Reading 1 Flashcards
_________________ the time between conception and birth
Prenatal Period:
__________________ the first 8 weeks in which all major organs are developed
Embryonic period=
________________“early form of the body”
Embryo:
_________________: the remaining 30 weeks in which organs grow larger and more complex
Fetal period
_________________ “the young in the womb”
Fetus:
Skin: has two layers _____________________
epidermis and dermis
__________________ consists most of trunk muscles and contains the vertebral column, the spinal cord and attaching ribs
Outer body wall:
__________________ is composed of the respiratory and digestive structures
Inner body cavity and inner tube:
The section through the abdomen shows the peritoneal cavity, lined by ___________ surrounding the digestive tube (stomach, intestines, and so on). The digestive tube has a muscular wall and is lined internally by a sheet of cells. (This lining is shown in yellow)
visceral and parietal serosae,
The respiratory structures (trachea, lungs, and bronchi) form from the inner tube. The body cavities in the thorax are _______________ around the lungs and the ________________ surrounding the heart. Parietal and visceral serosae line these cavities as well
the pleural cavity
pericardial cavity
Kidneys and gonads: The kidneys lie directly deep to the dorsal body wall,______________________________The gonads (testes or ovaries) originate in a similar position but migrate to other body regions during the fetal period.
in the lumbar region of the back posterior to the parietal serosa.
___________ toward the head or upper part of structure/ body
Superior/ Cranial:
_____________ away from the head or toward the lower part of a structure/body
Inferior/ Caudal:
_____________________ Toward the midline of the body, on the inner side of the body
Medial:
___________________Away from the midline of the body, on the outer side of the body
Lateral:
__________________ Closer to the origin of the body part or point of attachment
Proximal:
_____________ Further away from the origin of the body part or point of attachment
Distal:
______________on the same side as
Ipislateral:
__________ on the opposite side as
Contralateral:
_______________Toward the front or at the front of the body
Anterior/ventral:
________________Toward the back of the body
Posterior/ dorsal:
_______________ an immature egg that one of a fertile woman’s two ovaries releases
Oocyte:
______________ a direct route to the uterus (womb) and the sight of fertilization
Uterine tube:
______________ the fertilized oocyte
Zygote:
___________________ the rapid cell division of a zygote that provides enough cells to become an embryo. cell growth between divisions, the resulting cells become smaller and smaller.
Cleavage:
___________________: The fluid filled structure that results after the morula. During day 4, the late morula—now consisting of about 60 cells—enters the uterus. It takes up fluid, which gathers into a central cavity.
Blastocyst
_________________ The outer cells surrounding the cavity that will eventually form the placenta
Trophoblast:
__________________ The cluster of cells on one side of the blastocyst cavity, that will eventually form the embryo
Inner cells:
__________________ the final stage of the blastocyst in which the trophoblast layer erodes inward until the entire blastocyst is embedded in the uterine wall.
Implantation:
About 9 days after fertilization, the inner cell mass has divided into two sheets of cells, _______________________
the epiblast and hypoblast
__________________: the sheet on the top
Epiblast
_____________ the sheet on the bottom
Hypoblast:
____________________ the two layers disk made of the epiblast and hypoblast which will give rise to the whole body
Bilaminar embryonic disc:
__________________a sac formed by an extension of the epiblast
Amniotic sac:
__________________ outer membrane of the amniotic sac
Amnion:
_________________ internal cavity filled with amniotic fluid.
amniotic sac cavity:
__________________ formed by an extension of the hypoblast, holds a very small amount of yolk, which is insignificant as a food source.
Yolk sac:
During week 3, the embryo grows from a two layered disc to a 3 layered disc. This process is
gastrulation
_________________ the process of the embryo growing from a two layered disc to a three layered one
Gastrulation:
________________: the germ layer that begins to form a grove that appears on the dorsal surface of the dorsal side
Primitive streak:
___________________: the first cells that migrate through the primitive streak displace the cells of the underlying hypoblast
Endoderm:
_____________: the ingressing epiblast cells form a new layer between epiblast and endoderm,
Mesoderm:
______________The epiblast cells that remain on the embryo’s dorsal surface make up this the outer layer of the skin (epidermis), the brain, and the spinal cord.
