Spermatogenesis in Males
36 Questions
1 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 term for the production of spermatozoa in males?

  • Spermatogenesis (correct)
  • Gametogenesis
  • Fertilization
  • Oogenesis

    • At what age does spermatogenesis typically begin in males?

  • 35-40 years
  • 18-20 years
  • 12-14 years (correct)
  • 25-30 years

    • What is the ideal temperature for spermatogenesis?

  • 2-3°C below body temperature (correct)
  • 34°C
  • 37°C
  • 40°C

    • Where do the testes produce spermatozoa?

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

    What is the approximate number of spermatozoa produced per testis per day at peak?

    <p>150,000</p> Signup and view all the answers

    How long does it take for spermatogenesis to complete from spermatogonium to spermatozoon?

    <p>64 days</p> Signup and view all the answers

    What is the term for the production of gametes in females?

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

    What is the term for the female gametes?

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

    What is the ball of blastomeres at the 16-cell stage called?

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

    What is one of the obstacles that sperm encounter in the female genital tract?

    <p>The acidity of vaginal fluid</p> Signup and view all the answers

    What is a requirement for fertilization to occur?

    <p>The presence of a healthy secondary oocyte</p> Signup and view all the answers

    How long can a sperm survive in the female genital tract?

    <p>Up to 72 hours</p> Signup and view all the answers

    What is the third step in the fertilization process?

    <p>Not mentioned in the content</p> Signup and view all the answers

    What surrounds the primary oocyte inside a mature follicle?

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

    What occurs as a result of the release of cortical granules from the oocyte?

    <p>Zonal reaction and slow block to polyspermy</p> Signup and view all the answers

    What is the result of the sperm head releasing paternal chromosomes into the oocyte?

    <p>Formation of the male pronucleus</p> Signup and view all the answers

    What is the function of the second polar body?

    <p>Contains very little cytoplasm</p> Signup and view all the answers

    What event determines the genetic sex of the zygote?

    <p>Presence of XX or XY chromosomes</p> Signup and view all the answers

    What is the result of the combination of maternal and paternal chromosomes?

    <p>Formation of diploid zygote</p> Signup and view all the answers

    What is the immediate event of fertilization that involves the fusion of two pronuclei?

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

    What is the role of cross-over and independent assortment of chromosomes?

    <p>Introduction of genetic variation</p> Signup and view all the answers

    What is the immediate event of fertilization that involves the completion of the second meiotic division of the oocyte?

    <p>Completion of second meiotic division of oocyte</p> Signup and view all the answers

    What is the term for the fluid-filled cavity in the blastocyst?

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

    What is the process by which the blastocyst hatches out of the zona pellucida?

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

    What is the term for the week during which two cavities develop in relation to the two layers of the embryoblast?

    <p>The week of twos</p> Signup and view all the answers

    What is the process by which the bilaminar embryonic disc is replaced with a trilaminar disc?

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

    From which layer do all cell layers of the trilaminar disc originate?

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

    What is the term for the structure that forms from the epiblast during gastrulation?

    <p>Primitive streak</p> Signup and view all the answers

    What forms at the cephalic end of the primitive streak?

    <p>A primitive node</p> Signup and view all the answers

    What is the term for the single layer of outer cells that surround the blastocoel?

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

    During gastrulation, which layer of cells forms the notochord?

    <p>Primitive node cells</p> Signup and view all the answers

    What is the resulting structure formed after gastrulation?

    <p>Trilaminar embryonic disc</p> Signup and view all the answers

    Which tissue type arises exclusively from the mesoderm?

    <p>Connective tissue</p> Signup and view all the answers

    What is the origin of nerve tissue?

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

    Which of the following tissue types arises from all three primary germ layers?

    <p>Epithelial tissue</p> Signup and view all the answers

    What is the origin of muscle tissue?

