Chapter 4-6 Flashcards
Gonads
Organs that produce reproductive cells and sex hormones
Sex hormones
Chemical compounds that control development and function of reproductive systems
Primary Sex Characteristics
The structures that play a direct role in reproduction
Secondary Sex Characteristics
Males and females also have a distinct set of features that are not directly related to reproductive function
Sperm cells
Male gametes
Testes
2 male gonads, held outside the body in pouch of skin called the scrotum
Scrotum
Regulates temperature of the testes (sperm like 35 degree)
Seminiferous Tubules
Long coiled tubes that make up the testes, here sperm is produced
Interstitial Cells
Hormone secreting cells, that lie between the seminiferous tubules. Secrete male hormone testosterone
Spermatogenesis
°Starts with diploid germ cell “spermatogonium”
°Puberty - spermatogonium is stimulated to divide by mitosis to form two daughter cells
° 1st cell replenish spermatogonia population
° 2nd cell develops into primary spermatocyte > meiosis 1 > forms two secondary spermatocyte > meiosis 2 > form 4 spermatids > final set of stages to develop into sperm
Sertoli Cells
Supports and nourishes developing sperm (located in seminiferous tubules)
Epididymis
Duct where the sperm becomes mature and motile
(Vas) Ductus Deferenz
Connects epididymis and penis
Ejaculatory Duct
Tube connecting vas Deferens to the penis
Penis
Male organ for sexual intercourse, primary reproductive function is to transfer sperm from the male to the female reproductive tract
Seminal Vessicles
Produces mucus like fluid that contains sugar fructose and provides energy for the sperm
Prostate Gland and Cowpers Gland
Secrets mucus like fluids and alkaline fluid to neutralize acids from urine in the urethra
Semen
Combination of sperm cells and fluid. Semen enters urethra from ductus Deferens
Urethra
Duct that carries fluid through the penis (urinary and reproductive)
Ejaculation
Release of semen from the penis
Ovaries
2 female gonads, produce limited number of gametes (eggs or ova)
Eggs or ova
Female gametes
Oogenesis
°Starts with diploid germ cell “oogonium” > mitosis > two primary oocytes > prophase 1 remains until puberty > after puberty, every month one primary oocytes undergoes meiosis > unequal division of cytoplasm
°cell with most cytoplasm: secondary oocyte
other cell: first polar body not functional
°meiosis again
°cell with most cytoplasm: mature egg
Other cell: not viable
Follicles
Specialized cell structures within the ovary, one ovum develops in each follicle
Ovulation
Each month a follicle ruptures releasing ovum into oviduct
Fimbriae
Thread like projections that sweep over the ovary, ovum is released and is swept by fimbriae into an oviduct
Oviduct
Cilia-lined 10cm tube that carries ovum from ovary to uterus
Ovum
Contains large quantity of cytoplasm for the first days of fertilization
Uterus
Muscular organ holds and nourishes a developing fetus
Endometrium
Lining of the uterus richly supplied with blood vessels to provide nutrients for the fetus
Cervix
Base of the uterus small opening, connects to the vagina
Vagina
Serves as an entrance for the erect penis to deposit sperm, serves as an exit for fetus during childbirth
Zygote
Fertilized egg that moves through oviduct before reaching uterus
Vulva
Female external genital organs (opens from vagina)
Labia majora and labia minora
Two pairs of skin folds to protect vaginal opening, includes glans clitoris(becomes erect during intercourse)
STI
Sexually transmitted infection
HIV/AIDS
- acquired immunodeficiency syndrome caused by virus
- Attacks WBC helper T cells, becomes more vulnerable to infections
Hepatitis
A: drinking water contaminated with fecal matter
B: sexual contact with infected body fluids or blood
C: blood to blood contact through needles or syringes
Genital Herpes
Viral STI, blisters or sores of the mouth, genital, buttocks, thigh
Human Papilloma virus
Genital warts, caused by skin to skin contact that can lead to cervical cancer in women, tumors of vulva, vagina anus and penis
Chlamydia
Caused by bacteria chlamydium trachomatis
symptoms include discharge from penis or vagina, pain urinating, or fever
Cure - early antibiotics
Gonorrhea
Bacterial STI cause infection of the urethra, cervix, rectum and throat, pain when urinating, and thick green-yellow discharge from urethra
Syphilis and treatment
Bacterial STI proceeds in 3 stages and treated with antibiotics
Gonadotropin releasing hormone (Production, Target Organ, Function in male, Function in female)
Production Site: Hypothalamus
Target Organs: Anterior Pituitary Gland
Function in male: stimulates release of FSH and LH from anterior pituitary
Function in women: same
FSH in males (production site, Target organs, Function in male/female)
Production site: Anterior pituitary
Target organs: ovaries and testies
Function on in male/female reproductive system: stimulates development of sex organs and gamete production
LH (production site, Target organd, Function in male/female reproductive syste)
Production site: Anterior pituitary
Target Organs: ovaries and testes
Function in male: Stimulates production of testosterone
Function in female: triggers ovulation and with FSH stimulates estrogen production
Steroids
Mimic action of testosterone in promoting muscle development but disrupt reproductive hormone systems
Andropause
Gradual decline in testosterone levels (age 40+), drop in sperm count, depression, muscle loss
Menstrual Cycle
Female reproductive function follows a cyclical pattern, ensures an ovum is released same time as uterus is most receptive to a fertilized egg (28 days long)
Ovarian Cycle
One follicle matures, releases ovum, develops into yellowish Gland-like structure “corpus luteum”
2 stages
Corpus Luteum
A yellow gland like structure developed from a follicle
Follicular Stage
Increase in level of FSH stimulates follicle to mature, releases estrogen and progesterone.
