lecture 38 - coitus, fertilisation and contraception

Question 1

what does the word coitus mean

Answer 1

sexual intercourse = semen released into upper part of the vagina

Question 2

what is the erectile tissue of the penis surrounded by

Answer 2

different layers of fasica

Question 3

what is the trabecula in the penis

Answer 3

smooth muscle fibres

Question 4

what is the lucunae of the penis and what happens during and erection

Answer 4

columnar tissue that fills with blood during an erection

• this causes them to squish against the trabaculae
• which push against the fasica
• this compresses the venous plexua (minimizes blood exsiting the penis and returning to the body)

Question 5

why is the fasica that surrounds the corpus spongiosom not as ‘erectile’

Answer 5

it is not as dense or fibrous because it doesn’t become as erect because it can not block the urethra

Question 6

blood flow from the adbominal aorta to the internal pudendal artery

Answer 6

• abdominal aorta
• common illiac artery
• internal iliac artery
• internal pudendal artery

Question 7

what is the gonadal artery in males and females

Answer 7

males - testicular artery
females - ovarian artery

Question 8

what does the internal pudendal artery feed

Answer 8

perineum and external genetalia including penis

Question 9

where is the fasica in the penis

Answer 9

around the venous plexus

Question 10

what is the pudendal nerve

Answer 10

supplies sensory and somatic motor innervation to perineum and external genitalia, including penis

Question 11

what kind of nervous system response is an erection and what does it stimulate

Answer 11

parasympathetic

• stimulates production of nitric oxide (vasodilator)
• causes deep arteries to dilate and fill lacunae in the corpors cavernosa

Question 12

what kind of nervous system response is ejaculation and what does it stimulate

Answer 12

sympathetic

• stimulates contraction of smooth muscle
• reproductive ducts
• accessory glands

Question 13

the first stage of the male sexual act and what happens

Answer 13

erection
parasympathetic response to stimuli

• arteries in erectile tissues dilate
• erectile tissue becomes engorged with blood

Question 14

what is the second stage of the male sexual act and what happens

Answer 14

emission

• sympathetic response
• smooth muscle of the ductus deferens contracts to move sperm into ampulla
• smooth muscle of the ampulla, semnial vesicle and prostrate gland contract moving sperm and seminal fluid into urethra

Question 15

what is the third stage of the male sexual act and what happens

Answer 15

expulsion

semen in urethra activates somatic and sympathetic reflexes

• contractions of urethral and smooth muscles
• pelvic floor muscles contract

semen is ejected

Question 16

what is the fourth stage of the male sexual act and what happens

Answer 16

resolution

• blood flow to penis is reduced
• penis becomes flacid

Question 17

what happens in the female sexual act

Answer 17

• engorgment of clitoris, labia and vagina in response to autonomic stimulation
• lubricating fluid secreted through vaginal wall, secretion of mucus into vestibule
• rhythmic contraction of vaginal, uterine and pelvic floor muscles

Question 18

what happens after insemination

Answer 18

• sperm travel to uterine tube for fertilisation (ampulla)
• sperm fuses with secondary oocyte
• oocyte completes meiosis II
• fertilised oocyte /ovum known as zygote
• zygote initiates cleavage (takes about 7 days) and travels towards uterus for implantation

Question 19

what does the combined pill contain and what does it do

Answer 19

estrogen and progestin

• suppress ovulation (affect feedback loops to hypothalamus and pituitary)
• affect mucus produced by cervix

Question 20

what does the progesterone only pill effect

Answer 20

cervical mucus

Question 21

what does implant / injectable progestin do

Answer 21

act primarily by disrupting follicular growth and ovulation