HTHS Mod 20

• animals considered to be a transitional form btwn reptiles n mammals
• In these animals, defecation, urination, and oviposition (egg-laying) all occur through common orifice, the cloaca
• Ex: platypuses and echidnas

the body orifice in monotremes which defecation, urination, and oviposition (egg laying) all take place

• Make gametes
• Secrete hormones to maintain repro organs as well as other systems
• Have ducts for moving gametes around
• Have glands for lubrication and gamete support
• Have complementary anatomy, so partners are held together briefly as gametes are exchanged

the haploid cells that when combined, make a unique human being

• The genitals are all the structures of reproduction, both male and female
• The gonads: strucutre which produces gamates ~ testes and ovaries

• fertilization (union of gametes)
• implantation (attachment of embryo to uterus)
• parturition (labor and delivery)

the medical specialty that treats disorders and diseases of the male reproductive system

• Testes
• Ducts
• Accessory sex glands
• Urethra (shared btwn repro and urinary system)
• Penis (shared btwn repro and urinary systems)

• Ovaries
• Uterine (Fallopian) tubes
• Uterus
• Cervix
• Accessory sex glands
• Vagina

• Testes: produce continuous supply of sperm; also make testosterone & other androgens
• Ducts: transport, store, and assist in maturation of sperm
• Accessory Sex glands: secrete bulk of seminal fluid

• encloses urethra as passageway for excretion of urine
• Penis and urethra used to introduce semen into female by coitus and ejaculation

• produce oocytes, progesterone, estrogens, inhibin, and relaxin
• stores and matures eggs

• "Fallopian" tubes
• transport oocyte to uterus
• is site of fertilization

site of implantation of fertilized ovum and supports development of fetus

secrete fluid during coitus

• Vagina receives penis during coitus
• Cervix and vagina are passageways for childbirth

the making of sperm

• or simply sperm
• the gametes produced by the male
• are produced in the hundreds of millions
• Made in the testes, mature in the epididymis, then upon demand travel through ducts to be ejaculated

spermatozoon

• a loose sack of skin loosely attached to the body wall
• house the testes
• the loose attachment is important as sperm production is highest at a temp about 2-3° lower than body temp
• has 2 muscles: dartos & cremaster

a canal which carrie nerves, blood vessels, and the "vas" from inside the abdomen to the scrotum

• also called the vas deferens
• the ducts which carry sperm from seminiferous tubules to prostate
• one on each side, lead to midline urethra at prostate gland and end there

• one of two muscles of the scrotum that helps support the testes, spermatic cord and spermatogenesis 
• surrounds the scrotal sac subcutaneously
• In cold conditions, causes the scrotum to become firm, drawing the testes toward body
• will cause wrinkles to appear in the sac when the muscle contracts
• **Lets dart inside, it's cold

• one of two muscles of the scrotum that helps support the testes, spermatic cord and spermatogenesis 
• surrounds the testical; either draws the testes higher into the scrotal sac to protect them from danger or allows it to hang down
• **HAHA, I am your master, you will hang when I say you can hang

Each testis is divided into compartments called lobules

Each lobule contains 1 - 3 seminiferous tubules where sperm are produced

fibrous septum (collagen) which divides the testes into lobules

spermatogenic cells

• also called sustentacular cells
• support the function of spermatogenic cells
• basically make nursery environment for baby cells
• inside basement membrane
• stimulated by FSH from the pituitary
• **Sed (Syd) likes making babies in a tent (sustentacular cells). But Sadie said "Fuck Syd to Hell" (FSH hormone)

• hormones which support the male metabolism and secondary sexual characteristics
• (Ex: things that are typically male but are not scrotum or penis)

• cells which produce androgens (primarily testosterone)
• also called interstitial cells
• outside basement membrane
• stimulated by LH from the pituitary

another name for sertoli cells

another name for Leydig cells

• within each testis
• a series of tubules which lead to a central network; which then lead into the epididymis
• The tissue lining within generates gametes from a stem cell population; approx 600 per mm of tubule per day

• where spermatozoa are stored, and undergo final maturation
• closely associated w testis inside each scrotal sac

