Hsci 120 lec 3 anatomy

Gonads (Testes and Ovaries) are both derived from same_____

Gonadal primordium

What are the 2 sets of ducts that both female and male embryos initially develop?

Wolffian duct and Mullerian duct

Do male and females end up keeping Wolffian and Mullerian duct? what develops into what? how?

remember: Wolffian for man (wolf) and Mullerian for woman (M for mother)

-in males: gonadal primordium secrete anti-mullerian hormone AMH cause Mullerian duct degenerate, and gonadal primordium secrete testosterone which cause Wolffian ducts form seminal vesicles, vas deferens, ejaculatory duct, and epididymis

-in females: lack of AMH & testosterone cause Wolffian ducts degenerate, while Mullerian duct form fallopian tubes, uterus, upper vagin

development of primary sexual characteristic depend directly on:

endocrine environment

True or false: An induvidual can be forced into either female or male development by application of the appropriate hormones, regardless of genetic makeup

True

In the absense of hormonal stimulation, the gonadal primordium will develop into ____, while the Wolffian duct____

ovaries

wolffian duct regresses (get worse or underdeveloped)

what secretes testosterone and AMH (what this stand for)

gonadal primordium secrete them in males

AMH is anti mullerian hormone

Explain the role of Y chromosome and gonadal hormones in differentiation/develoment of mammal reproductive system (draw diagram with arrows)

-SRY (sex-determining region of Y gene) antigen causes gonad to become testis

-testis has Sertoli cells, secreting MIF (mullerian inhibiting factor aka AMH, which cause mullerian duct regression)

-testis also has leydig cells, secreting testosterone, which converts to DHT (dihydrotestosterone) by enzyme 5a-reductase that influences development of external genitalia. genital tubercle become penis, genital folds become shaft of penis, genital swellings become scrotum

-ALSO the testosterone maintains wolffian ducts which turn to epididymis, seminal vesicles, vas deferens, and ejaculatory duct

Which cell in testis secretes MIF? Which secretes Testosterone?

Sertoli cells secrete MIF (AMH) and Leydig cells secrete testosterone

Testosterone is converted into ________ by the enzyme _______

DHT (di-hydro-testosterone) by 5a-reductase (think reduction of test)

Without DHT, what happens to the external genitalia?

they are feminizied, so

genital tubercle becomes clitoris

genital folds become labia minora

genital swelling becomes labia majora (think swelling=big)

Circulating levels of ________ also trigger different development in brain. example of this?

androgens (and maybe estrogens)

-animals exposed to androgens in specific window develop MALE REPRODUCTIVE BEHAVIOUR regardless of genoytype/phenotype

What are Primary vs Secondary Sexual Characteristics? Fit the following in each category: vagina, clit, breasts, labia, uterus, facial hair, phallus, scrotum, prostate, corpus cavernosum, pubig hair

Primary: sex organs (and their ducts/glands)

Secondary: structures that arent required, but enhance reproduction. usually develop at pubery

-breasts, facial/pubic hair

What is the Mons Pubis? (external genital)

-the fatty pad covering pubic symphysis (left/right pelvis sides meet)

-covered in pubic hair after puberty

3 Potential functions of pubic hair covering mon pubis?

-signal sexual maturity

-protect against friction

-pheromonal signaling (makes warmer environment)

What is the Clitoris? and function?

-most sensitive part of vulva

-external part has glans

-function=SEXUAL STIMULATION

-shape/size/position differs between ppl

The clit is 10cm, around how much of that can we see?

1.5cm

During glans (of clit) stimulation, the following 3 things fill with blood and expand:

-vestibular bulbs

-corpora cavernosa

-crura clitoris (roots)

plural of corpus cavernosum?

corpora cavernosa (just end with a’s)

True or false: Men and Women BOTH have corpus cavernosum

true

Labia majora vs Labia minora

labia majora=outer lips, labia minora=inner lips

-majora has hair, minora are hairless folds of skin between majora

-majora have many NERVE endings

-both majora and minora important in sexual arousal

-minora important in sexual STIMULATION

-majora provides protection (darker than thighs)

Reasons and risks of Labiaplasty? and which lips does it change?

