Reproductive Physiology

Question 1

Male Reproductive Anatomy
- Glans Penis
- Root of Penis

Answer 1

Glans Penis
- composed of the termial aspects of the corpus spongiousum –> which comes from the posterior asepct of the penis (anteriorly is the corpus cavernosa) ‘

Root of Penis
- attached part of penis to the body: made of the bulb and the two crua
- the bulb = attached midline to perineal membrane & is the dilated part of the corpus spongiousum
- crua = paired sturcture attaching toe ishiopubic rami on either side

Body of Penis
- made of the corpus (corpus spongiousum and corpus cavernosa)
- Corpus spongiousum: erectile tissue surrounding the urethra (middle most)
- Corpus cavernosa: paired erectile tissue that forms majority of the body of penis (anteriorly) largest erticel part

Question 2

Male Anatomy

Testes

epididymis

& ductal system within

Answer 2

within the Scrotum

Testes: main male sex organ
- produces spematozoa and testosterone

Epididymis
- within the scrotum: stores sperm during maturational process (sperm maturing after being made in testes)
- sits atop the testes: with body, head and tail

Ductal System within the testes and epididymis
- Testes = tubes of lobules, made of seminiferous tubules
- these travel to the efferent tubule within the testes
- these effernt tubules merge togeher from th emultiple (hundreds) of lobubles and form the epididymis: this where where sperm is stored
- the sperm is not motile here: these actions from lobule to seminiferous tubules to efferent tubule in epidydmis is able to happen through the movement of the dutal wall
- sperm then stored in the Ampulla of vas deferens right between empydimis and vas deferens before ejactualtion

Question 3

Male anatomy
Spermatic Cord & contents
veins and arteries

Answer 3

The testicular complex
Spermatic Cord
- the decenting sturcture through the inguinal ligament to the testicles

inside the spermatic cords…

Vas Deferens: the thick hollow tube which is responsible for transporting sperm from the epididymis to the ejaculatory ducts in the prostate
- will go through the cord and up to inguinal lig.
- then down through the prostate to the penis

Veins: Pampiniform plexus
- valveless = thus varicoeles can occur buildup of blood (sign of a testicualr mass)

Artery: Testicualr artey

Cremaster Muscle
- pulls testes close to body in response to cold weather
- best sperm produced at 96F

Question 4

Male Anatomy
Seminal Vesciles
Prostate Gland
Bulbourethral Glands (Cowpers)

Answer 4

Seminal Vesicles
- tubes which secrete the “food” fluid for semen
- during ejaculation: they secrete fructose, porostaglandins and proteins for energy for the sperm to become motility
- help make cerival mucosa more receptive to the sperm (change pH)
- seminal vescile joins with vas deferens to form ejaculatory duct

Prostate Gland
- made of secretory glands; sits at base of bladder
- contracted during ejaculation: releases milky alkaline fluid (good environment for sperm)

Bubourethral Gland (belwo prostate)
- secrete proteins that lubricate urethra making urethral environment good for sperm to survive

Question 5

Spermatogeneis
- where does it occur
- cells involved and hormones

Answer 5

Spematogenesis
- occurs starting at age 13

Where
- seminiferous tubules of the testescontin sertoli cells:
- Sertoli cells here nourish immature sperm
- turn spermatocyte into sperm & created head/tail

Hormones
- sertoli cells: secreted AMH (anti-melluerian hormone) which PREVENT FEMALE sex organs during fetal development
- FSH: released and stimulate sertoli cells to start mkaing sperm

Question 6

Spermatogenesis

Stages of creation

Answer 6

Stages
- small unspecified germinal cells = mitosis to conitnue creating them
- mature spermatogonia = divide into two diploid daughters – each duaghter cell = primary spermatocyte
- primary spermatocyte (diploid) undergo Meiosis to create secondary spermatocytes (haploid)
- secondary spermatocytes (haploid) divide into two spermatids (23 chromosomes)

Spermatidies elogate to become spermatozoan = mature sperm

spermatogonia –> primary permatocyte —> secondary spermatocyte (haploid) –> spermatid (grows) –> spermatozoan

