Embryology 4: Gastrulation MCQ
45 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the main process that leads to the formation of the three germinal layers?

  • Gastrulation (correct)
  • Cleavage
  • Neurulation
  • Segmentation

    • Which of the following is NOT one of the three germinal layers formed during gastrulation?

  • Endoderm
  • Ectoderm
  • Dermatoderm (correct)
  • Mesoderm

    • What structural feature marks the start of gastrulation?

  • Primitive groove
  • Epiblast layer
  • Primitive node
  • Primitive streak (correct)

    • Which factor is involved in the migration of epiblast cells during the formation of the primitive streak?

    <p>FGF 8</p> Signup and view all the answers

    Which congenital condition is associated with the failure of proper gastrulation?

    <p>Sirenomielia</p> Signup and view all the answers

    In which week does gastrulation extend to the beginning?

    <p>Third week</p> Signup and view all the answers

    What morphological feature is recognized due to the presence of the primitive streak?

    <p>Body axes</p> Signup and view all the answers

    During the formation of the primitive streak, what role do epiblast cells play?

    <p>They migrate and form the streak.</p> Signup and view all the answers

    What is the primary function of the primitive endoderm?

    <p>Development of the yolk sac</p> Signup and view all the answers

    Which structures are formed by the endoderm?

    <p>Pancreas and liver</p> Signup and view all the answers

    What is the primary consequence of ethanol acting as a teratogen during development?

    <p>Failure of activation of the sonic hedgehog pathway</p> Signup and view all the answers

    How is the mesoderm subdivided?

    <p>Into paraxial, lateral, and intermediate compartments</p> Signup and view all the answers

    What role does the oropharyngeal membrane play?

    <p>Is the site where the digestive tract will develop</p> Signup and view all the answers

    Which developmental disorder is characterized by the non-development of the rostral part of the brain?

    <p>Holoprosencephaly</p> Signup and view all the answers

    What does the cloacal membrane ultimately develop into?

    <p>The anal canal and urinary tract</p> Signup and view all the answers

    What role does the primary cilium play in cellular function during development?

    <p>It is important for cell signaling and intercellular communication</p> Signup and view all the answers

    Which proteins are associated with the sonic hedgehog pathway?

    <p>Sonic, Indian, and Desert</p> Signup and view all the answers

    Which of the following is not a component formed by the mesoderm?

    <p>Thyroid</p> Signup and view all the answers

    What does the prechordal plate represent?

    <p>A layer associated with the anterior visceral endoderm</p> Signup and view all the answers

    What happens at the end of gastrulation in development?

    <p>Formation of the tail bud</p> Signup and view all the answers

    Which of the following correctly describes the intermediate mesoderm?

    <p>It gives rise to the cardiac mesoderm</p> Signup and view all the answers

    What type of cancer can develop from remnants of the notochord?

    <p>Chordomas</p> Signup and view all the answers

    Which mesodermal layer contributes to the formation of the kidneys and gonads?

    <p>Intermediate mesoderm</p> Signup and view all the answers

    What process occurs in the trunk region of the paraxial mesoderm?

    <p>Somitogenesis</p> Signup and view all the answers

    What structure is formed when the lateral plate mesoderm splits?

    <p>Intrambryonic coelom</p> Signup and view all the answers

    Where do chordomas typically develop?

    <p>Base of the skull or vertebral column</p> Signup and view all the answers

    What mesodermal component will not undergo segmentation in the head region?

    <p>Head mesenchyme</p> Signup and view all the answers

    Which of the following structures is formed from the splanchnic mesoderm?

    <p>Digestive tract</p> Signup and view all the answers

    What is the significance of the primitive heart field?

    <p>It guides the migration of cardiac cells.</p> Signup and view all the answers

    What structure do ectodermal cells differentiate into that forms the neural crest?

    <p>Neural plate</p> Signup and view all the answers

    Which of the following structures does NOT derive from the neural crest?

    <p>Epidermis</p> Signup and view all the answers

    What is the name given to the process that forms the neural plate?

    <p>Neurulation</p> Signup and view all the answers

    What defines the neural groove during the formation of the neural tube?

    <p>An indentation in the neural plate</p> Signup and view all the answers

    Which signals trigger the ectoderm to change its characteristics and form the neural crest?

    <p>Signals from the notochord and prechordal plate</p> Signup and view all the answers

    After the formation of the neural tube, what happens to the neural crests?

    <p>They migrate away</p> Signup and view all the answers

    Which of the following does NOT originate from ectoderm cells?

    <p>Notochord</p> Signup and view all the answers

    What role does the notochord play in early embryonic development?

