Reproduction Lectures 2021 - MALE REPRODUCTIVE SYSTEM Flashcards

Question

In terms of testicular mass:

Answer 1

the seminiferous tubules comprise of ~80% of testicular mass within each testicle

Answer 2

extremely imp. in communicating gamete dev. within males & communicate with sertoli cells

Answer 3

- INSIDE seminiferous tubule | - surrounded by layers of connective tissue & smooth muscle

Answer 4

- OUTSIDE seminiferous tubule - produce testosterone - communicate with the sertoli cells within the internal area of the seminiferous tubule & the dev. spermatids

Answer 5

support those dev. gametes (critical in terms of gamete dev.)

Answer 6

- this barrier, the basal lamina that separates the internal environment of the seminiferous tubule with the external environment of the body is critical & essentially acts v. similar to a blood brain barrier as the blood testis barrier that stops the immune system from attacking what would be otherwise unknown cells (the gametes that develop within the seminiferous tubule) - therefore, critical in gamete dev. - blood testis barrier is by the basal lamina

Answer 7

are found within the basal lamina - these specific cell types are really critical for communicating b/t the leydig cells & the sertoli cells within the seminiferous tubule - also help in movement of fluids from the external environment to the internal environment across that basal lamina *specific cell type around the basal lamina that aid in the communication b/t sertoli & leydig cells & also production of fluids

Answer 8

essentially separates the development of these spermatids b/t each other on either side

Answer 9

outside (periphery of the seminiferous tubule) to the internal region of the seminiferous tubule sertoli cells will support & aid all of these

Answer 10

High K+ ions & high in steroids (partic. testosterone)

Answer 11

- related to motility of sperm - with a higher K+ concen. the sperm tend to be less mobile or motile - as a conseq. are not needlessly burning energy that would be req. once released into the female reproductive tract - so they have a lower metabolic rate in the presence of high ECF K+ concens.

