Reproductive System Flashcards
Sexual reproduction in humans involves:
Meiosis
Fertilization
Prenatal Development
_____-Cell division producing four genetically unique haploid cells (called gametes= sperm in male or ova in female) from stem cells within the gonads that are diploid 2(n) = 46 (Containing two sets of chromosomes).
Gametes are haploid (n) = 23 having only one set of chromosomes
Meiosis
Meiosis
What are gametes?
sperm in male or ova in female
Meiosis
What do the diploid 2 (n) contain?
46 (Containing two sets of chromosomes).
Gametes are _____when having only one set of chromosomes?
Haploid (n) = 23 chromosomes
What is a zygote (2n)?
Fusion of sperm and egg
_____-Fusion of sperm and egg
Creates a zygote (2n), or fertilized egg that will develop into a new organism
Fertilization
_____-zygote grows as cells divide by mitosis:
Mitotic cell division produces two genetically identical cells.
Prenatal Development
Chromosomes:
Humans have _____pairs of chromosomes
23
Chromosomes:
Each somatic cell has two sets of chromosomes (one maternal, one paternal) and is said to be _____ so the chromosome number is 2n.
diploid
Chromosomes:
_____-matching pairs of chromosomes that carry equivalent genes.
Homologous chromosomes
Chromosomes:
There are alternative forms of each gene which are called _____
alleles
Chromosomes:
Gametes only have 23 chromosomes and are said to be_____
haploid (n)
Chromosomes;
One pair of chromosomes, called the _______, determines the sex of the individual (XX in females, XY in males).
sex chromosomes
_____-is a type of cell division that produces gametes (sperm and ova) from stem cells in the reproductive tissue
Meiosis
Meiosis:
______-in preparation for fusing with another gamete
Reduces the original number of chromosomes in half
Meiosis:
____-(scrambling) of parents’ genomes to create a unique set of chromosomes in each gamete
Recombination
Stage of meiosis?
overview Intrephase Meiosis I -Prophase I -Metaphase I -Anaphase I -Telophase I and cytokinesis
Meiosis II Prophase II Metaphase II Anaphase II Telophase II and cytokinesis
What stages of meiosis is this?
_____-In meiosis there is two rounds of division which results in 4 haploid cells:
1st round separates duplicated homologous chromosomes
2nd round separates sister chromatids
Overview
What stages of meiosis is this? \_\_\_\_\_\_\_\_- Occurs prior to Prophase I of meiosis G1 phase S-phase homologous chromosomes replicate into sisters G2 phase – checkpoint
Interphase
What stages of meiosis is this?
____-first division
Meiosis I
What occurs in Meiosis I?
______-
Duplicated homologous chromosomes pair up (tetrads)
Crossing over occurs: homologous chromosome exchange equivalent segments
Prophase I
What occurs in Meiosis I?
____-
Homologous chromosomes line up in pairs along the central plane in tetrads
Independent assortment: which side each chromosome lines up on is independently of the other pairs
Metaphase I
What occurs in Meiosis I?
_____-
Homologous chromosomes are separated and move to opposite poles
Anaphase I
What occurs in Meiosis I?
_____- Results in two haploid cells with 23 duplicated chromosomes
Telophase I and Cytokinesis
_____- second division
Meiosis II
What is the first step of Meiosis II?
Prophase
What occurs in meiosis II?
____- Sister chromatids (duplicated chromosomes) line up along midline
Metaphase II
What occurs in meiosis II?
____- Sister chromatids separate and are pulled towards opposite poles
Anaphase II
What occurs in meiosis II?