Estrogen triggers release of GnRH> increase in LH triggers ovulation> follicle bursts > releases ovum
Luteal Stage
LH causes follicle to develop into a corpus Luteum and secretes progesterone. As hormones rise FSH and LH are inhibited, corpus Luteum degenerates= decrease in estrogen and progesterone so the cycle begins again
Ovarian Uterine Cycle
Timing ensures uterus is prepared to receive and nurture a new life, causes a build up of blood vessels and tissues in the endometrium
Menstruation
If fertilization does not occur the endometrium degenerates and is released with blood
Menopause
End of the menstrual cycle (age 50) does not produce ova and is no longer fertile
Effects - rise cholesterol and cancer
Spermatid
Develops into mature sperm, has a nucleus and enzymes in the head regions, mitochondria in the midsection (energy), and a tail like flagellum for movement
Mature sperm
Tadpole shaped, with an oval head, cylindrical middle piece and extended tail
- head: nucleus, enzymes, 23 chromosomes and covered by acrosomes
- middle: mitochondria
What happens to penis during arousal?
Blood flow increases to specialized tissues, erectile tissues expand, veins compress, penis engorges with blood, erect sperm cells move out through ductus deferens
How is urine and semen prevented from mixing?
Sphincter tightens
What causes the movement of semen?
Series of interactions between the sympathetic, parasympathetic, and somatic nervous systems.
What causes ejaculation?
Sensory stimulation, arousal and co-ordinated muscular contractions contractions
Where are the two ovaries located?
Suspended by ligaments within the abdominal cavity
Mature ovum
Non-motile, large quantity of cytoplasm with nutrients for the first days of development after fertilization.
What mature ovum needs for fertilization?
Mature ovum is encased in a thick membrane which must be penetrate by a sperm cell before fertilization can take place.
What does the uterus connect to?
Connects to oviduct at upper end and vagina through cervix at base
How long can the ovum survive in oviduct?
24 hours
What happens to endometrium when egg is fertilized?
Thickens to prepare for zygote, zygote implants itself in it and embryo develops
What happens if egg doesn’t fertilize?
Doesn’t implant in endometrium, endometrium disintegrates, tissue and blood flow out of vagina
Causes of STI
Viruses, bacteria, parasites
Most common and viral STI
HIV/AIDS, hepatitis, genital herpes, HPV
Most common bacterial STI
Chlamydia, gonorrhea, syphilis
How is HIV/AIDS transmitted and cured?
- Sexual contact with infected person, drug users sharing needles children of mothers with HIV (during birth or breastfeeding)
- No cure, alleviation of symptoms carry severe side effects
Hepatitis symptoms
Flu-like, fever, headache, nausea, loss of appetite
Jaundice, liver infection/failure, cancer, death, infect unborn child
Hepatitis prevention
Vaccine for a+b
What happens if chlamydia goes undetected in women?
Spreads to cervix and oviduct > pelvic inflammatory disease (PID) > painful and can build up scar tissue in oviduct > maybe become fully blocked cause infertility.
Cervix infection can result in open sores increasing HIV risk
Babies during birth that come in contact with chlamydia can develop eye and respiratory infections
Untreated gonorrhea and treatments
Lead to PID, spread through bloodstream to joints, heart, brain
Baby birth-eye infection
Antibiotics
Syphilis effects and 3 stages
1: infectious ulcerated sores
2: rash
3: mentally ill, blind, heart disease, large/destructive ulcers on skin/internal organs
Can infect developing embryo - birth defect or still birth
When does male sex organ develop?
Before birth
Y chromosome
Carries gene called testis-determining factor triggering male sex hormone production “androgens” develops male sex organs and ducts in fetus
Male puberty
10-13
Beginning of puberty for males
Hypothalamus increases GnRH > anterior pituitary releases FSH and LH > testes produce sperm and release testosterone > complete sex organ/characteristic development
FSH negative feedback loop
While FSH causes interstitial cells in the testes to produce sperm, FSH also causes cells in seminiferous tubules to release inhibit to inhibit production of FSH.
LH negative feedback loop
LH causes testes to release testosterone, testosterone acts on anterior pituitary to inhibit LH release
Estrogen (Production, Target Organ, Function in male, Function in female)
Production site: ovary
Target Organs: entire body
Function in male: minor
Function in female: stimulates the development of the female reproductive tract and secondary sex characteristics
Progesterone (production site, Target organs, Function in male/female reproductive system)
Production: ovary
Target organ: uterus
Function in male:minor
Function in female:cause uterine thickening
Testosterone (production site, Target Organ, function in male/female reproductive system)
Production site: testes(interstitial cells)
Target Organ: entire body
Function in male: stimulates development of male reproductive tract and secondary sex characteristics
Function in female: minor
Inhibin(production site, Target Organ, Function in male and female reproductive system)
Production: testes (sertoli cells)
Target organ: Anterior pituitary and hypothalamus
Function in male: inhibit FSH production
Function in female: same
Beginning of puberty for females
Hypothalamus produce GNRH > release FSH + LH > act on ovaries produce estrogen + progesterone
Ovarian follicular stage
Increase FSH > stimulates follicle to mature > release estrogen + progesterone > inhibit FSH > sudden release of GNRH > increase LH > ovulation > follicle bursts > release ovum
Ovarian Luteal Stage
LH cause follicle to turn into corpus luteum > increase progesterone + estrogen > inhibit FSH + LH
corpus luteum either degenerates or gets fertilized
What happens when corpus luteum does not get fertilized
Degenerates, decrease in progesterone and estrogen, increase FSH, cycle restarts
What happens when ovum is fertilized?
Implants in endometrium, Estrogen and Progesterone remain high under stimulus of hCG
Hormone replacement therapy
Low levels of estrogen
Risks - coronary heart disease, stroke, blood clots, breast cancer