Chapter 28 Flashcards
Organs included in male reproductive system
- Testes
- Seminiferous tubules
- Epididymis
- Ductus (vas) deferens
- Ejaculatory ducts
- Urethra
- Seminal vesicles
- Prostate
- Bulbourethral glands
- External organs
Gonad
Organ that produces gametes/hormones
Male gonads and gametes
Testes and sperm
Gametogenesis
General term for production of male gametes
Specific term for production of male gametes
Spermatogenesis
Coiled tubules inside the testes that produce sperm
Seminiferous tubules
Length of epididymis
20 ft
Length of vans deferens
18 inches
Series of tubules/ducts in testes
Coiled seminiferous tubules > straight tubules > rete testis > efferent ducts > highly coiled ductus epididymis > vans deferens
Luteinizing hormone (LH)
Stimulates cells in testes to produce testosterone
Follicle stimulating hormone (FSH)
Stimulates spermatogenesis
Gonadotropin releasing hormone (GnRH)
Stimulates cells in the anterior pituitary gland to produce LH and FSH
Number of days required for spermatogenesis to complete
65-75 days
Location of nucleus in sperm
Head
Function of acrosome of sperm
Covers head and contains enzymes to help w/ penetration
Contained in neck of sperm
Centrioles that form microtubules that make up the rest of the tail
Contained in the middle piece of sperm
Mitochondria that make ATP for locomotion of sperm
Function of tail
Movement
Function of Leydig (interstitial) cells
Secrete testosterone
Function of Sertoli cells (sustentacular cells)
Nourish/support developing spermatozoa
Function of testosterone and dihydrotestosterone
- Prenatal development
- Development of male sexual characteristics
- Development of sexual function
- Stimulation of anabolism
Where ejaculatory ducts form from
Junction of duct from seminal vesicle and end of the vas defens
What accessory glands of male genitals do
Produce seminal fluid (mixes w/ sperm to produce semen)
Accessory glands of male genitals
- Seminal vesicles
- Prostate
- Bulbourethral glands (Cowper’s glands)
** Produce sperm and testosterone
Accessory glands that produce alkaline secretion and what this does
Seminal glands and bulbourethral glands; helps to neutralize acid conditions in female reproductive tract which would likely immobilize the sperm
2 additional functions of Sertoli cells
- Produce androgen binding protein (ABP)
» Binds/maintains high testosterone levels near spermatogenic cells - Release hormone inhibin when level of spermatogenesis required for male reproductive functions has been attained
Other name for Sertoli cells
Sustentacular cells
2 hormones involved in negative feedback mechanisms in hormonal control of male reproductive function
Inhibin/testosterone
Organs included in female reproducitve system
- Ovaries
- Uterine (fallopian) tubes (oviducts)
- Uterus
- Vagina
- External organs
Female gonads/gametes
Ovaries and eggs/ovum/ova
Oogenesis and where it occurs
- Formation of gametes in ovaries
- in ovaries
Inside ovarian follicle
Oocytes, follicular cells, granulosa cells
Released from mature follicle during ovulation
Secondary oocyte
Develops from empty follicle after ovulation
Corpus luteum
Differences in spermatogenesis and oogenesis
- Timing of onset of gametogenesis
» Males: spermatogenesis beings at puberty
» Women: oogenesis begins during fetal development - Spermatogenesis = 4 sperm produced from one spermatogonium that matures
» Oogenesis = one ovum (egg) produced from each one oogonium that matures - After puberty
» Spermatogenesis is continuous
» Oogenesis is cyclic
Occurs if only one follicle matures ea. month
One secondary oocyte released ea. month, only one ovum available for fertilization ea. month
Occurs when two or more follicles mature in a monthly cycle
- Each releasing of a secondary oocyte produces ovum
- Possibility of multiple birth if all ova fertilized
- Fraternal twins/triplets (developed from separate ova fertilized by separate sperm, producing separate zygotes)
Identical twins development
From fertilization of one ovum by one sperm, producing one zygote which is divided into 2+ embryos during very early embryonic stage
Uterine (fallopian) tubes
- Extend from ovaries to uterus
- Fertilization occurs here
- Cilia lining tubes helps move fertilized ovum (or oocyte if fertilization hasn’t occurred) toward uterus
Uterus
Where fertilized ovum implants
3 layers of uterus
- Perimetrium (serosa)
- Myometrium
- Endometrium
Layer where fertilized ovum implants/what happens if pregnancy doesn’t occur
Endometrium; layer is shed
Produced by secretory cells in cervix/advantages of this
Cervical mucus; makes it more chemically hospitable for sperm b/c it’s less viscous and more alkaline
What occurs in ovarian and uterine cycle
- Ovarian: series of changes in the ovary during which the follicle matures, the ovum is shed, and the corpus luteum develops
- Uterine: governs the preparation and maintenance of the uterine lining
Function of GnRH, FSH, and LH in female reproductive cycle
- GnRH: stimulates release of FSH and LH
- FSH: stimulates initial growth of ovarian follicles and further development of ovarian follicles/their secretion of estrogens and inhibin
LH: stimulates ovulation and corpus luteum/secretion of progesterone, estrogens, relaxin, and inhibin by corpus luteum
Functions of estrogens in female reproductive cycle
- Promote development of maintenance of female reproductive structures/secondary sex characteristics
- Incr. protein anabolism
- Lower blood cholesterol
- Stimulate proliferation of basal layer (forms new functional layer after menstruation)
Function of inhibin in female reproductive cycle
Inhibits release of FSH (and LH to a lesser extent)
Functions of relaxin in female reproductive cycle
Relaxes uterus by inhibiting contractions of myometrium
Function of progesterone
- Secreted mainly by cells of corpus luteum
- Cooperates w/ estrogens to
» Prepare/maintain endometrium for implantation of fertilized ovum
» Prepare mammary glands for milk secretion
Phases of female reproductive cycle
- Menstrual
- Preovulatory
- Ovulation
- Postovulatory
Phases of ovarian cycle
- Follicular phase: term for menstrual and preovulatory phases together
- Luteal
» Follicle w/ egg transforms into corpus luteum
» Progesterone/estrogen are released
» Levels of estrogen increase
Phases of uterine cycle
- Menstrual phase: functional/compact layers of endometrium are shed, discharging blood, tissue fluid, mucus, and epithelial cells
- Preovulatory phase: group of ovarian follicles begin to undergo final maturation; endometrial repair also occurs in uterus
- Ovulation: rupture of ovarian follicle/release of secondary oocyte into pelvic cavity
- Postovulatory phase: progesterone and estrogens are secreted by corpus luteum/uterine endometrium thickens in readiness for implantation
Increase in estrogen in early cycle results from growth of what
Dominant follicle
Increase in estrogen in early cycle leads to what change in uterus
Lining thickens
Peak of LH in mid-cycle results in this event in ovary
Ovulation
Release of hormones to corpus luteum in late cycle results in this phase of uterine cycle
Postovulatory