• consists of sponge-like venous passages which fill up with congested blood to make penis erect
• Has 3 chambers in penis

• Corpus spongiosum ~ a midline structure that surrounds the urethra (keeping it open during  arousal) and also makes up bulk of glans penis
• Corpora cavernosa ~ paired (left and right), each lie in the body of the penis

• "foreskin"
• found on uncircumcised men
• partially covering the glans

• Released into lumen of seminiferous tubules of testes
• Mature in epididymis, wait for ejaculation
• Upon sexual stimulation leading to ejaculation, travel via ductus deferens 
• Critical fluids from seminal vesicles and prostate added
• Ejaculation through urethra of erect penis

a basement membrane which separates the capillaries of the testes & interstitial cells from the lining of the seminiferous trubule

• stem cells found along the basement membrane of the seminiferous tubules, farthest from the luminal surface
• constantly divideing to either make more stem cells) new spermatogonia OR differentiated cells (primary spermocytes)

• Gametes mature progressively as they move from basement membrane to lumen:
• Spermatogonia (mitosis)
• Primary spermatocyte   (meiosis I)
• Secondary spermatocyte  (meiosis II)
• Early spermatid
• Late spermatid   (maturation)
• Spermatozoa (sperm cell)

• Starts w male gametes formed in seminiferous tubules
• They collect together in rete testis (network of testicle)
• effterent ducts ⇒ ductus epididymis ⇒ ductus deferens

• Sperm are only cells in human body with flagella
• Obviously, it allows them to be motile
• Spermatozoon is basically a "missile" (mitochondria for rocket fuel + flagellum) with a "payload" of paternal DNA

• created by seminiferous tubules collecting together
• After being produced in seminiferous tubules of testes, sperm move through here and cross imaginary border into the epididymis

another name for Cowper's glands

in the epididymis, sperm use this passage to enter ductus epididymis

• Where sperm wait up to 14 days to mature
• If sperm are there longer than 14 days, they will resorb
• During maturation, they acquire mobility and ability to fertilize ovum

• When sexual activity occurs, a smooth muscle "shell" around epididymis contracts
• expelling sperm into the ductus

• activated when spermatozoa are forced into ductus
• They secrete a small amount of alkaline fluid to lubricate and buffer pH of urethra
• Also called bulbourethral glands
• lie just inferior to prostate, on either side of urethra

• the ejaculatory duct (at the prostate)
• Here, secretions from the seminal vesicles and prostate are added
• Now the fluid is semen and can now be ejaculated

• Is a sympathetic reflex coordinated by lumbar spinal cord
• Internal urethral sphincter closes to prevent leakage of urine and backflow of sperm
• Contractions of muscles at root of penis result in emission

• Sperm from testes and epididymis
• secretions from seminal vesicles and prostate gland
• also a small contribution from bulbourethral glands

• Approx 600 spermatozoa/day
• Approx 2.5 to 5 mL semen in average ej.
• About 100 million spermatozoa per mL (below 20 mill/mL is defined as infertility)
• Is slightly alkaline @ 7.2 - 7.7, this helps neutralize acidity of male urethra and female vagina

• clots about 5 minutes after ejaculation ~ no one knows why, is from different clotting proteins than blood
• After about 10-20 minutes, semen liquefies
• PSA is one anti-clotting agents

• prostate-specific antigen
• one of the major anti-clotting agent in semen
• also used to detect prostate cancer in men; however it's controversial how to use PSA levels to detect cancer as there is no evidence to support the relationship

• it nutrients semen
• provides a buffer
• is a fluid medium for delivery of ejaculate

• helps w pH
• prostaglandins, and fructose (which is major nutrient which powers sperm motility)

• the secondary spermatocyte in the male is the haploid
• secondary oocyte is the "egg"

• contributes zinc, citrate and the enzyme acid phosphatase (used in forensic testing)
• Also gives semen a milky quality

the female gamete

sexual intercourse btwn male and female

• collective term for the externally visible parts of female reproductive system
• Includes:
• mons pubis (mount of adipose tissue)
• labia majora (labia = lips) - outer lips (similiar to scrotum in male)
• labia minora - inner lips (spread exposes vestibule), forms prepuce of clitoris, covers 2 openings: urethral opening and vaginal opening
• external urethral orifice
• clitoris
• vaginal orifice

