Life Sciences Term 1

Structure of the male reproductive system 

Consists of:

• A pair of testes situated in the scrotum
  
• The epididymis, vas deferens, ejaculatory duct and urethra
  
• The seminal vesicles, prostate gland and Cowper’s glands
  
• The penis
  

• The testes are the male sex organs occurring in the scrotum which lies outside the abdominal cavity
• The seminiferous tubules are found inside of each testis
• These tubules are lined with germinal epithelial cells which produce the spermatozoa by spermatogenesis
• Inside the seminiferous tubules there are specialized cells called Sertoli cells
• These cells are rich in glycogen which is thought to serve as nutrients for the spermatids as they develop into sperm or spermatozoa
• The epididymis is a coiled tube lying outside each testis within the scrotum. Leads off of the seminiferous tubule and stores sperm temporarily before sending it to the vas deferens
• The vas deferens Is also called the sperm duct it carries the spermatozoa from the epididymis through the abdomen into the ejaculatory duct
• Ejaculatory ducts join the urethra just after it leaves the bladder. Contractions of the muscular walls of the ejaculatory duct force the semen through the urethra
• The urethra is a tube which runs through the penis and opens at the tip of it. It is a common tube for urine and semen
• There are three accessory glands:
• Seminal vesicles – produce seminal fluid to transport the sperm cells
• 
  
• Prostate gland – secretes a clear, slightly alkaline fluid that makes up 1/3 of the volume of semen
• Cowper’s glands secrete fluid containing nutrients for the sperm
• Secretions of the prostate and Cowper's glands nourish the sperm enabling them to swim and provide protection
• The penis is the copulatory organ, made up of spongy tissue which fills with blood causing the penis to become erect before it is inserted into the female organ.
• Responsible for transferring spermatozoa from the male to the female.

The structure of the female reproductive system

Consists of:

• A pair of ovaries
• Fallopian tube leading from each ovary
• Uterus or womb
• Vagina or birth canal
• Vulva or external opening.

• The ovaries are the female sex organs

• Found in the lower part of the abdominal cavity
• Held in place by ligaments
• Made up of a covering of germinal  epithelium with a large number of follicles in it
• Germinal epithelium produces follicles
• Oogenesis takes place within follicles to produce ova
• Follicles secrete oestrogen and progesterone.

• Fallopian tubes transport the ova from the ovaries to the uterus
• The upper parts of the fallopian tubes are expanded into ciliated funnels which partially enclose the two ovaries

• The uterus is a pear shaped, hollow organ with muscular walls
  
• Endometrium lines the uterus and is richly supplied with blood vessels
  
• Neck of uterus is called the cervix and extends into the vagina
  
• Serves for attachment of the embryo if fertilization takes place
  
• The vagina is a cylindrical sheath like structure that leads from the cervix to the outside forming the opening called the vulva
  
• During copulation the penis is inserted into the vagina where spermatozoa are released