Question 7

Structure of a Mature Sperm Cell

Answer 7

Mature Sperm

Acrosome: most anterior 2/3 of head; resonsible for penitrating ova

Tail
- mitochondria in proximal part = energy
- flagelation to allow for motility

Question 8

Male Sex Hormones : how they’re made
Testosterone
Dihydrtestosterone
Androstenedione

Answer 8

Sex Hormones: from the testes (majority) and adrenal cortex

Testosterone (most abundant)
- produced from leydig cells within the testes
- leydig cells triggered by LH from pituitary
- in blood: testosterone bound to protein (albumin or sexhormone binding globulin)
- then passes intracellular to bind (to upreg. or downreg.)
- converted to dihydrotestosterone (active formation) via 5 alpha reductase

Dihydrotestosterone
- binds better to the receptors and elicts greater response
- more potent

Androstenedione
- from the adrenal cortex
- precursor formation for testosterone and dihydro.

Question 9

Testosterone
effects within the body

Answer 9

Effects
- induce differentiation of male genital tract in utero
- will created the external sex characterisitics (primary: penis and scrotum)
- Secondary Sex characteristics: gonal function, accessory organs & hair ditrubution

Anabolic Effects
- increased protein metabolism
- increases MSK growth
- influences subq fat

promotoes spermatogeneis (in FSH primed cells: sertoli to create sperm

stimualtes erythropoiesis: RBC formation

Question 10

HPA axis and testosterone and male hormones

Answer 10

hypothalmaus
- released gonadotropin realeasing hormone

pituitary
- releases FSH and LH
- FSH: to the sertoli cells - aid in spermatogensis
- LH: to the lydig cells- aid in testosterone production

negative feedback!!! increased testosterone - tells to downreg. this process at anterior pituitary and hypothalmus

testosterone also impacts sertoli cells to increases sperm production

Question 11

Neural Control of Sex Organs
Production of Erection

Answer 11

stimulation to glans penis = highest source of input control to stiumale response

• afferent nerves from glans penis –> pudundal nerve –> sacral plexus –> acending in SC
• can be stimulated in other ways, liks psychiatric

Erection : neurovascualr event
- blood is shunted TO the corpus cavernosum
- NANC system releases nitric oxide: relaxes smooth muscle = dilation of vessels

in flaccid state: vessels are contracted constantly via alpha adernergic receptors

Parasympathetic stimulation created erection via
- stopping sympatheic response
- released nitric oxide to relax smooth muscles in teh covernousum

Parasymp. innervation
- innervation here via pelvic nerve & sacral SC

sympathetic innervation
- L1 , L2 level

Question 12

Nerual involvment in Emission and Ejaculation

Answer 12

Emission
- spinal cord reflex: via L1 and L2 leave and go through hypogastric plexus to gential organs to initate emission
- this is movement from epididymis to urethera (vai vas derferns)
- the SC nerves are triggering contraction of smooth muscles in vas deferencs to move sperm forward

Seminal Vesicles AND prostate gland also contract = add fluid to the ejaculate (liquid)

Contraction of isocavernous and bulbocavernosus ase base of penis = ejcaulation force

Pudenal Nerve stimulated contraction of urethra to propel ejaculate forward to external environment

ejacuulation then erection gone 1-2 minutes
refractory: cannot produce another erection for some minutes

Question 13

Female Reproductive Anatomy
clitoris
Skene Glands
Bartholin Glands
vagina

Answer 13

Clitoris
- major sensory organ of the female; highly innervated and vascularized

Skene Glands
- lubricating function

Bartholin Gland (simialr to bulbouretheral of male)
- secrete mucous to lubricate vagina during sexual intercourse

Vagina
- the conduict from external to internal organs
- free of sensory nerves

Question 14

Female Reproductive Anatomy
Uterus
Cervix

Answer 14

Uterus : muscular organ of three layers

Perimetrium: outermost layer from peritoneum
- created the pouch of douglas (posteriormost)

