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PHYSIOLOGY TUTORIAL

Prepared byDr. Amel Eassawi

FUNCTIONAL ANATOMY OF THE REPRODUCTIVE SYSTEM

List the components of reproductive system?

1. Primary reproductive organ (Gonads)

2. Reproductive tract

3. Accessory sex glands

4. External genitelia

What are the primary reproductive organs?

Paired testes in the male and paired ovaries in the female.

FUNCTIONAL ANATOMY OF THE REPRODUCTIVE SYSTEM

What is the functions of mature gonads?

1. Producing gametes (gametogenesis)Spermatozoa (sperm) in male.

Ova (eggs) in female.2. Secreting sex hormones

Testosterone in males.Estrogen and progesterone in females.

FUNCTIONAL ANATOMY OF THE REPRODUCTIVE SYSTEM

What are the functions of the different organs of the reproductive system in males?

Testes: Production of sperm (spermatogenesis).Secretion of testosterone.

Accessory Sex GlandsSeminal vesicles, prostate gland, bulbourethral glandFunction: Secretions provide bulk of semen (liquid substance that is conducive to sperm viability)

Penis: Organ used to deposit semen in female Male Reproductive Tract

Epididymis, ductus (vas) deferens: Sperm maturation Ejaculatory duct: Empty into urethra (canal running length of penis that empties into exterior)

FUNCTIONAL ANATOMY OF THE REPRODUCTIVE SYSTEM

What are the functions of the different organs of the reproductive system in females?

Ovaries: Production of ova (oogenesis). Secretion of estrogen & progesterone.

Female Reproductive TractOviducts (uterine or Fallopian tubes): Pick up ova on ovulation,

serve as site for fertilizationUterus: Responsible for maintenance of fetus during development

Responsible for expelling fetus at end of pregnancyThe lower portion of the uterus is the cervix (projects in the vagina

and contain single, small opening the Cervical canal: Serves as pathway for sperm through the uterus to the site of fertilization. Serves as passageway for delivery of baby from

uterus. Vagina: Connects uterus to external environment.

SEX DETERMINATION

How is the genetic sex is determined?

Depends on combination of sex chromosomes. Determined at time of conception.Depends on which type of sex chromosome is contained within the fertilizing sperm.

SEXUAL DIFFERENTIATIONDiscuss the three levels of genetic, gonadal and phenotypic differences between males and females?

SEXUAL DIFFERENTIATION

Discuss the abnormalities that might take place during sexual differentiation?

Pseudo hermaphrodite: Gonad of one sex and genitalia of other 1. Male Pseudo Hermaphrodite:1. Genetic males whose target cells lack receptors for testosterone are

feminized ( testicular feminizing syndrome)2. Defective testicular development 3. 5α reductsae deficiency ( enzyme, coverts testosteron to DHT)

Female phenotype & XY male genotype

2. Female Pseudo Hermaphrodite:Congenital virilizing adrenal hyperplasiaAdministration of androgen to mother Male phenotype and XX female genotype

SEXUAL DIFFERENTIATION

Discuss the possible defects produced by maternal non-disjunction of the sex chromosomes at the time of meiosis?

(Turner’s syndrome)

(Klinefelter’s syndrome)

PUBERTY

Define puberty?

Puberty is defined as the stage of physical maturation in which an individual becomes physiologically capable of sexual reproduction.

PUBERTY

Discuss the two mechanisms that influence the onset of puberty?

1. An intrinsic brain timing mechanism

2. Changes in hypothalamic sensitivity to gonadal steroid feedback regulation. “Hypothalamic gonadostat “ theory.

PUBERTY

Which hormones will increase at time of puberty?

At puberty secretion of GnRH, FSH,& LH increases and become pulsatile.

During childhood , the hypothalamus is extremely sensitive to the negative feedback exerted by the small quantities of estrogen & testosterone produced by the child's ovaries or testes.

As puberty approaches , the sensitivity of the hypothalamus is decreased and subsequently , it increase the pulsatile GnRH secretion initially at night .

The anterior pituitary responds by progressive secretion of FSH and LH associated with increased secretion of growth hormone .

PUBERTY

What are the mechanism underlying the pulsatile GnRH secretion?

1. Melatonin secretion by pineal gland. 2. Leptin secretion by adipose tissue.

PUBERTY

What are the changes at puberty in females?

I. THELARCHE: The development of breast 2. PUBARCHE: The development of axillary and pubic hairs.

3. MENARCHE: The first menstrual period.

PUBERTY

Enlist the secondary sexual characteristic in females?

What is the characteristic of Puberty in Females?

1. Folliculogenesis proceeds2. Ovulation for first time3. The first menstrual period.4. Increase of Estrogen and progesterone

1. Broadening of hips.2. Subcutaneous fat( buttocks, breast, thighs).3. Growth of external genitalia.4. Pubic and axillary hair.5. Increased sebaceous gland secretions (adrenal androgens).

PUBERTY

Enlist the secondary sexual characteristic in males?

What is the characteristic of Puberty in males?1. Spermatogenesis initiates2. Increased androgen secretion3. Growth of accessory sex structures

ProstateExternal genitalia

1. Broadening of shoulders2. Facial and body hair3. Growth of larynx( deepening of voice)4. Pubic and axillary hair.5. Increased sebaceous gland secretions (adrenal androgens).

PUBERTY

What is the factors Influencing the Time of Puberty?

1. Individual factor (genetic factor)2. Environmental Factors

Socioeconomic statusNutritional statusHealth statusGeographyAltitude

MENOPAUSE

Define menopause?

Absence of menstrual cycle for at least 12 consecutive months

What is climacteric or perimenopause period?

Period of transition from sexual maturity to cessation of reproductive capability. characterized by: Increasingly irregular cycles. Declining estrogen levels. Loss of estrogen primarily affects skeleton and cardiovascular system.

MENOPAUSE

What is the characteristic of menopause?

Cessation of menstrual cycle

Loss of ovarian function

Infertility

Drop in ovarian steroids (estrogen and progesterone)

Rise in gonadotropin hormones

Decrease in ovarian inhibin production

ANDROPAUSE

Male reproductive aging.

Very gradual compared to menopause.

Gradual decrease in sperm production and in testosterone production.

May occur after 45 to 50 years. Results from degenerative changes in small testicular blood vessels.

What is the characteristic of andropause?