reproductive system Flashcards
what is the advantage of sexual reproduction for humans
it allows for genetic diversity and can help eliminate genetic mutations and create new defenses against diseases/parasites
what is the disadvantage of sexual reproduction for humans
It is not as fast, less offspring are produced, and there is a need for a mate. It also requires more energy
how do male and female reproductive system function similarly
they share the same basic tasks which include spermatogenesis and oogenesis, sexual intercourse (copulation), and fertilization
they both also are governed by the HPG axis
what is the function of the scrotum and its two assisted muscles
the scrotum and assisted muscles (tunic vaginalis, albuginea) is used to surround and protect the testes
vag-outer
alb-inner
what is the pathway of sperm from development (in seminiferous tubules), maturation (in the epididymis), and ejaculation (in the male duct system)
Seminiferous tubules → Rete testis → Efferent ductule → Epididymis → Vas deferens → Ejaculatory duct → Urethra.
what are the basic function of sertoli cells
they are the blood barrier for the testes
they nourish sperm, control spermiation, and secrete ABP and inhibin
what are the basic functions of leydig cells
their job is to secrete testosterone or “T”
what is spermatogenesis
it is the process that produces sperm located within the testes
what is spermiogenesis
it is the process where spermatids differentiate into mature spermatozoan
what is spermiation
the process where mature spermatids are released from sertoli cells into the lumen of seminiferous tubules
what are the steps of spermatogenesis, what is the location of each step and is a diploid or haploid cell present in the step
starts as spermatogonium (diploid), it will then divide into more spermatogonia through mitosis, differentiation will then occur creating primary spermatocytes (diploid), primary spermatocytes will undergo meiosis 1 forming secondary spermatocytes (haploid), secondary spermatocytes will undergo meiosis 2 creating spermatids (haploid), spermatids will then undergo spermiogenesis creating spermatozoa (haploid).
what is the purpose and location of sperm maturation
sperm maturation occurs in the epididymides, sperm needs to be matured so that it can acquire motility (be able to move) and the ability to fertilize an egg
what are the components of semen made from each male sex gland
seminal glands: fructose, prostaglandins, fibrinogen
prostate gland: citric acid, clotting & proteolytic enzymes, seminalplasmin
bulbourethral glands: alkaline mucus
what are the functions of each component of semen
-fructose produces atp for sperm movement
-prostaglandins stimulate uterine contractions
-fibrinogen allows semen to clump after ejaculation
-citric acid is a nutrient for the atp sperm uses
-clotting enzymes activate fibrinogen so the sperm can clot and proteolytic enzymes break it down into liquid
-seminalplasmin is an antibiotic that kills bacteria in semen or female tract
-alkaline mucus lubricates tip of penis, urethral lining, and neutralizes acids in urethra
what is the role of penile erectile tissues in the process of erection
the corpus cavernosa tissue fills with blood during an erection
the corpus spongiosum prevents the urethra from closing when the other tissue fills with blood
how does the parasympathetic reflex that generates and maintains an erection work
-erection can occur through physical stimulants but also through erotic smells, sights, and sounds.
-this occurs when the arterioles dilate to fill with blood and veins will constrict letting very little blood to come out
-on a cellular level, nitric oxide will generate an erection and acetylcholine will maintain an erection by stimulating large amounts of nitric oxide
how does the sympathetic and somatic reflex work in ejaculation
sympathetic reflexes: contractions occur in the wall of the duct system shooting sperm into the urethra, accessory glands add secretions to sperm, smooth muscle sphincter closes urinary bladder
somatic reflexes: bulbospongiosus muscles contract at base of penis and expel semen
what is the importance of HPG hormones in spermatogenesis, the development of male reproductive structures, and the development of male secondary sex characteristics
androgens will develop sex characteristics and reproductive structures they will also stimulate spermatogenesis
what are the homologous (similar) structures of the male and female reproductive systems
labia majora is the same as the scrotum
labia minora is the same as the shaft of penis
clitoris is the same as the glans penis
paraurethral glands is the same as the prostate gland
vestibular glands is the same as the bulbourethral gland
what are the functions of each part of the vulva
clitoris: only used for pleasure
labia majora: encloses and protects all external genital organs
labia minora: protects the opening of the urethra and vagina
vestibule: contain glands that secrete mucus for lubrication
what are the steps of oogenesis, what is the location of each step and is a diploid or haploid cell present in the step
starts as oogonium (diploid) which will then differentiate into primary oocytes (diploid) through mitosis, primary oocytes will undergo meiosis 1 creating secondary oocytes and a polar body (haploid), secondary oocytes will begin meiosis 2, if the secondary oocyte and polar body are ovulated then meiosis 2 will continue creating a mature egg cell (ovum) and a second polar body (haploid)
what is oogenesis
the process in which a mature egg is produced. This is located within the ovaries.