Myometrium- major protion of the wall

Endometrium
- innermost lining of the uterus

Cervix :the neck of the uterus
- projects inot the vagina
- location for cervical cancer
- composed of tissue matrix and glands/muscles that allow opening during pregnancy and birth

Question 15

Female Reproductive Anatomy
Fallopian tubes

Answer 15

Fallopian Tubes: cyldical tubes
- attach to the uterus and suspened via broad ligament
- near the ovaries with funnel opening, creatae finger-like projections to “catch” the ovum when released from the ovary into peritoneal cavity

Ovaries
- develop in utero: in full position and decended by third month
- remaining primitive genital ligaments: turn into round ligament and suspensory ligament to keep ovaries in place in peritoneum
- at menopause (1/4th the size)

4 Compartments of Ovary
- Stroma (supportive)
- Interstital cells (secrete estogen)
- Follicles
- Corpus Luteum

Question 16

Oogensis Process

Answer 16

Oogenesis
- process of mitosis begins at 6th week of fetal life
- all the eggs a women will have are there at birth (1-2 million)
- at puberty: 200,000 remain

Question 17

Ovarian Function

Estrogen: what is it and types
when does it peak

Answer 17

Two Functions
1. storage and released of female ova
2. prodcution of female sex hormones (estrogen and progesterone)

Estrogen (protein bound in circulation)
- family of female hormones secreted by ovaries (a little via adrenals)
- estradiol: most abupdent and potent
- estiol
- estrone
- PEAKS: before ovulation & middle of luteal phase

Question 18

Effects of Estrogen
inter gential
extra gential

Answer 18

Effects of Estrogen
- stimulate growth of endometrium during menstrual cycle
- devleop pirmary and secondary female sex characteritics
- roles in : ovulation, implantation, pregnany, birth, lactation
- in absence of androgens: estrogens trigger creationg of mullarian system (female in embryo)

Extra Genital Effects
- stimulate breast production at puberty
- stimualte bone growth and closure of growth plates
- maintain skin and vascualture in females
- maintains bone densitiy and resobrtion
- increased synthesis of transport porteins in liver
- neurotrophic and protective effects in cognition and memory

Question 19

Progesterone
what is it
effects

Answer 19

Progesterone
- secreted during menstrual cycle
- secreted via corpus luteum of ovary: after ovulation to help support pregnancy

Effects of Progesterone
- galdualr development of endometrium
- increased bosy temp after ovulation
- smooth muslxe relax for pregnancy
- adverse pregnancy: N/V, edema, HA, constipation, gase

Question 20

Role of FSH and LA in Female Reproductive SYStem

Answer 20

FSH
- stimulate growth of immature ovarian follicle in the ovary
- rescues small antral follicles from apoptosis
- luteal phase: lack of estrogen and progesteron triggers unregualted increase in FSH: peak at day 3 of cycle

LH
- support theca cells (precurosr to estradiol) in ovaries
- LG surger triggers ovulation: release ova from follicle
- triggers follicle to corpuc lutem = creates progesterone for implantation

Hromones Reminedr
- GnRH : from hypothalamus to pituitary
- pituitary released LH and FSH
- estradiol and progesterone stimulate postivie feeback (at some points in cycle: LH surge)
- estadiol and progesterone and inhibitn negative feeback

Question 21

Ovarian Follicle Development

Answer 21

Puberty: triggered by cyclic rise in FSH and LH: stimulates mature follicles to develop
- follicle = oocyte with single layer of connective protection

6-12 Follicles turn into Secondary follicles
- secondary = oocyte with biger size and more layers of protection
- this seocndary creationg triggered by FSH

cells from stromal tissue create cell wall = secondary follicle + cell wall = theca
- differentiates into inner and outer theca

Follicule Enlarges
- filles inside = antrum
- granulosa cells pushed to one side & fluid filled
- granulosa cells produce estrogen
- estrogen triggers only one follicle to remain: dominant one
- at ovulation: follicle ruptures & released ova into interstial fuid
- remains: corpus luteum

Question 22

The Ovulatory Cycle

Answer 22

average: 28 days (21-35)

day 1= first day of period (bleed)

