Biology 8 Lesson 60: Male genitalia
1. Summary of theory
1.1. Parts of the male genitalia
1. Testicles – Where sperm are produced
2. Epididymis – Where sperm continue to develop and perfect in structure
3. Scrotum – Ensure the right temperature for spermatogenesis
4. vas deferens – Carry sperm from testicles to seminal vesicles
5. Seminal vesicles – Place to store and nourish sperm
6. Prostate – secretes fluid mixed with sperm from the seminal vesicles to form semen
7. Urinary tract – Where urine and semen pass
8. Parietal gland (Copos gland) – Secretes fluid to neutralize acid in the urinary tract, prepare for ejaculation, and reduce friction during sexual intercourse
The place where sperm is produced is the testicles. The testicles are located in the scrotum on the outside of the body to create the right temperature conditions for sperm production (about 33-34 years old).0C).
– Located above each testicle is the epididymis – where the sperm continues to mature in structure. Sperm from the epididymis will follow the vas deferens to the seminal vesicles.
In the seminal vesicles, sperm continue to be nourished by the glucose-rich fluid secreted by the vesicle wall. Sperm from the seminal vesicles is mixed with fluid secreted by the prostate gland, forming semen to be ejected through the urinary tract during ejaculation.
– The genitals have 2 small glands located on either side of the base of the urinary tract that secrete an oily fluid that reduces friction during sex and clears the way for sperm to pass through called the bulb.
1.2. Testicles and sperm
a. Testicle structure
The testicles are located inside the scrotum, covered by a thick, white and inelastic fibrous sheath called the white mantle.
– In adulthood, each testicle weighs 20-25g on average, in old age, it is a little lighter, most of the right testicle is heavier than the left.
– The testicles are oval in shape. On average, each testicle weighs about 20-25 g.
Testicles are divided into 300-400 lobules. Each lobule has 2 to 4 spiral seminiferous tubules.
The testicles begin to produce sperm at puberty.
b. Functions of the testicles
The testicles have two main functions:
– Endocrine function: The testes also have another important function, which is to secrete male sex hormones (mainly testosterone), determine male characteristics and control the activity of the reproductive system.
Exocrine function: the testicles are the site of sperm production. Each day, the two testicles of a young man are capable of producing about 120 million sperm. A small amount is stored in the epididymis, but most of the sperm is stored in the vas deferens.
c. Sperm characteristics
- Usually very small and long.
- Includes: head, neck and long tail.
- Move by tail.
There are 2 types of sperm:
- X sperm: larger and have higher vitality than Y sperm.
- Y sperm: small, weak, easy to die.
2. Illustrated exercise
Lesson 1: Which of the following is not part of the male reproductive system?
D. The bladder.
- Choose the answer: A
- Explanation: The ovaries are part of the female reproductive organs.
Lesson 2: In the seminal vesicles, the sperm continues to be nourished by what?
A. Prostate secretions.
B. The gland secretes the fluid that nourishes the sperm.
C. Fluid secreted by the wall of the sac.
D. Glucose-rich fluid secreted by the testicles.
- Choose the answer:
- Explanation: In the seminal vesicles, sperm continue to be nourished by the glucose-rich fluid secreted by the sac wall.
Lesson 3: What is the function of the gland in the male sex organ?
- The gland in the male genitalia has the function of secreting fluid to neutralize the acid in the urinary tract, prepare for ejaculation, and reduce friction during sex.
3.1. Essay exercises
Question 1: Describe the structural features of the sperm involved in fertilization?
Verse 2: Describe the structure of the testicles.
Question 3: Why is the number of sperms per ejaculation so large, but only one sperm is fertilized for the egg? How to explain that contradiction?
3.2. Multiple choice exercises
Question 1: Where is sperm production?
C. seminal vesicles.
Verse 2: Where sperm continues to mature in structure, located above each testicle is
D. seminal vesicles.
Question 3: Which part of the male reproductive system is located outside the body that facilitates the production of sperm?
B. The seminal vesicles.
Verse 4: Why is the scrotum located outside the body and not inside like the liver, kidneys, etc.?
A. Because high body temperature is not suitable for sperm production.
B. Because there is no room in the body.
C. Because it is convenient for the outside of the body to ejaculate.
D. Because it’s been like that since birth, it can’t be explained.
Question 5: Sperm from the epididymis will follow the vas deferens to where?
B. Seminal vesicles.
After completing this lesson, students should know the following requirements:
- Must be able to name and identify the parts of the male reproductive system and the path of sperm from the place of birth to the outside of the body.
- State the basic functions of these parts. State the characteristics of sperm.
- Name and identify on the pictures the parts of the female reproductive organs.
- State the basic functions of the female reproductive organs. State the special characteristics of eggs.