what is folliculogenesis
the process in which the ovarian follicle becomes matured. This is located within the cortex of the ovary.
what is the relationship between fulliculogenesis and oogenesis
while oogenesis is happening the development of follicles is occurring around it
the oocyte is developing in the follicle
what are the differences and similarities of oogenesis and spermatogenesis
similarities: spermatogenesis and oogenesis both occur in the gonads, are regulated by the HPG axis, and create haploid gametes.
differences:
1. oogenesis starts with 1 gamete spermatogenesis starts with 4.
2. Oogenesis begins in fetal life spermatogenesis beings after puberty.
3. Oogenesis has many stop and go points and ends after menopause spermatogenesis continues throughout life.
4. Oogenesis has a 20% error rate while spermatogenesis has a 4% error rate.
what happens during the follicular phase of the ovarian cycle, when do these things happen
follicles become sensitive to FSH and are stimulated to grow
this happens between day 1 to 14
ovulation will occur after this
what happens during the luteal phase of the ovarian cycle, when do these things happen
ovulation occurs before this
during this phase the corpus luteum secretes high levels of estradiol and progesterone
this happens between days 14-28
what are the hormonal controls of the ovarian cycle
- the hormone controls come from the hypothalamus and the anterior pituitary
- the folicular phase is driven by high levels of FSH to grow follicles
- LH is also being produced during this time going to the thecal cells around the folicle which will produce T from granulosa cells to be converted to estradiol as a result there will be more estrogens
- high estrogen levels will signal hypothalamus to tell it it doesnt need more
- a high surge of LH will be secreted due to super high estrogen levels which will tigger ovulation
what is the location for fertilization and implantation
fertilization occurs in a fallopian tube while the uterus is the site for implantation
what is the composition and function of each uterine layer
perimetrium: protective layer outermost made of loose connective tissue
myometrium: expands and contracts is in middle and is made of smooth muscle
endometrium: lines the uterus is the innermost and is made of epithelium
what major events take place in each phase of the uterine cycle
menstrual: corpus luteum is broken down and released out, hormones drop, additional things start to degrade and break down
proliferative: stratum functionalis grows, regenerates, and thickens
ovulation: mature egg goes to fallopian tube
secretory: lipids and glycogen are secreted for potential embryo
if egg is not fertilized everything gets destroyed to start again
how do the events of the ovarian cycle work and drive the uterine cycle
the ovarian cycle will produce and release eggs and P and E while the uterine cycle will prep for a potential embryo
what is the role of LH, FSH, progesterone and estrogen in the uterine cycle
LH and FSH promote ovulation and stimulate the ovaries to produce estrogen and progesterone
E and P will stimulate the uterus to prepare for fertilization
what is the importance of HPG hormones in oogenesis, fulliculogenesis, the development of female reproductive structures, and the development of female sex characteristics
LH, FSH, GRH and progesterone will stimulate oogenesis folliculogenesis and uterine cycle
estrogen is what develops female sex characteristics and structures
what is the importance of SRY genes and androgens in the process of sex differentiation
SRY genes are what will form male development this will create testes and leydig cells will produce testosterone and sertoli cells that will produce a mullerian inhibiting hormone that will prevent female structures from developing
what are the basic events that occur in prenatal males and females for their development
testosterone that is released by developing embryo is converted to dht
males: dht is what generates male genitals
females: estradiol is what generates female genitals
this will usually happen between weeks 6-9