• found on younger women
• a membranous structure which partially or completely covers the vaginal orifice
• A girls "cherry"

• refers to disease of the upper reproductive organs
• recall cervix helps keep unwanted organisms out of uterus & upper reproductive organs
• STD usually happen at the cervix

• Recall the need for the uterine tube to have enough space for the oocyte and sperm to move around. 
• If there is any obstruction, such as scar tissue, there can still be enough room for a spermie to move past, but not enough room for an embryo
• Therefore, the egg attaches to the uterine tube. This is dangerous

the removal of ovaries, uterine tubes, and uterus

the oocyte

• ovum - plural
• female gametes
• begin as oocytes
• they mature in the ovaries

• a collective term referring to the structure (w/in the ovary) that encloses an oocyte, along w all the surrounding cells that help it grow and mature
• In general, the female repro system matures only one follicle per menstrual cycle
• Also, as more follicles develop, there will be an increase in estrogen production

Btwn menarche (first menstrual period) and menopause ( the time of last menstruation)

describes the precursors to ova which undergo their last cell division before birth and remain in a quiescent (dormant) state until after menarche

under the influence of pituitary hormones and w hormonal feedback from the overaries and uterus

• Primordial follicles
• Primary follicles
• Secondary follicle
• Mature (Graafian) follicle
• Ovulation → secondary oocyte expelled

• Corpus luteum
• Degenerating corpus luteum
• Corpus albicans (scar tissue)

• The very beginning... :-) the smallest follicle
• contain a primary oocyte, and a single layer of follicular cells (which, as they develop, will be the estrogen producing cells)

• a primordial follicle that has further developed:
• still has primary oocyte
• now there's multiple layers of follicular cells (granulosa cells- in several concentric layers) supporting the egg w hormones & nutrients

• (was a primary follicle)
• Is filling with follicular fuild & now has developed a follicular fluid-filled pocket (an antrum)

The fluid will not only provide the oocyte with nutrients, but it will also help in the detachment of the egg from the wall of the follicle so it can be released

• the follicular fluid-filled pocket, or space, that develops in a primary follicle
• after it's formed, the follicle is now a secondary follicle

it finishes meiosis I

• another name for a mature follicle, also referred to as the tertiary follicle
• refers to a follicle that was a secondary follicle, but now the fluid predominates
• Thus the follicle is due to rupture (ovulation)
• In this phase the oocyte undergoes it's first mitotic division

• They are lost... will always have one dominant follicle
• The rest disintegrate and are reabsorbed
• *In the case of having twins, there were two dominant follicles. So it can happen; these would be fraternal twins, since it was from two different eggs

• a process in which a mature follicle ruptures
• In response to a surge of luteinizing hormone (LH) released from the anterior pituitary once each month, the mature follicle ruptures and releases a secondary oocyte
• **LORD HAve mercy....

• HaHa... it's mother nature's evil trick on females
• Once a gal hits puberty, it sends pulses of hormones (Gonadotropin releasing hormone) from the hypothalamus
• *Recall  hormones with "releasing" in it's name comes from the hypothalamus

• LH = luteinizing hormone
• FSH = follicle-stimulating hormone
• BOTH released from the anterior pituitary

The hypothalamus releases GnRH (gonadotropin releasing hormone) into the hypohpyseal portal system; thus the anterior pituitary responds

• follicle-stimulating hormone
• released from the anterior pituitary
• is released early in the menstrual cycle
• stimulates development of the follicle in the ovary:
• promotes the maturation of a primary follicle into a secondary follicle, then into a mature follicle
• Therefore, FSH levels rise early in reproductive cycle

a burst of LH causes the mature follicle to rupture, releasing the oocyte

an oocyte that has been released from a ruptured follicle

refers to the changes in the ovary with each menstrual cycle

secreted by secondary and mature follicles

• An endocrine structure which is the remnants of the follicle after it has ruptured & released the oocyte
• a yellowish, waxy substance  fills the follicle
• It secretes estrogen and progesterone
• IF CONCEPTION HAPPENS, corpus luteum stays intact and continues to secrete hormones 
• IF CONCEPTION DOESN'T HAPPEN, it begins to atrophy & turn into a hunk of scar tissue

