Chapter 15: Doc.1 The Sexual Cycle

Question 1

Anatomy of the genital system

Answer 1

The genital system consists of 2 ovaries and the genital tract:
- Ovaries:
Responsible for: 1- the production of female sexual cells
2- secretion of female sexual
hormones
- Genital Tract:
It extends to the external surface and provides a favorable environment for the male gamete reception, the ova fertilization and the fetal development
This tract begins by oviducts, which conduct to the ova and then to the uterus

Question 2

Define Uterus and its anatomy

Answer 2

Uterus is a muscular organ made up of 3 layers :
1- The perimetrium (serous external layer):
It’s the outer layer
2- The myometrium ( muscular layer):
It’s a thick middle layer of smooth muscle
3- The endometrium ( internal layer):
It’s the most inner layer that’s made up of mucosa
It is made up of 3 layers:
- Superficial layer
- Functional Layer
- Basal Layer

Question 3

What layer of the uterus is rich in blood vessels and secretory glands?

Answer 3

Superficial layer of the endometrium

Question 4

What’s the place where the embryo develops

Answer 4

The uterine cavity

Question 5

Define the cervix

Answer 5

• The cervix is the lower constricted part of the uterus, connected to the vagina, it contains numerous mucus secreting glands.
• The constricted cervix and the secreted cervical mucus form a barrier against infection, between the uterus and the vagina; it also prevents the passage of the sperm cells throughout most of the cycle.

Question 6

Duration of the sexual cycle

Answer 6

In humans, the average duration of the sexual cycle is about 28 dyas. The cyclical changes at the level of both ovaries and endometrium are synchronized

Question 7

Stages of the ovarian cycle

Answer 7

1- Preovulatory phase:
Starts from day 0 to day 14 where cavitary becomes graafian follicle
2- Ovulation:
Starts at day 14 where graafian follicle bursts to release oocyte
3- Postovulatory phase or luteal phase:
Starts from day 14 to 28, where ruptured follicle becomes yellow body then degenerates

Question 8

What is remained in the ovaries and determine their fate

Answer 8

In the ovaries, what are remained are granulosa, theca interna & theca externa
- they become yellow body

Question 9

What is remained in the oviduct and determine their fate

Answer 9

Oocyte II, zona pelucida, corona radiata

- go to the oviduct

Question 10

Stages of the uterine cycle

Answer 10

1- During menstruation:
The superficial layer of endometrium degenerates and will be sloughed off, exposing the blood vessels situated below which leads to bleeding

2- During Proliferation:
The endometrium begins to thicken and becomes richly supplied with blood vessels, while the uterine tube-like glands enlarge.

3- During Secretory Phase:
The endometrium continues to thicken, the uterine glands start to secrete a fluid rich in nutrients(glycogen). The endometrium looks like a “uterine lace”

Question 11

Female sexual cells

Answer 11

ovaries

Question 12

site of fertilization

Answer 12

oviduct

Question 13

Site of implantation

Answer 13

uterus

Question 14

Copulatory organ

Answer 14

vagina

Question 15

Cervical mucus cycle

what are the 2 types of mucus secreted

Answer 15

The cervix and the vagina contain glands that secrete substances called mucus:
1- Thin & diluted
2- Thick & dense

Question 16

Stages of Cervical mucus cycle

Answer 16

• Outside Ovulation
  Day 0 to day 12 / Day 16 to day 28
  Secretion or cervical mucus will be very thick and dense, to form an impermeable membrane and prevent the penetration of sperm cells
• During Ovulation:
  2 days before/ 2 days after
  Secretion will be thin and diluted
  it will be an open road for the sperm cells to enter smoothly: facilitate penetration

Question 17

Stages of sperm cycle

Answer 17

• Preovulatory phase:
  The temperature fluctuates from 36.8 to 36.9
• Ovulation:
  temperature rapidly increases to 37.2
  This fluctuation is due to hormones such as progesterone (presence of yellow body) that increases the body temp.
• Postovulatory Phase:
  temperature fluctuates between 37 and 37.2