Podcast
Questions and Answers
Which of the following processes occurs during the pre-embryonic stage?
Which of the following processes occurs during the pre-embryonic stage?
- Histogenesis
- Morphogenesis
- Cleavage (correct)
- Organogenesis
The uteroplacental circulation is typically established:
The uteroplacental circulation is typically established:
- Starting at the end of the second week of gestation. (correct)
- By the end of the first week of gestation.
- During the first trimester.
- During the fourth week of gestation.
What is the primary event occurring during neurulation?
What is the primary event occurring during neurulation?
- Formation of the neural tube from the neural plate. (correct)
- Development of the digestive system.
- Formation of the mesoderm.
- Development of the circulatory system.
The neural crest cells, formed during neurulation, are crucial for the development of which of the following?
The neural crest cells, formed during neurulation, are crucial for the development of which of the following?
Which primary germ layer gives rise to the epidermis and its related structures?
Which primary germ layer gives rise to the epidermis and its related structures?
Histogenesis, the differentiation of cells into specialized tissues, occurs prominently during which period?
Histogenesis, the differentiation of cells into specialized tissues, occurs prominently during which period?
Which of the following structures is NOT derived from the ectoderm?
Which of the following structures is NOT derived from the ectoderm?
What adult structure is derived from the mesoderm?
What adult structure is derived from the mesoderm?
The paraxial mesoderm is responsible for the development of:
The paraxial mesoderm is responsible for the development of:
What structure forming during embryogenesis derives from the endoderm?
What structure forming during embryogenesis derives from the endoderm?
Which of the following events characterizes the embryonic period from weeks 4 to 8?
Which of the following events characterizes the embryonic period from weeks 4 to 8?
During which week of development does the bilaminar disc form?
During which week of development does the bilaminar disc form?
The formation of somites is a characteristic feature of which stage of development?
The formation of somites is a characteristic feature of which stage of development?
Which of the following is derived from the lateral mesoderm?
Which of the following is derived from the lateral mesoderm?
What is the primary function of the trophoblastic lacunae during early embryonic development?
What is the primary function of the trophoblastic lacunae during early embryonic development?
Which of the following processes is directly facilitated by cavitation during embryogenesis?
Which of the following processes is directly facilitated by cavitation during embryogenesis?
During gastrulation, the primitive streak plays a critical role in:
During gastrulation, the primitive streak plays a critical role in:
Which of the following structures is formed during the third week of human development?
Which of the following structures is formed during the third week of human development?
The initial formation of the heart begins in which of the following weeks of human development?
The initial formation of the heart begins in which of the following weeks of human development?
Which of the following events involves the rapid mitotic cell division of the zygote?
Which of the following events involves the rapid mitotic cell division of the zygote?
Which of the following is a hallmark event indicative of the transition from the bilaminar to the trilaminar disc in human embryogenesis?
Which of the following is a hallmark event indicative of the transition from the bilaminar to the trilaminar disc in human embryogenesis?
Consider a scenario where the notochord fails to properly induce the overlying ectoderm during neurulation. Which of the following developmental defects is most likely to occur?
Consider a scenario where the notochord fails to properly induce the overlying ectoderm during neurulation. Which of the following developmental defects is most likely to occur?
During week 3 of human development, the formation of the intraembryonic coelom by cavitation within the lateral plate mesoderm directly contributes to which of the following?
During week 3 of human development, the formation of the intraembryonic coelom by cavitation within the lateral plate mesoderm directly contributes to which of the following?
A researcher discovers a novel mutation in a gene expressed exclusively in the intermediate mesoderm. Which of the following developmental processes would be most directly affected?
A researcher discovers a novel mutation in a gene expressed exclusively in the intermediate mesoderm. Which of the following developmental processes would be most directly affected?
Aberrant migration of neural crest cells can lead to a variety of developmental disorders. Failure of neural crest cells to properly populate the developing pharyngeal arches would most likely result in abnormalities of which structures?
Aberrant migration of neural crest cells can lead to a variety of developmental disorders. Failure of neural crest cells to properly populate the developing pharyngeal arches would most likely result in abnormalities of which structures?