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

    Study Notes

    Gametogenesis in the Male (Spermatogenesis)

    • Gametogenesis in the male is known as spermatogenesis, which occurs in the testes after puberty (12-14 years) under the influence of follicle-stimulating hormone (FSH) and testosterone.
    • Spermatogenesis is optimal at 2-3°C below body temperature (37°C), which is why the testes are located in the scrotum below the pelvis.
    • This process is continuous throughout post-pubertal life and peaks at around 25 years of age, producing approximately 150,000 spermatozoa per testis per day at peak.

    Spermatogenesis - Summary

    • The entire process of spermatogenesis takes 64 days, broken down into:
      • 16 days from spermatogonium to primary spermatocytes
      • 24 days from primary spermatocytes to spermatids
      • 24 days from spermatids to spermatozoa

    Gametogenesis in the Female (Oogenesis)

    • Gametogenesis in the female produces secondary oocytes (commonly called ova).
    • The ball of blastomeres at the 16-cell stage is called the morula.

    Obstacles that Sperm Encounter in the Female Genital Tract

    • Sperm face obstacles such as:
      • Acidity of vaginal fluid, which kills many spermatozoa
      • Viscosity and acidity of cervical mucus, which weakens and traps many spermatozoa
      • Distance from the vagina through the uterine cervix and cavity to the ampulla of the oviduct
      • Must survive for 30 minutes to 12 hours and wait up to 72 hours for ovum

    Fertilization

    • Fertilization requires a healthy secondary oocyte (ovum) with:
      • No structural abnormalities
      • The correct number of chromosomes (22 autosomes + X)
      • Completion of the first meiotic division prior to ovulation
      • Encountering competent sperm within 24 hours of ovulation
    • Fertilization is a multistep process involving:
      1. Penetration of corona radiata
      2. Penetration of the zona pellucida
      3. Binding and fusion of the oocyte and sperm cell membranes
    • A slow block to polyspermy or zonal reaction is triggered by the release of cortical granules from the oocyte.

    Immediate Events of Fertilization

    • Immediate events of fertilization include:
      1. Completion of the second meiotic division of the oocyte and formation of the female pronucleus
      2. Formation of the zygote by fusion of the male and female pronuclei
      3. Determination of the genetic sex of the zygote (XX = female; XY = male)
      4. Restoration of the diploid number of chromosomes (23 + 23 = 46)
      5. Introduction of genetic variation via cross-over and independent assortment of chromosomes
      6. Differentiation of cells during the formation of the blastocyst

    Review - Implantation

    • Implantation is the process by which the blastocyst hatches out of the zona pellucida, and its trophoblast adheres, attaches, and burrows into the endometrium, where further development continues.

    The Second Week of Human Development

    • The second week of human development is characterized by the formation of two cavities in relation to the two layers of the embryoblast (the bilaminar embryonic disc).

    Week 3 of Human Development

    • Week 3 is characterized by the replacement of the bilaminar embryonic disc with a trilaminar disc, a process called gastrulation.
    • All cell layers of the trilaminar disc originate from the epiblast via a primitive streak.

    Gastrulation - Summary

    • Gastrulation involves:
      • Formation of the primitive streak from epiblast
      • Formation of a primitive node at the cephalic end of the primitive streak
      • One wave of cells migrating to form the notochord
      • A second wave of cells migrating to form a layer beneath the epiblast to form mesoderm
    • Thus, the trilaminar embryonic disc results from gastrulation, comprising ectoderm, mesoderm, and endoderm.

    Embryonic Origin of Basic Tissues

    • The four basic tissues arise from the trilaminar embryonic disc:
      1. Epithelia - arise from all primary germ layers
      2. Connective tissues - arise exclusively from mesoderm
      3. Nerve tissue - arise exclusively from ectoderm
      4. Muscle tissue - arise exclusively from mesoderm

    Studying That Suits You

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

    Quiz Team

    Related Documents

    Gametogenesis, Fertilization & First Three Weeks of Human Development 2024 PDF

    Description

    Learn about gametogenesis in males, also known as spermatogenesis, which occurs in the testes after puberty. Understand the optimal conditions and hormones involved in this process.

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser