Tag: human physiology

Quizzes (44) Questions (49)

Questions Related to human physiology

Multiple choice female reproductive structure reproductive system of human hormones, homeostasis, and reproduction human physiology biology

$32$ celled stage of human embryo is?

  1. Smaller than fertilized egg

  2. Same size of fertilized egg

  3. Two times the size of fertilized egg

  4. Four times the size of fertilized egg
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

During early cleavage, the embryo undergoes cell division without increasing in total volume, so the 32-celled stage (morula) is roughly the same size or smaller than the original fertilized egg due to the zona pellucida constraint.

Multiple choice female reproductive structure reproductive system of human hormones, homeostasis, and reproduction human physiology biology

Fertilizins are emitted by

  1. Immature eggs

  2. Mature eggs

  3. Sperms

  4. Polar bodies
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Mature egg secretes a chemical known as fertilizin, which is composed of glycoprotein (monosaccahride and fatty acid substance). Sperm has on its surface a protein substance known as antifertilizin, which is composed of acidic amino acids. The fertilizin and antifertilizin interacts together and this interaction makes the sperms stick to the egg surface. Hence, option B is correct answer.

Multiple choice female reproductive structure reproductive system of human hormones, homeostasis, and reproduction human physiology biology

Ovulation hormone is 

  1. FSH

  2. ICSH

  3. LH

  4. Testosterone
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The average length of the menstrual cycle is about 28 days. By convention the days of the cycle are numbered from the beginning of the menstrual phase of the menstrual cycle, which usually lasts about 4 days. This is followed by the proliferative phase (about 10 days), then by the secretory phase (about 14 days). 

The secretion of gonadotropins (LH and FSH) increases gradually during the follicular phase, and stimulates follicular development as well as secretion of estrogens by the growing follicles. Both LH and FSH attain a peak level in the middle of cycle (about 14th day). Rapid secretion of LH leading to its maximum level during the mid-cycle is called as LH surge, induces rupture of Graafian follicle and thereby the release of ovum (ovulation).

Multiple choice female reproductive structure reproductive system of human hormones, homeostasis, and reproduction human physiology biology

In mammals the female secondary sexual characters are developed mainly by the hormone

  1. Relaxin

  2. Estrogens

  3. Progesterone

  4. Ganadotropins
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Estrogens are the primary female sex hormones. They promote the development of female accessory/secondary sexual characteristics, such as breasts, and are also involved in the thickening of the endometrium and other aspects of regulating the menstrual cycle.

Multiple choice female reproductive structure reproductive system of human hormones, homeostasis, and reproduction human physiology biology

Estrogen is secreted by

  1. Ovary

  2. Membrana granulosa of Graafian follicle

  3. Germinal epithelium of ovary

  4. Pituitary
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A cross section of ovary reveals a cortex and a vesicular medulla. The cortex contains round epithelial vesicle or follicles; follicles are actual center of ovum production or oogenesis. Each primary oocyte is surrounded by a layer of granulosa cells and then called the primary follicle. Follicles are usually located directly beneath the cortex of the ovary. They secret estrogen. But once they begin to mature, they migrate towards the inner medulla. The medulla consists of layers of soft stromal tissue. The stromal tissue contains rich supply of blood vessels, nerves and lymph vessels.

Multiple choice female reproductive structure reproductive system of human hormones, homeostasis, and reproduction human physiology biology

In uterus, endometrium, proliferates in response of

  1. Relaxin

  2. Oxytocin

  3. Progesterone

  4. Estrogen

  5. LH
Reveal answer Fill a bubble to check yourself
C,D Correct answer
Explanation

In humans, the menstrual cycle starts with the menstrual phase, when menstrual flow occurs and it lasts for 3-5 days. The menstrual flow results due to breakdown of endometrial lining of the uterus and its blood vessels which forms liquid that comes out through vagina. Menstruation only occurs if the released ovum is not fertilised. 

The menstrual phase is followed by the follicular phase. During this phase, the primary follicles in the ovary grow to become a fully mature Graafian follicle and simultaneously the endometrium of uterus regenerates through proliferation. These changes in the ovary and the uterus are induced by changes in the levels of pituitary and ovarian hormones. The secretion of gonadotropins (LH and FSH) increases gradually during the follicular phase, and stimulates follicular development as well as secretion of estrogens by the growing follicles. Both LH and FSH attain a peak level in the middle of cycle (about 14th day). 
Rapid secretion of LH leading to its maximum level during the mid-cycle called LH surge induces rupture of Graafian follicle and thereby the release of ovum (ovulation). The ovulation (ovulatory phase) is followed by the luteal phase during which the remaining parts of the Graafian follicle transform as the corpus luteum. 
The corpus luteum secretes large amounts of progesterone, which is essential for maintenance of the endometrium. Such an endometrium is necessary for implantation of the fertilised ovum and other events of pregnancy. During pregnancy all events of the menstrual cycle stop and there is no menstruation. In the absence of fertilisation, the corpus luteum degenerates. This causes disintegration of the endometrium leading to menstruation, marking a new cycle. In the monthly menstrual cycle, the uterus undergoes cyclical changes of growth and degeneration. 
Estrogens produced from the developing follicles stimulate endometrial growth, and progesterone is responsible for converting the estrogen-primed endometrium into a receptive state. 

Multiple choice female reproductive structure reproductive system of human hormones, homeostasis, and reproduction human physiology biology

Number of eggs released in the life time of a woman is approximately

  1. 40

  2. 400

  3. 4000

  4. 20000
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

When a woman is born there are usually one million eggs in each ovary and one egg will be released, when she ovulates every month during her menstrual cycle, which is approximately 400-500 eggs over her lifetime. As a woman gets older the rest of the eggs disappear, break down or deteriorate and by the time she reaches menopause, there are no eggs left. Thus, the correct answer is option B.

Multiple choice female reproductive structure reproductive system of human hormones, homeostasis, and reproduction human physiology biology

Progesterone is secreted by

  1. Corpus aorta

  2. Corpus albicans

  3. Corpus luteum

  4. Corpus callosum
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Progesterone is produced in large amounts in the ovaries by the corpus luteum. It begins producing at the stage of puberty and produced till menopause. It is involved in the menstrual cycle, pregnancy and embryogenesis of humans and other species. 

Multiple choice female reproductive structure reproductive system of human hormones, homeostasis, and reproduction human physiology biology

The hormone that initiates ejection of milk, stimulates milk production and growth of ovarian follicles are respectively known as

  1. PRL, OT and LH

  2. OT, PRL and FSH

  3. LH, PRL and FSH

  4. PRH, OT and LH
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
I. Ejection of milk is stimulated by the hormone oxytocin (OT).
II. Milk production is stimulated by the hormone prolactin (PRL).
III. Growth of ovarian follicles is maintained by the hormone Follicle Stimulating Hormone (FSH).
So, the correct answer is 'OT, PRL and FSH'.