• to maintain the lining of the uterus and prepare the womans body for implantation of the fertilized ovum
• If fertilization does not occur, or if embryo does not implant, menstruation proceeds

• a knot of scar tissue with no endocrine function, gets reabsorbed
• results from the corpus luteum "burning out" if conception doesn't happen after 14 days; it no longer secretes hormones
• The sudden drop in hormone output is what begins the next menstrual cycle w the sloughing off of the endometrium menstrual flow

• Day 1-14 pre-ovulatory
• Day 14 - 28 post-ovulatory

• primordial follicle
• primary follicle
• secondary follicle
• mature (Graafian) follicle
• ovulation - secondary oocyte expelled
• corpus luteum
• degenerating corpus luteum
• corpus albicans (scar tissue)

• Latin for "fringe"
• Long "fingers" of the uterine tube
• acts to "sweep up" the secondary oocyte and send it on it's journey along the uterine tube
• takes about a week for the oocyte to traverse the length of the tube

• It can encounter sperm here
• if it does, the secondary oocyte rapidly undergoes a cell division to become an ovum
• The ovum can now be fertilized by the spermatozoa and become a zygote

• a female gamete that was fertilized by a spermatozoa and genetics combine
• after fertilization, the zygote continues it's journey out of the uterine tube and into the uterus, where it will find an inplantation site

• 3 layers:
• endometrium: inner layer
• myometrium: is thickest, middle layer (is smooth muscle)
• perimetrium: is outer, connective tissue layer (serosa layer, nearest the pelvic cavity)

• the inner lining of the uterus, nearest the lumen
• Has 3 layers: 
• simple columnar epithelium
• stratum functionalis
• stratum basalis
• *The stratum functionalis is shed monthly in menstrual cycle
• *The stratum basalis is the tissue from which the stratum functionalis generates from

• Blood flows from:
• the internal iliac arteries → uterine arteries → arcuate and radial arteries
• The radial arteries branch into spiral arterioles, (which are shed along w the stratum functionalis) and straight arterioles (in the basalis, which are not shed)
• ** I Usually Aint Right... Slap me Silly

Simply drains into the uterine veins and then into the internal iliac veins

• A secondary oocyte is released from ovary at ovulation
• Swept up by fimbriae of uterine tube
• Oocyte may encounter sperm in uterine tube
• IF IT DOES, secondary oocyte undergoes the final meiotic division to form an ovum

• If spermie & ovum unite, zygote is formed
• Zygote travels to uterus where it implants

• A female ovulates & releases a secondary oocyte
• When sperm enters egg, and egg finishes meiosis II, THEN it's an ovum
• When sperm and egg nuclei actually unite, then it's a zygote

• Generally the menstrual cycle is 28 days w menstruation lasting 7 days
• 3 "stages" :
• proliferative phase
• secretory phase
• menstruation
• *menstruation and proliferative phases are pre-ovulatory
• secretory is post ovulatory

• The menstrual cycle begins with the sloughing off of the previous cycles tissue (the menstrual flow)
• The constriction of the arteries leading into the stratum functionalis causes that layer to die and slough off

• the stratum functionalis and its associated blood vessels (spiral arterioles and venules) are lost w layer of endometrium
• Day 1 of menstrual cycle marked by the sloughing off of tissue that was build during previous cycle, flow can last 7 days depending on person

• Time in which the stratum functionalis is rapidly rebuilt, along w arterioles and venules
• Begins when menstruation ends, Goes up through about day 14
• *Recall main hormone coming from follicle during this time (approx day 5 - day 14) is estrogen, therefore estrogen is in direct correlation of menstrual flow
• If one cycle has more estrogen (for whatever reason) there will be an increase in flow

• It's influence is pre-ovulation
• follicles produce estrogen, estrogen causes rapid growth of stratum functionalis
• Other jobs:
• ~Promote development/maintenance of female repro structures, 2ndary sex characteristics, breasts
• ~Increase protein anabolism
• ~Lower blood cholesterol
• ~Moderate levels inhibit release of GnRH, FSH, and LH
• **I Love Rough Sex Inside

