Human Reproductive System - 14.1 Flashcards
What is the human reproductive system adapted to do?
To unit a single reproductive cell from a female parent with a single reproductive cell from a male parent
What are the organs in the male and female that produce reproductive cells?
The Gonads
What is the gonad in the male reproductive system?
Testis
What is the gonad in the female reproductive system?
Ovaries
What are the male and female reproductive cells also called?
Gametes
What two things do the male and female gonads release?
Gametes
Sex hormones
What are sex hormones?
Chemical compounds that control the development and function of the reproductive system
What are primary sex characteristics?
Organs, ducts, and glands that play a direct role in reproduction
(scrotum, penis, uterus, oviducts)
What are secondary sex characteristics?
Distinct features that are not directly related to reproductive function
(facial hair, deep voice, minimal body hair)
What is the main role of the male reproductive system?
To produce and store a large number of sperm
To deposit this sperm inside the female reproductive tract
Where are the two male gonads (testes) held inside the body?
They are held by the scrotum
What does the Scrotum do?
It helps regulate the temperature of the testes
What temperature is sperm production the most sucessful?
35 degrees celsius
In cold conditions what does the scrotum do?
It draws the testicles closer to the body so they stay warm
In hot conditions what does the scrotum do?
Holds the testicles more loosely allowing them to remain cooler than the body
Where is the sperm produced?
Inside the seminiferous tubules (site of spermatogenesis)
What secretes the male hormone testoserone?
Interstitial cells - in between the seminiferous tubules
What are the three parts of the sperm?
- The oval head
- Cyndrical middle piece
- Extended tail (Flagellum)
What does the head consist of?
- Contains 23 chromosomes
- Covered by a caplike structure (acrosome) - stores enzymes that penetrate the protective layer surrounding female egg
What does the middle layer consist of?
- Mitochondria - provides energy for the movement of the tail
What does the tail do?
Propels the sperm in lashing motions (sperm can move at a rate of about 3mm per hour)
What supports and nourishes developing sperm?
Sertoli cells
What is the epididymis?
Connected to the testis - place where sperm become mature and motile
What is the ductus deferens?
Storage duct that conducts and stores sperm
What is the primary reproductive function of the penis?
To transfer sperm from the male to female reproductive tract
What is the enlarged tip of the penis called?
Glans penis
What surrounds and protects the glans penis?
Sheath of skin - foreskin
What is circumsision?
Surgical removal of foreskin
How does the penis become erect?
Aroused - blood flow to erectile tissues increase - it expands
Veins that carry blood from penis become compressed
Penis is enlarged with blood and becomes erect
Sperm move from epidymis through ductus deferens
What does the seminal vesicles do?
Produces a mucus like fluid that contains the sugar fruticose - provides energy for the sperm
What does the prostate gland and cowpers gland do?
Produce a mucus and a alkaline fluid to neutralize the acids from urine in the urethra
What is the combination of sperm cells and fluids called?
Semes
What duct carries fluid through the penis?
The urethra
What prevents urine from mixing with semen during intercourse?
sphincters
What series of interactions move semen?
Sympathetic nervous system, parasympathetic nervous system, and somatic nervous system
What trigger the release of semen form the penis?
Sensory stimulation, arousal, and coordinated muscular contractions
What are the ovaries?
The site of oogenesis
Another name for ova?
oocytes
Do each ovary produce an egg each month?
No, ovaries alternate so that one produce an egg each month
Where does a single ovum develop?
Within a follicle in the ovary
What is the event of ovulation?
When a single follicle matures and ruptures - releasing the ovum into the oviduct
What sweeps the ovum from the ovary to the oviduct?
Fimbriae (thread like projections)
What is a mature ovum like?
A non motile sphere shaped cell - 0.1mm in diameters
What does the ovum contains?
A large quantity of cytoplasm - contains nutrients for the first days of development after fertilization
What is the uterus?
Muscular organ that holds and nourishes a developing fetus
What is the internal lining of the uterus?
The endometrium - richly supplied with blood vessels to provide nutrients for the fetus
What is the base of the uterus called?
Cervix
What is the entrance for the erect penis to deposit sperm during sexual intercourse?
The vagina
How long can an ovum survive in the oviduct?
Up to 24 hours after ovulation
What happens if an egg encounters a sperm in the oviduct?
Fertilization
What is a zygote?
A now fertilized egg
What must the endometrium do to prepare itself for zygote?
Thicken so that the zygote can implant itself there
What happens if the egg is not fertlized?
The endometrium disintegrates - its tissue and blood flow out of the vagina
What is another term for the endometrium degenerating?
Menstruations
What are the female externa genital organs?
Vulva
- Labium minora - protect vaginal opening
- Labium majora - protect vaginal opening
- Glands clitoris - becomes erect during sexual intercourse