Follicular Phase: Day 1-14 = follicule maturing (FSH high)

Ovulation (day 14.5) LH high at ovulation
- highest estrogen at this elve: negative feedback to FSH
- this negative feedback released ovum from follicle

Luteal Phase (FSH low)
- the follilce after ova releases: creates granular tissues, vessels & lipo-chrome cells = theca layer
- theca layer created corpus luteum
- lutem = releases progestrone
- progesteone: helps iffertilization occured

IF fertilixation occured: HCG from egg prevents luteal regression and keeps it to support cell

IF fertilixation does not occur, lutem involutes and sheds: period

Question 23

The Endometrial Cycle

Answer 23

within uterus, this cycle occurs coinciding with ovairan cycle

Proliferative Cycle: pre-ovulation phase (first 14 days)
- glands and stroma grow rapid
- estrogen triggers

Secretory Phase: progesterone dominant
- progesterone prodcues glaundular dilation and active mucus secrtion
- creating contiditions peak for implantation

Menstrual Phase
- sperfisical layer degeneration and period
- dropoff of progesterone

Question 24

What happens after Fertilization (three stages)

Germinal phase

Answer 24

Germinal Phase: first 2 weeks
Embrynoci Phase: 3-8 weeks
Fetal period: 9 weeks to birth

Germinal Phase
- fertilized egg called zygote (diploid)
- zygote travels down fallopian tubes to uterus hours after creation
- cell division: 24-36 hours after conception : mitosis
- once 8 cell point: differentiation occurs
- two masses form: placenta and embryo

placenta forming from the same as zygote

divide = blastocyst: not yet attached to wall; not implanted!!!

Blastocyst has three layers
- ectoderm: skin and NS
- endoderm: digestive and respiratory (inner guts)
- mesoderm: muscle and bones

Question 25

Germinal Stage: Implantation

Answer 25

once blastocyst migrates to uterus: it will atach to uterine wall = implanation

this blastocyst: burrow into lining, ruputrue vessels and a web of membrane and vessels connects the lining and the blastocyst

when implanation is success: menstration stops (HCG produced)

Question 26

Embryonic Stage

Answer 26

once blastocyst is implanted = called embryo

Embryo will develop within the amniotic sac
most vulerable stage of pregnancy : infection, drugs, etc.

• most organs form after 3 weeks from fertilization (5 weeks since LMP: so 5 weeks into pregnancy)
• neural tubes = 4-6 weeks closed
• heart and vessels at day 16
• heart pumps at day 20 : RBC formation
• almost all organs are formed at 12 weeks (except CNS)

Question 27

Placentation Phase: of Embryonic

placental blood supply

Answer 27

at 8 weeks: placenta forms vili which extend into the wall of uterus

• the blood vessesls from embryo pass through umbilical cord to placenta developed here in villi

a thin membrane separates embryo’s blood in vili from the mothers blood in the intervillous spcae AKA the moms blood is not the placental blood

thin membrane separates the embryos blood from mom : but allos gas exchanges (O2, CO2)

this prevents moms immune system from attacking babies (antibodies too big)

Branching Pattern of Vasculature
- increases SA of placenta into the uterine wall allows for greater contact between uterus and placenta; increased exchagne of nutrients

placenta formed at 18-20 weeks fully

Question 28

Amnioitic SAc

Answer 28

Amniotic Sac
- embryo floats within fluid: contained within sac
- sac allows for embryo to grow freely and protect it from injury

Question 29

Fetal Period

Answer 29

10 weeks of pregnancy, 8 weeks after implantation

at this time: considered a fetus

• organs formed, except CNS
• CNS begings to develop
• lungs mature
• by 24 weeks, fetus could survive outside (premie)

Question 30

Sexual Differentiation in the Fetus

genetic v gondal v phenotypical gender

Answer 30

Genetic Gender
- XX or XY : determined at fertilization
- for first 6 weeks: they look the same

