Lab 8b: Excretory and Reproductive Systems Flashcards
Birth Control
Barrier Methods
Prevent sperm from gaining access to uterine cavity and oviducts.
External condom
Non-porus sheath placed over penis; collects sperm and prevents movement into vagina.
Only birth control method that offers some protection from STIs.
Chemical methods (spermicides)
Foams, jellies etc. that kill sperm and make vagina unfavorable for sperm survival.
Long-acting reversible constraceptives (intra uterine device)
Device that is inserted into cavity of the uterus. Effective for 2.5-5 yrs.
* Copper IUD: prevent pregnancy by stopping sperm from fertilizing an egg. Prevent implantation of a fertilized egg in endometrium.
* Hormonal IUD: contains small amounts of progesterone, which thickens cervical mucus, making it difficult for sperm to fertilize egg.
Hormone methods
Most common is oral contraceptive (birth control pill). Contain estrogen and progesterone. Adjusts hormone levels in body and prevent pregnancy in 3 ways:
1. Prevent ovulation.
1. Thins lining of uterus to prevent implantation of fertilized egg.
1. Thicken cervical mucus making it difficult fot sperm to fertilize egg.
Evra ring: patch on skin that delivers hormones via skin absorption.
Nuva ring: ring inserted in vagina and releases hormones.
Other benefits and risks of hormonal birth control
Helps regulate menstrual cycles.
Makes women less prone to ovarian cysts and endometrial and ovarian cancer.
Can’t be taken by people:
* with heart disease.
* who smoke, bc it increases odds of heart attack or stroke.
Surgica steriliztion
Surgical procedures that prevent sperm from coming into contact with egg.
Non-latex sheath separated by 2 rings.
Does a vasectomy affect male sex drive?
Vasectomy involves cutting and tying the vas deferens to prevent sperm produced in testes from entering urethra. It does not directly affect the testes. Testosterone, the hormone that contributes to male sex drive, is still produced in the testes.
Vasectomy
Vas deferense is cut and tied so sperm cannot ejaculate. Semen is still produced but will contain no sperm cells.
Tubal ligation
Oviducts are cut and tied. Sperm can’t pass thru tubes to fertilize egg and the egg will be reabsorbed by body.
Does tubal ligation interfer with ovarian/uterine cycle?
Prevents egg from moving from ovary to uterus by cutting oviduct. It doesn’t directly affect the ovaries. Therefore, the uterine cycle, which is regulated through estrogen and progesterone produced by the ovary would be unaffected. Likewise, the ovarian cycle is also unaffected. Maturation and release of egg in ovulation still occurs, only that the egg is reabsorbed by the body.
Post Conception Measures
- Emergency contraceptive pill: contains progesterone, prevents fertilized egg from attaching to uterine wall.
- IUD.
- Chemical abortion: drug is injected into th euterus; affects any fast-growing tissue and leads to death of embryo. A 2nd drug (misoprospol) is given to stimulate uterine contractions.
- Surgical abortions.
Which STIs are curable
Antibiotics cure bacterially-caused STIs. Viral STIs (herpes, HIV) are incurable, but can be treated by anti-viral medicines.
3 ways that STIs are acquired
- Contact from contaminated blood or body fluids.
- Passed to infant during vaginal birth.
- Direct contact like vaginal, oral, or anal sex.
Can STIs be passed to an infant during c-section?
Depends on what type of STI is present in the mother. A c-section may reduce risk of diseases being passed to and infant during vaginal birth (ie. those that can be passed to baby in the birth canal).
