RACHNA YADAV

B.Tech,M.Sc.(MLT),MBA

Used for producing offspring

Essential for propagation of the species

Doesn’t work continuously

Activated at puberty

Humans are dieocious

Genes responsible for gonad differentiation

activated at 7th week

TESTIS-reproductive male organ

PENIS-organ of copulation

DARTOS-involuntary muscle responsible for scrotal wrinkles

Epididymis- 4-6 meters in length

Spermiogenesis (sperm maturation) occurs in epididymis

Sperms take about 12 days to traverse the epididymis.

Spermatogenesis (production of sperm) occurs in the seminiferous tubules.

Testes produce the sperm and secrete testosterone.

The seminal vesical secretes fructose, vitamin C, prostaglandins, amino acids and the bulk of the semen

The prostate gland contains two lobes and is a firm organ

Plasmin secreted by prostate

Cowper's glands are useful for flushing the urethra of residual urine or other substances that may damage sperms while passing through the urethra

Total volume of semen per ejaculation is about 3-6 mL and contains nearly300 to 400 million sperms

Stage I: Pre-adolescent; no pubic hair

Stage II: Scrotum/testes enlarge; texture of

scrotum changes; scrotum begins to redden;

rugae appear

Stage III: Growth of penile length; Further

growth of testes/ scrotum; first pubic hair

Stage IV: Penis increases in length AND width;

development of the glans; further darkening of

scrotal skin

Stage V: Genitalia adult in size and shape and

color; no further enlargement occurs after this

stage

Ovaries are the primary organs of

reproduction in the female

Vagina is organ of copulation

Labia minora contain no hair, but external

layer of the labia majora have hairs

There are about one million follicles at birth

between both ovaries

About 400 follicles reach maturity

throughout the woman's reproductive life

Ovaries secrete estrogens and progesterone

Female urethra is only about 4 cm in length

Normally uterus is anteflexed

Site of follicular development

Primary follicle develops into a primary oocyte

When primary oocyte develops into the Graafianfollicle around 14 days into the cycle,estradiolinhibit the release of FSH and stimulate the release of LH

LH surge leads to release of secondary oocytefrom the graffian follicles into the abdominal cavity

LH levels decrease after ovulation

Fimbria moves the ovum into into the tubule for fertilization or for excretion if fertilization doesn't occur

The remaining follicle tissue differentiates from the corpus hemorrhagicum (bloody body) into the corpus luteum (yellow body; CL)

The CL secretes progesterone to prepare the inner lining of the uterine wall for implantation if fertilization occurs

The CL differentiates to the corpus albicans(white body) if there is no fertilization and progesterone and estradiol levels drops and leads to menstrual bleeding

If fertilization occurs, the CL continues to secrete progesterone until the placenta is sufficiently prepared to do so

Typically takes 28 days to cycle through 4

phases

– Follicular

– Ovulation

– Luteal

– Menstruation

Begins when estrogen levels are low

Anterior pituitary secretes FSH and LH,

stimulation follicle to develop

Cells around egg enlarge, releasing

estrogen

This causes this uterine lining to thicken

LH and FSH still being released, for another

3-4 days

Follicle ruptures, releasing ova into the

Fallopian tubes

Now empty follicle changes to a yellow

colour, becomes corpus luteum

Continues to secrete estrogen, but now

brings to release progesterone

Progesterone further develops uterine lining

If pregnant, embryo will release hormones to

preserve corpus luteum

If no embryo, the corpus luteum begins to

disintegrate

Progesterone levels drop, uterine lining

detaches, menstruation can begin

Tissue, blood, unfertilized egg all discharged

Can take from 3-7 days

Fertilization-union of a male sperm and

female’s egg

Zygote-as soon as the ovum is fertilized

Protective membrane. (Day 1-4)

Blastocyst-cluster of cells characterized by

hallow center (Day 4-6)

Embryo-cluster of cells that develop between

3-8 weeks following implantation

Multiple factors leads to normal development of the breasts during puberty

CNS contributes via psychological factors and catecholamines

PIF, LH, FSH, TRH, GnRH and PRL released by hypothalamus and pituitary glands play role in normal breast development

Thyroid hormones adrenal corticoids helps in development of mammary appendages

Estrogens and progesterone from ovaries and sensory input through the peripheral nervous system also helps in breast development

1.Aereola

2.Nipple

3.Pectoralis major

4.Fat globule

5.Milk ducts

6.Connective tissue

1.Fat

2.Cooper's ligament

3.Connective tissue

4.Pectoralismajor

5.External intercostal

6.Internal intercostal

7.Nipple ducts

2N spermatogonium undergoes mitosis to

form a primary spermatocyte and is

arrested in prophase I at birth

At puberty 2N cell undergoes meiosis I to

form two secondary spermatocytes

Secondary spermatocytes then undergo

meiosis II to form four early spermatids

which mature to late spermatids, then to

spermatozoa

2N cells (oogonium) arrested as primary

oocytes in prophase I at birth

At puberty primary oocyte undergoes meiosis

I to form a polar body and a secondary

oocyte

After ovulation secondary oocyte must be

fertilized by a sperm BEFORE it can undergo

meiosis II

zygote is formed after fertilization that will

differentiate into an embryo and then into a

fetus.