Chapter 16, Problem 1RQ

Distinguish between:

1. a. seminiferous tubule and vas deferens
2. b. sperm and semen
3. c. Leydig cells and Sertoli cells
4. d. primary oocyte and secondary oocyte
5. e. follicle and corpus luteum
6. f. the three phases of the menstrual cycle

Summary Introduction

To distinguish: Between seminiferous tubule and vas deferens.

Introduction: Reproductive system (or genital system) is involved in sexual reproduction. The male and female reproductive systems’ function is to propagate the species. Gametogenesis is a process by which male and female gametes are produced. Spermatogenesis and oogenesis are the two types of gametogenesis processes present in the sexual reproduction of animals.

Explanation of Solution

Tabular representation: Table 1 shows the differences between seminiferous tubule and vas deferens.

Table 1: Differences between seminiferous tubule and vas deferens:

Characteristics	Seminiferous tubule	Vas deferens
Definition	It is a narrow coiled tube that produces sperm in the testes.	Vas deferens, also called ductus deferens, is a narrow tube that carries sperm from the epididymis toward the urethra.
Function	Spermatogenesis process that involves the development of sperm occurs inside the seminiferous tubule of the testis.	The smooth muscle in the walls of the vas deferens contracts reflexively during ejaculation, thus, helping in propelling the sperm forward.

Summary Introduction

To distinguish: Between sperm and semen.

Introduction: Reproductive system (or genital system) is involved in sexual reproduction. The male and female reproductive systems’ function is to propagate the species. The primary reproductive structures of male reproductive system are testes. The accessory structures of the male reproductive system include a group of male accessory glands, the penis (organ of copulation), and a complex set of tubules and ducts from testis to penis.

Explanation of Solution

Tabular representation: Table 2 shows the differences between sperm and semen.

Table 2: Differences between sperm and semen:

Characteristics	Sperm	Semen
Definition	It is the male reproductive cell.	The seminal fluid combines with the sperm to form semen.
Formation	It is produced in the testis by spermatozoa.	It is a collection of sperm and seminal fluid (fluid that is produced by bulbourethral gland, prostate gland, and seminal vesicle).
Function	It carries the male genetic information to an egg cell of the same species and undergoes fertilization with the egg cell.	It carries the sperms, nourishes the sperm cells, and maintains their mobility.

Summary Introduction

To distinguish: Between Leydig cells and Sertoli cells.

Introduction: Reproductive system (or genital system) is involved in sexual reproduction. The male and female reproductive systems’ function is to propagate the species. Leydig cells and Sertoli cells are the two types of cells found in the testicles of humans.

Explanation of Solution

Tabular representation: Table 3 shows the differences between Leydig cells and Sertoli cells.

Table 3: Differences between Leydig cells and Sertoli cells:

Characteristics	Leydig cells	Sertoli cells
Location	These types of cells are situated in the testicle just adjacent to the seminiferous tubules.	These types of cells are found in the seminiferous tubules.
Single or groups	They are found in small groups.	They are found as single, not in groups.
Produces	This type of cells secretes testosterone by the influence of luteinizing hormone (LH).	This type of cells produces androgen-binding protein in the lumen of tubules in the presence of follicle-stimulating hormone (FSH).
Shape	They are large cells that are polyhedral in shape.	They are elongated cells.
Function	These cells play an important role in producing testosterone.	These cells have a major function in support.

Summary Introduction

To distinguish: Between primary oocyte and secondary oocyte.

Introduction: Reproductive system (or genital system) is involved in sexual reproduction. The male and female reproductive systems’ function is to propagate the species. Gametogenesis is a process by which male and female gametes are produced. Spermatogenesis and oogenesis are the two types of gametogenesis processes present in the sexual reproduction of animals.

Explanation of Solution

Tabular representation: Table 4 shows the differences between primary oocyte and secondary oocyte.

Table 4: Differences between primary oocyte and secondary oocyte:

Characteristics	Primary oocyte	Secondary oocyte
Definition	The primary oocytes are produced from the primordial germ cells during the embryonic development of the female. The division in primary oocyte results in the formation of secondary oocyte.	Post-puberty meiosis resumes the primary oocyte and becomes an ovarian follicle with layers of cell around it and completes meiosis II as a secondary oocyte.
Meiosis	They are then halted during prophase I of meiosis.	The secondary oocyte is halted at metaphase II and is not resumed until fertilization.

Summary Introduction

To distinguish: Between follicle and corpus luteum.

Introduction: Reproductive system (or genital system) is involved in sexual reproduction. The male and female reproductive systems’ function is to propagate the species. Gametogenesis is a process by which male and female gametes are produced. Spermatogenesis and oogenesis are the two types of gametogenesis processes present in the sexual reproduction of animals.

Explanation of Solution

Tabular representation: Table 5 shows the differences between follicle and corpus luteum.

Table 5: Differences between follicle and corpus luteum:

Characteristics	Follicle	Corpus luteum
Consists of	An oocyte, zona pellucida, cellular membranous granulose surrounded by theca cells.	Luteum cells, fibrin, and blood clot.
Contains	It contains follicular antrum filled with follicular fluid.	It contains blood clot.
Formed by	It is formed by the germinal epithelium of the ovary.	It is formed after the release of secondary oocyte from the Graafian follicle.
Secrete	Its granular cells secrete estrogens.	It secretes progesterone.

Summary Introduction

To distinguish: Between the three phases of the menstrual cycle.

Introduction: The developing follicles and the corpus luteum secrete estrogen and progesterone hormones. In the endometrial lining, cyclic changes occur under the influence of estrogen and progesterone. The three phases of uterine cycle are menstrual phase, proliferative phase, and secretory phase.

Explanation of Solution

Tabular representation: Table 6 shows the differences between the three phases of the menstrual cycle.

Table 6: Differences between the three phases of the menstrual cycle:

Criteria	Menstrual phase	Proliferative phase	Secretory phase
Time duration	This phase occurs during the first five days of the uterine cycle.	This phase occurs between 6–14 days of the uterine cycle.	This phase occurs between 15–28 days of uterine cycle.
Events occurs during the phase	In this phase, the functional layer of the endometrium sloughs off and lasts till the period of menstrual bleeding ends.	The proliferative phase is marked by the development of follicle, estrogen secretion, and formation of new functional layer of the endometrium.	Vascularization increases, and the uterine gland develops in response to the secretion of progesterone from the corpus luteum.