How the Reproductive System Works in a Fetal Pig

Exercise 1: Histology of the Ovary and Testis 

Data Table 1. Images from the Ovary and Testis Slides. 

Questions 

The slide you viewed in this exercise was from a mammal, but not a human. How is the slide you viewed differently than that of a human? 

There is a specific size of organs in mammals and humans. The organs above are the size of mammals. Female mammals have mammary glands, uterus, vagina, and oviducts. Male mammals have prostate glands and a penis. 

What is the SRY gene and how does it lead to sex determination? 

It is the Sex-determining region of the Y chromosome found in males. The gene produces an SRY protein that leads to the activation of other genes. Processes started with the protein lead to the development of male gonads in the fetus. This prevents the development of the uterus and fallopian tubes which are female reproductive organs. 

Describe spermatogenesis. 

Spermatogenesis is a process in males that leads to the production of sperms from immature germ cells. The process takes place in the seminiferous tubules. The process begins through mitosis where two diploid daughter cells are produced from one cell. Through meiosis 1, the primary spermatocyte divides into four haploid secondary spermatocytes. In meiosis 11, two secondary spermatocytes divide into four spermatids. The spermatids develop into sperms through spermiogenesis. 

Describe oogenesis. 

Oogenesis is a process in females that leads to the production of the mature ovum. During this process, the egg mother cell is divided into the diploid primary oocyte. It undergoes meiosis I and forms two haploid cells that are unequal. The secondary oocyte undergoes meiosis II giving rise to an ovum and a second polar body. 

The ovary that is on the prepared slide is in what phase of the ovarian cycle? What is happening to the uterus during this time? 

The ovary is in the proliferation phase. During this stage, follicles in the ovary mature preparing themselves for ovulation. 

What are the Sertoli and Leydig cells? 

Sertoli cells are located in seminiferous tubules to nourish the developing sperm cells. They consume residual cytoplasm during the process of spermatogenesis. 

Leydig cells are located next to the seminiferous tubules. In the presence of luteinizing hormone, they produce testosterone. 

Exercise 2: Fetal Pig Dissection – Reproductive System 

Data Table 2. Reproductive Organs of the Pig. 

Questions 

Where are the testes located and why? 

Testes in male reproductive organs which are in the scrotum are located outside the body in front of the pelvic region. They are located outside the body to maintain low temperatures which are effective for the production of sperms. 

What is the purpose of the fallopian tubes? 

The fallopian tube in the female reproductive system functions to carry a fertilized egg from the ovary to the uterus. 

What is semen? 

Semen is a fluid that is secreted by the gonads and contains sperms. 

What are some of the differences between the reproductive structures of a pig and those of a human? 

Pigs have a large uterus which has four layers and can carry up to ten piglets. This type of uterus is known as bicarbonate. The uterus of a human is simple. Humans have a urogenital sinus during the development of an embryo which is then lost. The urogenital sinus of pigs is relatively long and it is formed by the fusion of the vagina with the urethra.