Definitions

Question 1

Mesodermal domain composed of the parietal layer of lateral plate mesoderm and somite cells from the myotome and sclerotome regions that migrate across the lateral somitic frontier

Answer 1

Abaxial domain

Question 2

Release of enzymes from the acrosome on the head of sperm that assists in sperm penetration of the zona pellucida. Zona proteins induce the reaction following sperm binding

Answer 2

Acrosome reaction

Question 3

Anterior portion of the pituitary derived from Rathke pouch

Answer 3

Adenohypophysis

Question 4

Sensory area in the dorsal region of the spinal cord and brain

Answer 4

Alar plates

Question 5

Vestigial structure that serves as a respiratory and waste storage organ for avian embryos. It extends from the ventral region of the urogenital sinus to the umbilicus. Later, its distal portion, called the urachus, becomes a fibrous cord and forms the median umbilical ligament. If it remains patent, then it may form a urachal fistula or cyst in this region

Answer 5

Allantois

Question 6

Process of removing introns to create different proteins from the same gene

Answer 6

Alternative splicing

Question 7

Cells lining the alveoli. Type I cells are involved in gas exchange. Type II cells produce surfactant

Answer 7

Alveolar cells

Question 8

Complete absence of a limb

Answer 8

Amelia

Question 9

Procedure used to used to withdraw amniotic fluid for analysis of factors, such as alpha-fetoprotein (AFP), and cells (chromosomes), which provide information about the status of the fetus

Answer 9

Amniocentesis

Question 10

Membrane formed when expansion of the amniotic cavity obliterates the chorionic cavity, causing the amnion to contact the chorion and the two to fuse. This membrane serves as a hydrostatic wedge during the initiation of labor

Answer 10

Amniochorionic membrane

Question 11

Membrane derived from the epiblast that surrounds the fluid-filled amniotic cavity around the embryo and the fetus. The fluid cushions the fetus and forms a hydrostatic wedge to assist with dilation of the cervix during labor. The fluid itself can be used for analysis of fetal well-being

Answer 11

Amnion

Question 12

Pieces of amnion that tear loose and can wrap themselves around digits and limbs causing constrictions and amputations or can be swallowed by the fetus causing disruptions in facial development. Their origin is unknown.

Answer 12

Amniotic bands

Question 13

Neural tube defect in which the cranial neural folds fail to close, leading to tissue degeneration and little or no formation of higher brain centers, cerebral cortex, etc. The abnormality is lethal, but 70% of the defects can be prevented by daily maternal use of 400 ug of folic acid beginning 2 to 3 months prior to conception and continuing through pregnancy

Answer 13

Anencephaly

Question 14

Formation of blood vessels by sprouting from existing vessels

Answer 14

Angiogenesis

Question 15

Outer ring of fibrous tissue in an intervertebral disc

Answer 15

Annulus fibrosis

Question 16

Collection of endoderm cells at the cranial end of the bilaminar disc responsible for inducing the head region through secretion of transcription factors, including OTX2, LIM1, and HESX1

Answer 16

Anterior visceral endoderm (AVE)

Question 17

Another term for mülerian-inhibiting substance produced by Sertoli cells that causes regression of the mülerian (paramesonephric) ducts in males

Answer 17

Anti-mülerian hormone

Question 18

Branch from the aortic sac to the dorsal aorta traveling in the center of each pharyngeal arch. Initially, there are five pairs, but these undergo considerable remodeling to form definitive vascular patterns for the head and neck, aorta, and pulmonary circulation

Answer 18

Aortic arch

Question 19

Layer of thickened ectoderm at the distal tip of the limb that controls outgrowth of the limb by maintaining a rapidly proliferating population of adjacent mesoderm cells, called the progress zone.

Answer 19

Apical ectodermal ridge (AER)

Question 20

Programmed cell death, for example, between the digits

Answer 20

Apoptosis

Question 21

Congenital absence of an opening or lumen, for example, in the gut

Answer 21

Atresia

Question 22

Composed of the sympathetic and parasympathetic nervous systems that control smooth muscle and glands

Answer 22

Autonomic nervous system

Question 23

Motor area in the ventral portion of the spinal cord and brain

Answer 23

Basal plates

Question 24

Ventral body wall defect caused by lack of closure of the lateral body wall folds in the pelvic region resulting in protrusion of the bladder through the defect

Answer 24

Bladder extrophy

Question 25

Stage of embryogenesis at the time of implantation where outer trophoblast cells from a fluid-filled sphere with a small group of embryoblast cells, the inner cell mass, at one pole

Answer 25

Blastocyst

Question 26

Members of the TGF-beta family that serve as signal molecules for a number of morphogenetic events, including dorsalizing the central nervous system. participating in bone formation, etc.

Answer 26

Bone morphogenetic proteins (BMPs)

Question 27

Cup-shaped structure at the end of each proximal convoluted tubule that partially surrounds a glomerulus

Answer 27

Bowman’s capsule

Question 28

Type of craniosynostosis in which the coronal sutures close prematurely resulting in a tall, short head shape

Answer 28

Brachycephaly

Question 29

Short digits

Answer 29

Brachydactyly

Question 30

Once the neural tube closes, expanded spaces in the brain fill with fluid to form three primary _______: the proencephalon (forebrain), mesencephalon (midbrain), and the rhombencephalon (hindbrain). These three primary _____ form the five definitive ______ : the proencephalon divides into the telencephalon and diencephalon; the mesencephalon does not divide; an dthe rhomboencephalon forms the metencephalon and myelencephalon.

Answer 30

Brain vesicles

Question 31

“Lower” centers of the brain, including the myencephalon, pons of the metencephalon, and the mesencephalon

Answer 31

Brainstem

Question 32

The period of sperm conditioning in the female reproductive tract lasting about 7 hours that is required for sperm to be able to fertilize an egg

Answer 32

Capacitation

Question 33

Through this process, bending of the heart tube positions the hear the heart in the left thoracic region and creates the “typical” heart shape with the atria posterior to the ventricles

Answer 33

Cardiac looping

Question 34

System of anterior, posterior, and common cardinal veins that drain the head and body of the embryo in the late third and early fourth weeks

Answer 34

Cardinal veins