The Reproductive System

The Endocrine System is a module in the Anatomy and Physiology course we provide as an E-Course. 

If you are studying anatomy and physiology and have missed a class or need some extra help with a particular system, you can buy each body system individually.  The Anatomy and Physiology of the Reproductive system including; film, workbook, online assessments, supplementary notes and self assessment questions. (FHT CPD Value = 1 Point) Price £14.25

FUNCTION 

The male reproductive system: 

• Production of male gametes 
• Transmission of spermatozoa to female Sperm and testosterone are produced in the testes.  The sperm travel up the testes via the epididymis and the vas deferens into the penis.  The prostate gland, which surrounds the base of the bladder, secrets a fluid during ejaculation which helps to nourish the sperm as well as changing the environment of the urethra from acid to alkaline.  Testosterone is the hormone responsible for male sexual characteristics. 

 
The female reproductive system: 

• Formation of female gametes 
• Reception of male gametes 
• Provision of suitable environment for fertilisation of the ovum by sperm and development of the resulting foetus 
• Childbirth 
• Lactation, nourishment of the baby with breast milk until it can take a mixed diet 

THE FEMALE REPRODUCTIVE SYSTEM

  
FUNCTIONS OF OESTROGEN 
 

• To cause lining of womb to grow thicker 
• Produces female sex characteristics 
• Contributes to calcification of bones 
• Helps lower blood cholesterol 

 
FUNCTIONS OF PROGESTERONE 
 

• Causes laying down of nutrient rich lining in womb 
• Inhibits contraction and tone of uterus 
• Maintains tone in cervix

OVARIES 

• Produce: 
  • Ova 
  • Oestrogen
  • Progesterone 
• Contains thousands of immature follicles 
• Each month one follicle matures – the graafian follicle - ruptures and releases its egg --- OVULATION --- 
• The ruptured follicle is then called the corpus luteum 
• Oestrogen is produced as the follicle matures 
• Progesterone is produced by the corpus luteum 

 
FALLOPIAN TUBES 

• Egg travels down these with the aid of fronds and peristalsis 
• Fertilisation takes place here 

UTERUS 

• Hollow muscular cavity 
• Lining --- ENDOMETRIUM --- grows under influence of ovarian hormones 
• Fertilisation of an egg needs to occur between 8-48 hours after ovulation 
• If fertilisation does not occur then the corpus luteum disintegrates, hormone levels decrease and the lining of the womb is shed 

 
MENSTRUAL CYCLE 

• Occurs approx every 26-30 days 
• Involves stimulation of ovaries by hypothalamus and pituitary 
• hormonal secretions: 
  • Follicle Stimulating Hormone (FSH) 
  • Luteneising Hormone (LH) 

NORMAL MENSTRUAL CYCLE – 3 phases involved: 
 
Proliferative Phase (Days 4-13) 

• Here the womb lining is being stimulated to grow or proliferate under the influence of oestrogen Continues up to ovulation 
• There is an increase in blood vessels and mucus producing cells 
• Secretory Phase (Days 14-28) 
• Progesterone continues to stimulate womb lining but now it is richer in nutrients, water and mucus 
• Menstrual Phase (Days 1-4) 
• If the egg has not been fertilized then the production of progesterone and oestrogen falls 
• The lining of the womb starts to break down and the period starts 

TIMING 
 
Days 1~2  Period begins – lining of uterus comes away. Low levels of oestrogen and progesterone 
 
        3~7 Follicle growing and beginning to secrete oestrogen 
 
        8~13 Oestrogen levels high and lining of uterus thickening 
 
        14 Ovulation occurs, oestrogen levels high.  Once egg has left the follicle the remaining corpus luteum produces progesterone 
 
        15~20 Oestrogen levels start to fall slightly 
 
        21~25 Progesterone levels high 
 
        26~28 Oestrogen and progesterone levels falling now that fertilisation has not taken place 

MENOPAUSE 

• The cessation of periods due to the falling off of ovarian function 
• Normally occurs about 45-55 years old 
• May take several years to be complete 

 
THE BREASTS 
Breasts are considered accessory organs to the reproductive system as their main purpose is to provide nourishment for the baby. 
Throughout pregnancy there is growth of milk producing ducts and after birth there is the production and secretion of milk.   
They are made up of glandular tissue, which forms milk ducts, as well as connective, fibrous and adipose tissue and are divided into lobes and lobules. 

Additional Information - VTCT Qualification 

The Female breast 
Breasts are considered accessory organs to the reproductive system as their main purpose is to provide nourishment for the baby. They are made up of glandular tissue, which forms milk ducts, as well as connective, fibrous and adipose tissue and are divided into lobes and lobules. 
They have a rich blood supply as well as lymphatic drainage – mainly to the axillary nodes .The breasts are surrounded and supported by Cooper’s ligaments which then attach to the chest wall. These ligaments can become irreversibly stretched if the breasts grow very large or are unsupported during vigorous exercise. 
The increase in hormones during puberty and pregnancy are responsible for their development and growth. Changes also take place during the menstrual cycle as the body prepares itself for pregnancy and this can cause discomfort and sensitivity in some women in the pre menstrual phase. After the menopause when there is no longer any hormonal stimulation through a menstrual cycle the breasts tend to lose their elasticity and support. 

In men there is a condition called gynaecomastia where there is excessive growth of breast tissue. Normally it only affects one side 
and is benign but it may be the result of an underlying hormonal or liver disorder. 
 
Female Genitalia 
The vulva is the general term for the major external female genitalia: 
the labia, clitoris, vaginal and urethral openings and the mons pubis (the pad of fat over the symphysis pubis) 
The perineum is the muscular area between the anus and the vulva. It may become torn during childbirth. 

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