Tag: human physiology

Questions Related to human physiology

A woman whose pituitary was damaged by disease can have a baby if she is given 

  1. Small quantities of FSH and LH each day

  2. Small quantities of FSH and LH each day and one large dose of LH on 15th day

  3. 20 microgram each of estrogen and progesterone each day for 14 days

  4. Small quantity of estrogen every day for 28 days after ovulation


Correct Option: B
Explanation:

  • LH and FSH are pituitary hormones. 
  • These hormones are essential for the growth of follicle from day 1 to day 15 of the menstrual cycle.
  • On the 15th day, high level of LH secretion ( known as LH surge ) causes release of the ovum from Graafian follicle.
  • The release of ovum is absolutely essential for having a baby in normal adult females.
So, the correct option is 'Small quantities of FSH and LH each day and one large dose of LH on 15th day'.

The ratio of the number of chromosomes in a human zygote and a human ovum (egg) is

  1. 1 : 2

  2. 1 : 4

  3. 2 : 1

  4. 4 : 1


Correct Option: C
Explanation:

The reproductive cells contain only half the number of chromosomes as compared to the normal body cells of an organism. The human sperm and egg have 23 chromosomes each. So when they fuse together, the zygote formed has 23+23=46 chromosomes. So the required ratio is 46 : 23, i.e., 2 : 1.

Perineum is the area in the female reproductive system that lies.

  1. Above the external genitalia

  2. Below the external genitalia

  3. Sides of external genitalia

  4. Centre of genitalia


Correct Option: A
Explanation:

In the female reproductive system, the perineum is the area that lies between the vaginal opening and the anus. It represents the most inferior part of the pelvic outlet. Thus it lies above the external genitalia.

So the correct option is 'Above the external genitalia'.

Gonadotropic hormone is secreted by

  1. Adenohypophysis of the pituitary gland

  2. Parathyroids

  3. Interstitial cells of the testes

  4. Adrenal medulla


Correct Option: A
Explanation:

Gonadotropin is secreted from the anterior pituitary gland and it acts on the gonads (i.e., the ovaries or testes). The anterior pituitary contains five types of endocrine cell, and they are defined by the hormones they secrete-somatotropes (GH); Lactotropes (PRL); gonadotropes (LH and FSH); corticotrophs (ACTH) and thyrotropes (TSH). Gonadotrophs, cells that constitute about 10 percent of the pituitary gland, secrete two primary gonadotropins: luteinizing hormone (LH) and follicle-stimulating hormone (FSH). Secretion of LH and FSH is low in both males and females prior to puberty

So, the correct answer is 'adenohypophysis of the pituitary gland'

The female equivalent of the glans of the penis is

  1. Clitoris

  2. Hymen

  3. Vestibule

  4. Vas deferens


Correct Option: A
Explanation:

The glans is a vascular structure of the clitoris. The clitoris is composed of multiple parts: the glans, the clitoral body, and the paired crura and vestibular bulbs. The glans clitoris is the name of the part that most people call the “clitoris.” It is the external part of the clitoris, about the size of a pea, and is located above the urethra. Because the glans is the most highly innervated area of the clitoris, it’s extremely sensitive to touch.

So the correct option is 'clitoris'.

Polar bodies

  1. Nurse the egg as it leaves the follicle

  2. Is extra chromosomal material representing the X chromosome in each female cell

  3. Orient the sperm toward the egg

  4. Allow a reduction in chromosomes while preserving all the food for one egg


Correct Option: D
Explanation:

The cell that results from the asymmetric division of an oocyte is a polar body. In animals and humans, polar bodies are produced after every meiotic division. They are relatively smaller in size due to less cytoplasm compared to the gametocyte that will become the ovum. This is essential so that much of the cytoplasm is available and the chromosomal content is halved at the time of fertilization. The polar bodies will eventually degenerate.

So the correct option is 'allow a reduction in chromosomes while preserving all the food for one egg'.

Estrogen is one of the hormones produced by:

  1. Ovaries

  2. Suprarenal glands

  3. Testis

  4. Pituitary


Correct Option: A
Explanation:

Suprarenal glands secrete adrenaline, testis secrete testosterone, pitutary gand secrete oxytocin and ovaries produce estrogen.

So the correct option is 'ovaries'

Below is given the unorganised list of some important events in the human female reproductive cycle. Identify the correct sequence of these event and select the correct option.
(i) Secretion of FSH
(ii) Growth of corpus luteum
(iii) Growth of the follicle and oogenesis
(iv) Ovulation
(v) Sudden increase in levels of LH

  1. (i) $\rightarrow$ (iv) $\rightarrow$ (iii) $\rightarrow$ (v) $\rightarrow$ (ii)

  2. (ii) $\rightarrow$ (i) $\rightarrow$ (iii) $\rightarrow$ (iv) $\rightarrow$ (iv)

  3. (iii) $\rightarrow$ (i) $\rightarrow$ (iv) $\rightarrow$ (ii) $\rightarrow$ (v)

  4. (i) $\rightarrow$ (iii) $\rightarrow$ (v) $\rightarrow$ (iv) $\rightarrow$ (ii)


Correct Option: D
Explanation:

During the follicular phase, the secretion of FSH happens and this leads to the development of a mature follicle (Graafian follicle). This process of formation of a mature female gamete is called oogenesis. The FSH level increase causes the development of follicles and secretion of estrogen by the growing follicles. Rapid secretion of LH leads to the rupture of Graafian follicle and release of ovum called ovulation. This phase is followed by the remaining parts of Graafian follicle transform into the corpus luteum. 

So, the correct option is '(i) 
 (iii)  (v)  (iv)  (ii)'.

Follicle-stimulating hormone (FSH)

  1. Is secreted by females but not males

  2. Stimulates the seminiferous tubules to produce sperm

  3. Secretion is controlled by gonadotropin releasing hormone (GnRH)

  4. Both (B) and (C)


Correct Option: D
Explanation:

Follicle stimulating hormone is produced by the pituitary gland. It regulates the functions of both the ovaries and testes. Follicle stimulating hormone is one of the gonadotropic hormones, the other being a luteinising hormone. FSH enters the testes, stimulating the Sertoli cells, which help to nourish the sperm cells that the testes produce, to begin facilitating spermatogenesis. The Sertoli cell is a kind of sustentacular cell which serves as a “nurse” cell of the testes and which is part of a seminiferous tubule.

So the correct option is 'both (b) and (c)'.