The Reproductive System Flashcards
The reproductive system is designed to
perpetuate the species
Male gametes
sperm cells
Female gametes
ova
Fertilization
joining of a sperm cell and an ovum
results in formation of a zygote
The reproductive system includes
- gonads (testes/ovaries)
- reproductive tract
- accessory glands
- perineal structures (external genetalia)
Structures of the male reproductive system
(know the picture)
- testis
- epididymis
- ductus deferens
- ejaculatory duct
- spongey urethra
- seminal gland
- prostate gland
- bulbo-urethral gland
Where are the testes?
They hang inside a pouch called the scrotum, which is on the outside of the body
Development of the testes
testes form inside the abdominal cavity near the kidneys
they descend toward the scrotum by passing through the inguinal canals
Spermatic cords
bundle the ductus deferens, blood vessels, lymphatics, and nerves to the testes
Temperature for testicle development
Temperature for sperm development
98.6; which is why they develop in the abdominal cavity
96.6; which is why they the testes are outside the body
Two chambers of the scotum
scrotal cavities
Peripheral raphe
separate the chambers
can be seen as thickened tissue that extends from the anus, across the scrotum, and along the anterior surface of the penis
Tunica vaginalis
a serous membrane that covers the outside of each testis and covers the inside lining of each scrotal cavity
Dartos muscle
contraction causes the wrinkling of the scrotal surface
Cremaster muscle
contraction tenses the scrotal sac and pulls it closer to the body to maintain proper temperature
Cold temp = testes move closer to the abdomen
Tunica albuginea
a tough fibrous lining of the testes
separates the testes into lobules -> seminiferous tubules -> epididymus
Interstitial cells
- location + hormone
found within the space between the coils of the seminiferous tubules
produce and release testosterone
Epididymus
sperm cells move from the seminiferous tubules (via fluid movement) eventually to the epididymis to mature a little longer
recycling center for damaged spermatozoa
stores spermatozoa for further maturation (about two weeks) to get activated
Process of capacitation
sperm cells become motile when mixed with secretions from the seminal glands
become capable of fertilizing an egg when exposed to the female reproductive tract
Ductus deferens alternate name
vas deferens
know the pathway of the vas deferens
Prostatic urethra
extends from the urinary bladder through the prostate gland
Membranous urethra
the merging of the prostatic urethra and the ejaculatory duct
Spongey urethra
passes through the penis
sometimes called the penile urethra
Male accessory glands
- seminal glands
- prostate gland
- bulbo-urethral glands
Seminal glands
produce 60% of the semen volume
produce seminal fluid
contents empty into the ductus deferens
Seminal fluid consists of
- a high concentration of fructose
- prostaglandins
- clotting factors
Prostate gland
produces 20-30% of semen volume
contents empty into the prostatic urethra
weakly acidic
Bulbo-urethral glands
produces 5% of semen volume
paired glands at the base of the penis
contents empty into the spongey urethra
Bulbo-urethral glands secretions
consists of thick, sticky, alkaline mucus
neutralizes urinary acids that are remaining in the urethra
provides lubrication for the tip of the penis
How many mL of semen per ejaculation?
2-5mL
Ejaculation material consists of
- <5% spermatozoa
- seminal fluid
- enzymes that dissolves vaginal mucus and acts as an antibiotic
Penis regions
Root: each one attaches to the rami of the ischia
Body: consists of erectile tissue
Glans: expanded distal end of the penis that surrounds the external urethral orifice
3 cylindrical columns of erectile tissue and blood vessels
2 corpora cavernosa
1 corpus spongiosum
Corpora cavernosa
- contains the deep artery of the penis in the center
- each cavernosum extends posteriorly forming a crus of the penis
- each crus is bound to the ramus of the ischium
Corpus spongiosum
consists of spongey urethra
Erection of the penis steps
- parasympathetic nerves are activated
- arterial vessels dilate
- arterial vessels and vascular channels in corpus cavernosa become engorges with blood
- erection occurs
Ovaries
consist of a cortex (where gamete production takes place) and a medulla
What initiates the ovarian cycle and what happens
FSH initiates the cycle
then, follicles begin to mature and produce estrogen
Ovulation =
- gamete release
A rise in what causes weakening in the follicular wall?
Leutinizing hormone
once the wall breaks, the egg is released into the uterine tube
Corpus luteum
Corpus albigans
corpus luteum: empty follicle that produces progesterone
corpus albigans: forms as a result of corpus luteum decomposition
Progesterone
prepares the body for pregnancy
4 regions of the uterine tubes
isthmus
ampulla
infundibulum
fimbrae
Fimbrae
creates a current to draw egg into uterine tube
Uterus functions
- provides protection and nutrient support for embryo
- removes waste made by embryo
Uterine walls
- Endometrium
- Myometrium: longitudinal, circular, and oblique smooth muscles
- Perimetrium
Endometrium layers
Functional layer: closest to the uterine cavity, contains the uterine glands, and undergoes cyclic changes due to hormones
Basilar layer: closest to the myometrium and stays relatively constant
3 phases of the uterine cyle
- proliferative phase
- secretory phase
- menses
Proliferative phase
increase in estrogen
endometrial lining thickens to prepare the body for the implantation of a fertilized egg
Secretory phase
increase in progesterone
endometrial glands enlarge and blood vessels elongate
if present, the egg is ready to implant
Menses
(menstruation) decrease in estrogen and progesterone
causes constriction of blood vessels and results in loss of endometrial cells
The vagina extends from
the cervix of the uterus to the external genetalia
edges of the cervix form the fornix
Normal population of bacteria in the vagina
- get nutrients from the cervical mucus
- create an acidic environment that reduces the growth of many pathogenic organisms
- reduces sperm mobility (counteracted by buffers in seminal fluid)
Histology of vagina
- lined with stratified squamous epithelium
- tissue forms rugae when relaxed
- contains lamina propria (thick + elastic)
Vulva
entire genitalia area
Vestibule
opening into vagina surrounded by the labia minora
Clitoris
contains erectile tissue that swells with blood during sexual arousal
Labia majora + mons pubis
forms lateral and superior edges of the vestibule
Crus of the clitoris
extends along the medial surface of the pubic arch
