reproductive system Flashcards
what are the gonads and what do they do?
-testes
-produce sperm and secrete hormones
what does the system of ducts include?
-ductus epididymis
-ductus deferens
-ejaculatory duct
-urethra
what does the system of ducts do?
-transports and stores sperm, assists in their maturation, conveys them to the exterior
what do accessory sex gland include?
-seminal vesicles
-prostate gland
-bulbourethral glands
what do accessory sex glands do?
-add secretions to semen
what are the supporting structures of the male reproductive system and what do they do?
-scrotum-supports testes
-penis-delivers sperm into the female reproductive tract
what is the scrotum?
-a cutaneous out pouching of the abdomen that supports the testes
what temp does normal sperm production and survival require?
-a temp 2-3*c below core body temp
what are the two halves the scrotal septum divides the scrotum into?
-cremaster muscle
-dartos muscle
what does the cremaster muscle do?
-contracts to elevate the testes on exposure to cold and moves the testes close to the pelvic cavity (skeletal muscle fibres)
what does the dartos muscle do?
-contracts and makes the scrotal skin wrinkle minimising heat loss (smooth muscle fibres)
what are the testes/testicles?
-paired oval glands that descend from the abdomen to the scrotum during the 7th month of fetal development
what is the structure of the testes/testicles?
-it is covered by a fibrous tissue called tunic albuginea
-invaginations form 200-300 compartments called lobules
-each lobule is filled with 2 or 3 seminiferous tubules (spermatogenesis)
what is the pathway for sperm transport?
-seminifrous tubule
-straight tubule
-rete testis
-epididymis (head, body,tail)
-ductas vas deferens
-exit through the spermatic cord which also contain blood vessels and nerves
what are the cells of the testes?
-leydig cells (interstitial endocrinocytes)
-large sertoli cells
what do leydig cells do?
-they are found in spaces between adjacent seminiferous tubules which secrete the male hormone testosterone
where are large Sertoli cells found?
-embedded among the spermatogenic cells in the tubules
what do large Sertoli cells do?
-form the blood testes barrier
-nourish spermatocytes
-mediate the effect of testosterone and FSH on spermatogenesis
-phagocytose excess spermtids
-secrete the hormone inhibit which helps regulate sperm production by inhibiting the production of FSH
what does spermatogenesis do?
-produces haploid sperm (one set of 23 chromosomes) from diploid spermatogonia
how many days does the process of spermatogenesis take?
74 days
what happens in meiosis one? (reduction division)
- homologous pairs line up to form a tetrad (four chromatids from each homologous pair)
-the two cells formed by this first nuclear division (meiosis 1) are called secondary spermatocytes
-each of the 23 chromosomes are still made up of 2 chromatids attached at a centromere
what happens in meiosis 2 (equatorial division)?
- 2 chromatids separate (no replication of DNA)
-this results in 4 spermatids-each is haploid and unique,there is 50% X chromosome and 50% Y chromosome
-spermiogenesis happens
-spermination happens
what is spermiogenesis?
-involves the development of spermatids into sperm,acrosome(head) and flagella (tail) form and the mitochondria multiply
what is spermination?
-the release from connections to sertoli cells
what is sperm morphology?
-how sperm are adapted for reaching an penetrating a secondary oocyte
how are sperm adapted for reaching and penetrating a secondary oocyte?
-the head contains DNA and acrosome
-acrosome contains enzymes (hyaluronidase and proteinase) that help sperm penetrate secondary oocyte
-midpiece contains mitochondria to form ATP
what is the rate at which sperm is produced?
300mill every day
what is the life expectancy of sperm in the female reproductive tract?
-48hrs
what are the reproductive system ducts in males?
-ducts of testis
-epididymis
-ductus vas deferens
-spermatic cord
-ejaculatory ducts
-urethra
what are the ducts of testis?
-a series of coiled efferent ducts that empty a single duct (epididymis)
what is the epididymis?
-a site of sperm maturation and storage
what does the ductus vas deferens do?
-conveys sperm during sexual arousal through peristaltic contractions
what does the spermatic cord do?
-it has deferens ascend out of the scrotum with arteries/veins,autonomic nerves, lymphatic vessels and cremaster muscles
what are ejaculatory ducts?
