CHAPTER 9 REPRODUCTION AND DEVELOPMENT...Ovarian cycle ii. Uterine / menstrual cycle. Human...

CHAPTER 9

REPRODUCTION AND

DEVELOPMENT

Human

Reproductive

System

Male reproductive organ

Female reproductive organ

Spermatogenesis

Oogenesis

MALE

FEMALE

Role of hormones in spermatogenesis

Role of hormones

in ovarian cycle &

menstrual cycle

+ve & -ve feedback

mechanism in the

cycles

9.2 HUMAN REPRODUCTIVE SYSTEM: MALE

Learning outcomes:

•Overview male reproductive organ (testis) and the structure of spermatozoa [C1]•Explain the structure of spermatozoa [C2]•Explain the role of hormones in spermatogenesis: GnRH, LH, FSH and Testosterone [C2]•Explain the stages in spermatogenesis and its hormonal control [C2]

At the end of the lesson, students should be able to:

9.2 HUMAN REPRODUCTIVE SYSTEM: FEMALE

Learning outcomes:

At the end of the lesson, students should be able to:

Overview female reproductive organ (ovary) and the structure of

secondary oocyte [C1]

Explain the structure of the secondary oocyte [C2]

Explain the role of hormones in female reproductive cycle:

GnRH, LH, FSH, Estrogen and Progesterone [C2]

Explain the stages in oogenesis [C2]

Explain female reproductive cycle and its hormonal control [C2]

i. Ovarian cycle

ii. Uterine / menstrual cycle

Human reproductive system

• Human reproductive system consists of:

– a pair of primary reproductive organs, or gonads

that produce gametes in a process called

gametogenesis

Male gonads

Female

gonads

Testes (pl) : produce sperms

/ spermatozoa by

spermatogenesis

Ovaries : produce ovum

(pl:ova) by oogenesis

testis

sperms

ovary

eggs (ova)

zygote

embryo

foetus

baby

mitosis

meiosis

fertilization

meiosis

Male Reproductive Organ

Male Reproductive Organ

Site of sperms

production

Male Reproductive Organ

Scattered between

tubules

- Produce

testosterone

• Nourish the deve-

loping and mature

sperm cells

• Produce inhibin

Structure of Sperm

- Consist of a nucleus

- Part of the nucleus

is covered by

acrosome

- Contains lots of

mitochondria

🡪 provide ATP

energy

- Has 9 + 2

arrangement of

microtubules

- Provide movement

Organs Structure Function

Testes Produce sperms and sex hormones

Epididymis Site of sperm maturation and some storage of

sperm

Vas deferens 2 ducts that run from scrotum around and

behind urinary bladder

Conduct and store sperm

Seminal

vesicle

A pair of glands that contributes 60% of

semen total volume (semen – thick,

yellowish, alkaline and contain mucus,

fructose, coagulating enzyme, ascorbic acid

& prostaglandin

Contain

- fructose - nourish the sperm and

- prostaglandin - stimulate contraction of female

reproductive tract & help the semen up the

uterus

Prostate gland Secrete an alkaline fluid (neutralize the acidic

environment of vagina)

Bulbourethral

gland

Secrete mucus

- neutralize any acidic urine

remaining in the urethra

- lubricates the penis, facilitating its

penetration into vagina

Urethra Drains both urine and semen

Penis

Role of Hormones in Spermatogenesis

Hormone Function

Gonadotropin-Releasing

Hormone (GnRH)

Stimulates anterior pituitary gland to secrete

FSH and LH

Luteinizing Hormone (LH) Stimulates Leydig cells to secrete

testosterone

Follicle-Stimulating

Hormone (FSH)

Promotes spermatogenesis by

• stimulating Sertoli cells to synthesize

Androgen binding protein (ABP)

• Stimulates Sertoli cells to secrete

inhibin

Role of Hormones in Spermatogenesis

Hormone Function

Testosterone

Stimulate Primary Sex Characteristics

• Growth of reproductive organs

• Spermatogenesis

Stimulate Secondary Sex Characteristics

• Growth of facial and body hair

• Muscle development

• Voice deepening

Inhibin Inhibits FSH secretion

Role of Hormones in Spermatogenesis

Androgen

binding protein

(ABP)

Spermatogenesis

The formation and development of sperm

Spermatogenesis

Spermatogenesis

SpermiogenesisThe maturation of spermatids into mature, motile spermatozoa

Female Reproductive Organ

Female Reproductive Organ

Structure of Secondary Oocyte

Released during ovulation

Structure of Secondary Oocyte

Granulosa cells

Corona radiata

Zona pellucida

Plasma membrane

Cytoplasm

Nucleus

Secondary Oocyte

Plasma membrane cytoplasm

Granulosa cell

- Secretory cells in

Graafian follicle that

surrounds the oocyte

- Supply nutrients to

the developing oocyte

Zona Pellucida

- A layer of

glycoprotein that

surrounds the

plasma

membrane of a

mammalian egg

cell.

- It develops as a

jelly coat.

First Polar Body

one small cell that

is produced

during the

development of an

oocyte (in the first

of meiotic division)

and finally

degenerates.

- The membrane of

ovum

Roles of Hormones in Female Reproductive Cycle

Hormone Secreted by Function

Gonadotropin-

Releasing Hormone

(GnRH)

Hypothalamus Stimulates anterior pituitary gland

to secrete FSH and LH

Follicle-Stimulating

Hormone(FSH)

Anterior pituitary

gland

- Stimulates follicle

development

Luteinizing

Hormone

(LH)

- Assist FSH in stimulating the

follicles

- Stimulates ovulation

- Stimulates development of

corpus luteum

Roles of Hormones in Female Reproductive Cycle

Hormone Secreted by Function

Estrogen

Ovaries (developing

follicles) and

corpus luteum

- Repair and thickening of

endometrium wall

Progesterone Corpus luteum

- Thicken and maintain the

thickening of endometrium wall/

double thickening

Oogenesis

The development of mature oocytes in the ovaries

• Oogenesis

starts during

embryonic

development

Oogenesis

Oogenesis

Oogenesis

Female Reproductive Cycles1. The Ovarian Cycle 🡪 The cyclic events occur in ovaries

2. The Uterine/Menstrual Cycle 🡪 The changes in endometrial wall of uterus.

Ovarian Cycle

Follicular Phase

(Day 1 – 14)

Luteal Phase

(Day 15-28)

Uterine/Menstrual Cycle

Menstrual Phase

(Day 1-5)

Proliferative Phase

(Day 6-14)

Secretory Phase

(Day 15-28)

Female Reproductive Cycles

Ovarian Cycle Uterine / Menstrual Cycle

Female Reproductive Cycles

• Regulated by

positive and

negative feedback

mechanisms.

• Ovarian cycle

hormones controls

the uterine cycle

endometrial growth

and loss.

Female Reproductive Cycles

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