Vertebrate Body Plan Flashcards
Dorsal ventral axis refers to
Dorsal = back
Ventral = stomach
Cranial caudal axis refers to
Cranial = head
Caudal = tail
Superior referes to
Top
Inferior refers to
Bottom
Medial lateral refers to
Medial= towards midline
Lateral = away from midline
Proximal distal refers to
Proximal=towards where its attached to the body
Distal = away from attachment point
Dorsal ventral refers to
Back and front (when bent over, dorsal is the actual back facing the sky, ventral is the chest facing the ground)
What does a Sagittal plane split
Right and left
What does a frontal plane split
Front and back
**standing in anatomical position, face is on one side and butt is on other
What does the transverse plane split
Top & bottom
** in anatomical position, waist up versus waist down; viewpoint is as if you are looking through body from top of head
What are the two steps after gastrulation in the development of a baby
Body plan formation, organogenesis
When is the period of organogenesis ?
What is happening during this stage of development
Weeks 3-8
Organs are being created
Looking from a caudal/cranial point of view at a transverse section of the trilaminar, what can you see
The primitive streak in the middle, the epiblast, hypoblast, invaginating mesoderm
Epiblast cells migrate through primitive node and streak in which directions
Caudal to cranial and medial to lateral
Where is the urogenital system derived from
The intermediate mesoderm
The future body wall is derived form the
Lateral plate mesoderm
The notochord is derived from the ____ and is a precursor to the ___
Mesoderm, axial skeleton (vertebrae)
What does the notochord form in the intervertebral discs
Nucleus pulposus
The neural groove forms above the _____ from the ____ layer
Notochord, ectoderm
The paraxial mesoderm is located ?
What happens to this area as the neural groove folds
Below the ectoderm layer
It fills up the space to support the folding layer of ectoderm
What are somites
Epithelial balls of cells formed in segmental Paris along the neural tube form paraxial mesoderm
Differentiate into vertebrae, muscles of the back and body wall, dermis of the skin
What does somites differentiate into
Vertebrae, muscles of the back and body wall, dermis of the skin
What is the process of neurulation
The flat ectodermal plate folds and forms tube
Signals form the _____ cause inward folding of the _____ at the ____
Notochord, ectoderm, neural plate
Ends of neural plate ____ and ____ to form an _____ neural tube
Fuse, disconnect, autonomous
At week ___, the ventral folding causes a ___fold and a ___fold to form
4, head, tail
In the embryonic development (weeks ___ thru ___) , _____ is happening and there are two periods, highly critical and sensitive
3, 8
Organogenesis
During the fetal period …
Structures just grown larger in size, partuition
Fertilization begins at ___
In relation, gestational age begins ___
Conception, two weeks earlier at the beginning of the last period
When is the period of maximal sensitivity to abnormal development
Weeks 3-8
When is the critical period for the development of the heart?
When is it just sensitive
3-6/7 weeks, 6/7-8 weeks
Birth defect definition
Term for a congenital malformation (physical anomaly)
Congenital disorder definition
A condition existing at birth and often before birth that develops during the first month of life regardless of causation
Teratology is the study of
Causes and biological processes leading to abnormal development
Teratology is the study of
Causes and biological processes leading to abnormal development
Why would thalidomide not be prescribed to pregnant women to treat nausea?
What was the resulting condition called
Thalidomide can cross the placental barrier and though it was effective in decreasing nausea and morning sickness, is interrupts the blood supply during the formation of long bones, leaving babies with hands connected to shoulder bones
***4-5 weeks is the critical period for limb formation and also a period where many women experience morning sickness
Phocomelia
What are the factors that impact risk for congenital anomalies ?
Maternal age = as it increases, risk grows
Genetic predisposition = heart defects, neural tube defects, Down syndrome
Environmental factors = maternal smoking, drugs, chemical exposure, infections, diet
Unknown