1
Key Reproductive Events in Humans:
1. Gametogenesis → Formation of gametes (sperm in males, ovum in
females).
2. Insemination → Transfer of sperms into the female reproductive tract.
3. Fertilization → Fusion of sperm and ovum, forming a zygote.
4. Blastocyst Formation → Zygote undergoes multiple divisions and forms
a blastocyst.
5. Implantation → Blastocyst attaches to the uterine wall.
6. Gestation (Pregnancy) → Embryonic development inside the uterus.
7. Parturition (Birth) → Delivery of the baby.
Important Points:
Reproductive events begin after puberty.
Males produce sperms throughout life.
Females stop ovum production around 50 years (menopause).
Humans are VIVIPAROUS
Feature Viviparous Oviparous
Birth Type Live young Eggs
Embryo Outside in
Inside mother
Development eggs
Internal or
Fertilization Internal
External
Parental Care High Low
Survival Rate Higher Lower
Birds,
Examples Humans, Dogs
Frogs
, 2
MALE REPRODUCTIVE SYSTEM:
Component Description
Location Pelvic region
Testes – Produce sperms & male hormone
Primary Sex Organs
(testosterone)
Rete testis – Collects sperms from seminiferous
Accessory Ducts
tubules
Vasa efferentia – Transfers sperms to epididymis
Epididymis – Stores and matures sperms
Vas deferens – Carries sperms to the urethra
Ejaculatory duct – Pushes sperms into the urethra
Urethra – Passage for both sperms & urine
Seminal vesicles – Produce fructose-rich fluid for
Accessory Glands
sperm energy
Prostate gland – Activates sperms
Bulbourethral glands – Secrete mucus for
lubrication
External Genitalia Penis – Transfers sperms into the female body
Glans Penis – Soft tip, covered by foreskin
The male reproductive system is located in the pelvic region and includes:
1. Primary sex organs – Testes
2. Accessory ducts – Rete testis, Vasa efferentia, Epididymis, Vas deferens, Ejaculatory
duct, Urethra
3. Accessory glands – Seminal vesicles, Prostate gland, Bulbourethral (Cowper’s)
glands
4. External genitalia – Penis
1. Testes (Primary Sex Organ)
The testes are oval-shaped organs located outside the abdominal cavity in a sac
called the scrotum.
The scrotum maintains a temperature 2–2.5°C lower than the body, essential for
spermatogenesis.
Each testis is 4–5 cm long and 2–3 cm wide and is covered by a dense layer.
Inside each testis, there are about 250 testicular lobules, and each lobule contains
1–3 seminiferous tubules.
Seminiferous Tubules
, 3
The site of sperm production (spermatogenesis).
Lined by two types of cells:
1. Male germ cells (Spermatogonia) – Undergo meiosis to form sperms.
2. Sertoli cells – Provide nutrition to developing sperm cells.
Leydig Cells (Interstitial Cells)
Found in the interstitial spaces outside seminiferous tubules.
Secretes testicular hormones (Androgens, mainly Testosterone).
2. Accessory Ducts
These store and transport sperms from the testes to the outside.
Accessory Function Location
Duct
Collects sperms from seminiferous
Rete testis Inside testes
tubules
Vasa Transports sperms from rete testis to
Leaves the testis
efferentia epididymis
Epididymis Stores and matures sperms Posterior surface of testes
Carries sperms from epididymis to Ascends to the abdomen, loops
Vas deferens
ejaculatory duct over bladder
Ejaculatory Carries sperms + seminal fluid to Formed by vas deferens and
duct urethra seminal vesicle
Urethra Common passage for urine and semen Extends through the penis
3. Accessory Glands
These produce secretions that nourish and transport sperms.
Accessory Gland Secretion Function
Seminal fluid (Fructose, enzymes, Provides energy to
Seminal Vesicles
calcium) sperm
Neutralizes vaginal
Prostate Gland Alkaline secretion
acidity
, 4
Accessory Gland Secretion Function
Bulbourethral (Cowper’s) Lubricates urethra &
Mucus secretion
Glands penis
4. External Genitalia (Penis)
The penis helps in insemination (transfer of sperm into the female reproductive
tract).
Contains erectile tissue that allows it to become rigid.
The glans penis (enlarged tip) is covered by foreskin (prepuce).