The precise timing of somitogenesis is critical for proper segmentation of the vertebrate body plan. Disruptions in the Notch signaling pathway during this process are most likely to result in which of the following?
The precise timing of somitogenesis is critical for proper segmentation of the vertebrate body plan. Disruptions in the Notch signaling pathway during this process are most likely to result in which of the following?
Which alteration during gastrulation would MOST severely impact the formation of ALL three primary germ layers?
Which alteration during gastrulation would MOST severely impact the formation of ALL three primary germ layers?
The development of the vertebrate limb involves complex interactions between the ectoderm and the underlying mesoderm. Specifically, what is the primary role of the apical ectodermal ridge (AER) in limb development?
The development of the vertebrate limb involves complex interactions between the ectoderm and the underlying mesoderm. Specifically, what is the primary role of the apical ectodermal ridge (AER) in limb development?
Which of the following cellular processes is most crucial for the correct positioning and segregation of tissue types during organogenesis?
Which of the following cellular processes is most crucial for the correct positioning and segregation of tissue types during organogenesis?
The development of the pancreas involves intricate inductive interactions between the endoderm and the surrounding mesenchyme. What specific factor, secreted by the notochord and blood vessels, inhibits the formation of the pancreas in the dorsal region of the foregut?
The development of the pancreas involves intricate inductive interactions between the endoderm and the surrounding mesenchyme. What specific factor, secreted by the notochord and blood vessels, inhibits the formation of the pancreas in the dorsal region of the foregut?
What is the consequence if the allantois fails to develop completely?
What is the consequence if the allantois fails to develop completely?
Which of the following is the most accurate description of the role of the stratum intermedium during the fourth month of fetal integument development?
Which of the following is the most accurate description of the role of the stratum intermedium during the fourth month of fetal integument development?
Defects in ventral body wall closure can result in conditions such as gastroschisis or omphalocele. What specific developmental process is disrupted in these malformations?
Defects in ventral body wall closure can result in conditions such as gastroschisis or omphalocele. What specific developmental process is disrupted in these malformations?
Considering the complex interactions of multiple signaling pathways: what would occur if there were complete absence of Wnt signaling in a developing limb?
Considering the complex interactions of multiple signaling pathways: what would occur if there were complete absence of Wnt signaling in a developing limb?
Genetic analysis reveals that a developing embryo has a homozygous loss-of-function mutation in the TBX5 gene. Which of the following structures would most likely exhibit severe developmental abnormalities?
Genetic analysis reveals that a developing embryo has a homozygous loss-of-function mutation in the TBX5 gene. Which of the following structures would most likely exhibit severe developmental abnormalities?
The development of the secondary palate is essential for separating the nasal and oral cavities. Failure of the palatal shelves to fuse properly results in cleft palate. Which of the following cellular processes is most critical for the elevation and fusion of the palatal shelves?
The development of the secondary palate is essential for separating the nasal and oral cavities. Failure of the palatal shelves to fuse properly results in cleft palate. Which of the following cellular processes is most critical for the elevation and fusion of the palatal shelves?
During the fetal period, significant changes occur in the circulatory system to prepare for postnatal life. Which of the following fetal structures allows oxygenated blood to bypass the liver and directly enter the inferior vena cava?
During the fetal period, significant changes occur in the circulatory system to prepare for postnatal life. Which of the following fetal structures allows oxygenated blood to bypass the liver and directly enter the inferior vena cava?
Which of the following best describes the function of the foramen ovale?
Which of the following best describes the function of the foramen ovale?
What would be prevented by an improperly closed foramen ovale?
What would be prevented by an improperly closed foramen ovale?
In which congenital defect is the urachus still present?
In which congenital defect is the urachus still present?
Flashcards
Neurulation
Neurulation
The process by which the neural plate folds and closes to form the neural tube, the precursor to the central nervous system.
Ectoderm
Ectoderm
The outermost of the three primary germ layers formed in early embryonic development, giving rise to the epidermis, nervous system, and various other structures.
Mesoderm
Mesoderm
The middle of the three primary germ layers in the early embryo that gives rise to a variety of tissues including muscle, bone, blood vessels, and connective tissue.
