Sex

Question 1

How to measure penis length

Answer 1

Erect length the same as stretched flaccid

Question 2

What is the tunica albuginea. what is its function

Answer 2

Only in males
Fibrous sheath
Push against veins when erect
Less blood leaves penis

Question 3

What happens to vasculature during erection

Answer 3

Vein compression
Artery vasodilation
Sinusoidal spaces fill/engorge
Helicine arteries no longer constricted

Question 4

Male sexual response sympathetic NS: what nerve, what functions

Answer 4

SHOOT- ejaculation
Hypogastric nerve (NA)
Contraction: epididymis, vas deferens, prostate, seminal vesicles
- semen travels to proximal urethra

Perineal nerve (branch of pudendal)
Contraction: pelvic floor, ischeo/bulbocavernosus, internal urethral sphincter
- forcible semen expulsion

Question 5

Male sexual response parasympathetic NS: what nerve, what functions

Answer 5

POINT = parasympathetic NS

Cavernous nerve (ACh, NO, VIP)
Vasodilation of penile arteries causes erection:
Smooth muscle relaxation (corpus cavernosa and corpus spongiosa)
Cavernous sinusoids fill- penile expansion and stiffening
Compression of veins- reduced blood drainage

Pelvic plexus
Bulbourethral glands- lube fluid
urethra- sphincter closed
Lubrication
Mucus secretion (sent to semen in proximal urethra- part of SNS)

Question 6

How can the male sexual response occur

Answer 6

Sensory stimulation- penile mechanoreceptors
Pudendal nerve to sacral spinal cord
Sympathetic and parasympathetic outputs

Psychic stimulation- visual, olfactory, emotional
Cerebral cortex to
Hypothalamus (paraventricular nucleus, medial preoptic area)
To sacral spinal cord
Sympathetic and parasympathetic outputs

Question 7

Name parasympathetic neurotransmitters and where they bind

Answer 7

Nitric oxide, acetylcholine, vasoactive intestinal peptide
Bind at penile arteries to induce vasodilation

Question 8

Describe in full the male sexual response

Answer 8

Check pg. 5

Question 9

What is considered emission

Answer 9

Contraction of vas deferens, seminal vesicles, prostate that propels semen towards ejaculatory duct

Question 10

What is considered ejaculation

Answer 10

Expulsion of seminal fluid from body

Question 11

What initiates emission

Answer 11

Hypogastric nerve

Question 12

What causes ejaculation

Answer 12

fullness near ejaculatory duct (caused by emission) cause pudendal nerve to send sensory stimulus to brain. This initiates rhythmic contractions that lead to ejaculation

Question 13

What blocks PDE5? What is the function of PDE5

Answer 13

Phosphodiesterase E5
Sildenafil = viagra blocks PDE5
PDE5 (found in reproductive tissue) job to break down cGMP causes PLB (phospholamban) to inhibit SERCA activity therefore less relaxation
So Sildenafil will increase relaxation to allow erection

Question 14

Function of Sildenafil and the cause of its effect (MBB pathway)

Answer 14

Block PDE5 therefore allows cGMP to activate PKG which phosphorylates PLB (PLB release inhibition on SERCA) causing an increase in SERCA activity (faster relaxation- vasodilation)

Question 15

Explain NO pathway

Answer 15

Ach from parasympathetic efferent bind to M3 Gq
Gq causes increase Ca levels that activate eNOS
eNOS converts L-arginine to NO
NO diffuse from endothelium to VSM and activate GC- guanylyl cyclase
GC convert GTP to cGMP
cGMP activate PKG which phosphorylates PLB (increasing SERCA)

PDE5 break down cGMP to GMP (Sildenafil block PDE5)

Question 16

How erection and ejaculation are effected by an upper motor neuron lesion

Answer 16

Reflexogenic erection- present (semen winds up in bladder since urethral sphincter open)
Psychogenic erection- absent (can’t reach pudendal nerve)
Effect of ejaculation- significantly impaired

Question 17

How erection and ejaculation are effected by a lower motor neuron lesion

Answer 17

Reflexogenic erection- absent
Psychogenic erection- present (must be constant to maintain)
Effect of ejaculation- less impaired

Question 18

Female sexual response sympathetic and parasympathetic

Answer 18

Sympathetic- Hypogastric nerve
Orgasm
Contractions: pelvic floor, perineal muscles, cervical dilation
Assumption is that uterine contractions propel sperm

Parasympathetic
Pelvic nerve: Ach, NO, VIP
vasodilation- vaginal wall, labia minora, clitoris
Increased vaginal tone
Causes arousal- smooth muscle relaxation, clitoral and vaginal engorgement, lengthening and dilation of vagina

Pelvic Plexus
Bartholin glands (labia minora), vaginal epithelium -> lubrication, mucus secretion

Question 19

How does female psychic stimulation work

Answer 19

Visual, olfactory, emotional
Cerebral cortex
Hypothalamus (paraventricular nucleus, medial preoptic area)
Oxytocin (secreted by posterior pituitary)
Uterine contractions

Question 20

Scientists who documented female sexual response

Answer 20

William Masters and Virginia Johnson

Question 21

What age related changes occur related to sex

Answer 21

Greater stimulation to achieve erection with increasing male age
Less lubrication with increasing female age

Question 22

Explain 4 phases of human sexual response

Answer 22

Excitement- increased muscle tone, heart rate, breathing, blood pressure. Flushed skin, erect nipples and breast swelling, engorgement and lubrication of genitals. Testes swell and scrotum tightens.

Plateau- intensification of excitement. Increased muscle tension and muscle spasms. Testes withdraw into scrotum. Increased clitoral sensitivity. Vaginal engorgement and swelling.

Orgasm- climax is a few seconds. Involuntary muscle contractions/spasm. Further increases in heart rate, blood pressure, breathing. F: Rhythmic contractions of vagina and uterus (full sperm in). Flushed skin. Rhythmic contraction of pelvic floor, bulbo/isheocavernosus, internal urethral sphincter. Increased lubrication.

Resolution- endorphins, sense of well-being, intimacy, fatigue. Return to normal state. Refractory state in men

Question 23

Experiment testing orgasm facial expressions proved what

Answer 23

That pain face and sex face are not the same

Question 24

What are females sexual performance concerns

Answer 24

• sexual dysfunction
• issues with arousal, desire, orgasm
• physical, psychological, hormonal
• pain during sexual activity

Question 25

What are male sexual performance concerns

Answer 25

• erectile dysfunction
• premature ejaculation

Question 26

General suggestions for premature ejaculation and erectile dysfunction

Answer 26

Premature- topical = lidocaine, methodological = alternate foreplay and intercourse

Erectile- physical aid (pressure ring) or therapeutics