Key Reproductive Events in Humans:
1. Gametogenesis → Formation of gametes (sperm in males, ovum in
females).
2. Insemination → Transfer of sperms into the female reproductive tract.
3. Fertilization → Fusion of sperm and ovum, forming a zygote.
4. Blastocyst Formation → Zygote undergoes multiple divisions and forms
a blastocyst.
5. Implantation → Blastocyst attaches to the uterine wall.
6. Gestation (Pregnancy) → Embryonic development inside the uterus.
7. Parturition (Birth) → Delivery of the baby.
Important Points:
Reproductive events begin after puberty.
Males produce sperms throughout life.
Females stop ovum production around 50 years (menopause).
Humans are VIVIPAROUS
Feature Viviparous Oviparous
Birth Type Live young Eggs
Embryo Outside in
Inside mother
Development eggs
Internal or
Fertilization Internal
External
Parental Care High Low
Survival Rate Higher Lower
Birds,
Examples Humans, Dogs
Frogs
, 2
MALE REPRODUCTIVE SYSTEM:
Component Description
Location Pelvic region
Testes – Produce sperms & male hormone
Primary Sex Organs
(testosterone)
Rete testis – Collects sperms from seminiferous
Accessory Ducts
tubules
Vasa efferentia – Transfers sperms to epididymis
Epididymis – Stores and matures sperms
Vas deferens – Carries sperms to the urethra
Ejaculatory duct – Pushes sperms into the urethra
Urethra – Passage for both sperms & urine
Seminal vesicles – Produce fructose-rich fluid for
Accessory Glands
sperm energy
Prostate gland – Activates sperms
Bulbourethral glands – Secrete mucus for
lubrication
External Genitalia Penis – Transfers sperms into the female body
Glans Penis – Soft tip, covered by foreskin
The male reproductive system is located in the pelvic region and includes:
1. Primary sex organs – Testes
2. Accessory ducts – Rete testis, Vasa efferentia, Epididymis, Vas deferens, Ejaculatory
duct, Urethra
3. Accessory glands – Seminal vesicles, Prostate gland, Bulbourethral (Cowper’s)
glands
4. External genitalia – Penis
1. Testes (Primary Sex Organ)
The testes are oval-shaped organs located outside the abdominal cavity in a sac
called the scrotum.
The scrotum maintains a temperature 2–2.5°C lower than the body, essential for
spermatogenesis.
Each testis is 4–5 cm long and 2–3 cm wide and is covered by a dense layer.
Inside each testis, there are about 250 testicular lobules, and each lobule contains
1–3 seminiferous tubules.
Seminiferous Tubules
, 3
The site of sperm production (spermatogenesis).
Lined by two types of cells:
1. Male germ cells (Spermatogonia) – Undergo meiosis to form sperms.
2. Sertoli cells – Provide nutrition to developing sperm cells.
Leydig Cells (Interstitial Cells)
Found in the interstitial spaces outside seminiferous tubules.
Secretes testicular hormones (Androgens, mainly Testosterone).
2. Accessory Ducts
These store and transport sperms from the testes to the outside.
Accessory Function Location
Duct
Collects sperms from seminiferous
Rete testis Inside testes
tubules
Vasa Transports sperms from rete testis to
Leaves the testis
efferentia epididymis
Epididymis Stores and matures sperms Posterior surface of testes
Carries sperms from epididymis to Ascends to the abdomen, loops
Vas deferens
ejaculatory duct over bladder
Ejaculatory Carries sperms + seminal fluid to Formed by vas deferens and
duct urethra seminal vesicle
Urethra Common passage for urine and semen Extends through the penis
3. Accessory Glands
These produce secretions that nourish and transport sperms.
Accessory Gland Secretion Function
Seminal fluid (Fructose, enzymes, Provides energy to
Seminal Vesicles
calcium) sperm
Neutralizes vaginal
Prostate Gland Alkaline secretion
acidity
, 4
Accessory Gland Secretion Function
Bulbourethral (Cowper’s) Lubricates urethra &
Mucus secretion
Glands penis
4. External Genitalia (Penis)
The penis helps in insemination (transfer of sperm into the female reproductive
tract).
Contains erectile tissue that allows it to become rigid.
The glans penis (enlarged tip) is covered by foreskin (prepuce).
