Biology Chapter 3 Embryogenesis And Development Flashcards
Where does fertilization occur?
Ampulla of the Fallopian tube
What enzymes do sperm use to penetrate the corona radiata and zona pellucida.
Acrosomal enzymes
What apparatus do sperm establish once connected to the oocyte plasma membrane?
Acrosomal apparatus
What ion is released once sperm penetrate the ovum?
Calcium
After the first cleavage division what is the new cell called?
Embryo
What is indeterminate cleavage?
Cleavage that results in a cell that is capable of becoming any cell in the organism.
What is determinate cleavage?
Cleavage that results in a cell that is only capable of being a specific cell type.
Morula
Solid mass of cells seen in early development
Blastula
Mass with a fluid filled center called a blastocoel and two different structures the trophoblast (becomes placental structures) inner cell mass (becomes the developing organism)
What is the trophoblast?
Structure within the blastula that becomes placental structure)
What is the inner cell mass?
Structure within the blastula that becomes the developing organism
What is the blastocoel?
Fluid filled center of the blastula
Where does the blastula implant?
In the endometrial lining.
What is the chorion?
An extra-embryonic membrane that develops into the placenta.
Contains chorionic villi which penetrate the endometrium and create an interface between maternal and fetal blood.
What is the allantosis?
One of two extraembryonic membranes. Involved in early fluid exchange between the embryo and the yolk sac.
The other extraembryonic membrane is the amninon.
What is the amnion?
One of two extraembryonic membranes.
Lies just inside the chorion
The amnion contains amniotic fluid which acts as a shock absorber for movements of the mother.
What does the ectoderm form?
Hair, nails, epithelial of the nose mouth and anal canal. Nervous system and the lens of the eye.
What does the endoderm form?
Epithelial linings of the respiratory and digestive tracts, parts of the pancreas, thyroid, bladder, distal urinary tracts.
What does the mesoderm form?
Musculoskeletal, circulatory and excretory systems. Gives rise to the gonads, muscular and connective tissue layers of the digestive and respiratory systems, adrenal cortex
What is neurulation and when does it occur?
Development of the nervous system. After formation of the three germ layers.
What makes up the neural tube? What does it become?
Notochord induces furrowing of ectodermal cells to form neural folds. Neutral folds fuse to form the neural tube which becomes the central nervous systems.
What makes up the neural crest cells?
What does it develop into?
Tip of the neural fold. Develops into the peripheral nervous system: sensory ganglia, autonomic ganglia, adrenal medulla and Schwann cells) specific cell types in other tissues (calcitonin producing cells of the thyroid, melanocytes in the skin)
What is a teratogen and what are examples?
Substances that interfere with development causing defects or death of the developing embryo.
Alcohol, certain prescription drugs, viruses, bacteria environmental chemicals.
What maternal conditions can affect development?
Diabetes (Increased fetal size and hypoglycemia after birth) and Folic Acid Deficiency (neural tube defects)