_____- Results in 4 haploid gametes from each diploid cell that enters meiosis.
Telophase II and Cytokinesis
____-production of gametes
Gametogenesis
Where does the production of gametes begin?
in utero and resumes during puberty
Mitotic divisions in embryonic gonads increases number of ______.
spermatogonia or oogonia
DNA replication (S-phase) to the primary gametes with 46 duplicated ______
chromosome
Meiosis I to ______ with 23 duplicated chromosomes
secondary gametes
Meiosis II to ______ with 23 chromosomes
egg (ova) or spermatid
______-responsible for the production of sperm and male sex hormone testosterone.
Testes
_____-sac of skin that contains the testes outside the abdominopelvic cavity.
Scrotum
______-smooth muscle in the dermis of the scrotum
Dartos muscle
What are the two protective tunics (tissue layers)
Tunica Vaginalis
and
Tunica albuginea
What type of protective tunics (tissue layers) is this?
_____-serous membrane lining the scrotal cavity, derived from the parietal peritoneum
Tunica vaginalis
What type of protective tunics (tissue layers) is this?
_____-fibrous capsule surrounding the testes
Tunica albuginea
____-tightly coiled tubes found in the testis. Responsible for sperm production.
Seminiferous tubules
_____-is the process by which haploid sperm are produced
Spermatogenesis
_____- stem cells found in the outermost layer of the seminiferous tubule
Spermatogonia
_____-pushed towards the lumen as they undergo meiosis
Spermatocytes
____-immature haploid cells that mature into spermatozoa
Spermatids
____-mature sperm cells.
Spermatozoa
____-support cells surrounding the spermatocytes within the seminiferous tubule.
Sertoli cells
____-endocrine cells that produce testosterone, found in the interstitial space between seminiferous tubules.
Leydig (Interstitial) cells
_____-travels through the inguinal canal to the scrotum
*• Connective tissue and muscle bundles the ductus deferens, nerves, lymph vessels, and testicular artery and vein supplying the testes
Spermatic cord
_____-band of skeletal muscle arising from the internal obliques contracts to elevate testes and pulls them closer to the body to conserve heat
Cremaster
• Regulation of Spermatogenesis
______-
Testosterone also stimulates sex characteristics
Testosterone triggers negative feedback loop to decrease GnRH and LH and secretion
o GnRH to LH to Leydig cells to testosterone to spermatogenesis
• Regulation of Spermatogenesis
_____- Inhibin triggers negative feedback loop for FSH secretion
o GnRH to FSH to Sertoli cells to spermatocyte maturation
_____-spermatozoa flow through the twisted seminiferous tubules of the testes into a series of ducts which transport and store the sperm
Ducts
_____-long coiled tube that hugs the posterior-lateral surface of the testes
o Temporary storage and maturation site for sperm
Epididymis
______- transports sperm from the epididymis to the ejaculatory duct by peristalsis
Ductus (Vas) Deferens
_____-formed by the union of the ductus deferens and the seminal vesicle duct
o Travels through the prostate gland and empties sperm into the urethra
Ejaculatory duct
______-common path for urine and semen, extends from the prostate to the end of the penis
Urethra
_____-secrete the bulk of semen. Semen is a liquid that provides nutrients and chemicals that protect and aid in the movement of sperm.
Accessory sex glands
Accessory sex glands _____-pair of glands on the posterior surface of the bladder
Seminal vesicles
Accessory sex glands _____-single gland inferior to the bladder and encircles the prostatic urethra
Prostate gland
Accessory sex glands _____-pair of pea sized glands inferior to the prostate and secrete into the penile urethra
Bulbourethral gland
_____-delivers sperm to the female reproductive tract
Penis
What three regions is the penis divide?
Root
Body
Extremity
Penis
______-anchored to the ischial ramus
Root
Penis
_____-contains three cylindrical bodies of erectile tissue
Corpora cavernosa – found on the anterior surface
Corpus spongiosum – surrounds the urethra
Glans – expanded distal end
Body
What type of the three cylindrical bodies of erectile tissue is this?
____- found on the anterior surface
Corpora cavernosa
What type of the three cylindrical bodies of erectile tissue is this?
_____-surrounds the urethra
Corpus spongiosum
What type of the three cylindrical bodies of erectile tissue is this?