• occurs at ovulation, ideally at day 14
• the venules and spiral arterioles in endometrium enlarge
• this is in preparation for the implantation of the zygote 
• Hormone that is post-ovulatory coming from corpus luteum is progesterone
• ~if embryo does implant in uterine lining, will occur about day 21. It will need rich blood supply to build placenta and feed embryo
• ~If no implantation happens, around day 26 the endometrial lining loses hope and menstruation begins

• It's influence is post-ovulation
• Is secreted by the corpus luteum
• Causes the endometrium to mature in preparation for implantation of a zygote
• make "potting soil"
• pro- in favor of; -gestation
• Also:
• ~works w estrogens to prepare for implantation
• ~Prepares mammary glands to secrete milk
• ~Inhibits release of GnRH and LH

• abnormal bleeding (menstrual)
• While the average is  36mL per cycle, more than 80mL is considered abnormal

Hormones secreted by pituitary , follicle, corpus luteum and endometrial glands are used to coordinate ovarian and uterine cycles

• During last half of menstruation, FSH released from anterior pituitary causes one lucky primordial follicle in ovary to start developing. 
• It becomes a primary follicle
• As FSH remains high, the primary follicle develops into a secondary follicle at the beginning of endometrial proliferation phase

• At beginning of proliferation, a secondary follicle was formed
• As it further develops into a mature follicle, it begins secreting estrogens to help maintain the growth & development of the stratum functionalis 
• At midpoint of cycle, approx day 14, a burst of FSH and LH triggers ovulation which marks  beginning of secretory phase

• At beginning of cycle, FSH spikes a little to encourage follicle development
• As follicles develop, a increase in estrogen occurs
• At ovulation, LH suddenly spikes to release egg, which then drops back off
• That's when progesterone increases, along with a slight increase in estrogen, from the corpus luteum
• Once progesterone drops (if not fertilization occurs) triggers menstration

• hormone secreted by corpus luteum
• Inhibits release of FSH (mostly) and, to lesser extent, LH
• Simply keeps body from starting another cycle before it's ready

• hormone secreted by corpus luteum
• Inhibits contractions of uterine smooth muscle to allow easier implantation (from cycle to cycle)
• Plays key role during labor= increases flexibility of pubic symphysis & dilates uterine cervix, also relaxation so baby can drop

childbirth

• There are 3 different chemicals call estrogens:
• E1 estrone is main form found in body during menopause and later
• E2 17β-estradiol is the predominant estrogen found in nonpregnant females
• E3 estriol is main estrogen during pregnancy & is made by fetal liver

• Sex-determining region Y
• All 5 wk embryos start out w indifferent gender
• After that, a small region of the Y chromosome kicks into action (SRY)
• IF SRY is present & active & not mutated, then embryo develops male gonads
• *oddly, is only important gene on Y chromosome

• more modern term is intersex
• describes individuals who had errors in the SRY gene
• Therefore, they developed gonads somewhere btwn "SRY-on" and "SRY-off"

• The same embryonic structures develop into one thing if SRY is active, another if it's not
• Therefore, the same lump of tissue will develop into one thing if its male, another if it's female

• Male: testes
• Female: ovaries

• Male: [degenerate]
• Female: uterine tubes, uterus, vagina

• Male: glans penis, corpora cavernosum
• Female: clitoris

• Male: penile urethra
• Female: labia minora

• Male: Penis, Scrotum
• Female: Labia majora

• Male: corpus spongiosum
• Female: pubocervical fascia, vestibular bulb

• Male: prostate
• Female: Paraurethral glands (G-spot)

• Male: bulbourethral glands
• Female: greater vestibular glands
• Both contribute to lubrication

• the region surrounding the genitals and anus
• one area where males & females differ (duh)
• Traditionally divided into 2 regions: urogenital triangle and anal triangle

• the channel through which the descent of the male testes from the embryonic position in the abdomen, into the scrotal sac (approx 7 months gestation)
• Is a mechanically weak point and common place for inguinal hernias for males