    <p>It guides the development of the axial skeleton and neural plate.</p> Signup and view all the answers

    What tissue will the neural tube eventually form after closure of the ectoderm?

    <p>Central nervous tissue</p> Signup and view all the answers

    Which mesoderm develops directly adjacent to the notochord?

    <p>Paraxial mesoderm</p> Signup and view all the answers

    What happens to the notochord as the primitive streak shortens?

    <p>It elongates towards the prechordal plate.</p> Signup and view all the answers

    The notochord initially forms as which of the following structures?

    <p>A tubular structure with a lumen inside.</p> Signup and view all the answers

    In which area of the embryo does the primitive heart field develop?

    <p>Rostral to the oropharyngeal membrane.</p> Signup and view all the answers

    Which mesodermal layer is formed more laterally than the intermediate mesoderm?

    <p>Lateral plate mesoderm</p> Signup and view all the answers

    What occurs to the notochord after it fuses with the endoderm?

    <p>It pinches off to become a solid rod.</p> Signup and view all the answers

    What is the significance of the notochord in vertebrate development?

    <p>It acts as a signaling center for organizing surrounding tissues.</p> Signup and view all the answers

    Study Notes

    Embryonic Development

    • Gastrulation transforms two embryonic layers into three, occurring during weeks 3-4 of development.

    • The stages of gastrulation:

      • The embryo starts as a disk (epiblast).
      • An invagination called the primitive streak appears on the dorsal pole.
      • The primitive streak is divided into the primitive node (which contains a primitive pit) and the primitive groove.
      • This marks the initiation of gastrulation.
      • Cells in the epiblast move to the primitive streak, dedifferentiate, and migrate towards the streak, forming the node and pit.

    • The three germ layers are:

      • Endoderm (internal layer)
      • Mesoderm (middle layer)
      • Ectoderm (external layer)
      • These layers develop into different tissues. Examples include the gut, muscle, and skin
    • Sirenomelia: fusion of the legs and sometimes internal organs.
    • Conjoined twins: incomplete separation during development.
    • Situs inversus: organs are in the opposite position to normal locations.

    Epithelial-Mesenchymal Transition (EMT)

    • EMT is the dedifferentiation of epithelial cells and is crucial for development.
    • This is driven by a zinc finger transcription factor called Snail.
    • Snail binds to DNA regions and represses factors linked with epithelial integrity (desmoplakin, cytokeratin, E-cadherin).
    • This leads to the expression of undifferentiated traits (vimentin, fibronectin).
    • Snail activation drives cells to lose their differentiated traits, enabling them to migrate and proliferate through the basement membrane.

    Mesenchymal Stem Cells (MSCs)

    • MSCs are undifferentiated cells with multi-potent capabilities.
    • They differentiate into connective tissue components like osteoblasts, chondroblasts, fibroblasts, and adipocytes.
    • They produce an extracellular matrix (ECM) rich in hyaluronic acid, essential for tissue development and regeneration.

    Formation of the Endoderm, Mesoderm, and Ectoderm Layers

    • Endoderm forms the lining of the gut.
    • Mesoderm develops tissues like muscle, bone, and blood.
    • Ectoderm gives rise to epidermis, nerve tissue, and sense organs.

    Development of the Notochord

    • The notochord is a rod-like structure that forms in the dorsal midline, elongating rostrally toward the cranial end and caudally toward the primitive pit.
    • It's critical to vertebrate development and provides signals to adjacent cells, guiding the development of the nervous system and skeletal structures.
    • The notochord is initially a hollow, tubular structure with an open bottom, which then fuses with the endoderm and condenses into a rod-like structure.

    Teratogens, Malformations, and Dysplasias

    • Ethanol is a teratogen, which disrupts development.
    • Malignant cancers deriving from notochord remnants (e.g., chordomas) can arise.
    • Defects in the caudal structure (e.g., caudal dysplasia) can impact the development of organs.
    • Anomalies that result from problems in development can affect the lower limbs and the urinary system, or the lumber vertebrae for instance.
    • Sirenomelia is related to defects in the caudal mesoderm.
    • Abnormal cilia can lead to Situs inversus totalis.
    • Kartagener's syndrome causes immotile respiratory cilia and sperm flagella.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Related Documents

    Embryology 4 - Gastrulation PDF

    Description

    Test your knowledge on the processes of gastrulation and the formation of the three germinal layers. This quiz covers key concepts, structural features, and congenital conditions associated with improper gastrulation. Challenge yourself with questions that explore the role of epiblast cells, the significance of the primitive streak, and related developmental disorders.

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser