rachna yadav b.tech,m.sc.(mlt),mba · testis-reproductive male organ penis-organ of copulation...
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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.
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