fertilization and sex

Question 1

when does the sperm gain its capability of movement?

Answer 1

once in the tail of the epididymis

Question 2

what else happens in the epididymis?

Answer 2

it adds secretery products on surface of sperm to protect it from the harsh environment if the female reproductive tract!

Dependent on support of the epididymis by androgens

Question 3

what is semen?

what is it composed of?

Answer 3

Semen, also known as seminal fluid, is an organic fluid that may contain spermatozoa.

• Spermatozoa
• Seminalplasma

Question 4

describe the functions of the main constituents of semen.

Answer 4

Seminal plasma derived from accessory glands of the male reproductive tract.

• Function:
– Transport (vehicle)

– Nutrition

– Buffering capacity (bc vagina is so acidic)

Question 5

describe the source of the main constituents of semen.

Answer 5

Seminal vesicles-60%

• alkaline fluid (neutralizes the acid: male urethra & female reproductive tract)
• fructose, prostaglandins, clotting factors (particularly semenogelin)

Prostate gland-25%

• milky, slightly acidic fluid
• proteolytic enzymes (breakdown clotting proteins, re-liquefying semen in in 10-20 minutes )
• citric acid, acid phosphotase

Bulbourethral glands (Cowper’s glands)

– Very small volume

– alkaline fluid

– a mucous that lubricates the end of the penis and urethral lining.

Question 6

what gives the semen its milky appearence?

Answer 6

the prostate gland

Question 7

what is the volume and pH of seminal fluid?

Answer 7

volume= 2–6 mL

pH= 7–8

Question 8

Describe the phases of the human sexual response?

Answer 8

4 phases

Question 9

list the stages of the male sexual act (4)

Answer 9

stimulation, erection, emission and ejaculation.

Question 10

what r the Stimulants in the male sexual response? (2)

Answer 10

1. Psychogenic
2. Tactile (sensory afferents of penis and perineum)

Question 11

what is the most important source of sensory nerve signals for intitiating the male sexual act?

Answer 11

Glans penis

slippery massaging action of intercourse on the glans stimulates sensory end organs > sexual signals pass through PUDENDAL NERVE

then through sacral portion

then brain

Question 12

what nerves r the efferents of the male sexual response going to the spinal cord?

Answer 12

pelvic and pudendal nerve

Question 13

what happens during erection

Answer 13

caused by Parasympathetic impulses through pelvic n.

release NO and ach

increase amounts of cyclic GMP

1. this relaxes arteries of penis
2. and trabecular meshwork of SM fibers in corpus cavernosa & corpus spongiosum

Question 14

how does the penis eject (boner)

Answer 14

as vascular smooth muscle relaxes, BF to penis increases> causing release in NO> further vasodilation

erectile tissue of penis consists largely of cavernous sinosoids that r normally empty of blood, but now blood is rushing to them under high pressure! (compress on venous outflow)

Question 15

role of parasympathetic

via what nerves

Answer 15

needed for erection and lubrication!

• Fibres
– Lumbar and sacral spinal levels

Pelvic nerve and pelvic plexus

Cavernous nerve to corpora and vasculature

(if doesnt lubricate, its painful)

Question 16

explain role of NO in erection?

Answer 16

NOS= nitric oxide synthase

Question 17

what can be reasons for erectile dysfunction?

Answer 17

Question 18

How can you treat erectile dysfunction?

Answer 18

Viagra^TM

slows rate at which cGMP is degraded

there fore

Question 19

what happens after erection has acheived?

Answer 19

when the sexual stimulus becomes extremely intense...reflex centers of spinal cord begin to emit

sympathetic impulses!

then emission and ejaculation can take place!

Question 20

how does emission take place?

Answer 20

contraction of vas deferens & ampulla causes expulsion of sperm into the urethra!

then SM of prostate & contraction of seminal vesicles release fluid also in urethra!>> forcing sperm FORWARD!

all these fluids mix in the internal urethra to form

the semen!

Question 21

hoe does ejaculation take place?

Answer 21

filling of semen in the urethra send sensory signals through pudendal nerve to low spinal cords>> giving feeling of fullness in the internal genital organs>>these senspry signlas further excite rythmateical contractions of ischiocavernous and bulbocavernousus muscles that compress the base of the erectile tissue of penis.

ejeaculate sperm to exterior

once muscles start squeezing, a guy cant stop the semen frrom not coming out “thats why they cant stop”

Question 22

what makes sure the ejaculate doesnt retrograde?

