Developmental Anatomy: Extraembryonic Membranes
26 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 structure is formed by the complex of cotyledons and caruncles?

  • Diffused placenta
  • Zonary placenta
  • Discoid placenta
  • Placentome (correct)

Which type of placenta retains all six layers intact?

  • Epitheliochorial (correct)
  • Endotheliochorial
  • Synepitheliochorial
  • Hemochorial

Which type of placenta is specifically found in carnivores such as cats and dogs?

  • Zonary
  • Epitheliochorial
  • Endotheliochorial (correct)
  • Hemochorial

In which type of placenta does only one maternal layer remain intact?

<p>Endotheliochorial (C)</p> Signup and view all the answers

Which of the following species typically have a diffuse placenta?

<p>Pigs and Horses (C)</p> Signup and view all the answers

Which type of placenta is characterized by a band of tissue surrounding the fetus?

<p>Zonary placenta (C)</p> Signup and view all the answers

What term describes the contact sites formed by the maternal tissue in placentary anatomy?

<p>Caruncles (B)</p> Signup and view all the answers

Which of the following layers would be absent in a hemochorial placenta?

<p>Maternal connective tissue (B)</p> Signup and view all the answers

What distinguishes viviparous animals from oviparous animals?

<p>They give birth to live young after internal development. (B)</p> Signup and view all the answers

Which extraembryonic membrane functions primarily in gas exchange and liquid waste collection?

<p>Allantois (A)</p> Signup and view all the answers

What is a primary function of the amniotic sac?

<p>Contains the embryo and protects it from injury. (C)</p> Signup and view all the answers

What is the role of the chorion in embryonic development?

<p>Forms the fetal part of the placenta. (A)</p> Signup and view all the answers

Which statement accurately describes the yolk sac?

<p>It serves as a nutrient supply in early development phases. (C)</p> Signup and view all the answers

What is the significance of the decidua in placentation?

<p>It's the maternal part rich in blood vessels supplying oxygen and nutrients. (A)</p> Signup and view all the answers

Which extraembryonic membrane is involved in maintaining the fetus's body temperature?

<p>Amnion (D)</p> Signup and view all the answers

How does the umbilical cord function in fetal development?

<p>It connects the fetus to the maternal blood supply. (A)</p> Signup and view all the answers

What occurs during the implantation phase of mammalian embryonic development?

<p>The blastocyst adheres and invades the uterine lining. (A)</p> Signup and view all the answers

What is the main characteristic of ovoviviparous animals?

<p>They retain eggs that hatch inside the mother's body. (B)</p> Signup and view all the answers

What type of implantation involves the blastocyst becoming completely cut off from the uterine lumen?

<p>Interstitial implantation (C)</p> Signup and view all the answers

Which type of implantation is commonly observed in rodents?

<p>Eccentric implantation (C)</p> Signup and view all the answers

What is histotroph commonly referred to as?

<p>Uterine milk (B)</p> Signup and view all the answers

Which of the following mammals lack a placenta?

<p>Duckbilled platypus (B)</p> Signup and view all the answers

What term describes the vascular organ that develops inside the uterus of most pregnant mammals?

<p>Placenta (D)</p> Signup and view all the answers

Which of the following structures is part of fetal membranes?

<p>Allantoic endothelium (A)</p> Signup and view all the answers

What type of placentation involves the entire surface of the allantochorion participating in the formation of the placenta?

<p>Diffuse (A)</p> Signup and view all the answers

Which type of nutrient absorption occurs through the allantochorion?

<p>Hemotroph absorption (B)</p> Signup and view all the answers

Flashcards

Oviparous Reproduction

Animals that lay eggs; development occurs outside the mother's body.

Viviparous Reproduction

Animals give birth to live young; embryos develop inside the mother, typically through a placenta.

Oviviparous Reproduction

Eggs hatch inside the mother's body, resulting in live births.

Yolk Sac

Provides nutrients early in embryonic development, disappearing later.

Signup and view all the flashcards

Allantois

A membrane involved in waste collection and gas exchange in many embryos, includes umbilical cords in mammals.

Signup and view all the flashcards

Amnion/Amniotic Sac

Surrounds the fetus, containing amniotic fluid, protecting and supporting.

Signup and view all the flashcards

Chorion

Outer trophoblast layer, forming the fetal part of the placenta, essential for nutrient and gas exchange.

Signup and view all the flashcards

Decidua

Maternal portion of the placenta, rich in blood vessels, expelled after childbirth.

Signup and view all the flashcards

Umbilical Cord

Connects the fetus to the placenta, delivering oxygenated blood and nutrients.

Signup and view all the flashcards

Implantation

The process of the blastocyst embedding in the uterine wall.

Signup and view all the flashcards

Endometrium

Inner lining of the uterus, where implantation occurs.

Signup and view all the flashcards

Interstitial Implantation

Blastocyst implants within the uterine wall.

