What is the function of the zona pellucida in an egg cell?
The zona pellucida supports communication between oocytes and follicle cells during oogenesis; protects oocytes, eggs, and embryos during development, and regulates interactions between ovulated eggs and free-swimming sperm during and following fertilization.
What does the zona pellucida secrete?
The zona pellucida first appears in unilaminar primary oocytes. It is secreted by both the oocyte and the ovarian follicles. The zona pellucida is surrounded by the corona radiata. The corona is composed of cells that care for the egg when it is emitted from the ovary….
What is the role of zona pellucida quizlet?
Inner layer of cells surrounding the oocyte, secreted by follicle cells. Penetration of the Zona Pellucida by a sperm forces the secondary oocyte to undergo meiosis II.
What is the importance of zona pellucida during fertilization?
Zona pellucida glycoproteins are responsible for species-restricted binding of sperm to unfertilized eggs, inducing sperm to undergo acrosomal exocytosis, and preventing sperm from binding to fertilized eggs.
Which enzyme is involved in digestion of zona pellucida?
Spermatozoa must pervade the corona radiata and the zona pellucida before reaching the ovum proper; they do so by releasing hydrolytic enzymes from the acrosome – the corona-penetrating enzyme (hyaluronidase) and acrosin (a trypsin-like protease which digests the zona pellucida).
What process does the secondary oocyte go through to give rise to the ovum egg cell )?
During each reproductive cycle, several follicles begin to develop. Typically, only one oocyte each cycle will become a mature egg and be ovulated from its follicle. This process is known as ovulation.
What prevents polyspermy during fertilization?
To prevent polyspermy, the zona pellucida, a structure that surrounds mammalian eggs, becomes impermeable upon fertilization, preventing the entry of further sperm. The structural changes in the zona upon fertilization are driven by the exocytosis of cortical granules.
What is the zona pellucida and where is it found?
The zona pellucida is a noncellular layer of carbohydrates and proteins located between the surface of the oocyte and the granulosa cell layer that secrete it (Guraya, 1978; Chieffi and Pierantoni, 1987; Pierantoni and Fasano, 1991).
How do the egg cells block polyspermy?
An egg must be fertilized by a single sperm only. To prevent polyspermy, the zona pellucida, a structure that surrounds mammalian eggs, becomes impermeable upon fertilization, preventing the entry of further sperm. The structural changes in the zona upon fertilization are driven by the exocytosis of cortical granules.
Which structure is responsible for collection of ovum after ovulation?
When the follicle ruptures, the egg is released from the ovary and is then captured and guided by the fallopian tubes. Muscular contractions of the fallopian tubes move the egg to the cavity of the uterus.
What is the function of the corona radiata?
Function of the Corona Radiata The nerve cells of the corona radiata are afferent and efferent, meaning they carry messages to and from the body. Afferent refers to sensory input and other input sent from the body to the brain. Efferent refers to messages sent from the brain to the body to control motor function.
Where is the zona pellucida?
Which part of oviduct is responsible for collection of ovum?
The infundibulum catches and channels the released eggs; it is the wide distal (outermost) portion of each fallopian tube. The endings of the fimbriae extend over the ovary; they contract close to the ovary’s surface during ovulation in order to guide the free egg.