_____-expanded distal end
Glans
_____-the female gonads are responsible for producing ova (female gametes commonly known as eggs) and the steroid sex hormones estrogens and progesterone.
• Paired oval shaped organs each about 2 to 3 cm in length.
o About the size of an almond.
• Located within the pelvic cavity and supported by ligaments:
Ovaries
_____-an extension of the peritoneum that envelops the ovaries, uterine (fallopian) tubes, and uterus
Broad ligament
_____-part of the broad ligament that connects to the superior aspect of the ovary.
Mesovarium
____-anchors the ovaries to the posterior pelvic wall and contains the ovarian blood vessels and lymph vessels.
Suspensory ligament
_____-anchors ovaries to the uterus
Ovarian ligament
Structure of the ovary:
_____-superficial outer covering of cuboidal epithelium.
Surface epithelium
Structure of the ovary:
_____-dense connective tissue covering deep to the surface epithelium and superficial to the cortex.
Tunica albuginea
Structure of the ovary:
_____-outer portion composed of a tissue framework called the ovarian stroma that forms the bulk of the adult ovary
Cortex
Structure of the ovary: in cortex:
Oocytes
and follicle
Structure of the ovary: in cortex:
_____-(cells that divide by meiosis forming ova) develop within follicles in the cortex.
Oocytes
Structure of the ovary: in cortex:
_____-ovarian structure of one oocyte and surrounding support cells
Follicle
______-deep layer beneath the cortex contains blood vessels, lymph vessels, and the nerves of the ovary.
Medulla
_____-also known as female gametogenesis is the process of producing female gametes known as ova (commonly known as eggs).
Oogenesis
The _______process begins with the ovarian stem cells, or oogonia. Oogonia are formed during fetal development via mitosis.
Oogenesis
Oogenesis;
• ______ form primary oocytes in the fetal ovary prior to birth. These primary oocytes are then arrested in prophase I of meiosis I, only to resume it years later, beginning at puberty.
o The initiation of ovulation—the release of an oocyte from the ovary—marks the transition from puberty into reproductive maturity for women. From then on ovulation occurs approximately once every 28 days until the woman is near menopause (the cessation of a woman’s reproductive functions).
o Just prior to ovulation, a surge of luteinizing hormone triggers the resumption of meiosis in a primary oocyte.
Oogonia
Oogenesis;
• Completion of meiosis I produces a secondary oocyte and a smaller cell, called the first polar body that eventually disintegrates.
• ________ begin meiosis II but arrest at metaphase II.
o The secondary oocyte is released from the ovary during ovulation.
o Meiosis II of a secondary oocyte is completed only if a sperm succeeds in penetrating its barriers. Meiosis II then resumes.
• Completion of meiosis II occurs in the uterine tube and produces an ovum and second polar body that disintegrates.
o The haploid ovum forms at the beginning of fertilization.
o During fertilization (haploid) sperm combines with the haploid ovum producing the first diploid cell of the new offspring (a zygote).
Secondary oocytes
______-development of ovarian follicles from primordial to tertiary under the stimulation of gonadotropins.
Folliculogenesis
• Folliculogenesis begins with follicles in a resting state. These small ________ are present in newborn females and are the prevailing follicle type in the adult ovary. Primordial follicles have only a single flat layer of support cells, called granulosa cells, that surround the oocyte, and they can stay in this resting state for years.
primordial follicles
• After puberty, each day a few primordial follicles are activated to join a pool of immature growing follicles called ________ Primary follicles start with a single layer of granulosa cells, but the granulosa cells then become active and transition from a flat or squamous shape to a rounded, cuboidal shape as they increase in size and proliferate.
primary follicles.
