Human Reproduction Class 12 Notes Biology Chapter 2

 Page 1


Revision Notes
Chapter 3
Human Reproduction
Male and Female Reproductive Systems
? Human beings reproduce sexually and are viviparous.
? In humans, the reproductive phase starts after puberty.
? It involves:
(i) Gametogenesis
(ii) Insemination
(iii) Fertilisation
(iv) Implantation
(v) Gestation
(vi) Parturition
The Male Reproductive System
? It is located in the pelvic region.
? It consists of:
(i) A pair of testes
(ii) Accessory glands and ducts
(iii) External genitalia
Page 2


Revision Notes
Chapter 3
Human Reproduction
Male and Female Reproductive Systems
? Human beings reproduce sexually and are viviparous.
? In humans, the reproductive phase starts after puberty.
? It involves:
(i) Gametogenesis
(ii) Insemination
(iii) Fertilisation
(iv) Implantation
(v) Gestation
(vi) Parturition
The Male Reproductive System
? It is located in the pelvic region.
? It consists of:
(i) A pair of testes
(ii) Accessory glands and ducts
(iii) External genitalia
Testes
? Situated within the scrotum, which protects the testes and also helps in maintaining the
temperature.
? Each testis is 4 to 5 cm in length, and 2 to 3 cm in width, and has about 250
compartments called testicular lobules. Testicular lobules have seminiferous tubules
which are the sites of sperm formation.
? Seminiferous tubules are lined by two types of cells:
(i) Male germ cells - They undergo meiosis to form sperms.
(ii) Sertoli cells - They provide nourishment to the germ cells.
? Region outside the seminiferous tubules is called the interstitial space, which contains
Leydig cells (interstitial cells). The Leydig cells produce androgens.
Accessory Ducts and Glands
? Accessory ducts include:
(i) Rete testis
(ii) Vasa efferentia
(iii) Epididymis
(iv) Vas deferens
? The seminiferous tubules open into the vasa efferentia through the rete testis.
? The vasa efferentia open into the epididymis, which leads to the vas deferens. The vas
deferens opens into the urethra along with a duct from the seminal vesicle called the
ejaculatory duct.
? The ejaculatory duct stores the sperms and transports them to the outside
? The urethra starts from the urinary bladder, extends through the penis and opens via the
urethral meatus.
Page 3


Revision Notes
Chapter 3
Human Reproduction
Male and Female Reproductive Systems
? Human beings reproduce sexually and are viviparous.
? In humans, the reproductive phase starts after puberty.
? It involves:
(i) Gametogenesis
(ii) Insemination
(iii) Fertilisation
(iv) Implantation
(v) Gestation
(vi) Parturition
The Male Reproductive System
? It is located in the pelvic region.
? It consists of:
(i) A pair of testes
(ii) Accessory glands and ducts
(iii) External genitalia
Testes
? Situated within the scrotum, which protects the testes and also helps in maintaining the
temperature.
? Each testis is 4 to 5 cm in length, and 2 to 3 cm in width, and has about 250
compartments called testicular lobules. Testicular lobules have seminiferous tubules
which are the sites of sperm formation.
? Seminiferous tubules are lined by two types of cells:
(i) Male germ cells - They undergo meiosis to form sperms.
(ii) Sertoli cells - They provide nourishment to the germ cells.
? Region outside the seminiferous tubules is called the interstitial space, which contains
Leydig cells (interstitial cells). The Leydig cells produce androgens.
Accessory Ducts and Glands
? Accessory ducts include:
(i) Rete testis
(ii) Vasa efferentia
(iii) Epididymis
(iv) Vas deferens
? The seminiferous tubules open into the vasa efferentia through the rete testis.
? The vasa efferentia open into the epididymis, which leads to the vas deferens. The vas
deferens opens into the urethra along with a duct from the seminal vesicle called the
ejaculatory duct.
? The ejaculatory duct stores the sperms and transports them to the outside
? The urethra starts from the urinary bladder, extends through the penis and opens via the
urethral meatus.
? Accessory glands include:
(i) A pair of seminal vesicles
(ii) Prostate gland
(iii) A pair of bulbourethral glands
? The secretions of these glands make up the seminal plasma, and provide nutrition and a
medium of motility to the sperms.
Mnemonics to Remember Male Reproductive Parts
SEVEn UP
? S – Seminiferous tubule
? E – Epididymis
? V – Vas deferens
? E – Ejaculatory duct
? U – Urethra
? P – Penis
** SEVEn UP is also a quick mnemonic for memorizing the pathway of the sperm.
Page 4


