conception

Question 1

4 step sexual response cycle

Answer 1

applies to both sexes

excitement
plateau
orgasm
resolution

Question 2

excitement

Answer 2

Heightened sexual awareness/arousal and blood flow to erectile tissues (erection of the penis in males; erection of clitoris in females); vaginal and Bartholin’s gland secretions lubricate the female; male scrotum tightens and male secretes a lubricating fluid (bulbourethral glands)

Question 3

plateau

Answer 3

Intensification of excitement phase responses, plus body responses (increased heart rate, respiratory rate, BP, muscle tension)

Question 4

orgasmic

Answer 4

Male ejaculates semen; feeling of intense pleasure for sexual partners (orgasm); females may under multiple orgasms in
succession

Question 5

resolution

Answer 5

Genitalia and body systems return to pre-arousal state; general feeling of relaxation; refractory period for males to repeat the cycle (varying length)

Question 6

what mediates erection and ejaculation

Answer 6

spinal reflexes

Question 7

hardening of the normally flacid penis to permit its entry to the vagina

Answer 7

erection

Question 8

emptying the spem and excessory sex gland secreitons (semen) into the urethra

Answer 8

ejaculation- emmision phase

Question 9

forceful expulsion of semen from the penis

Answer 9

ejaculation- expulsion phase

Question 10

how is erection accomplished

Answer 10

engorgement fo the penis erectile tissue with blood as a result of marked parasympatheticaly induced vasodialation of the penile arterioles and mechanical compression of the veins

Question 11

how is the emmision phase accomplished

Answer 11

sympathetically induced contraciton of the smooth muscle in the walls of the ducts and accesory sex glands

Question 12

how is the expulsion phase accomplished

Answer 12

motor neuron induced contraction of the skeletal muscles are the base of the penis

Question 13

where si the erection generating centre

Answer 13

lower spinal chord

Question 14

how is the erection generating centre triggered

Answer 14

mechanically by touch sensitive glans penis; higher brain centres facilitate or inhibit this spinal reflex

Question 15

spinal reflexive dialation of the penile arterioles

Answer 15

non adrenogenic neurons release NO to relax the arterioles and blood enters the erectile tisssues

Question 16

engorgement

Answer 16

vacocongestion

Question 17

how quickly is erection achieved

Answer 17

5-10 seconds

Question 18

erection reflex summary

Answer 18

Lower spinal cord is the site of the
erection generating center;
mechanically triggered by the touchsensitive glans penis; higher brain
centers facilitate or inhibit this spinal
reflex
Spinal reflexive dilation of the penile
arterioles; non-adrenergic neurons
release nitric oxide (NO) to relax the
arterioles and blood enters the
erectile tissues
Draining veins are compressed by
engorgement (vasocongestion),
creating a closed system

Question 19

what does vasocongestion lead to

Answer 19

creating a closed system

Question 20

what undergoes vasocongestion

Answer 20

draining veins are compressed by engorgement/ vasoconstriction

Question 21

vascular component of the penis- erection

Answer 21

• Increase in blood flow due to decreased arterial resistance results in some erection
• Venous compression to trap blood volume enhances penile rigidity (tumescence)

Question 22

tumerscence

Answer 22

penile rigidity

Question 23

corpus spongiosum

Answer 23

Open system
High flow
Low pressure
Does not impinge on urethra

Question 24

corpus cavernosum

Answer 24

• Closed system
• Outflow obstructed
• Low flow
• High pressure

Question 25

remedy for erectile dysfunction

Answer 25

inhibit cGMP breadown to maintain relaxation of corpus cavernosum by inhibiting phosphodiesterase type 5

Question 26

how is the emisison phase accomplished

Answer 26

Sympathetic control leads to sequential contractions of smooth muscles of the reproductive tract and accessory glands to deliver things to the posterior urethra

Question 27

what is delivered to the posterior urethra

Answer 27

1) prostate gland delivers fluid 2) epididymis and vas deferens (ductus deferens) deliver spermatozoa 3) seminal vesicle delivers fluid (all combined = semen)

Question 28

what prevents retrograde ejaculation

Answer 28

Sphincter at the bladder neck contracts to prevents retrograde ejaculation and to prevent urine from being mixed with semen

Question 29

what triggers nerve impulses that activate skeletal muscles at the base of the penis

Answer 29

urethra filling with semen

Question 30

what increases the system pressure in the penis and what does this lead to

Answer 30

Rhythmic contractions increase the system pressure, leading to forcible expulsion of semen outside of the body via the urethra

Question 31

average semen voluem

Answer 31

1.5-6 ml with many million sperm per ml

Question 32

what happens when male ejaculation occurs during sexual intercourse with female that has recently ovulated

Answer 32

oocyte fertilization by a single spermatozoan and pairing of the haploid genomes to form a diploid zygote is the moment of conception

Question 33

when must fertilization occur

Answer 33

within 24 hrs of oculation

Question 34

why is semen temporarily clotted

Answer 34

to remain in the vagina it then liquifies to release the sperm

Question 35

what happens to sperm in the female reproductive tract

Answer 35

Spermatozoa undergo an enhanced maturation process called “capacitation” in the female reproductive tract; they exhibit hypermotility and become competent to fertilize an ovum

Question 36

what propells the spermatozoa to the oviduct

Answer 36

Spermatozoa are also propelled to the oviduct by contractions of the female reproductive tract

Question 37

what helps spermatozoa and oocyte meet

Answer 37

evidence of chemo attractants bw the two

Question 38

how many sperm reach the ovum

Answer 38

very few

Question 39

what causes acrosome reaction anad what is it

Answer 39

Physical binding of sperm head with zona pellucida (ZP) leads to the “acrosome reaction” and acrosomal enzymes are released to drill through the ZP

Question 40

what happens when spermatozoan fuses its plasma membrane with the oocyte membrane

Answer 40

its nucleus is released into the cytoplasm

Question 41

what does sperm fusion trigger

Answer 41

ca signalling cascade in the oocyte cytoplasm which triggers; a) Triggers the completion of MII b) Releases cortical granules into the space between the membrane and ZP; inactivates ZP binding proteins (blocks polyspermy)

Question 42

when does conception occur

Answer 42

Within an hour, the oocyte and sperm nuclei fuse to form a diploid zygote

Question 43

what happens as acrosome drills throug the ovum membrane

Answer 43

its acrosomal membrane becomes disrupted

Question 44

IVF female oocyte fertilization

Answer 44

stimulated by exogenous hormone sequence

Question 45

ivf

Answer 45

Collection of ovulated oocytes (stimulated by exogenous hormone sequence in the female) and semen from separate partners * Fertilization (conception) under lab conditions; * Monitor the early embryo development and selection for re-implantation in the prepared uterus (secretory phase of the cycle; prepared endometrium + hormone administration to be sure)

Question 46

ICSI

Answer 46

Direct injection of the spermatozoan nucleus into an isolated MII oocyt

Question 47

ART

Answer 47

assited reproductive technologies therapeutic option for heterosexual couples experiencing infertility, and a fertility option for same-sex couples, surrogate pregnancies, etc.