Sperm Motility, Epididymal Transport, Erection, and Ejaculation

Question 1

Which components of sperm are important for sperm motility?

Answer 1

all components

Question 2

Function of laminated columns of mid piece?

Answer 2

give neck region flexibility allowing for lateral movement from side to side during flagellar beating

Question 3

Function of the mitochondrial helix of mid piece?

Answer 3

metabolic powerplant; ATP production

Question 4

Function of course outer fibers?

Answer 4

fibrous sheath surrounds the tail except at the end of the tail

Question 5

What is the metabolic powerplant?

Answer 5

the mitochondrial helix where ATP is produced to allow for fuel source for motility

Question 6

Function of axoneme?

Answer 6

the axial filament complex that originates from the distal centriole with the same organization of cilia and flagella but it has a 9+2 complex of microtubules and extends through the entire length of the tail of the sperm

Question 7

Where is the dynein arm located?

Answer 7

axoneme

Question 8

9+2 complex?

Answer 8

9 pairs of MT surrounding a core of 2 MT

Question 9

Does the principal piece have the 9+2 complex?

Answer 9

no, it doesn’t have any mitochondria

Question 10

How does MT sliding in the sperm tail create motility?

Answer 10

occurs as a result of the sliding of those microtubules (derived from ATP derived from ATPase); the dynein arm detaches in the presence of ATP and shortens; once that energy is made, the dynein arm tilts and elongates to attach to a lower side and then shortens and returns to its original position; this generates the sliding forces that move the tail in a helical fashion

Question 11

To provide energy for motility, sperm must __.

Answer 11

metabolize

Question 12

anerobic metabolism?

Answer 12

glycolysis

Question 13

aerobic metabolism?

Answer 13

TCA cycle

Question 14

sperm metabolism?

Answer 14

through a series of enzymatic processes, they produce products that can enter glycolysis to enter TCA cycle to produce ATP

Question 15

In sperm metabolism, can both fructose and glucose be utilized?

Answer 15

yes

Question 16

sperm metabolism is dependent upon what?

Answer 16

temperature

Question 17

the amount of ATP that can be produced depends on what?

Answer 17

the temperature of the environment

Question 18

When temperature increases, motility ___.

Answer 18

increases

Question 19

ATP is utilized for ___ and ____.

Answer 19

motility and substrate cycling

Question 20

Some ATP is wasted in sperm metabolism by what process?

Answer 20

substrate cycling (glucose 6-phosphate to glucose)

Question 21

Only a small amount of ___ is used to maintain the other important components of the sperm.

Answer 21

ionic gradients

Question 22

Bulk flow alone will help get sperm out of the ST. How?

Answer 22

on the outside, it is lined with myoid cells that help through minor subtle contractions to assist with releasing bulk fluid flow)

Question 23

What does bulk fluid flow help with?

Answer 23

to get out of ST as well as from the rete testis from the contractions of the mediastinum

Question 24

What happens once sperm is released from the rete testis?

Answer 24

the sperm must be released from the vas deferentia (escapes from the cilia of epithelial to help bulk fluid flow to allow release of sperm)

Question 25

Why can't you rely on bulk fluid flow when sperm reaches the caput, corpus, and cauda?

Answer 25

because contractions of vas deferens propel sperm forward

Question 26

Muscle contractions is which testes parts?

Answer 26

caput, corpus, cauda, vas deferens

Question 27

Bulk fluid flow in which testes parts?

Answer 27

vas efferentia, rete testis, ST

Question 28

Where is bulk fluid flow from in the rete testis?

Answer 28

fluid from ST and rete testis with some contractions of mediastinum

Question 29

Where is bulk fluid flow from in the ST?

Answer 29

fluid from sertoli cells with contractions from myoid cells

Question 30

Where is bulk fluid flow in the vas efferentia?

Answer 30

fluid from ST and rete testis with cilia on the epithelial cells

Question 31

DHT?

Answer 31

dihydotestosterone

Question 32

What does DHT affect?

Answer 32

the functional ability of principal cells

Question 33

Importance of prinipal cells in caput and corpus epididymis environment?