Answer 12

``` lipid soluble (won't dissolve easily within this water based fluid in the lumin of the seminiferous tubule) - so as a conseq. of that there are ABP, that is also released into the lumen of the seminiferous tubule ```

Answer 13

- imp. to facilitate the concen. of testosterone in the seminiferous tubule fluid - b/c it is a water fluid environment & testosterone is a steroid so it's lipophilic - binds to the testosterone in the seminiferous tubules so that more testosterone can come in from the outside/is available - total concen. of testosterone within the fluid of the seminiferous tubule is higher b/c you have a large proportion bound to the BP & a small proportion that is free

Answer 14

barrier to prevent the immune system from attacking these unknown cells

Answer 15

tails of spermatids within the lumen of the seminiferous tubule & diff. cell types that might support dev. of those sperm cells at diff stages

Answer 16

Androgen Deficiency in Aging Males (ADAM)

Answer 17

a degradation in the blood vessels supplying the testis & as a result, an imperfect balance b/t leydig & sertoli cell communication as a conseq. of an imperfect release of antigens that can lead to a reduction in fertility in those males

Answer 18

lie within the interstitium b/t seminiferous tubules

Answer 19

the production of testosterone primarily

Answer 20

– Influence the reproductive system prior to birth – Influence sex-specific tissues after birth (requires LH stimulus) * has a link to HPG axis – Additional reproductive effects * libido – Development of secondary sexual characteristics – Non-reproductive actions * bone growth - males don't produce a lot of estrogen but there is aromatase expressed within the blood tissue that converts those androgens (testosterone in partic.) to estrogens to facilitate & regulate bone growth) * aggression - increased testosterone is known to induce a more aggressive phenotype in males

Answer 21

testosterone that regulates the growth of the reproductive system & the secondary sexual characteristics in males

Answer 22

libido (sexual drive), but isn't essential for maintenance of that libido

Answer 23

reduce their sexual drive & that is not true | - actually males who had one report a greater sexual drive

Answer 24

Accessory sex glands - Wolffian duct differentiation and growth External genitalia - Growth and differentiation (scrotum and penis)

Answer 25

Skeleton & muscle - Masculine physique, epiphyseal closure Vocal cords - Voice deepening Skin - Facial hair growth and/or cranial hair loss Testis - Sertoli cell maturation and androgen binding protein synthesis External genitalia - Penile and scortal growth Accessory sex glands - Prostate, seminal vescile and bulbourethral growth CNS - libido hypothalamus/pituitary - Inhibition of LH secretion (-ve feedback)

Answer 26

sex determination

Answer 27

Undifferentiated germ cells containing a diploid complement of 23 pairs of chromosomes (1 paternal and 1 maternal) - post puberty

Answer 28

fully differentiated sperm cells containing a random haploid set of 23 chromosomes

Answer 29

– Mitotic proliferation – Meiosis – packaging

Answer 30

~64 days - constant, ongoing within the seminiferous tubules - have huge amount of viable sperm throughout their lifetime

Answer 31

~2 million | - massive production & energy req. within males (not near energy req. in females in terms of their role in reproduction)

Answer 32

~16 - but that's not always the case (upwards of 40-60% of these cells might die in the process of gamete dev.) - this is another job of SERTOLI CELLS, that they will scavenge that material & clean it up & get rid of the cells that have divided & gone wrong

Answer 33

• Meiotic division and the development of the secondary spermatocyte CROSSING OVER occurs between paired chromosomes - get the unique genetic code to each of those final spermatozoa * The cytoplasm of spermatids is always JOINED until complete differentiation and sperm development has occurred * Half the spermatids have an X and half have a Y chromosome

Answer 34

there are key genes on the X chromosome that are absolutely critical for development & final dev. (maturation) & that's why they remained joined right up until that last little bit

Answer 35

doesn't express as many of the genes that are critical for dev. - hence why they're joined just prior to that separation

Answer 36

does express the SRY gene, & that SRY gene is critical for sexual dev.

Answer 37

1. Head 2. Acrosome 3. Mid Piece 4. Tail

Answer 38

contains nucleus with DNA

Answer 39

contains enzymes req. for breaking through the corona radiata in the egg & ultimately fertilizing the egg

Answer 40

mitochondria rich - maybe at a lower temp like 3 degrees lower than core body temp - promotes generation of those mitochondria that will promote capacity for that sperm to swim

Answer 41

swimming | - flagellum - beating of the tail can promote potential fertilization

Answer 42

1. Protect sperm cells 2. Feed sperm cells 3. Remove unwanted cells 4. Secrete seminiferous tubule fluid 5. ABP secretion 6. Endocrine feedback regulation - inhibin

Answer 43

imp. as those sperm are stored prior to release

Answer 44

a single daughter cell in theory can produce 16 mature spermatozoa, but that doesn't happen & so those dead cells are reabsorbed & reprocessed by the sertoli cells (the sertoli cells will also secrete fluid into the seminiferous tubule to aid in supporting cell viability & life & it will also secrete ABP)