-they are formed by the union of ducts from seminal vesicle and ductus deferens,terminating in the prostatic urethra
what is the urethra?
-a shared terminal duct of reproductive and urinary systems, it is subdivided into the prostatic urethra,membranous urethra and a spongy penile urethra
what do accessory sex glands do?
-secret the liquid portion of the semen
what does the liquid portion of the semen consist of?
-seminal glands
-prostate glands
-paired bulbourethra (Cowper’s) glands
what does seminal vesicles contain?
-contains viscous alkaline fluid that helps neutralise acid environment
-contains fructose for ATP production by sperm and prostaglandins which contribute to sperm motility and viability
what does prostate glands contain?
- a single donut shaped gland that secretes milky, slightly acidic fluid containing:
*citric acid (ATP production via Krebs cycle)
*several proteolytic enzymes
*PSA-prostate specific antigen
*semisinalplasmin (antibiotic)
what does paired bulbourethral (Cowper’s) glands?
-secrte alkaline fluid that protects passing perm by neutralising acids from urine in urethra
-mucus lubricates the end of the penis and the lining of the urethra
what is the penis?
-a passageway for the ejaculation of semen
-the body is composed of three erectile tissue masses filled with blood sinuses surrounded by smooth muscle and elastic connective tissue
what is the process of erection?
-parasympathetic fibres release/cause local production of nitric oxide (NO)
-it dilates arterial smooth muscle
-large amounts of blood enter blood sinuses
-compresses veins draining the penis
what does the female reproductive system consist of?
-gonads(ovaries)
-uterine(fallopian) tubes or oviducts
-uterus
-vagina
-external organs~vulva or pudendum
-mammary glands
what does the gonads do?
-produce secondary oocytes and hormones
what does the uterine (fallopian) tubes do?
-transports fertilised ova
what does the uterus do?
-it is where fatal development occurs
what do the mammary glands do?
-produce milk
what are the ovaries?
-paired glands homologous to the testes
what do the ovaries produce?
-gametes=secondary oocytes that develop into matured ova (eggs) after fertilisation
-hormones inc progesterone,oestrogen,inhibin and relaxin
what are ovarian ligaments?
-a series of ligaments that hold the ovaries in place
what are the three types of ovarian ligaments?
-broad ligament=a fold of parietal peritoneum
-ovarian ligament=anchors ovaries to the uterus
-suspensory ligament=attaches ovaries to the pelvic wall
what are the different parts that form the histology of the ovary?
-germinal epithelium
-tunica albuginea
-ovarian cortex
-ovarian medulla
-ovarian follicles
-mature (graffian) follicle
-corpus luteum
what does the germinal epithelium do?
-covers the surface of the ovary
where is the tunica albuginea located?
-underneath the epithelium
what does the ovarian cortex do?
-it contains the ovarian follicles and stromal cells
what does the ovarian medulla do?
-contains blood vessels, lymphatic vessels and nerves
where is the ovarian follicle located and what does it do?
-In the cortex and it consists of oocytes in various stages of development
what is the mature (graffian) follicle?
-a large fluid filled follicle ready to expel secondary oocytes during ovulation
what is the corpus luteum?
-a remnant of mature follicles after ovulation
what does oogenesis and follicular development result in?
-the formation of a single haploid secondary oocyte
when does oogeneis and follicular development happen?
-during early fatal development and primitive germ cells migrate from yolk sac to ovaries and then differentiate into oogonia (diploid) stem cells
how are the primary oocytes that enter meiosis I during fetal development?
-before birth most germ cells degenerate (asteria) and a few develop into primary oocytes
-each is covered by a single layer of flat follicular cells
-a lot remain at puberty (40,000) and around 400 will mature and ovulate during a lifetime
what happens in follicular development?
-each month from puberty to menopause,FSH and LH stimulate the development of sexual primordial follicles (one reaches ovulation)
-just before ovulation, diploid primary oocyte completes meiosis 1
-this produces 2 unequal sized haploid cells~the secondary oocyte and first polar body
what happens during oogenesis?