• Similar to females, GnRH is secreted (from hypothalamus) which acts to secrete FSH or LH
• *No follicles in males, duh
• FSH acts as stimulant to spermatogenic cells and Sertoli cells of testes
• LH acts on Leydig cells of testes, which secrete testosterone...which may be converted to the active form DHT

• dihydrotestosterone
• a male hormone that alters secondary sexual characteristics

In the presence of FSH, testosterone and androgen-binding protein (from Sertoli cells) promote spermatogenesis

Controls a negative feedback loop which ensures that sperm are not over-produced

• Is the reproduction of somatic cells; where DNA content is doubled (during S phase) and then divided equally btwn 2 daughter cells
• retains it's ploidy (chromosome content)
• Therefore, somatic cells are diploid

refers to a cell which has two copies of every chromosome

• The ploidy of a cell refers to the number of copies of each chromosome present in the cell nucleus
• The n number refers to the number of copies of each unique DNA strand in the nucleus
• As each chromosome contains 1 or 2 strains of DNA at different stages of the cell cycle (whether mitotic or meiotic) these numbers do not always coincide

• refers to mature gametes that have only one copy of each chromosome
• Therefore, haploid gametes w one DNA strand per chromosome are said to be 1n
• In some stages of cell cycle, diploid cells also have 1 DNA strand per chromosome, and hence are  2n 
• During earlier stages or meiosis or mitosis, each chromosome of a diploid cell has 2 strands of DNA (has a sister chromatid)= 4n

• an important feature unique to meiosis
• In prophase of meiosis I, genetic recombination occurs (scrambling of pieces of chromosome)
• Ensures twins are not born years apart

Mitosis is cell division where DNA of daughter cells is exactly the same sequence as parents (daughters are clones)

Meiosis involves tetrad formation and crossing over

Mitosis preserves the ploidy & n # of cell. Always diploid, and alternates btwn 2n and 4n. Multiplication of n number during S phase, division during M phase.

Meiosis is a reduction division. The precursors of gametes are diploid (2n). The resulting cells are haploid. It's when 2 haploid cells meet, it returns to being diploid.

Mitosis is a cyclical process. It repeats

Meiosis is a "one-way street"; once cells become gametes, they cannot ever reproduce new cells except by joining another gamete in fertilization

• Recall in males, gametogenesis begins with the stem cell, spermatogonia
• Spermatogonia undergo mitosis to produce a clonal population
• As long as they stay near the basement membrane, they remain a stem cell and divide by mitosis 

• If a spermatogonia leave the basement membrane of seminiferous tubule, they begin the process of differentiation.
• They become primary spermatocytes (diploid, 4n)
• Primary spermatocytes undergo meiosis I to become secondary spermatocytes (haploid, 2n)
• In meiosis II, they split their DNA into individual chromatids (1 copy DNA per cell), so they end up haploid, 1n spermatids
• They continue further differentiation but no further changes in DNA content is made, so they end up as haploid, 1n spermatids

• OOgonia undergo their last mitotic division in female fetus
• Meiosis I begins at that time, generating primary oocytes
• The primary oocytes lie suspended halfway through meiosis I for 10-50 years.
• Each month after menarche, 5-12 primary oocytes respond to hormonal signals 
• In general, only 1 progresses to 2ndary oocyte
• remaining material becomes first polar body

• first polar body: the remaining genetic material that is "tossed in the garbage disposal" after a primary oocyte progresses all the way through meiosis 1 to form a secondary oocyte
• second polar body: only formed is a spermatozoon penetrates the egg, and the 2ndary oocyte is able to complete meiosis II to become an ovum. Again, the left over genetic material from the reduction division

• Once a primary oocyte completes meiosis I and forms a secondary oocyte, that secondary oocyte begins, but doesn't complete, meiosis II. 
• Meiosis II is only completed is a spermatozoon penetrates the 2ndary oocyte.
• Then it completes meiosis II and becomes an ovum (this also generates the second polar body)

• describes the female DNA (n DNA content) and male DNA (n) after an ovum is produced (via penetration of sperm into egg)
• They remain separate as male and female pronuclei
• Eventually they will fuse to form the diploid zygote (2n)

• - of embryonic development
• refers to the fusion of the male and female pronuclei to form a zygote