• As the granulosa cells divide, the follicles—now called ________—increase in diameter, adding a new outer layer of connective tissue, blood vessels, and theca cells—cells that work with the granulosa cells to produce estrogens. Theca cells produce an androgen steroid (androstenedione) that is converted to estrogens by granulosa cells.
secondary follicles
o Within the growing secondary follicle, the ______ now secretes a thick fluid, called follicular fluid, that forms between the granulosa cells and begins to collect into one large pool, or antrum.
primary oocyte
• Follicles in which the antrum has become large and fully formed are considered ______ (or antral follicles). The process of folliculogenesis from activation of a primordial follicle to the formation of a tertiary follicle takes about two months. Several follicles reach the tertiary stage at the same time, and most of these will undergo atresia (death of ovarian follicles).
tertiary follicles
o The one tertiary follicle that does not die will continue to grow and develop. The primary oocyte will complete meiosis I and enter meiosis II becoming a _______that is released from the ovary during ovulation
secondary oocyte
______-changes that occur in the ovaries over a period of approximately 28 days, divided into three phases: the follicular phase, ovulation, and the luteal phase.
Ovarian cycle
Ovarian cycle:
_______-follicular growth in ovary during the first two weeks of the ovarian cycle.
o FSH stimulates the follicles to grow, secondary follicles mature to form tertiary follicles, and the tertiary follicles expand in diameter.
o LH stimulates the granulosa and theca cells of follicles to produce the steroid sex hormone estradiol, a type of estrogen (other estrogens: estrone is a produced as a precursor to estradiol that only weakly stimulates receptors, estriol strongly stimulates receptors but is only significantly produced during pregnancy).
o Negative feedback leads to decreased FSH and LH leading to atresia of all tertiary follicles except one dominant tertiary follicle that survives
Follicular phase
Ovarian cycle:
_____-occurs around day 14 when the secondary oocyte is released from ovary.
Ovulation
______-o Granulosa and theca cells of the dominant tertiary follicle produce increasing amounts of estradiol through a positive feedback mechanism. High levels of estradiol stimulate the production of GnRH thus triggering increased production of FSH and an especially large increase in the production of LH known as the LH surge
Ovulation
_______;• Completion of meiosis I by the primary oocyte within the dominant tertiary follicle forming a secondary oocyte.
• Ovulation releasing the secondary oocyte from the ovary.
• Luteinizing of the tertiary follicle remnant to form the corpus luteum
The LH surge stimulates:
______-corpus luteum produces hormones to prepare for pregnancy
Luteal phase
Luteal phase
______-remnant of the ovulated follicle, produces increasing amounts of progesterone and some estrogen for about two weeks after ovulation
Corpus luteum
Luteal phase:
o High levels of ______- during the luteal phase inhibits LH and FSH production.
progesterone
Luteal phase:
the corpus luteum degenerates into scar tissue (corpus albicans) and the resulting drop in progesterone triggers menstruation.
If fertilization does not occur
Luteal phase:
_______-the implanted embryo (developing placenta) produces human chorionic gonadotropin (hCG) which causes the corpus luteum to persist and maintains the production of progesterone so the menstrual cycle will not be initiated.
If fertilization occurs
_____-muscular tube extending from the cervix to the vestibular orifice of the vulva (external genitalia).
• Lined by stratified squamous
Vagina
_____-the female external genitalia
Vulva
Within Vulva:
______-area containing the external openings of the urethra and vagina
Vestibule
Within Vulva:
_____-thin folds, laterally enclosing the vestibule
Labia minora
Within Vulva:
______fatty skin folds lateral to the minora
Labia majora
Within Vulva:
_____-erectile tissue, contains numerous sensory nerve endings responsible for sexual stimulation.
Clitoris
_____-external region located anterior to the urethra
Glans
_____-internal regions located deep to labia surrounding the vagina.
Bulb of vestibule
______-internal regions located deep to labia along the pubic bones.
Crus
_____-muscular organ that nourishes and supports the growing embryo/fetus.
Uterus
Within the Uterus
_____-the portion of the uterus superior to the opening of the uterine tubes.
• Fundus-
Within the Uterus
_____– the middle section of the uterus
• Body
Within the Uterus
_____– the narrow inferior portion of the uterus that projects into the vagina.
• Cervix-
Ligaments stabilize the position of the uterus:
Broad ligament
Round ligament
Uterosacral ligament
Ligaments stabilize the position of the uterus:
____-is a fold of peritoneum that serves as a primary support for the uterus, extending laterally from both sides of the uterus and attaching it to the pelvic wall.