Answer 22

bladder internal sphincter contract!

Question 23

what is orgasm?

Answer 23

period of both ejaculation and erection

Question 24

explain the autonomic control of sexual function

Answer 24

erection> parasympathetic

Ejection & ejaculation> sympathetic

so if u give sympathetic antagonist ex: when treating high BP, u can get a dry orgasm

Question 25

describe how the character of **cervical mucus** _changes_ over the course of the menstrual cycle. and the hormoes responisble for this change! ## Footnote *what is the term which refers to the stringy or stretchy property found to varying degrees in mucus?*

Answer 25

estrogen make it *thin*\>\>so perm can get in\>\> up to the point of ***_OVULATION_***

Question 26

where is Semen deposited in the female repro tract? and where does fertilization occur?

Answer 26

Question 27

what happens to the semen when it gets into the cervix of the female repro tract?

Answer 27

it undergoes temporary coagulation to make sure it doesnt get out of the vagina! *(stay in bitch)*

Question 28

what is the primary method that allows spermatozoa to get to the site of fertilisation?

Answer 28

**under their own control! their motility tail!**

Question 29

describe the physiological changes in the female which facilitate coitus

Question 30

Define fertilization?

Answer 30

fertilization is the union of a human egg and sperm

Question 31

what is the fertile window in sperm and egg?

Answer 31

**• Spermatozoa** \>\> 48-72 hr **• Oocytes** \>\> 6 – 24 hr (max)

Question 32

Describe the process involved in sperm transport through the cervix and uterus

Question 33

Describe the processes of capacitation of sperm and the acrosome reaction

Answer 33

sperm tail in capacitation also starts to move vigoursly!

Question 34

where is the acrosome on the sperm derived from?

Answer 34

Derived from ***golgi region*** of developing spermatid

Question 35

how does transport of oocyte and sperm differ?

Answer 35

***• Gamete transport*** * – Oocyte:* beating cilia & peristalsis of uterine tube * – Sperm:* own propulsion

Question 36

descrobe processes of cortical reaction and its importance? functions of Ca+ surge? (2)

Answer 36

Question 37

what happens after zygote is formed?

Answer 37

***cleavage and blastocyst formation!*** 36 hrs after fertilization, the 1st cleavage division of zygote has made 2 IDENTICAL cells called *blastomeres* * these divide and become 4 cells\>\> then 8\>\>so on* * AFTER 3 days of fertilisation\> MORULA!*

Question 38

Morula is totipotent what does this mean?

Answer 38

capable of giving rise to **_any_** cell type *its identical to parent cell*

Question 39

when the ZP starts to break down an inner strucutre is now formed called the\_\_\_\_\_ describe its structure. why does it need to hatch from the ZP?

Answer 39

Blastocyst! so it can implant! no longer contrained! IMMM FREEEE AND IMMA BLAST OFF!

Question 40

Answer 40

Question 41

Describe processof implantation

Answer 41

Question 42

what happens if u get Implantation in lower uterine segment?

Answer 42

can cause **placenta praevia** *placenta is your baby's 'life support' system during pregnancy. It is shaped a bit like a pancake attached to the inside of your womb (uterus)*

Question 43

what part of the blastocyst interacts with the endometrium?

Answer 43

the trophoblsts!

Question 45

Hyperprolactinaemia may lead to infertility. What clinical sign may indicate a diagnosis of hyperprolactinaemia?

Answer 45

Production of small quantities of milk

Question 46

what drug could be used to treat hyperprolactinaemia. How does it work?

Answer 46

**Bromocryptine** ## Footnote **Dopamine agonist** – mimics effects of prolactin inhibitory hormone

Question 47

How might you test whether uterine tubes are patent? (opened up and normal)

Answer 47

Passage of radio-opaque dye from uterine cavity, **hysterosalpingography** ## Footnote *is an x-ray examination of a woman's uterus and fallopian tubes that uses a special form of x-ray called fluoroscopy and a contrast material.*

Question 48

How might you establish whether cervical sperm transport is disturbed?

Answer 48

**Post coital test** – collect cervical mucus from women soon after intercourse