-because a secondary oocyte has been formed it begins meiosis II but stops at metaphase
-at ovulation, a secondary oocyte is expelled with the first polar body
-fertillisation
-if a sperm penetrates a secondary oocyte,meiosis 2 resumes
what happens if fertilisation doesn’t occur in oogenesis?
-the cells degenerate
what happens to the secondary oocyte at the end of oogenesis?
-they split into two cells of unequal size:second polar body (discarded) and ovum or mature egg
-the nuclei of the sperm cell and ovum unite to form a diploid zygote (fertilisation)
what is the functions of the uterus?
-transport of spermatozoa
-menstruation
-implantation of fertilised ovum
-development of foetus during pregnancy and labour
how is the uterus anatomically divided?
-fundus
-body
-isthmus
-cervix (opens into vagina)
what is the histology of the uterus?
-it has 3 layers:
perimetrium (outer layer)
myometrium
endometrium (inner layer, highly vasculated)
-it also has a stratum functionalis and stratum basalis
what does the myometrium consist of and what does it do?
-3 layers of smooth muscle
-has contractions in response to oxytocin from the posterior pituitary
what does the stratum functionalis do?
-lines the cavity and sloughs off during menstruation
what does the stratum basalis do?
-it is permanent and gives rise to new stratum functionalis after each menstruation
how is the blood supply of the uterus?
-uterine arteries branch as arcuate arteries and radial arteries that supply the myometrium
-straight and spiral branches penetrate to the endometrium
-spiral arteries supply the stratum functionalis
-their constriction due to hormonal changes starts the menstrual cycle
what is cervical mucus produced by?
-secretory cells of the mucosa of the cervix
what happens when cervical mucus is thin or thick?
-when thin it is more receptive to sperm
-when thick it forms a cervical plug that physically impedes sperm penetration
what does cervical mucus consist of?
-a mixture of water, glycoprotein,serum type proteins,lipids,enzymes and inorganic salts
what does cervical mucous do?
-supplements the energy needs of the sperm
-the cervix and the mucus plays a role in capacitation-this renders them competent to fertilise an oocyte
what is the vagina?
-a 4-inch long fibromuscular canal extending from the exterior of the body to the uterine cavity, it ends at the cervix
what is the structure of the vagina?
-it has a mucosal layer
-a muscularis layer that is smooth muscle and allows considerable stretch
-it has adventitia-loose connective tissue that binds it to other organs
what does the vulva/pudendum consist of?
-mons pubis
-labia majora
-labia minora
-clitoris
-vestibule
-bulb of vestibule
what is the mons pubis?
-fatty pad cushions pubic symphysis
where is the labia majora and minora?
-labia majora-homologous to scrotum
-labia minora-homologous to spongy (penile) urethra
what is the clitoris?
-a small mass of erectile tissue and numerous nerve/blood vessels, it is homologous to the glans penis
what is the vestibule and bulb of the vestibule?
-vestibule=region between labia minora
-bulb of the vestibule=2 elongated masses of erectile risse,it is on either side of the vaginal office
what is the perineum?
- a diamond shaped area medial to the thighs and buttocks of males and females
-it contains the external genitalia and anus
what may happen to the perineum during childbirth?
-the emerging foetus may cause excessive stretching and tearing of the perineum
what may a physician do in the area of the perineum?
-may make a surgical incision (episiotomy) to prevent excessive jagged tears
what are mammary glands?
-modified sudoriferous( sweat) glands that produce milk
-15-20 lobes are divided into lobules composed of alveoli (milk secreting glands)
how do milk secreting glands open?
-by lactiferous ducts at the nipple
what is the areola?
-pigmeneted area around the nipple
what is the female reproductive cycle?
-cycle that encompasses ovarian and uterine cycle, hormonal cha get that regulate them and related changes in the breast and cervix
what is the female reproductive cycle controlled by?
-monthly hormone cycles of the anterior pituitary,hypothalamus and ovary
what is the ovarian cycle?
-changes in the ovaries that occur during and after maturation of oocytes
what is the uterine (menstrual) cycle?
-a concurrent series of changes in the uterine endometrium preparing it for the arrival of the fertilised ovum
what happens if implantation does not occur during the menstrual cycle?
-the stratum functionalis is shed during menstruation
