Module 11:Human Health and

Physiology 2

11.4 Reproduction

11.4.1 Annotate a light micrograph of testis tissue to show the location and function of interstitial cells (Leydig cells), germinal epithelium cells, developing spermatozoa and Sertoli cells.

11.4.1 Annotate a light micrograph of testis tissue to show the location and function of interstitial cells (Leydig cells), germinal epithelium cells, developing spermatozoa and Sertoli cells.

(Interstitial cells)

(Germinal epithelial cells)

11.4.2 Outline the processes involved in spermatogenesis within the testis, including mitosis, cell growth, the two divisions of meiosis and cell differentiation

Spermatogonia = germinal epithlelial cellsSpermatogonium = plural of spermatogoniaSpermatozoa (spermatazoon)

Outline the role in spermatogenesis in humans [5 marks]

11.4.3 State the role of LH, testosterone, and FSH in spermatogenesis

• LH: stimulates Leydig cells to make testosterone• FSH and testosterone stimulate meiotic divisions

of spermatogonia into spermatozoa

11.4.7 Outline the role of the epididymis, seminal vesicle and prostate gland in the production of semen.

• Epididymis: Stores sperm while they gain motility. Upon sexual arousal, sperm is moved to vas deferens

• Seminal Vesicles (70%): glands that add high fructose fluid to semen.

• Prostate gland (30%): alkaline fluid added to semen that helps sperm survive in vagina

11.4.4 Annotate a diagram of the ovary to show the location and function of germinal epithelium, primary follicles, mature follicle and secondary oocyte Prophase I

metaphase II(meiosis II will only finish after

fertilisation)

Graafian follicle

prophase II

(2n)

(2n)

(2n)

(n)

(n)

11.4.5 Outline the process involved in oogenesis within the ovary, including mitosis, cell growth, the two divisions of meiosis, the unequal division of cytoplasm and the degeneration of the polar body

Outline the process involved in oogenesis in the human ovary [8 marks]

11.4.6 Draw and label the structure of a mature sperm and egg

11.4.6 Draw and label the structure of a mature sperm and egg

11.4.8 Compare the processes of spermatogenesis and oogenesis, including the number of gametes and the timing of the formation and release of gametes

Spermatogenesis OogenesisNumber of gametes produced

Products of meiosis

Start of process

Duration of production

Timing of release

11.4.8 Compare the processes of spermatogenesis and oogenesis, including the number of gametes and the timing of the formation and release of gametes

Spermatogenesis OogenesisNumber of gametes produced

Many/millions per day one per month/menstrual cycle/28 days / about 400 eggs per life time;

Products of meiosis four / equal division of the cytoplasm / no polar bodies

one / unequal division of the cytoplasm / polar bodies;

Start of process At puberty begins during fetal development;

Duration of production

Throughout adult life Ends at menopause;

Timing of release produced continuously / released during ejaculation

released at ovulation / in the middle of the menstrual cycle;

Both involve meiosisBoth produce haploid cells/nucleiBoth occur in gonads Testes Ovaries

11.4.9 Describe the process of fertilisation, including the acrosome reaction, penetration of the egg membrane by a sperm and the cortical reaction

11.4.10 Outline the role of HCG in early pregnancy

• HCG = human chorionic gonadotrophin• Hormone secreted by embryo after implantation which

prevents degeneration of corpus luteum

11.4.11 Outline early embryo development up to the implantation of the blastocyst• First 24hr: first mitotic division• First 5 days: dividing and moving along oviduct into

uterus• When it reaches uterus, it is called a blastocyst and is

ready to implant into the endometrium

11.4.12 Explain how the structure and functions of the placenta, including its hormonal role in secretion of oestrogen and progesterone, maintain pregnancy• First 24hr: first mitotic division• First 5 days: dividing and moving along oviduct into uterus• When it reaches uterus, it is called a blastocyst and is ready

to implant into the endometrium

Disc-shaped structure that develops from about 12 weeks after corpus luteum stops secretion

Placental villi increases SA for exchange

11.4.13 State that the foetus is supported and protected by the amniotic sac and amniotic fluid

11.4.14 State that materials are exchanged between the maternal and fetal blood in the placenta

Foetus to mother via placenta:•CO2

•Urea•Water•Hormones (i.e. HCG)

Mother to Foetus via placenta:•Oxygen•Nutrients (glucose, amino acids…)•Water•Hormones•Vitamins•Minerals•Drugs•Viruses (i.e. HIV)

Explain the structure and function of the placenta [8 marks]

11.4.15 Outline the process of birth and its hormonal control, including the changes in progesterone and oxytocin levels and positive feedback.

• Drop in progesterone at end of pregnancy• Low oxytocin associated with first contractions of labour

• Positive feedback: mechanoreceptors in uterus sends signals to posterior pituitary gland to produce more oxytocin

• Cervix dilates to 10cm• Babies are typically head first, face down• Afterbirth (expelled placenta)• Lactation occurs shortly after