Answer 45

creates a (+) pressure - as fluid builds up within the seminiferous tubule - the (+) pressure pushes sperm down the length of the seminiferous tubule into the epididymis (storage area just prior to the vas deferens) - that fluid buildup is imp. for transporting sperm that are otherwise non-motile at this stage (higher concen. of K+ limiting motility of the sperm within the seminiferous tubule)

Answer 46

BP req. for testosterone to bind & promote concen. of testosterone within the lumen of the seminiferous tubule

Answer 47

imp. hormone in syn. & release by the sertoli cells - will selectively inhibit FSH over LH - this is key in terms of the endocrinology of male gametogenesis & dev.

Answer 48

Direct (-) feedback inhibition of LH, but an indirect (-) feedback inhibition of both FSH & LH through inhibiting GnRH

Answer 49

sertoli function & viability of sperm

Answer 50

NO androgen receptors on male gametes & so testosterone is converted to estrogen & there are estrogen receptors on male gametes that promote dev. of the gamete

Answer 51

fluid of the seminiferous tubule

Answer 52

- prior to arriving in the epididymis sperm are non-motile and infertile - concentrates sperm through reabsorption of seminiferous fluid. Also protects sperm with defensin

Answer 53

Low pH - due to CO2 production by infertile sperms - so that lowers the pH of the fluid

Answer 54

reabsorbed by phagocytotic mechanisms

Answer 55

sperm obtain the ability to fertilise the egg and become somewhat mobile in the epididymis (this is completed in the female reproductive tract) - with the help of defensin & changes in chemistry of the surrounding fluid within the epididymis

Answer 56

storage site can be days in length (prior to those sperm dying & becoming infertile) - semi-motile sperm are stored

Answer 57

empties into the ejaculatory duct | - fructose, PG's, ~50% of the seminal fluid, fibrinogen

Answer 58

seminal vesicle

Answer 59

aids in the retention of sperm within the female reproductive tract - promote clotting of the sperm - ejaculation of sperm into female repro. tract is associated also with clotting enzymes, so the fibrinogen aids in that clotting

Answer 60

- alkaline fluid, clotting enzymes & fibrinolysin

Answer 61

viability of sperm

Answer 62

aids in the BREAKDOWN of that fibrinogen & that clotting & the release of the sperm into the female repro. tract

Answer 63

promotes the retention of the viable sperm within the female repro. tract - then the fibrinolysin quickly gets to work on the fibrinogen breaking that up & releasing the sperm within the female repro. tract

Answer 64

- mucus like substance | - aids in sexual act as a lubricant

Answer 65

1. Excitement 2. Plateau phase 3. Orgasmic phase 4. Resolution phase

Answer 66

females can repeatedly go through the orgasmic phase (phase 3), males cannot (so they then go to phase 4, the resolution phase)

Answer 67

arousal & erection

Answer 68

an imbalance b/t blood flow & blood out flow - inflow is more b/c the penis has to be engorged with blood - get an inhib. of vasoconstricted neurons & sympathetic neuons that synpase with the penile arterioles (blood flows into the penis, it can't flow out quite as well & so an erection enforms) * - parasympathic via nitrogenous (nitric?) oxide will dilate penile arterioles

Answer 69

continued arousal includes increased heart rate, mean arterial blood pressure, respiration rate and muscle tension

Answer 70

ejaculation and muscle contraction combined with intense physical pleasure - females can repeatedly go through this phase, males cannot

Answer 71

return to pre-arousal state

Answer 72

state of vasocongestions | - blood flow within the penis itself

Answer 73

Stimulation of mechanoreceptors in the glans penis 1. STIMULATES PARAsympathetic supply to BULBOURETHRAL & URETHRAL GLANDS - -> mucus --> lubrication 2. STIMULATES PARAsympathetic supply to PENILE ARTERIOLES - -> penile arterioles dilate --> erection --> compresses veins --> erection 3. INHIBITS SYMpathetic supply to PENILE ARTERIOLES - -> penile arterioles dilate --> erection --> compresses veins --> erection

Answer 74

* Emission: preparatory phase a few seconds prior to ejaculation * Expulsion of seminal fluid and sperm from the penis

Answer 75

• Average volume approximately 3ml but can range considerably

Answer 76

~ 66million.ml-1

Answer 77

< 20million.ml-1 - shows what a huge req. is needed from males to produce a huge # of sperm & to ensure successful reproduction

Answer 78

- NOT an infertile individual, but they're not capable of the sexual act - ~50% suffer from this (normally in older men in 40-70's) - viagra can sustain an erection (not able to cause it), but can combat that dysfunction

Answer 79

• Nitric oxide is released in response to parasympathetic stimulation • NO acts through an enzyme linked receptor pathway that uses cGMP as a second messenger • cGMP initiates the PKG pathway which leads to the activation of SR Ca2+-ATPase (SERCA) * • cGMP is broken down by the cellular enzyme phosphodiesterase 5 * Sidenafil INHIBITS the action of phosphodiesterase 5 - so it maintains cGMP, maintaining the activation of SR Ca2+-ATPase, so it maintains the erection in the individual (*but cannot initiate the erection)

Reproduction Lectures 2021 - MALE REPRODUCTIVE SYSTEM Flashcards

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