Exam 1 Lecture Notes

Question 1

seminiferous tubules function

Answer 1

sperm production

Question 2

rete testis function

Answer 2

network of collecting tubules

Question 3

efferent ducts function

Answer 3

fluid absorption

Question 4

epididymis function

Answer 4

transport, concentration, maturation, storage of sperm

Question 5

vas deferens function

Answer 5

transport of sperm into the body

Question 6

sperm in the epididymis head vs the tail

Answer 6

in the head the sperm are immature and less concentrated, in the tail the sperm are mature and stored there so they are more concentrated

Question 7

explain the tubular system of the testis

Answer 7

sperm is made in the seminiferous tubules, the sperm then moves into the collecting tubules called the rate testis, sperm is them moved into the efferent tubules where fluid absorption occurs, then it moves into the head of the epididymis (sperm is not yet matured), then into the body of the epididymis (sperm begins to mature), and finally into the tail of the epididymis where the sperm is matured and stored, when ready to leave the body sperm is moved from the tail of the epididymis into the vas deference where the sperm can be transported to the body

Question 8

what does the histology of the epididymis look like?

Answer 8

the epididymis is one tube that is highly convoluted so when a cross section is made there are many little circles

Question 9

histology of the head of the epididymis vs the tail of the epididymis

Answer 9

• head = more white (more of the lumen) because there is a lower concentration of sperm
• tail = more purple (less lumen) because there is a higher concentration of sperm

Question 10

sperm characteristics at the head of the epididymis

Answer 10

• not motile
• not fetile
• cytoplasmic droplet (attached to the head)

Question 11

sperm characteristics at the body of the epididymis

Answer 11

• some motility
• some fertility
• movement of cytoplasmic droplet (on tail)

Question 12

sperm characteristics at the tail of the epididymis

Answer 12

• normal motility
• fertile potential
• distal droplet (will eventually disappear)
• 7-8 times more concentrated

Question 13

caput

Answer 13

head of the epididymis

Question 14

corpus

Answer 14

body of the epididymis

Question 15

cauda

Answer 15

tail of the epididymis

Question 16

what affects sperm production?

Answer 16

• size of the testes
• size of the tail of the epididymis
• cryptorchidism
• effect of ejaculation on sperm production

Question 17

false mounting

Answer 17

allowing the male to mount but moving him off before ejaculation to increase the amount of sperm concentration because it allows for multiple emissions

Question 18

emission

Answer 18

movement of sperm from tail of the epididymis to the vas deference

Question 19

structures in the spermatic cord

Answer 19

• paminiform plexus
• testicular artery
• ductus deference
• cremaster muscle

Question 20

somatic cord functions

Answer 20

• provide nerves, blood vessels and lymphatic vessels of the testes
• contain pampiniform plexus
• contains cremaster muscle
• contains ductus deference

Question 21

semen

Answer 21

sperm and seminal fluid

Question 22

accessory glands

Answer 22

• vesicular / seminal glands
• prostate gland
• bulbourethral gland

Question 23

functions of accessory gland fluid

Answer 23

• volume
• nutrients
• buffer
• decapacitation (ensure sperm doesn’t activate immediately)

Question 24

structures in the penis

Answer 24

• erection canals
• helicine arteries
• corpus spongiosum penis
• corpus caverosum penis

Question 25

helicine arteries

Answer 25

vasodilate when stimulated by nitric oxide

Question 26

nitric oxide is turned on by ___________

Answer 26

cGMP (when GTP is converted to cGMP by guanylate cyclase)

Question 27

nitric oxide is turned off by ___________

Answer 27

phosphodiesterase

Question 28

viagra blocks _____________________

Answer 28

phosphodiesterase

Question 29

why would you give oxytocin to a boar during mating?

Answer 29

to help with ejaculation, oxytocin is needed to have a sudden and powerful contraction of the urethralis, bulbospongiosus, and ischiocaverosus muscles to have an expulsion of semen

Question 30

ischiocaverosus muscle function

Answer 30

contracts to smash the vessel stopping venous return and keep the penis erect

Question 31

bulbospongiosus muscle function

Answer 31

assists in ejaculation (explosion of semen)

Question 32

glans penis

Answer 32

the tip of the penis, looks different in different species

Question 33

frenulum

Answer 33

a membrane that hold the glans penis back at birth and should sever as the animal grows (bulls and rams)

Question 34

persistent frenulum

Answer 34

the frenulum does not sever so it must be done surgically

Question 35

boar glans penis

Answer 35

corkscrew shape to lock into the cervix

Question 36

stallion glan penis

Answer 36

it will expand so that it can expand the cervix (mare cervix is soft) and deposit sperm directly into the uterus

Question 37

erection

Answer 37

1. vasodilation of the arteries 2. ischovernosus muscle contracts to block venous return, compression forces blood into the erection canals to fill the corpus caverosum 3. decrease in venous return, increase in blood flow 4. retractor penis muscles relax and sigmoid flexure straightens

Question 38

emission (more detail)

Answer 38

oxytocin stimulates contractions in the tail of the epididymis and vas deference to move sperm into the pelvic urethra in from of the collicus seminalis (mis fluid and sperm)

Question 39

ejaculation

Answer 39

1. contraction of urethras muscle moves sperm to root of penis 2. contraction of bulbospngious muscle sends pulse down corpus sponsiosum to move sperm out

Question 40

after ejaculation

Answer 40

ischiovermosus muscle strops contracting so venous return resumes, blood pressure in corpus cavernous and retractor penis muscles contract to form the sigmoid flexure

Question 41

3 main parts of sperm

Answer 41

- head - midpiece - tail

Question 42

functions of the 2 centrioles in sperm

Answer 42

one forms the tail, the other is in the midpiece

Question 43

where is mitochondria located in the sperm

Answer 43

midpiece

Question 44

acrosome

Answer 44

- contains enzymes to attach and blow open for fertilization - stains bright green

Question 45

head of sperm - structure

Answer 45

- apical ridge - acrosome - equatorial segment - post acrosomal region - inner and outer acrosomal segment - implantation socket - nucleus

Question 46

acrosome

Answer 46

attaches to the egg and will eventually blow the cap off to release the enzymes from the Golgi