Medicine Core Block - Physiology - The Reproductive System- UCLan

Introduction to the Reproductive System

• Functions: To produce egg and sperm cells as well as to transport and sustain these cells, they may also produce hormones that they are also controlled by.

• Organs: 

  • Male: Scrotum, Penis, Testis, Vas deference, Sperms, Seminal Vesicles, Prostate
  • Female: Labia majora and minora, Ovaries, Fallopian tubes, Ovum, Breast.

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2.11 Male reproductive organs and function

• Scrotum: Outside of the pelvis and 1’C  less body temperature

• Testis: Seminiferous tubules (location of meiosis)

  • Sertoli cells: Sperms (spermatogenesis)
  • Leydig cells: Testosterone

• Epididymis: Functional maturation of sperm

• Vas/ Ductus: Transportation of sperm using smooth muscle and peristalsis

• Semen Composition:

  • Bulbourethral (10%): Produces a clear lubricating fluid
  • Prostate (30%): Silky white acidic milky white fluid, Prostatic fibrinolysin that is a decoagulant.
  • Seminal Vesicle (60%): Alkaline solution, Fructose, Prosaglandis that stimulates uterine contraction and decreases cervical viscosity, Coagulate that turns semen into a bolus and readily propelled into the vagina.

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2.12 Hypothalamic Pituitary Gondal Axis

• Hormones: From the hypothalamus, the hormone GnRH every 2 hours is released into the blood, will arrive at the anterior pituitary and in response to this release there will be 2 hormones traveling via blood and will arrive at the testes

  • Follicle Stimulating Hormone: Act on the Sertoli cells and will produce sperm in the process of spermatogenesis
  • Luteinizing Hormone: Act on the Leydig cells producing testosterone 

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2.13 Female reproductive organs and functions

• Ovary: Oocyte (egg), oestrogen, and progesterone

• Fallopian tube: Contains the infundibulum, ampulla, and fimbriae. Is the site of fertilization where the cilia can be used to help transport the zygote to the uterus

• Uterus: Has the Endometrium which sheds off monthly and where implantation of zygote takes place. There is also the Myometrium where smooth muscle is present and contacts during that are influenced by the hormone oxytocin.

• Cervix: The base of the uterus closed by a narrow passageway, has an alkaline pH as well as columnar epithelial with branched glands. It may be subject to hormonal changes such as during ovulation it is wet, slippery, and stretchable due to spinnbarkeit which is a stretchable mucus. During pre-or-post ovulation there it is in a dry state with thick mucus.

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2.14 Ovarian Cycle

• Ovarian Cycle: This takes place in the period of 28 days and the timing of the eggs is present.
• Mature Ovum Production: 
  • Follicular Phase Days 1-13
  • Ovulation Day 14
  • Luteal Phase Days 15-28
• Sex Hormones:
  • Ovary - Oestrogen
  • Corpus Luteum - Progesterone
• Uterine Cycle:
  • Menstrual Phase Days 1-6
  • Proliferate Phase Days 7-13
  • Secretory Phase Days 15-28
• Menstruation Contains:
  • Stratum functionalist tissues
  • Blood
  • Mucus
  • Secondary Oocyte
  • Endometrial repair starts
• Proliferative Phase:
  • An increasing level of oestrogen
  • Stimulate endometrium to thicken
• Secretory Phase:
  • Continuous secretion of oestrogen and progesterone from Corpus Luteum
  • Continuation of thickening and vascularisation of the endometrium