Chapter 28: The Reproductive System Flashcards
What are the accessory ducts of the male reproductive system?
- epididymis
- ejaculatory duct
- vas deferens
- urethra
What are the accessory glands of the male reproductive system? How much seminal fluid does each one add?
Seminal vesicles (2) - adds 60% of semen
Prostate gland (1) - adds 35% of semen
Bulbourethral glands (2) - adds 5% of semen
What temperature in the scrotum is needed for sperm production?
Approx. 34°C
(At least 3° below body temp, so it must be slightly colder)
Where in the testis is sperm produced? In what tunica?
In the seminiferous tubules held in the tunica albuginea
What are the 2 types of cells in the seminiferous tubules? What do they do?
- Spermatogenic cells - give rise to sperm
-
Sertoli cells
- nourish and protect spermatogenic cells
- control release of sperm into lumen
- secretes androgen, and inhibin
What do leydig cells do?
Produce the testosterone hormone to begin spermatogenesis
How long does spermatogenesis take?
About 64-72 days
Dartos muscle
Smooth muscle within the scrotum that contracts when cold to wrinkle the scrotal skin and reduce heat loss.
Cremaster muscle
Skeletal muscle in the scrotum which contracts when cold to move the testes closer to the body to retain heat
What are the steps of spermatogenesis?
Spermatogonia (2n) divide by mitosis to make primary spermatocytes (2n). Those divide through meiosis I to make secondary spermatocytes (n), then divide by meiosis II to become spermatids (n). Those develop into spermatozoa (n)
What are the 3 parts of a spermatozoa? (Sperm)
- Head - contains nucleus
- Midpiece - contains mitochondria
- Tail - is a flagellum for movement
What hormone stimulates leydig cells to release testosterone?
Luteinizing hormone (LH)
What hormone stimulates Sertoli cells to release androgen binding protein to bind testosterone
Follicle stimulating hormone (FSH)
What hormone stimulates the release of LH and FSH?
Gonadotropin releasing hormone
What does the hormone inhibin do in regards to spermatogenesis?
- Stops the production of FSH
- lowers amount of LH being released when testosterone levels are too high.
What is the pathway of sperm?
- Seminiferous tubules
- Straight tubules
- Rete testis
- Efferent ducts of epididymus
- Epididymus
- Vas deferens
- Ejaculatory duct/prostate gland
- Urethra
What are the 3 parts of the male urethra in order? How long is each part approximately?
- Prostatic urethra - passes through prostate gland (2-3cm long)
- Intermediate urethra - passes through pelvic cavity (1cm long)
- Spongy urethra - goes through penis to the exterior (15 cm long)
What are the 3 masses of erectile tissue
2 corpora cavernosa (outer masses)
1 corpus spongiosum (inner mass containing the spongy urethra)
Where in the ovary are the ovarian follicles located?
The cortex (outer region)
Where does fertilization occur?
In the oviduct (fallopian tubes)
What are the 3 layers of the uterus wall? (From outermost to innermost)
- Perimetrium - part of the visceral peritoneum
- Myometrium - 3 lays of smooth muscle
- Endometrium - produces a new layer of menstruation
Where does oogenesis occur
In the ovarian follicles of the ovary cortex
What are the steps to oogenesis?
Oogonia (2n) are formed as a fetus and will divide by mitosis to make primary oocytes (2n). They begin meiosis I but are stopped in prophase I until puberty. Once puberty occurs it will complete meiosis I and make a secondary oocyte (n) and a polar body (n). The secondary oocyte will begin meiosis II if fertilized and split into an ovum (n) and a second polar body (n). The ovum will become the zygote (2n)
What is the corpus luteum and what does it do?
It consists of the follicle cells that the secondary oocyte shed when ovulated.
It will secrete estrogen and progesterone hormones.
What is the pathway of the oocyte?
- Ovary
- Body cavity
- Fimbriae
- Infundibulum
- Oviduct (fallopian tube)
- Uterus
a) if fertilized it will be implanted
b) if not fertilized it will go through menstruation - Cervix
- Vagina
- Exterior
In what stage of oogenesis is there a mature Graafian follicle?
The secondary oocyte stage
The ovarian cycle
Event involved in maturation of an oocyte. (2 phases:)
1. Follicular phase - (days 1-14) involves follicle growth using LH and FSH, follicle cells make estrogen. Ovulation occurs on day 14 triggered by LH surge. Graafian follicle ruptures to release secondary oocyte.
2. Luteal phase - (days 15-28) involves corpus luteum secreting estrogen and progesterone. If secondary oocyte is not fertilized, the corpus luteum will degenerate to corpus albicans
How many days after fertilization does the embryo implant in the uterus?
6 days after fertilization
Menstrual cycle
Involves events that prepare the uterus endometrium to receive a fertilized ovum. (3 phases:)
1. Menstrual phase - (days 1-5) involves blood flow from shedding layer of endometrium
2. Proliferative phase - (days 6-13) involves regenerating the new endometrium layer
3. Secretory phase - (days 14-28) involves endometrium preparation for embryo implantation
Progesterone hormone
(Pregnancy hormone)
- Stimulates development of memory glands
- Causes cervical mucus to become thick and sticky to plug cervix if conception occurs
Estrogen hormone
- Promotes growth and development of the female reproductive organs at puberty
How long is sperm viable after depositing in the vagina?
48 hours
How long is the secondary oocyte viable after being ovulated?
24 hours
