Embryology – Part 1
Introduction
Male Reproductive System
- Primary sex organs: Testes (gonads)
o Exocrine function - sperm production
o Endocrine function - testosterone production
- External genitalia
o Penis
o Scrotum – contains gonads (testes)
o Accessory organs: Duct system and glands
Female reproductive system
- Primary sex organs: ovaries (gonads)
- Accessory organs:
o Uterine tubes
o Uterus
o Vagina
o Clitoris
o Mammary glands
Sexual reproduction = the process of creating new organisms by combining genetic information from
two individuals
Introduction to Gametogenesis
- Germ cells can convert into either male or female gametes
- Two process are needed for this to successfully occur: meiosis and mitosis
- Daughter cells are diploid and are genetically identical to the parent
o diploid = 2n
, - In meiosis the chromosomes pair and form chiasma
- They pull apart and form the first stage of meiotic division – the cell splits into two
leaving 23 chromosomes pairs (46 chromosomes) in each daughter cell
- These daughter cells are genetically different from the parent cells in which they’ve
derived from
- These two daughter cells split again – these cells contain 23 chromosomes
Parthenogenesis
- The ability for a species to produce offspring through form of asexual reproduction
- One known case in humans!
Male reproductive system: Spermatogenesis
- Primordial germ cell enters the
adluminal portion of the seminiferous
tubule to from spermatogonium
- Divides by mitosis inside seminiferous
tubule
o The division of the diploid by
mitosis produces daughter cells
- The process then goes into meiosis –
meiotic division I and II sees through
primary and secondary spermatocytes
- This progresses and forms into
spermatids – 4 are produced
o 2 spermatids contain X sex
chromosomes and 2 contain Y
sex chromosomes
- The spermatids mature through the
process of spermiogenesis
o Develop tails
Introduction
Male Reproductive System
- Primary sex organs: Testes (gonads)
o Exocrine function - sperm production
o Endocrine function - testosterone production
- External genitalia
o Penis
o Scrotum – contains gonads (testes)
o Accessory organs: Duct system and glands
Female reproductive system
- Primary sex organs: ovaries (gonads)
- Accessory organs:
o Uterine tubes
o Uterus
o Vagina
o Clitoris
o Mammary glands
Sexual reproduction = the process of creating new organisms by combining genetic information from
two individuals
Introduction to Gametogenesis
- Germ cells can convert into either male or female gametes
- Two process are needed for this to successfully occur: meiosis and mitosis
- Daughter cells are diploid and are genetically identical to the parent
o diploid = 2n
, - In meiosis the chromosomes pair and form chiasma
- They pull apart and form the first stage of meiotic division – the cell splits into two
leaving 23 chromosomes pairs (46 chromosomes) in each daughter cell
- These daughter cells are genetically different from the parent cells in which they’ve
derived from
- These two daughter cells split again – these cells contain 23 chromosomes
Parthenogenesis
- The ability for a species to produce offspring through form of asexual reproduction
- One known case in humans!
Male reproductive system: Spermatogenesis
- Primordial germ cell enters the
adluminal portion of the seminiferous
tubule to from spermatogonium
- Divides by mitosis inside seminiferous
tubule
o The division of the diploid by
mitosis produces daughter cells
- The process then goes into meiosis –
meiotic division I and II sees through
primary and secondary spermatocytes
- This progresses and forms into
spermatids – 4 are produced
o 2 spermatids contain X sex
chromosomes and 2 contain Y
sex chromosomes
- The spermatids mature through the
process of spermiogenesis
o Develop tails