-changes labia minora to make plumper, smaller, or symmetrical

-reasons: appearance, sexual/nonsexual discomfort, transition

-risks: infection, pleasure decrease, scarring, hypersensitivity

A tear-drop shaped area of vulva within labia minora, having lots of nerve endings/blood vessels, and contains vaginal/urethral openings

The Vulvar Vestibule

Urethra

tube that takes urine from bladder to exit

True or false: in general, the urethral opening is highly sensitive to sexual stimulation

false, in general, its not highly sensititve to sexual stimulation

A very senstitive region of vulvar vestibule that varies in size across ppl, and lies below urethral opening

vaginal opening

What is the Hymen? Explain how it differs between people

-thin membrane partially covering vaginal opening

-differs by:

-amount it covers

-if present at birth (usually is)

-if bleeds/painful when torn

-when its torn (intercourse, sports, medical procedure, etc)

True or false: Most of the time, tampons tear hymens when inserted

FALSE. most hymen openings are large enough for tampon to go in without tearing and allow blood flow

4 different types of hymens?

Normal hymen, imperforate hymen (no opening), microperforate hymen (tiny opening), septate hymen (septum (band of tissue) across opening, seperate into 2 small openings basiclaly)

True or false: the existence of the G-spot is under debate among researchers

True

Vagina canal starts at ___ and extends to ___

starts at vaginal opening and extends to base of spine

what is the vagina connected to? (think ur body)

cervix (entrance of uterus)

approx how many cm vagina extend by when aroused?

5 to 7.5cm extended from original: 1.5-12.5cm at rest

Why is the vagina elastic? For what?

for childbirth

3 vaginal layers? Describe each one

-Vaginal mucosa (inner, soft/moist)(secretions & lubrication)

-Middle/Muscular layer (muscles contract during sex/orgasm)

-Fibrous layer (inflexible, keeps vagina in pelvis)

-remember vaginal mucosa for mucus (soft) iside, MM for middle muscle (contract), and fibrous for firm (outer shield)

Which vaginal layer maintains a healthy vaginal environment via secretions? What is a “healthy” enviro?

-the inner Vaginal mucosa

-healthy enviro: moist and slightly acidic

What are the 2 functions of lubrication during sexual arousal by the Vaginal mucosa? And how many seconds after stimulation does it lubricate?

10-30 seconds after

1. increase alkalinity (ability to stabilize pH)

2. increase sexual pleasure

What does G-Spot stand for?

Grafenberg Spot

Where is the G-spot in females?

highly sensitive area on FRONT WALL of vagina about 5cm from opening

G-spot includes large area, what does it include?

Skene’s glands, their ducts, surrounding vaginal/urethral tissue

True or false: Some females ejaculate a fluid (from urethra) very similar to male prostate fluid

True (only abt 10-50% females squirt)

Some argue that rather than pleasure being from G-SPOT, its from______________

result of pressure in the area INDIRECTLY STIMULATING roots of clitoris (above)

Location and function of Bartholin Glands (Greater Vestibular Gland)

-2 glands inside labia minora

-function UNKNOWN (may secrete b4 orgasm for more lube)

describe Skene’s gland

-2 small glands on each side of lower urethra

-empty contents into urethra

Lesser Vestibular and Paraurethral Gland are also names of what gland

Skene’s gland

What female internal sex organ/gland is believed to be prostate equivalent and source of female ejaculate

Skene’s gland

What is the opening of cervix called

Os

What do the glands of Cervix secrete? (2)

mucous and hormones (think cervix=sneeze mucous)

major function of uterus

hold/nourish developing fetus

After ejaculation, sperm travels thru vagina into uterus via what opening?

Os

3 layers of Uterus

1. Endometrium (inner-think bad period is deep and inner uterus)(hormone-secreting glands/blood vessels)(shed during menstruation then usually regenerates)

2. Myometrium (middle muscular)(help change uterine shape during pregnancy and contract during layer)

3. Perimetrium (outer, thin/smooth membrane)

What layer of Uterus contracts during labour and accomodates change in uterine shape during pregnancy?

