsal side |
|
|
When does the body begin to fold? When do limb buds appear? |
Week 4 Week 5 |
|
|
Events of Week 1 |
Fertilization Cleavage
|
|
|
Events of Week 2 |
Development of Bilaminar Disk
|
|
|
Events of Week 3 |
Gastrulation Neurulation |
|
|
Events of Week 5-8 |
Limb buds Sense organs and Face Embryo takes recognizable form Development of gonads |
|
|
Events of 1st Trimester |
Embryo is fetus All major organ systems are present |
|
|
Events of 2nd Trimester |
Brain enlarging, eye developing, movement
|
|
|
Events of 3rd Trimester |
Hair on head, lungs complete development, immune system develops |
