Reproductive System - Review Flashcards
Parts of the male reproductive system
- testis
- system of Ducts
- glands
- penis
producs sperm and sex hormoes
testis
secrete seminal fluid
glands
delivers semen
penis
meiosis produces gametes in the seminiferous tubules
spermatogenesis
functional unit in the testis that produces spermatozoa (haploid, 1n) from spermatogonia (diploid, 2n) during spermatogenesis
seminiferous tubule
types of cells in the seminiferous tubules
- spermatogenic series
- nonspermatogenic series
cells in spermatogenic series
- spermatogonia
- spermatocytes
- spermatids
- spermatozoa
- primordial male germ cells that are the precursors of spermatozoa
- diploid, 2n
Spermatogonia
- cells in the testis that produce sperm cells
- are created from spermatogonial stem cells and undergo meiosis to produce haploid spermatids, which eventually become sperm
Spermatocytes
product of the second meiotic division that undergoes a complex process of morphological and functional changes known as spermiogenesis, transforming from a round cell with a central nucleus to a specialized sperm cell.
spermatid
male sex cells that carry genetic material
Spermatozoa (sperm)
cells in nonspermatogenic series
- Sertoli C.
- Leydig cells
secrete inhibin
Sertoli C.
cells in the testes that produce testosterone and other androgens
Leydig cells
Structure of the Sperm
- head
- middle piece
- tail or flagella
contains the half of the genome and acrosome containing the enzymes
head
- vesicle in the sperm head that contains enzymes that help the sperm penetrate an egg
- cap-like structure that sits over the sperm nucleus.
acrosome
contain the mitochondria which provide the ATP for its journey to the egg
middle piece
for locomotion
tail or flagella
human sperm cell size
50-70 μm
human sperm cell shape
ovoid
human sperm cell number
200 M
external parts of female reproductive system
- clitoris
- labia minora and majora
- most sensitive part of your vulva
- capable of producing the most intense and most pleasurable sexual responses in your body
clitoris
fleshy outer lips of the vulva are known as the
labia majora
The inner lips, which usually lead the way to the vaginal opening
labia minora
internal parts of the female reproductive system
- ovary
- system of ducts
- uterus
produces egg cells and hormones
ovary
- development of a mature egg
- a prolonged process
oogenesis
where do immature eggs form
female embryo
lots of connective tissue, blood vessels in center of ovary
ovarian medulla
has numerous, small, microlecithal oocytes
ovarian cortex
- same number of chromosomes (diploid or haploid)
- 2 daughter cells
- cells are identical genetically
mitosis
- half the number of chromosomes (haploid)
- 4 daughter cells
- cells are not identical genetically
meiosis
- production of offspring by a single parent
- offspring inherit DNA from only one parent
- require less energy
asexual reproduction
formation of sex cells or gametes from germ cells
gametogenesis
end product of gametogenesis
haploid cells
gametogenesis in males
spermatogenesis
gametogenesis in females
oogenesis
no of gametes produced per 1^0 cyte in spermatogenesis
4
no of gametes produced per 1^0 cyte in oogenesis
1
availability of 1^0 cyte in spermatogenesis
1^0 spermatocytes are produced throughout the male’s reproductive years
availability of 1^0 cyte in oogenesis
number of 1^0 oocytes is fixed at birth
is there interruption in spermatogenesis?
uninterrupted
is there interruption in oogenesis
not completed without stimulation from a sperm
differentiation of the spermatid into a sperm
spermiogenesis
- produces a clear, viscous secretion known as pre-ejaculate that helps to lubricate the urethra for spermatozoa to pass through, neutralizing traces of acidic urine in the urethra, and helps flush out any residual urine or foreign matter.
- It is possible for this fluid to pick up sperm in the urethral bulb from previous ejaculations, and carry them out prior to the next ejaculation.
Bulbourethral gland / Cowper’s gland
helps lubricate the urethra for spermatozoa to pass through, neutralizing traces of acidic urine in the urethra, and helps flush out any residual urine or foreign matter
pre-ejaculate
- store and secrete a slightly alkaline fluid, milky or white in appearance, that usually constitutes 20–30% of the volume of the semen along with spermatozoa and seminal vesicle fluid
- The alkalinity of semen helps neutralize the acidity of the vaginal tract, prolonging the lifespan of sperm
prostate gland
what does the alkalinity of semen help neutralize
acidity of vaginal tract, prolonging sperm lifespan
hormonal control of the testes
- hypothalamus
- anterior pituitary
- testis
release releasing hormone
hypothalamus
- receives releasing hormone
- secretes follicle stimulating hormone (FSH) and luteinizing hormone (LH)
anterior pituitary
what does the anterior pituitary of males secrete
- follicle stimulating hormone (FSH)
- luteinizing hormone (LH)
what does the testis produce
- androgen
- sperm
secrete mucus to lubricate the vagina and are homologous to bulbourethral glands in males
Bartholin’s gland
- stage after fertilization in humans where a blastocyst develops from a fertilized zygote
- egg moves along oviduct to uterus
implantation
when does the blastocyst attach to uterine wall
6th day after fertilization
uterine wall
endometrium
Human embryonic and fetal development
- human gestation time
- embryonic development
- fetal development
human gestation time
- from conception to birth
- approx. 9 mon.
embryonic develop
1-2 months
fetal development
3-9 months
blocks certain stages of reproduction
contraceptives
what are the following stages of reproduction that contraceptives can block
- release and transport of gametes
- fertilization
- implantation
types of contraceptives
- ovulation-suppressing methods
- barrier methods (physical and chemical)
- surgical methods
- implantation-suppressing methods
- others
ovulation-suppressing methods
- oral contraceptives
- time-release capsules
usually contin a combination of hormones that prevent release of FSH and LH, inhibiting development of the follicle so that no oocytes are released
oral contraceptives
can be implanted under the skin of the upper arm and offer long-term suppression of ovulation
time-release capsules (eg. Norplant)
Barrier methods (physical)
- condoms
- diaphragm
- cervical cup
- fitted over the erect penis or
- placed inside the vagina
condoms
cap the cervix and block the passage of the sperm into the uterus
- diaphragm (shallow)
- cervical cup (deeper in shape)
barrier methods (chemical)
spermicidal jelly or foam
kill sperm on contact and must be placed in the vagina prior to intercourse
spermicidal jelly or foam
surgical methods
- vasectomy (men)
- tubal ligation (women)
the vas deferens connecting the testes with the urethra is cut and sealed to prevent the transport of sperm
vasectomy
oviduct is cut and ends tied off to prevent eggs from reaching the uterus
tubal ligation
implantation-suppressing methods
- morning-after pill
- intra-uterine device (IUD)
morning-after pill types
- RU-486
- Plan B
- interferes with the implantation of the fertilized egg into the uterine wall
- blocks the action of progesterone, which leads to the non-synthesis of the proteins necessary to begin and maintain pregnancy
RU-486
contains progestin that blocks ovulation, fertilization, and implantation
Plan B
physically blocks the fertilized egg from implanting
intra-uterine device (IUD)
other methods
- coitus interruptus
- abortion
- deliberate removal of the fetus or embryo before it is ready for birth
- done mechanically or chemically
abortion
- requires the man to withdraw his penis from the vagina before ejaculation
- very unreliable
coitus interruptus
suction for less than 3 months and surgery for older
mechanical abortion
RU-486 and prostaglandins to expel the embryo and the endometrial discharge
chemical abortion