Gonadal Gender
- determined by differential by primodial gonad into testes or ovaries
- this is determined by if a Y chromosome is present
- if there is no Y chromosomes (SDR: SRY) then female creation will occur

Phenotypical Gender
- apparant at 8 weeks: US
- differentiation determined by SRY areas on Y chromosomes and due to testicaulr function
- if testis there: testosteronae will trigger male pheontype
- wihtou: female will occur

Question 31

Mullerian Duct

Role of AMH

Answer 31

Mellerian Ducts
- tubes that decend and form the external genitaliga
- end at mullerian eminence (formation of urianry and genital organs)
- present for first 6 weeks of all embryos

the mullerian duct will only fully develop in females: forming female reprodcution

if male embryo: the ducts degenerate via the influence of anti-mullerian hromone (AMH) made in testis

this is dependent on the Y chromosomes SRY gene: if this is there: triggers AMH to allow for testicular differntiation

AMH
- the fetal testis produces AMH in the presence of SRY gene
- this will cause mullerigan duct regression
- AMH made in the sertoli cells: NOT due to testosterone
- AMH before the lydig cells and testosterone is produced
- 7weeks: earliest secretion, done at 9/10 weeks

Only local AMH effect, not systemic

Question 32

after AMH, how is the Wollifan Duct stimulation for sexual differntiation

Answer 32

after AMH released from sertoli cells in testis of male embryo….

Lh and HCG stimulate the testes to produce testosterone: which then goes and triggers wollfian duct activity
Wollfican = vas deferens, epidydimyis, seminal vesicles

then testosterone enters fetal circualtion and cases creation of external genitalia

Question 33

Human Chorinoic Gonadotropin Effectsin Pregnancy

Answer 33

Effects
- HCG: promotes the maitnence of corpus luteum - alowing secretion of progesterone to continue
- HCG produced from placenta after implantation (serum an urine)
- used as a marker for pregnancy : doubles every 72 hours in early pregnancy
- similar to LH: to induce ovulation or produce testosterone in males
- role in cellular differntiation & apoptosis

Question 34

Progesterone Effect during Pregnancy

Answer 34

Progesterone during pregnancy: develops fetus
- converts endometrium to prepare uterus for implantation
- enchanges placental growth for nutrients to fetus
- decreases immune response to allow for mom to accept fetus

decreased utrine smooth muscle contraction: prevent pre-term labor (a drop in progesterone can lead to labor)

inhibits lactation during pregnancy: fall in progesterone triggers milk!

Question 35

Estrogen Role in Pregnancy

Answer 35

Estrogen
- causes uterine enlargement
- role in breast and dutal structure development
- relaxs pelvic ligaments
- high estrogen in pregnancy: promotes coagulation: high coag. state

Question 36

Relaxin Hormone in Pregnancy

Answer 36

Relaxin
- stops contractions that occur with growth of uterus (prevent early labor)
- later in pregnancy: loosens ligaments to allow pelvis to accomodate baby in delivery

Question 37

Parturition: Birth

Answer 37

Parturition
- orchestrated movements of fetus through canal : triggered by biochemical cahnges and mechanical cahnges of myometrium, decidua and cervix

the 3 Ps of Partutrion Influence
Power: force of contractions (of uterus)
Passenger: fetus size, way it slaying, postion, etc. want baby facing down
Passageway; the boney and soft tissue

Question 38

Cervical Changes in Parturition

Answer 38

Cervical Changes
- changes in the cervix precede the increased contraction of the uterus

Cervical Dilation: widening of teh cervical os
Cervical Effacement: thinning of the cervix

need to occur before contraction

full dialation = 10 cm

Question 39

Oxytocin Effects

Answer 39

Oxytocin
- posterior pituitary release
- stimulates cervical dilation and uterine contraction
- involved in milk let down
- love hormone for bonding!

Question 40

Prolactin Effects

Answer 40

Prolactin : from anterior pituitary
- stimulate milk production
- increased concentrations during pregnancy trigger enlargement of mammary glands to prepare for milk production

Milk Production
- starts with fall of porgesterone at end of pregnancy
- sucking stimuli
- crying stimuli