Ectoderm:
_________________(“middle skin”; colored red in Figure 3.5) forms muscle, bone, and connective tissues.
Mesoderm
_____________ (“inner skin”; colored yellow in Figure 3.5) forms the innermost lining of the inner tube (epithelial lining).
Endoderm
Ectoderm and endoderm are ___________________—sheets of tightly joined cells.
epithelial tissues, or epithelia
Mesoderm, by contrast, is a __________________
mesenchyme tissue (mes′eng-k¯ım; mesen = middle; chyme = fluid).
________________: a swelling At one end of the primitive streak
Primitive node
____________________ defines the body axis (the midline that divides the left and right sides of the body). It extends the length of the body and is the site of the future vertebral column.
Notochord:
__________________ As the notochord develops, it signals the overlying ectoderm to start forming the spinal cord and brain
Neurolation:
____________________ the ectoderm in the dorsal midline thickens into this during the development of the notochord
Neuroplate:
____________________the neuroplate begins to fold inward into this
Neurogroove:
_______________ begins at the end of week 3 in the region that will become the neck and then proceeds both cranially
Neural tube:
During neurolation the mesoderm is divided into three sections
somite
intermediate mesoderm
lateral plate
_____________: A mesodermal segment of the body of the embryo
Somite
________________ divides into spherical segments in a cranial-to-caudal sequence
Intermediate mesoderm
_______________ begins as one layer, but soon splits into two. A wedge of space is formed between these two sheets. This space is called the coelom. The two resulting divisions of the lateral plate are the somatic mesoderm, next to the ectoderm, and the splanchnic mesoderm, next to the endoderm
lateral plate
the wedge of space in the lateral plate
coelom
what are the 2 divisions of the lateral plate
somatic mesoderm, next to the ectoderm,
splanchnic mesoderm, next to the endoderm
_________________ As the embryo becomes cylindrical, it encloses a tubular part of the yolk sac,
Primative gut:
_____________The embryo takes on a cylindrical shape when its sides fold medially and it lifts off the yolk sac and protrudes into the amniotic cavity
Folding:
_________________
The ectoderm becomes the brain, spinal cord, and epidermis of the skin. The early epidermis, in turn, produces the hair, fingernails, toenails, sweat glands, and the oil glands of the skin.
Derivative of the ectoderm:
____________
The notochord gives rise to an important part of the spinal column, the springy cores of the discs between the vertebrae.
Derivative of the mesoderm/notochord:
__________________: Somatic mesoderm, just external to the coelom, produces the parietal serosa and the dermal layer of the skin in the ventral body region. Its cells migrate into the forming limbs and produce the bone, ligaments, and dermis of each limb. splanchnic mesoderm gives rise to the entire wall of the digestive and respiratory tubes, except the inner epithelial lining; that is, it forms the musculature, connective tissues, and the slippery visceral serosae of the digestive and respiratory structures.
Unsegmented mesoderm:
The intermediate mesoderm lies in the same relative location as the ______________
adult kidneys, outside the peritoneal cavity
__________ becomes the inner epithelial lining of the gut tube and its derivatives: the respiratory tubes, digestive organs, and the urinary bladder, and the epithelium.
endoderm
During these weeks the embryo becomes less tad pol like
Week 5-8:
__________________The upper limb buds appear slightly earlier than the lower limb buds.
Limb buds:
The protruding tail of the 1-month-old embryo disappears at the end of ________________
week 8.
All major organs are in place by the end of month 2, at least in ________________
rudimentary form.
____________spans weeks 9 through 38
fetal period
Normal births typically occur
38 weeks after conception.
________________ is one that occurs before that time. Infants born as early as week 30
A premature birth
________________ Premature removal of the embryo or fetus from the uterus.
Abortion:
_____________ A procedure for obtaining a sample of amniotic fluid. A needle is inserted through the abdominal and uterine walls, and a small amount of amniotic fluid is obtained.
Amniocentesis:
___________________ The study of birth defects and of fetuses with congenital deformities.
Teratology:
