ReproductiveSystems

1 Mark Questions

1. Why are humans testes located outside the abdominal cavity? Name the pouch in which they are present. [All India 2014]

Ans. Human testes are located outside the abdominal cavity as it helps in maintaining low temperature, (2-2.5°C lower than body temperature), required for spermatogenesis. Testes are enclosed in a pouch called scrotum.

1. Write the location and functions of following in human testes.

(i)Sertoli cells (ii)Leydig cells [All India 2014]

Ans.(i) Location of Sertoli cells Within the lining of seminiferous tubule of testis.

Function of Sertoli cells They provide nutrition to the developing sperm cells.

1. Location of Leydig cells In the interstitial spaces between the seminiferous tubules.

Function of Leydig cells It synthesises and secrete hormones androgens, e.g. testosterone

3.List the different parts of human oviduct through which the ovum travels till it meets the sperm for fertilisation.[Delhi 2014 C]

Ans. The different parts of human female oviduct through which the ovum travels, till it gets fertilised are given below in the sequence.

1. Fimbriae, finger-like projections Collect or catch the ovum, after ovulation.

(ii)Infundibulum Ovum from fimbriae is guided into funnel-shaped infundibulum, part of Fallopian tube.

1. Ampulla A wider part of oviduct that leads ovun into isthmus.
2. Isthmus With narrow lumen, and in the portion or junction of ampulla-isthmus, the ovum gets fertilised..

4. Write the location and function of Sertoli cells in humans. [Delhi 2012]

Ans.Location of Sertoli cells Within the lining of seminiferous tubule of testis.

Function of Sertoli cells They provide nutrition to the developing sperm cells.

2.Mark Questions

1. Where are fimbriae present in a human female reproductive system. Give their function.

[Delhi 2009]

Ans. Fimbriae are present in funnel-shaped edges of the Fallopian tube or oviduct in human female reproductive system. They help in the collection of ovum/secondary oocyte after ovulation.

6. Where are Leydig cells present? What is their role in reproduction? [All India 2009]

Ans. Location of Leydig cells In the interstitial spaces between the seminiferous tubules. Function of Leydig cells It synthesises and secrete hormones androgens, e.g. testosterone

3 Marks Questions

7. Name and explain the role of inner and middle walls of human uterus. [Delhi 2014]

Ans. The innermost wall of uterus is called endometrium.

Role of Endometrium

1. It lines the uterine cavity and is glandular in nature
2. It undergoes cyclical changes during menstrual cycle.

The middle wall or layer of uterus is called myometrium.

Role of Myometrium

1. It is made up of thick layer of smooth muscles.
2. It shows strong contractions during delivery of baby.

8.Draw a labelled diagrammatic view of human male reproductive system.[Delhi 2014]

Ans Male reproductive system

Male reproductive system includes a pair of testes, accessory ducts, glands and the external genitalia.

1. Testes are located outside the abdominal cavity within a pouch called Scrotum maintains

the low temperature of the testes (2-2.5°C lower than the normal body temperature) required for spermatogenesis.

(a)Each testis is oval-shape (length 4-5 cm and width 2-3 cm) and covered by a dense covering called tunica albuginea.

(b)Internally it is divided into about 250 compartments known as testicular lobules.

(c)Each lobule contains 1-3 highly coiled (structural and functional units of testis) called seminiferous tubules in which sperms are produced.

(d)Seminiferous tubule is lined on its inside by two types of cells called male germ cells (spermatogonia) and Sertoli cells.

(e)Male germ cells undergo meiotic divisions finally leading to sperm formation.

(f)Sertoli cells provide nutrition to the germ cells.

(g)Interstitial spaces are present in outside regions of seminiferous tubules which contain small blood vessels and interstitial cells or Leydig cells.

(h)Leydig cells synthesise and secrete the testicular hormones called androgens

1. Male accessory ducts include rete testis, vasa efferentia, epididymis and vas deferens.
2. The intratesticular duct system starts with tubuli recti, which are short, straight end segments of the seminiferous tubules. These tubules connect the seminiferous tubules to the highly anastomosing, cuboidal epithelium-lined channels called rete testis.

(b)From rete testis, 10-25 fine tubules arise called vasa efferentia that leave the testis and open into the epididymis.

1. Epididymis leads to vas deferens that ascends to the abdomen and loops over the urinary bladder