Endoderm
Endoderm
Signup and view all the flashcards
Histogenesis
Histogenesis
Signup and view all the flashcards
Bilaminar Disc
Bilaminar Disc
Signup and view all the flashcards
Trilaminar Disc
Trilaminar Disc
Signup and view all the flashcards
Gastrulation
Gastrulation
Signup and view all the flashcards
Organogenesis
Organogenesis
Signup and view all the flashcards
Morphogenesis
Morphogenesis
Signup and view all the flashcards
Ectoderm Superficial Derivatives
Ectoderm Superficial Derivatives
Signup and view all the flashcards
Neural Tube
Neural Tube
Signup and view all the flashcards
Neural Crest
Neural Crest
Signup and view all the flashcards
Study Notes
- Embryogenesis occurs during the 1st through 8th weeks of development.
Stages of Development
- Pre-Embryonic: Includes cleavage, cavitation, and transport.
- Embryonic: Includes gastrulation, implantation, morphogenesis, histogenesis, and organogenesis.
- Fetal: Body growth occurs at this stage which is week 9-38
Utero-Placental Circulation
- Established at the end of the second week, beginning of the third week of gestation.
- Trophoblastic lacunae in the embryonic pole are in contact with maternal vessels of the endometrial stroma.
- The exocoelomic membrane lines the primitive yolk sac.
- Extraembryonic coelom formation takes place.
Third Week
- At the end of the third week, the primitive node, primitive streak, bucopharyngeal membrane, prenotochordal cells, and cloacal membrane can be seen
Neurulation
- This is a process that begins around day 17
- The neural plate forms the neural tube.
Neural Tube Formation
- Neuroectodermal tissues differentiate from the ectoderm, thickening into the neural plate.
- The neural plate border separates the ectoderm from the neural plate.
- The neural plate bends dorsally, its ends joining at the borders, now the neural crests.
- Closure of the neural tube separates the neural crest from the epidermis.
- Neural crest cells differentiate to create the peripheral nervous system.
- The notochord degenerates, remaining only as the nucleus pulposus of intervertebral discs.
- Other mesoderm cells differentiate into somites, which are precursors of the axial skeleton and skeletal muscle.
22 Days
- Seven distinct somites are visible on each side of the neural tube
23 Days
- The pericardial bulge is visible on each side in the cephalic part of the embryo
Ectoderm Derivatives
- Organs and systems that have contact with the external world
- Central and peripheral nervous systems
- Sensory epithelium of the ear, nose, and eye
- Epidermis and adnexa
- Other adnexa such as subcutaneous glands, mammary glands, hypophysis, and dental enamel.
Histogenesis
- This is the first stage of Week 4 of gestation
- The embryo cells begin to differentiate and become more specialized
Germ Layer Derivatives
- Ectoderm (Superficial): Epidermis, hair, nails, skin and mammary glands, anterior pituitary, dental enamel, inner ear, and crystalline lens
- Ectoderm (Neural Tube): Central nervous system, retina, pineal gland, and posterior pituitary
- Ectoderm (Neural Crest): Connective tissue and bones of the face and skull, adrenal medulla, melanocytes, dermis of the face and neck, C cells, cranial nerve ganglia, sympathetic and parasympathetic ganglia, the heart's trunconal septum, Schwann cells, glia, odontoblasts, and smooth muscle of vessels in the face and prosencephalon.
- Mesoderm: Forms the skeletal muscle of the head, trunk, and extremities, and the skeleton except for the cranium, and dermis and connective tissue.
- Mesoderm (Intermediate): Forms the urogenital system
- Mesoderm (Lateral): Forms connective tissue and muscle of the viscera, serous membranes (pleura, pericardium, and peritoneum), the heart, blood and lymphatic cells, the spleen, and the suprarenal cortex.
- Mesoderm (Head): Forms the cranium, connective tissue of the head, and dentin.
- Endoderm Derivatives: Epithelial lining of the respiratory tract, parenchyma of the thyroid and parathyroid glands, liver and pancreas, epithelial lining of the urinary bladder and urethra, reticular stroma of the tonsils and thymus, and epithelial lining of the tympanic cavity and auditory canal.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
