Reproductive System Flashcards
role of testes
- synthesis of sperm
2. secretion of male hormones such as androgens and testosterone into the bloodstream
seminiferous tubules
sites of spermatogenesis
What produces semen
the seminal vesicles, prostrate, and bulbourethral glands
What causes an erection
Blood accumulation at high pressure in the erectile tissue
Three stages of male/female sexual act
arousal (dependent upon sympathetic system, divided into erection and lubrication), orgasm (dependent upon sympathetic), resolution (dependent upon sympathetic)
Resolution takes longer for females
emission/ejaculation
emission - propulsion of sperm and semen into urethra by contractions of smooth muscle surrounding these organs
ejaculation - semen propelled out of urethra by rhythmic contractions of muscles surrounding base of penis
role of sperm
to swim through the female genital tract to reach the egg and fuse with it.
germ cells
cells that give rise to spermatogonia
spermatogonium role
mitotically reproduces prior to meiosis and replicates DNA in S phase of meiosis (GONium is GONna be a sperm)
primary spermatocyte/ secondary spermatocyte
meiosis 1/2 (cyte = meiosis)
spermatid
turn into spermatozoan (mature sperm)
spermatozoan
finish maturing in seminiferous tubule/ epididymus
acrosome
compartment on the head of the sperm that contains hydrolytic enzymes required for penetration of the ovum’s protective layers
testosterone role
stimulates division of spermatogonia
LH role in men
stimulates interstitial cells to secrete testosterone
FSH/ inhibin role in men
FSH stimulates sustenacular cells
inhibin is secreted by these cells to inhibit FSH release
What is true about the sex development of early embryos
They have undifferentiated gonads and possess both Wolffian ducts that can develop into male internal genitalia and Mullerian ducts that can develop into female internal genetalia
What produces Mullerian inhibiting factor/ testosterone and what is its role?
testes, causes male internal and external genitalia to form by causing regression of Müllerian ducts
What causes development of testes
presence of Y chromosome
What kind of testosterone leads to development of male genitalia?
dihydrotestosterone
Wolffian ducts vs Müllerian ducts
Wolffian- disappear in female reproductive system
Mullerian - disappear in male reproductive system and form internal genitalia of female system
androgens vs estrogens
androgens are involved in development and maintenance of male characteristics and estrogens are involved in development and maintenance of female characteristics
What is the role of estrogen
At puberty, it is required to regulate the uterine cycle and for the development of female secondary sex characteristics
GnRH role
found in hypothalamus, stimulates pituitary to release gonadotropins FSH and LH
FSH and LH role in women
FSH stimulates secretion of estrogen by granulosa cells and LH stimulates formation of corpus luteum and progesterone secretion
uterus
opens into upper portion of vagina via cervix
endometrium
innermost lining of uterus responsible for nourishing a developing embryo, shed each month in absence of pregnancy
ovary
female gonad
oogonia
produced by mitotic division of germ cells, enter first phase of meiosis and are arrested in prophase I, they are then ovulated as oocytes after puberty
What is required for a second meiotic division to occur during oogenesis
fertilization of secondary oocyte by sperm
Where is primary oocyte found
in a clump of supporting cells called granulosa cells creating a follicle
What happens during ovulation?
mature follicle bursts, releasing secondary oocyte with its zone pellucida and protective granulosa cells into the fallopian tube
phases of menstrual cycle
follicular phase - primary follicle matures and secretes estrogen, under control by FSH
ovulatory phase - secondary oocyte is released from ovary, triggered by LH surge from anterior pituitary, remnants of follicle become corpus luteum
luteal phase - begins with full formation of corpus luteum in ovary
uterine cycle phases
- menstruation - triggered by degeneration of corpus luteum and subsequent drop in estrogen and progesterone levels
- proliferative phase - estrogen produced by follicle induces proliferation of new endometrium
- secretory phase - estrogen and progesterone produced by corpus luteum further increase development of endometrium
what does the corpus luteum secrete?
Estrogen and progesterone
When do FSH and LH levels peak?
During ovulation
When do estrogen levels peak?
Right before ovulation
hCG function
takes the place of LH in maintaining the corpus luteum during pregnancy
acrosome reaction
mechanism by which sperm penetrates corona radiate to penetrate the zona pellucida
bindin
a protein in the acrosomal process that binds to receptors in the zona pellucida
What occurs as a result of fertilization
secondary oocyte completes meiosis II giving rise to an ootid and secondary polar body. This ootid then matures to become an ovum. The sperm and egg then fuse to form a zygote.
What are the stages of embryogenesis
zygotę to morula (cleavage)
morula to blastocyst
placenta
facilitates exchange of nutrients, gases, and even antibodies between the maternal and embryonic bloodstreams
What structures are derived from the inner cell mass?
embryo, amnion, yolk sac, and allantois
gastrulation
when the three primary germ layers (ectoderm, mesoderm, and the endoderm) become distinct
What is derived from the ectoderm?
entire nervous system, pituitary gland, cornea and lens, epidermis of skin and derivatives, epithelia
What is derived from mesoderm
all muscle, bone, and connective tissue, cardiovascular/lymphatic system, including blood, urogenital organs (kidneys, ureters, gonads, reproductive ducts), dermis of skin
what is derived from endoderm
gi tract epithelium (except mouth/anus) gi glands respiratory epithelium epithelial lining of urogenital organs and ducts urinary bladder
neurulation
formation of the nervous system, begins when a portion of the ectoderm differentiates into neural plate
differentiation/ dedifferentiation
when cells specialize, becoming better at performing a particular task
cells can also become unspecialized and totipotent
what leads to labor contractions
positive feedback release where increased pressure on cervix leads to posterior pituitary increasing oxytocin secretion and oxytocin causing uterine contractions to increase, leading to more pressure on cervix.
What causes milk production
decrease in estrogen and progesterone after birth leading to prolactin release
what is the pathway of sperm from the male testis to point of fertilization
sperm travels through the epididymism to the vas deferens and into the urethra, then enters the female vagina, traveling through the cervix and uterus, then entering the fallopian tube
