Lec 14 Erectile dysfunction

Question 1

What percent of testicular volume dedicated to spermatogenesis?

Answer 1

80%

Question 2

What carries out spermatogenesis?

Answer 2

seminiferous tubules

sertoli cells

Question 3

What makes testosterone?

Answer 3

leydig cells

Question 4

What is function of sertoli cells?

Answer 4

• blood-testis barrier
• nourish sperm
• help transport sperm into epididymis

Question 5

What is role of FSH in males?

Answer 5

FSH stimulates sertoli cells and spermatogenesis

Question 6

What is role of LH in males?

Answer 6

LH stimulates leydig cells

Question 7

What feedback does testosterone have?

Answer 7

• negative feedback on both GnRH from hypothalamus and FSH/LH from pituitary

Question 8

What feedback does inhibin have?

Answer 8

inhibin secreted by sertoli cells has negative feedback on FSH

Question 9

How long does one full cycle of spermatogenesis take?

Answer 9

64 days

Question 10

WHat is acrosome?

Answer 10

lysosome-like organelle of sperm involved in penetration of egg

Question 11

What composes semen?

Answer 11

60-75% from seminal vesicles
25-30% from prostate
5% from bulbuourethral glands
5% contains sperm

Question 12

What is significance of fructose in semen?

Answer 12

lack of fructose means obstruction of or after seminal vesicles

Question 13

Where do mature sperm live?

Answer 13

stay in vas deferens until ejaculation

Question 14

What normal LH and testosterone but high FSH tell you?

Answer 14

germinal cell aplasia = failure to make sperm

Question 15

WHat does high FSH and LH but normal/low testosterone tell you?

Answer 15

primary testicular failure

Question 16

What does low FSH/LH/testosterone tell you?

Answer 16

hypogonadotropic hypogonadism = problem from hypothalamus or pituitary

Question 17

What ia a varicocele?

Answer 17

varicose vein of the pampiniform plexus; keeps testicles a degree or two warmer than normal

usually L > R

Question 18

What is intrauterine insemination?

Answer 18

aids in delivering sperm; turkey baste sperm into uterus directly

Question 19

What is intracyctoplasmic sperm injection [ICSI]?

Answer 19

IVG = requires much less sperm so good if male infertility problem

Question 20

What are functions of DHT?

Answer 20

• differentiation of penis/scrotum/prostate
• male hair pattern and baldness
• prostate growth
• sebaceous gland activity

Question 21

What is mech of action finasteride?

Answer 21

5a reductase inhibitor; controls prostate growth and increases hair growth

good for treatmetn of BPH or male pattern baldness

Question 22

What is bioavailability of testosterone?

Answer 22

1-2% free is the biologically active T
40-60% bound to sex hormone binding globulin
40-60% bound to albumin

Question 23

What are symptoms of hypogonadism?

Answer 23

• loss of muscle mass
• weight gain
• loss of libido or erectile dysfunction
• depression/fatigue
• osteoporosis
• regression of 2ndary sex characteristics
• azoospermia

Question 24

What are two causes of secondary [pituitary] congenital hypogonadism?

Answer 24

kallmans = anosmia and hypogonadism

prader willi = deletion/non-expression of paternal 15Q; low muscle tone; short stature; cognitive problems; excess hunger [obesity]; hypogonadism; behavioral disorders

Question 25

What chronic diseases associated with hypogonadism?

Answer 25

- obesity - DM - htn - asthma - hyperlipidemia

Question 26

What causes low T in older men?

Answer 26

decreased frequency of GnRH pulses

Question 27

What is effect of low T on bones?

Answer 27

low T can cause osteoporosis--> more hip fractures

Question 28

What are benefits of T replacement?

Answer 28

- improved muscle mass and strength - increased bone density - restored or maintained secondary sex characteristics - restored libido, better erectile function - increased energy and improved mood

Question 29

What are risks of T replacement?

Answer 29

- suppress testicular function --> decreased sperm production and infertility - increased plasma estrogen --> gynecomastia

Question 30

What are contraindications of T replacement?

Answer 30

- known or suspected prostate cancer - male breast cancer - HCT > 50% - women - untreated prolactinoma

Question 31

What do vascular causes of ED suggest?

Answer 31

cardiovascular risk --> more likely to have an early CV event

Question 32

What is action of PDE-5 inhibitors [sildenafil, vardenafil]?

Answer 32

- cause increase cGMP --> smooth muscler relaxation in corpus cavernosum and increased blood flow / erection

Question 33

What are adverse events of PDE-5 inhibitors [sildenafil, vardenafil]?

Answer 33

``` headache flushing nasal congestion blue-green color vision impaired hypotension in pt taking nitrates ```

Question 34

What are advantages/disadvantages of intraurethral alprostadil?

Answer 34

direct vasodilator its minimally invasive, few side effects, fast acting disadvantage: urethral burning

Question 35

Who should get penile prostheses?

Answer 35

pts refractory to other treatments suffering severe priapism [sickle cell] with severe peyronie's