o The broad ligament
Ligaments stabilize the position of the uterus:
_______-attaches to the uterus near the uterine tubes and extends to the labia majora.
round ligament
Ligaments stabilize the position of the uterus:
_______-stabilizes the uterus posteriorly by its connection from the cervix to the pelvic wall.
uterosacral ligament
The wall of the uterus is made up of three layers:
Perimetrium
Myometrium
Endometrium
The wall of the uterus is made up of three layers:
o The most superficial layer is the serous membrane, or _______, which consists of epithelial tissue that covers the exterior portion of the uterus.
perimetrium
The wall of the uterus is made up of three layers:
o The middle layer, or _______ is a thick layer of smooth muscle responsible for uterine contractions
myometrium,
The wall of the uterus is made up of three layers:
o The innermost layer of the uterus is called the _______. The endometrium contains a connective tissue lining, the lamina propria, which is covered by epithelial tissue that lines the lumen. Structurally, the endometrium consists of two layers:
Stratum basalis
stratum functionalis
endometrium
epithelial tissue that lines the lumen. Structurally, the endometrium consists of two layers:
The ______ is part of the lamina propria and is adjacent to the myometrium; this layer does not shed during menses.
stratum basalis
epithelial tissue that lines the lumen. Structurally, the endometrium consists of two layers:
The thicker ________layer contains the glandular portion of the lamina propria and the endothelial tissue that lines the uterine lumen.
stratum functionalis
______-(also called fallopian tubes, oviducts, or salpinges) serve as the conduit of the oocyte from the ovary to the uterus.
Uterine Tubes
Uterine tubes:
The _____ is the narrow medial end of each uterine tube that is connected to the uterus.
isthmus
Uterine tubes:
The middle region of the tube, called the _______, is where fertilization often occurs.
ampulla
Uterine tubes:
The wide distal infundibulum flares out with slender, finger-like projections called _______
fimbriae.
Uterine tubes:
The uterine tubes also has three layers: ________
an outer serous membrane, a middle smooth muscle layer, and an inner mucous membrane layer containing ciliated simple columnar epithelium.
Hypothalamic-Pituitary-Gonadal Axis:
The hypothalamus produces gonadotropin releasing hormone (GnRH), a hormone that signals the _______ gland to produce the gonadotropins.
anterior pituitary
Hypothalamic-Pituitary-Gonadal Axis:
• Gonadotropins follicle stimulating hormone (FSH) and leutinizing hormone (LH) are produced by the pituitary and travel through the bloodstream to the gonads (ovaries), where they bind to receptors on the granulosa and theca cells of ovarian follicles stimulating the production of the _______
steroid hormones.
• Granulosa and theca cells of ovarian follicles produce the steroid sex hormones estrogens and progesterone. As a typical negative feedback mechanism, these steroid hormones bind to receptors in the hypothalamus and pituitary to inhibit the release of GnRH, FSH, and LH. However, a positive feedback mechanism drives a surge in ________ during ovulation.
estrogen and LH
_______-changes in the endometrial lining of the uterus that occurs over a period of approximately 28 days, divided into three phases: menses, the proliferative phase, and the secretory phase.
Uterine cycle
Uterine cycle
______-shedding of stratum functionalis of the endometrium the inner lining of the uterus.
o Triggered by drop in progesterone and estrogen
Menses
Uterine cycle:
_____-endometrial lining adds new layers
o Stimulated by increasing estradiol levels
Proliferation phase
Uterine cycle:
_____-
increased blood flow to endometrium, increased glandular secretions
o Stimulated primarily by increased progesterone
Secretory phase