Myometrium (middle muscle layer)

What layer of uterus secretes hormones and sheds during menstruation?

Endometrium (inner layer)

-remember inner sheds, and inner is endo

what is the A-spot?

aka deep spot is the Anterior Fornix Erogenous Zone

(deep in vagina)

How many ovaries we have?

2

Are Ovaries endocrine or reproductive glands?

BOTH

Ovaries are endocrine glands that produce 2 hormones: _________ that have 2 functions

estrogens (especially estradiol) and progesterone

-regulate secondary sexual characteristics and menstrual cycle

Females are born with ovaries that have about ______ immature eggs (oocytes)

2 million

What happens with egg and ovary during mentrual cycle

-one egg matures per cycle, and is released by ONE ovary (they alternate)

Is it possible for 2 oocytes to mature and get released?

yes but less common

-called hyperovulation

-same or both ovaries

Fallopian tubes function

carry oocyte from ovaries to uterus

How does oocyte move through fallopian tubes

via cilia and peristaltic muscle contractions

approx length of fallopian tubes

Whats the difference between a normal and ectopic pregnancy

normal: egg implants itself in UTERUS

ectopic: egg implants in fallopian tubes or vagina or abdominal cavity

In males and females, arousal is controlled by:

parasympathetic stimulation (think pathetic for sympathetic)

What happens in parasympathetic stimulation? (when aroused)

-engorgement (overfilling) of erectile tissues

-increased blood flow to EXTERNAL genitalia and vaginal walls

-secretion of cervical mucous glands and Bartholin glands

stimulation of clit and _______, reinforced by touch sensations from the ______ and other stimuli can lead to female orgasm

vaginal walls

breasts

female climax results in:

rhythmic peristaltic contractions of uterus/vagial walls and skeletal muscles

What do male and female climax results have in common

rythmic contractions and skeletal muscles

Possible function/debate about rhythmic contractions in climax?

thought by some to enhance sperm migration up female reproductive tract

Penis 3 functions (easy)

-sexual pleasure (glans most sensitive), urination, reproduction

penis is mostly made of 3 things:

blood vessels, fibrous tissue (think firm for fibrous) and 3 tubes of spongy tissue (think soft)

If uncircumsized, foreskin partially or fully covers ______

glans (sensitive part)

_____ holds testes

scrotum

List some pros and cons of circumcision

pros: -less infant UTI (urinary tract infections)

-less STI (like HIV and warts)

-Less PENILE CANCER

-prevents/corrects phimosis (inability to pull back foreskin)

cons: -procedure risks of infection, hemorrhage, shock, penile mutilation

-trauma

-may or may not affect pleasure

what muscle makes up penis?

smooth muscles (3 cylindrical spongy bodies) (remember what muscle makes up? think abt skin texture)

2 cylinders on each side of penis and stiffens penis

corpora cavernosa

-when filled with blood, pulls tight, stiffens penis

what happens in corpora cavernosa veins during arousal

veins compress due to increased blood pressure in penis (reduce blood flow out of penis)

Cylinder that remains soft/spongy during erection and forms the glans

Corpus spongiosum

urethra runs through what? (males)

corpus spongiosum

what happens to the sponges of corpus spongiosum during erection

fills with blood

True or false: corpus cavernosa turns into roots of penis

true

first phase of male sexual response is _______ that allows penis to _____

erection, allows penis to penetrate

when does erection occur?

when erectile tissue fills with blood

what happens to arterioles supporting erectile tissue when male isnt sexually aroused?

the arterioles are constricted

during sexual excitement, what causes the arterioles to dilate?

trigger of parasympathetic reflex

what happens after the trigger of parasympathetic reflex (male sex respose)

vascular(means relating to vessels) spaces of penis fill with blood, causing penis to grow/hard

what does expansion of penis do to veins?

compress veins =slow blood outflow =more swelling of penis

parasympathetic reflex initiated by various stimuli including ____ and _____ (think what cause arousal)

thought and touch

inside scrotum, the ____ surrounds testis

Epididymis