Answer 33

lined with cilia and are important for lining the region of epididymis as well as secreted various products used to modify sperm so that as it progresses through, it will require the ability to become motile as well as fertile

Question 34

Importance of ABP?

Answer 34

binding testosterone and delivering it to the epididymis to convert it to DHT

Question 35

When sperm is in the epididymis (cauda) they are quiescent. What does this mean?

Answer 35

they don't move so they can be modified as well as not to lose energy which is why contractions are used to move them

Question 36

When will sperm be motile again?

Answer 36

when they are removed from the environment and the things surrounding them are diluted

Question 37

What are the four functions of the epididymis?

Answer 37

1) maturation 2) concentration 3) Secretion 4) Transport 5) Storage

Question 38

What is the ejaculatory reserve?

Answer 38

cauda epididymis

Question 39

Up to __ days of sperm produced and stored in cauda.

Answer 39

4

Question 40

What allows for repetitive ejaculations of a short period (only a limited number of reserves)?

Answer 40

Important for environment to be effective for arresting sperm metabolism before it is released into female reproductive tract

Question 41

Factors conducive to sperm storage?

Answer 41

reduced pH; low oxygen high CO2; high K:Na ratio; low concentrations of energy substrates

Question 42

hormones in caput?

Answer 42

tubal testosterone

Question 43

hormones in corpus?

Answer 43

tubal dihydrotestosterone, vascular testosterone

Question 44

hormones in cauda?

Answer 44

tubal DHT, vascular testosterone

Question 45

Why are androgens needed for hormonal control of epididymis?

Answer 45

because we are talking about 2 different forms of testosterone (tubal and vascular)

Question 46

erection?

Answer 46

process by which the penis elongates and becomes more rigid

Question 47

emission?

Answer 47

movement of seminal fluids from the accessory sex glands into the colliculus seminalis so they can be mixed with sperm

Question 48

ejaculation?

Answer 48

process by which sperm moves out of the colliculus seminalis through the urethra and expelled out the end of the penis

Question 49

What two inputs play a major role in erections?

Answer 49

sensory and psychic inputs

Question 50

sympathetic NS affects on erections?

Answer 50

involved in inhibited vasoconstriction

Question 51

parasympathetic NS affects on erections?

Answer 51

allows blood to come in through the dilation of vessels and engorgement of the corpus cavernosum and contractions of ischiocavernosus to decrease venous outflow

Question 52

What are the steps of penile erection?

Answer 52

1) flaccid penis 2) arousal 3) vasodilation (increased blood flow) 4) increased blood flow to cavernosus tissue and decreased venous outflow 5) ejaculation due to penile veins compressing from the build up of blood in penis corpus cavernosum 6) venous outflow

Question 53

how is sperm transported from the epididymis to the pelvic urethra?

Answer 53

with sensory stimulation via muscle contractions the act of the posterior pituitary caused the release of oxytocin which acts on smooth muscle cells to let the sperm move up into the pelvic urethral area

Question 54

Sympathetic NS leads to emission. how?

Answer 54

smooth muscle contractions of prostate, seminal vesicles, vas deferens, cauda; closure of sphincter to bladder; sperm moves to colliculus seminalis and mixed with accessory sex gland secretions

Question 55

Parasympathetic NS leads to ejaculation. how?

Answer 55

striated muscle contractions of ishiocavernosus, bulbospongiosus, pelvic urethral; forceful contractions propel sperm mixed with ASG secretions out through an erect penis

Question 56

intromission?

Answer 56

successful entrance of penis into vagina

Question 57

explain the simple neural reflex of ejaculation.

Answer 57

when intromission occurs, there is specific and needed stimulation of the glans penis which can then alone be sufficient to induce ovulation

Question 58

what two stimulants can alone be effective for inducing strong, forceful contractions needed for ejaculation?

Answer 58

temperature or pressure

Question 59

semen components?

Answer 59

water, sperm, substrates, inorganic salts, proteins

Question 60

minor contributions to seminal plasma?

Answer 60

testis, epididymis, vas deferens

Question 61

major contributions to seminal plasma?

Answer 61

ampulla, seminal vesicles, prostate, cowpers (bulbourethral)