Signup and view all the flashcards

Centric/Superficial Implantation

Blastocyst enlarges to fill most of the uterine cavity.

Signup and view all the flashcards

Eccentric Implantation

Blastocyst lodges in a fold of the uterine lumen.

Signup and view all the flashcards

Embryotroph

Early nourishment of the embryo.

Signup and view all the flashcards

Histotroph

Uterine milk for early embryonic nutrition.

Signup and view all the flashcards

Hemotroph

Nutrient derived from maternal blood.

Signup and view all the flashcards

Placentation

Formation, types, and structure of placentas.

Signup and view all the flashcards

Diffuse Placenta

Placenta that involves almost the entire surface.

Signup and view all the flashcards

Cotyledonary Placenta

Placenta with discrete attachment areas (cotyledons).

Signup and view all the flashcards

Zonary Placenta

Band-like placenta.

Signup and view all the flashcards

Discoid Placenta

Single, disc-shaped placenta.

Signup and view all the flashcards

Epitheliochorial Placenta

Placenta with all six layers intact; minimal maternal loss.

Signup and view all the flashcards

Synepitheliochorial Placenta

Placenta with five layers intact; some maternal loss.

Signup and view all the flashcards

Endotheliochorial Placenta

Placenta with four layers intact, including maternal endothelium.

Signup and view all the flashcards

Hemochorial Placenta

Placenta with only three layers from the fetus; vessels exposed in the mother.

Signup and view all the flashcards

Study Notes

Animal Reproductive Strategies

  • Oviparous: Animals that lay eggs; development occurs outside the mother's body.
  • Viviparous: Animals give birth to live young; embryos develop inside the mother, typically through a placenta.
  • Oviviparous: Eggs hatch inside the mother's body, resulting in live births.

Extraembryonic Membranes

  • Yolk Sac: Provides nutrients early in development, disappears later.
  • Allantois:
    • Ventral outgrowth in reptiles, birds, and mammals.
    • Vestigial in humans; contains umbilical arteries and veins.
    • Functions in waste collection and gas exchange.
  • Amnion/Amniotic Sac:
    • Surrounds the fetus, containing amniotic fluid.
    • Protects the fetus, allows movement, prevents adherence, and maintains temperature.
  • Chorion:
    • Outer trophoblast layer that forms the fetal part of the placenta.
    • Involved in nutrient absorption, gas exchange, and hormone production.

Placenta Anatomy

  • Decidua: Maternal portion rich in blood vessels, expelled at birth.
  • Umbilical Cord/Urachus: Connects fetus to placenta; delivers oxygenated, nutrient-rich blood.

Embryonic Development and Implantation

  • Implantation: Phase where the blastocyst embeds into the endometrium of the uterus.
  • Endometrium: Inner uterine lining where implantation occurs.

Types of Implantation

  • Interstitial Implantation: Blastocyst implants within the uterine wall (e.g., primates, guinea pigs).
  • Centric/Superficial Implantation: Blastocyst enlarges to fill most of the uterine cavity (e.g., ungulates, carnivores).
  • Eccentric Implantation: Blastocyst lodges in a fold of the uterine lumen (e.g., rodents).

Early Nutrition

  • Embryotroph: Early nourishment comprising:
    • Histotroph: Uterine milk for early nutrition before placenta is established.
    • Hemotroph: Nutrition derived from maternal blood through allantochorion or vitellochorion.

Comparative Placentation

  • Placentation: The formation, type, and structure of placentas.
  • Most mammals have a placenta except monotremes (e.g., platypus) and marsupials (e.g., kangaroos).
  • Placenta Functions: Supplies oxygen/nutrients, removes waste, expelled after birth.

Types of Placenta Based on Appearance

  • Diffuse: Involves almost the entire placenta surface (e.g., pig, horse).
  • Cotyledonary: Features discrete attachment areas called cotyledons (e.g., ruminants).
  • Zonary: Forms a band of tissue around the fetus (e.g., cats, dogs).
  • Discoid: A single, disc-shaped placenta (e.g., humans, mice).

Types of Placenta Based on Morphology

  • Epitheliochorial: All six layers intact; no maternal tissue loss (e.g., horse, pig, cow).
  • Synepitheliochorial: Five layers intact; some maternal tissue loss (e.g., sheep, goat).
  • Endotheliochorial: Four layers intact; includes maternal endothelial cells (e.g., carnivores).
  • Hemochorial: Only three fetal layers intact; uterine blood vessels are exposed (e.g., rodents, primates, humans).

Studying That Suits You

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

Quiz Team

Description

This quiz covers extraembryonic membranes and comparative placentation in animal reproductive strategies. Explore the differences between oviparous, viviparous, and oviviparous animals. Test your understanding of these concepts and their significance in developmental anatomy.

More Like This

Use Quizgecko on...
Browser
Open
Browser
Browser