Reproductive 3 - Coitus, Fertilisaton and Contraception

Question 1

This occurs when an erect penis is introduced into the vagina.

Answer 1

Intromission

Question 2

This occurs when semen is released into the upper part of the vagina so that sperm can travel to appropriate site for fertilisation.

Answer 2

Insemination

Question 3

This is when the erectile tissue of male becomes engorged with blood.

Answer 3

Erection

Question 4

This occurs when the smooth muscle contractions of ductus deferens moves sperm into the ampulla, and then the smooth muscle of the ampulla contracts to move sperm into the urethra.

Answer 4

Emission

Question 5

This occurs when urethral smooth muscles contract to release semen.

Answer 5

Expulsion

Question 6

What are the 2 phases of ejaculation? What’s the difference between both? (in terms of what happens and the nervous regulation)

Answer 6

Emission: movement of sperm from ampulla (due to smooth muscle, prostate gland and seminal vesicles) into the urethra (sympathetic control)

Expulsion: release of semen from urethra (sympathetic control)

Question 7

Is erection a sympathetic or parasympathetic response?

Answer 7

Parasympathetic; just think rest and digest - but in this case, it’s rest and dilate which causes the penis to be filled with blood and have an erection.

Question 8

What are the 3 stages of the male act?

Answer 8

Erection, Ejaculation and Resolution

Question 9

This is the specific nerve that supplies sensory and somatic motor inner vat ion to perineum and external genitalia including the penis.

Answer 9

Pudendal nerve

Question 10

The autonomic innervation to the penis is derived from?

Answer 10

Pelvic plexus

Question 11

What is the main artery that supplies blood to the perineum and external genitalia including the penis?

Where does it branch off from?

Answer 11

Internal pudendal artery; branches off from abdominal aorta

Question 12

What are the arteries that the internal pudendal artery branches off to to supply blood to the penis?

Answer 12

DUAD

dorsal artery, urethral artery, artery to bulb, deep cavernosal artery

Question 13

This is when the blood flow to the penis is reduced and it becomes as a result, flaccid.

Answer 13

Resolution

Question 14

How does fertilisation occur? (4 Steps) IFSC

Answer 14

1) Insemination
2) Fertilisation (once the sperm reaches ampulla of the fallopian tube - sperm fuses with secondary oocyte)
3) Secondary oocyte finishes meiosis and forms a secondary polar body + a fertilised egg = ovum/zygote
4) Cleavage is initiated aka mitosis and the zygote travels to uterus for implantation.

Question 15

What are the 3 natural methods of contraception?

Answer 15

1) periodic abstinence (rhythm method)
2) coitus interruptus (withdrawal method)
3) lactational infertility

Question 16

These are a method of contraception which must remain at least 6 hours after intercourse. Usually used in conjunction with spermicidal foams, jellies, creams and sponges.

Answer 16

Caps and diaphragms

Question 17

This is a method of contraception which is cheap, readily available, easy to use and reduces the risk of STDs.

Answer 17

Condoms

Question 18

This is a method of contraception which reduces sperm transport and impairs implantation. It causes low grade inflammation to the lumen of the uterus and is toxic for the oocyte and the zygote.

Answer 18

Copper IUD (non hormonal IUD)

Question 19

What do steroidal contraceptives do?

Answer 19

> suppress ovulation by sending negative feedback loops to hypothalamus and APit
affect mucus produced by cervix to prevent sperm penetration
deliver progestin (which also affects follicular growth)

Question 20

What are the 2 methods of sterilisation?

Answer 20

• tubal ligation for female (cutting the uterine tubes)
  > cutting it would mean fertilisation can’t happen
• vasectomy (cutting vas deferens)
  > which prevents sperm from being delivered to the ampulla/stored