embryo-lec_2

Page 1: Testes

  • Testes Definition: The testes, also known as testicles, are male reproductive organs responsible for producing sperm cells.

  • Anatomy:

    • The testes are egg-shaped structures about one inch (2.54 cm) long.

    • They rest inside the scrotum.

  • Hormone Production:

    • The testes produce hormones, including testosterone.

    • Testosterone stimulates sperm production and facilitates male maturation.

Page 2: Sperm Components

  • Structures Involved in Fertilization:

    • Corona radiata cells

    • Sperm nucleus

    • Acrosome

    • Plasma membrane

    • Polar body in division

    • Fusion of oocyte and sperm cell membranes

  • The inner acrosomal membrane dissolves during fertilization.

  • Secondary oocyte participates in the second meiotic division.

  • The fusion of gametes initiates the continuity of cell membrane.(Cited from Langman, 1995)

Page 3: Formation of Gametes

  • Chemical Involvement:

    • Chemicals are crucial for the formation of gametes.

    • Fertilizin: A chemical surrounding the egg.

    • Antifertilizin: A chemical surrounding the sperm.

Page 4: Acrosomal Reaction

  • Stages of Acrosomal Reaction:

    1. Sperm reaches the egg through chemical attraction (chemoattraction).

    2. Contact with egg jelly triggers the acrosomal reaction.

    3. Exocytosis of the acrosomal vesicle occurs, releasing protolytic enzymes to create a path through the jelly coat.

Page 5: Acrosomal Reaction Components

  • Dependence on Calcium:

    • The release of protolytic enzymes relies on calcium (Ca+) concentration.

    • Contact between sperm head and egg jelly binds compounds, opening ionic channels.

  • Two Components of Acrosomal Reaction:

    1. Release of protolytic enzyme.

    2. Extension of acrosomal process.

Page 6: Male Reproductive System

  • Anatomy:

    • Main male sex organs: penis and testes.

  • Functions:

    • The testes produce semen and sperm, which fertilize an ovum in the female body.

    • The fertilized ovum (zygote) develops into a fetus.

Page 7: Structure of Sperm

  • Components of Sperm:

    • Typical sperm features include:

      • A head containing the nucleus and acrosome.

      • A middle piece with mitochondria.

      • A tail composed of 9+2 microtubule pattern.

  • Sperm shape and structure vary across species.

  • Nucleus Composition:

    • Contains condensed chromatin (DNA) and proteins.

Page 8: Definition of Sperm

  • Etymology:

    • The term