Reproduction System
Dr Robert B. Mbelwa
MD (dar)
Msc Physiology (Makerere)
Definition of terms
• Sexual reproduction:-Is
a physiological
process that creates a new organism by combining
the genetic material of two organisms in a process
that start with meiosis, a specialized type of cell
division
•Reproductive system:-
is a system of sex
organs within an organism which work together
for the sake of sexual reproduction
Function
• Is not for homeostasis of the individual
– A person can survive indefinitely without a
reproductive system
• Is for continuation of the species
– i.e continuation of genes beyond the lifespan of
a single individual
Organization of reproductive
system
• Comprises of
1. Primary reproductive organs (gonads)
2. Secondary reproductive tracts
3. External genitalia
Ctd - General Reproductive
System Organization
A. Primary Reproductive Organs (Gonads)
 Testes (male) and Ovaries (female)
 Whose main functions are to
1. Produce gametes
–
Sperm and Ova
2. Produce and secrete sex steroid hormones
–
–
testosterone, estrogen and progesterone
responsible for gamete development, development of
reproductive tract and secondary sex characteristics
General Reproductive System
Organization
B. Secondary Reproductive Organs
1. Reproductive tract
•
tube connecting gametes to external environment
2. accessory sex glands
•
Produce supportive secretions
C. External Genitalia
– visible portions of reproductive tract
– sexual stimulation
Male Reproductive System
1. Primary sex organs
 Testis
2. Accessory organs
1. Duct system
1.
2.
3.
Epididymis
Vas deferens
Urethra
2. Glands
1.
2.
3.
Seminal vesicle
Prostate
Bulbourethral
3. Penis
Purpose of Male reproductive
system
1. To produce, maintain and transport
sperm (the male reproductive cells) and
protective fluid (semen)
2. To discharge sperm within the female
reproductive tract during sex
3. To produce and secrete male sex
hormones responsible for maintaining
the male reproductive system
External structures
•Unlike the female reproductive system;
most of the male reproductive system is
located outside the body
•This external structures include
•The penis:- Male organ used in intercourse &
urination:•Scrotum:-contains testicles (testes) and act as climate
control system for the testes
•Testicles:-responsible for making testosterone & sperm
generating
Testes
• Sperm production
• Secretion of testosterone
– Interstitial cells
Internal organs of the male
reproductive system
(accessory organs)
1.
Epididymis


2.
Duct System
Transport & Stores sperm until ejaculation
Mature and gain motility
Vas deferens
 Peristaltic contractions propel /transport
mature sperm toward urethra
 Terminates at ejaculatory duct
(seminal vesicle)
3.
Urethra


Tube carrying urine from bladder to outside the
body
Ejaculates semen during orgasm
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Glands
1.
Seminal Vesicles (seminal fluid)
–
Alkaline fluid
•
•
2.
Prostate
i.
ii.
3.
Fructose- energy for sperm movement
prostaglandins- assist in fertilization
Fluid that helps to nourish the sperm
Sperm activating enzyme
Bulbourethrals
–
Clears ,slippery fluid which
Lubricates the urethra and neutralizes acidity
•
Sperm + glandular secretions = semen
–
2 – 5 ml, 110 million sperm per ml
Male external genitalia
Penis
• Copulatory organ in males
• Erectile tissue
– Corpora spongiosum
– Corpora cavernosa
Female reproductive function
Same as in male
Gametogenesis
Hormone production
Copulatory organs
Nurture and develop embryo
Purpose Female reproductive
•External female reproductive structures
•Enable sperm to enter the body
•Protect the internal genital organs from
infectious organisms
Female reproductive function
• Internal female
reproductive structures
• Vagina
• Uterus
• Ovaries
• Fallopian tubes
Female Reproductive System
Internal structures
• Primary Sex organ
– Ovaries
• Accessory Organs
– Duct system
• Uterine tubes
• Uterus
• Vagina
Duct System
1. Uterine tubes
– Receives oocytes
– Site for fertilization
2.
Uterus
– Receive, nourish fertilized ovum
– Site of embryological and fetal
development
3. Vagina
– Copulatory organ
– Birth canal
Female Reproductive System
– External genitalia
•
•
•
•
•
Mons pubis
Labia
vestibule
Greater vestibular gland
clitoris
The External Genitalia
• External genitalia are collectively called the vulva or pudendum
 mons pubis - mound of fat over pubic symphysis bearing most of
the pubic hair
 labia majora – pair of thick folds of skin and adipose tissue inferior
to the mons
• Enclose and protect other external reproductive organs
• Contains sweat and oil secreting glands
 labia minora – medial to labia majora are thin hairless folds
 clitoris - erectile, sensory organ with no urinary role
• primary center for erotic stimulation
 vestibular bulbs - erectile tissue deep to the labia majora
• cause the vagina to tighten around the penis, enhancing sexual
stimulation
 greater and lesser vestibular and paraurethral glands open into
vestibule for lubrication
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