Embryology Lec 1: Embryogenesis Overview
32 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 term is used to describe the developmental stage beginning from the ninth week of gestation?

  • Blastocyst
  • Embryo
  • Zygote
  • Fetus (correct)
  • Which hormone is NOT involved in regulating the female monthly cycle?

  • Follicle-stimulating hormone (FSH)
  • Luteinizing hormone (LH)
  • Estrogen (correct)
  • Gonadotropin-releasing hormone
  • During which process does the fertilized egg transition through multiple stages before implantation?

  • Mitosis (correct)
  • Developmental cleavage
  • Embryonic folding
  • Gamete approximation
  • Which stage comes immediately after fertilization in early human development?

    <p>Morula formation</p> Signup and view all the answers

    Which of the following is NOT considered a major event in the first week of embryonic development?

    <p>Neural tube formation</p> Signup and view all the answers

    What is the multi-layered structure that develops after morula formation?

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

    What is the term used to describe a solid sphere of cells within the zona pellucida when there are around sixteen cells?

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

    What biological process describes the division of a fertilized egg into smaller cells post-fertilization?

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

    What is the primary factor that ensures the successful fertilization and implantation of the embryo?

    <p>All of the above</p> Signup and view all the answers

    What forms the inner cell mass (ICM) of the blastocyst?

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

    During which process does the blastocyst begin to burrow into the endometrium?

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

    What is the first cavity formed during embryonic development?

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

    What process follows the initial formation of the morula in terms of the embryonic developmental stages?

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

    Which of the following describes the period of apposition during implantation?

    <p>Weak interactions between the blastocyst and the uterine wall</p> Signup and view all the answers

    The outer layer of the blastocyst is known as what?

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

    What initiates the process of implantation in the embryonic development timeline?

    <p>Hatching of the blastocyst</p> Signup and view all the answers

    What triggers the ovaries to produce follicles each month?

    <p>Hormones released by the pituitary gland</p> Signup and view all the answers

    Which type of follicle matures right before ovulation?

    <p>Graafian follicle</p> Signup and view all the answers

    What occurs to the follicle after ovulation?

    <p>It turns into a corpus luteum</p> Signup and view all the answers

    What is the role of the corpus luteum?

    <p>To release progesterone and estrogen</p> Signup and view all the answers

    What is the cumulus oophorus?

    <p>A group of cells surrounding the oocyte</p> Signup and view all the answers

    Which layer surrounds the zona pellucida?

    <p>Corona radiata</p> Signup and view all the answers

    What happens to the corpus luteum if fertilization does not occur?

    <p>It shrinks and forms corpus albicans</p> Signup and view all the answers

    What composition primarily makes up the corona radiata?

    <p>Proteins, carbohydrates, and hyaluronic acid</p> Signup and view all the answers

    What is the primary outcome of fertilization regarding chromosome number?

    <p>Restoration of the diploid number of chromosomes with genetic variation.</p> Signup and view all the answers

    What initiates the acrosome reaction in sperm during fertilization?

    <p>Binding to the zona pellucida.</p> Signup and view all the answers

    What is the significance of capacitation for sperm before fertilization?

    <p>Only capacitated sperm can penetrate the corona cells.</p> Signup and view all the answers

    What is produced during the cleavage process after fertilization?

    <p>Blastomeres are produced as cell division occurs.</p> Signup and view all the answers

    Which sperm chromosome combination leads to a male embryo?

    <p>XY combination from the male parent.</p> Signup and view all the answers

    What describes the zygote's size during the cleavage process?

    <p>It remains similar in size and form despite increased cell number.</p> Signup and view all the answers

    What role do zona proteins play in fertilization?

    <p>They induce the acrosome reaction.</p> Signup and view all the answers

    What is true about the conceptus after fertilization and during the cleavage phase?

    <p>It includes both embryonic and extraembryonic structures.</p> Signup and view all the answers

    Study Notes

    Embryogenesis Overview

    • Human embryogenesis transforms a fertilized egg into an embryo over the first eight weeks of development.
    • The embryo progresses from a zygote to a multi-layered, multi-dimensional structure with primitive organs.
    • By the ninth week, the embryo is referred to as a fetus, characterized by recognizable features and developing organs.

    First Week of Development

    • The early developmental events crucial for fertilization and implantation occur, including:
      • Gamete approximation
      • Contact and fusion of gametes
      • Fertilization
      • Mitotic cleavage of the blastomere
      • Morula and blastocyst formation
      • Implantation of the blastocyst

    Ovulation

    • Begins at puberty, regulated by gonadotropins from the hypothalamus; includes follicle-stimulating hormone (FSH) and luteinizing hormone (LH).
    • The pituitary gland controls ovarian cycles, leading to the release of an egg (ovulation).
    • Follicles grow, with typically only one reaching maturity while others degenerate.
    • After ovulation, the Graafian follicle ruptures, releasing the oocyte and forming the corpus luteum, which produces progesterone and estrogen.

    Key Structures

    • Cumulus Oophorus: A cluster of cells surrounding the oocyte, with the innermost layer known as the Corona Radiata.
    • Zona Pellucida: Glycoprotein layer that protects the oocyte's plasma membrane.

    Fertilization Process

    • Fusion of mature male and female gametes creates a zygote.
    • Sperm undergo capacitation in the female reproductive tract, allowing them to penetrate the oocyte.
    • Acrosome Reaction: Release of enzymes necessary to penetrate the zona pellucida after sperm binds with it.

    Results of Fertilization

    • Restoration of the diploid chromosome number, combining genetic material from both parents.
    • Determination of genetic sex based on the sperm type (XX for female, XY for male).
    • Initiates cell cleavage.

    Morula Formation

    • Following fertilization, rapid mitotic cleavage transforms the zygote into a morula, which is a solid sphere of cells.
    • Morula remains the same size as cell count increases due to compaction, within the zona pellucida.

    Blastulation and Blastocyst Formation

    • The blastocyst forms a few days post-fertilization and comprises:
      • An Inner Cell Mass (ICM), later developing into the embryo.
      • An outer Trophoblast layer surrounding the ICM and the blastocoel (first cavity).
    • The blastocyst hatches through the zona pellucida as it enlarges.

    Implantation Process

    • Implantation is a critical biochemical and mechanical process occurring in the first week, extending into the second.
    • Subdivided into:
      • Apposition Phase: Weak interactions between blastocyst and uterine wall.
      • Attachment Phase: Stronger binding to the uterine epithelium.
      • Invasion Phase: Blastocyst burrows into the endometrium.

    Studying That Suits You

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

    Quiz Team

    Related Documents

    Embryology Lec 1 PDF

    Description

    This quiz focuses on the first week of embryogenesis, covering key processes such as ovulation, fertilization, and implantation. Understand the intricate development from a zygote to a complex embryo with functioning organs during the critical first eight weeks. Test your knowledge on this fundamental phase of human development.

    More Like This

    Human Embryogenesis Lecture 1 Quiz
    8 questions
    Biologie de la Fécondation
    14 questions
    Use Quizgecko on...
    Browser
    Browser