Revision Notes
Chapter 3
Human Reproduction
Male and Female Reproductive Systems
? Human beings reproduce sexually and are viviparous.
? In humans, the reproductive phase starts after puberty.
? It involves:
(i) Gametogenesis
(ii) Insemination
(iii) Fertilisation
(iv) Implantation
(v) Gestation
(vi) Parturition
The Male Reproductive System
? It is located in the pelvic region.
? It consists of:
(i) A pair of testes
(ii) Accessory glands and ducts
(iii) External genitalia
Testes
? Situated within the scrotum, which protects the testes and also helps in maintaining the
temperature.
? Each testis is 4 to 5 cm in length, and 2 to 3 cm in width, and has about 250
compartments called testicular lobules. Testicular lobules have seminiferous tubules
which are the sites of sperm formation.
? Seminiferous tubules are lined by two types of cells:
(i) Male germ cells - They undergo meiosis to form sperms.
(ii) Sertoli cells - They provide nourishment to the germ cells.
? Region outside the seminiferous tubules is called the interstitial space, which contains
Leydig cells (interstitial cells). The Leydig cells produce androgens.
Accessory Ducts and Glands
? Accessory ducts include:
(i) Rete testis
(ii) Vasa efferentia
(iii) Epididymis
(iv) Vas deferens
? The seminiferous tubules open into the vasa efferentia through the rete testis.
? The vasa efferentia open into the epididymis, which leads to the vas deferens. The vas
deferens opens into the urethra along with a duct from the seminal vesicle called the
ejaculatory duct.
? The ejaculatory duct stores the sperms and transports them to the outside
? The urethra starts from the urinary bladder, extends through the penis and opens via the
urethral meatus.
? Accessory glands include:
(i) A pair of seminal vesicles
(ii) Prostate gland
(iii) A pair of bulbourethral glands
? The secretions of these glands make up the seminal plasma, and provide nutrition and a
medium of motility to the sperms.
Mnemonics to Remember Male Reproductive Parts
SEVEn UP
? S – Seminiferous tubule
? E – Epididymis
? V – Vas deferens
? E – Ejaculatory duct
? U – Urethra
? P – Penis
** SEVEn UP is also a quick mnemonic for memorizing the pathway of the sperm.
The Female Reproductive System
? It is located in the pelvic region:
? It includes:
(i) A pair of ovaries
(ii) A pair of oviducts
(iii) Uterus
(iv) Cervix
(v) Vagina
(vi) External genitalia
Page 5


Revision Notes
Chapter 3
Human Reproduction
Male and Female Reproductive Systems
? Human beings reproduce sexually and are viviparous.
? In humans, the reproductive phase starts after puberty.
? It involves:
(i) Gametogenesis
(ii) Insemination
(iii) Fertilisation
(iv) Implantation
(v) Gestation
(vi) Parturition
The Male Reproductive System
? It is located in the pelvic region.
? It consists of:
(i) A pair of testes
(ii) Accessory glands and ducts
(iii) External genitalia
Testes
? Situated within the scrotum, which protects the testes and also helps in maintaining the
temperature.
? Each testis is 4 to 5 cm in length, and 2 to 3 cm in width, and has about 250
compartments called testicular lobules. Testicular lobules have seminiferous tubules
which are the sites of sperm formation.
? Seminiferous tubules are lined by two types of cells:
(i) Male germ cells - They undergo meiosis to form sperms.
(ii) Sertoli cells - They provide nourishment to the germ cells.
? Region outside the seminiferous tubules is called the interstitial space, which contains
Leydig cells (interstitial cells). The Leydig cells produce androgens.
Accessory Ducts and Glands
? Accessory ducts include:
(i) Rete testis
(ii) Vasa efferentia
(iii) Epididymis
(iv) Vas deferens
? The seminiferous tubules open into the vasa efferentia through the rete testis.
? The vasa efferentia open into the epididymis, which leads to the vas deferens. The vas
deferens opens into the urethra along with a duct from the seminal vesicle called the
ejaculatory duct.
? The ejaculatory duct stores the sperms and transports them to the outside
? The urethra starts from the urinary bladder, extends through the penis and opens via the
urethral meatus.
? Accessory glands include:
(i) A pair of seminal vesicles
(ii) Prostate gland
(iii) A pair of bulbourethral glands
? The secretions of these glands make up the seminal plasma, and provide nutrition and a
medium of motility to the sperms.
Mnemonics to Remember Male Reproductive Parts
SEVEn UP
? S – Seminiferous tubule
? E – Epididymis
? V – Vas deferens
? E – Ejaculatory duct
? U – Urethra
? P – Penis
** SEVEn UP is also a quick mnemonic for memorizing the pathway of the sperm.
The Female Reproductive System
? It is located in the pelvic region:
? It includes:
(i) A pair of ovaries
(ii) A pair of oviducts
(iii) Uterus
(iv) Cervix
(v) Vagina
(vi) External genitalia
(vii) Mammary glands (not part of the reproductive system, but aids in child care)
(viii) Ovaries
? They are the primary female sex organs. They produce the ovum and other ovarian
hormones.
? They are located in the lower abdomen, and are 2 to 4 cm in length.
? They are connected by ligaments to the pelvic walls and to the uterus.
? Each ovary is covered by epithelium, and contains the ovarian stroma.
? The ovarian stroma is made up of:
(i) Peripheral cortex
(ii) Inner medulla
(iii) Oviducts
? They are also called fallopian tubes.
? They are 10 to 12 cm long, and extend from the ovary to the uterus.
? The part of each oviduct lying towards the ovary is funnel shaped, and is called
infundibulum. It has finger-like projections called fimbriae.
? The infundibulum leads to the ampulla, and then to the isthmus, which has a narrow
lumen opening into the uterus.
Uterus
? It is also called womb, and is pear shaped.
? It is connected to the pelvic walls by ligaments.
? The uterine wall consists of:
(i) External perimetrium
(ii) Middle myometrium
(iii) Internal endometrium, which lines the uterine cavity.
? The endometrium undergoes changes during the menstrual cycle.
Cervix and Vagina
? The cervix connects the uterus to the vagina.
? The cervix and the vagina constitute the birth canal.
External Genitalia
? Consists of:
Mons pubis - Fatty tissue covered by skin and pubic hair
Labia majora - Extends from mons pubis and surrounds the vaginal opening
Labia minora - Fold of skin beneath the labia majora
Hymen - Partially covers the vaginal opening
Clitoris - Lies at the junction of labia minora