• During fetal development, meiosis I begins
• After puberty, primary oocytes complete meiosis I, which produces a 2ndary oocyte and a first polar body that may or may not divide again

• The secondary oocyte begins meiosis II
• A secondary oocyte (and first polar body) is ovulated
• After fertilization, meiosis II resumes. The oocyte splits into an ovum and a second polar body

• Male: spermatogonia continuously undergo mitosis to generate primary spermatocytes
• Meiosis 1 generates 2ndary spermatocytes
• Meiosis II generates spermatids
• continues throughout lifetime

• Female: All oogonia generated b4 birth
• Primary oocytes start meiosis I
• After completion of meiosis I, just b4 ovulation, Primary oocyte becomes 2ndary oocyte; meiosis II begins
• Meiosis II only completed at fertilization

• Males: spermatogenesis
• Females: menarche

Also, both are marked by development of 2ndary sexual characteristics

Male: penis, scrotum, associated glands

Female: vulva, ovaries, uterine tubes, uterus, associated glands

They define gender

• those that are different btwn genders but not definitive
• Ex: males tend to be more muscular w deeper voices
• Male: body hair on face, chest, pubic region, arms and legs, deeper voice, adams apple

Female: body hair in pubic region, arms and legs, larger breasts, wider hipds

• internal cues
• external cues
• increased obesity
• ~adipose tissue acts as an endocrine organ and may alter the developmental clock

an instrument for measuring penile erection

• There are at least 2:
• reflexive, mechanical dimension ~ which is obviously easier to study than the other mentioned... also easiest to study in men
• spiritual dimension

• Thanks be to the landmark studies in 1948 by:
• Kinsey, Pomeroy and Martin
• They began the field of study

Masters and Johnson advanced the field greatly in the 1960's

• Primarily controlled by autonomic nervous system 
• Incoming sensory info from structures which produce sexual arousal: S2-S4 
• Outgoing striated motor and parasympathetic autonomic also S2-S4 
• Outgoing sympathetic autonomic at T10-T12

The brain clearly influences this basic reflex pathway

• Penile erection results from congestion in the corpora cavernosa
• 3 processes working together:
• ~relaxation of smooth muscle in corpora cavernosa, allowing blood to fill open spaces in this spongy tissue
• ~increase in arterial blood flow to penis
• ~restricted flow of blood out of the penis (venous congestion)

• NO (nitric oxide)
• VIP (vasoactive intestinal polypeptide)
• CGRP (calcitonin gene-related peptide
• prostaglandin

• ~ nitric oxide
• Promotes dilation of blood vessels through out body
• In turn, promotes penile erection by stimulating all 3 processes

• Viagra
• causes penile erection by inhibiting an enzyme which breaks down an NO-related signaling molecule (PDE5)
• Therefore, Viagra blocks PDE5 and prolongs smooth muscle relaxation

• only 2 have been found:
• the clitoris and vestibular bulb

the area surrounding the female introitus

the entrance to the vagina

• the vestibular bulb
• the pubocervical fascia (Halban's fascia)

and the paraurethral glands (Skene's glands)

the idea that women engage in sexual intercourse because of desire for emotional closeness

• 3 competing models:
• Masters n Johnson: based on "male", hydraulic model of sexual arousal
• Kaplan: motivational motel
• Basson: sexual neutrality

• 4 stages of sexual arousal
• excitement
• plateau
• orgasm
• resolution
• Focus is on physiological response; based on modification of male sexual response

• is a modification of Masters and Johnson, but w an additional phase added at beginning & 4 stages compressed to only two
• 1. Desire ~ a psychological motivation to engage in sexual behavior
• 2. Excitement ~ similar concept as in Masters and Johnsons model
• 3. Orgasm ~ reflexive component, w reflexive pelvic muscle contractions

• Based on "sexual neutrality"
• posits that emotional intimacy is primary motivator
• Once search for intimacy leads to sexual behavior, the physically pleasurable aspects take over, and sexual arousal occurs

• takes place in the uterine tube
• flagella are stimulated to beat more vigorously
• # of chemicals (cholesterol, glycoproteins, and proteins) r removed from spermatozoa in preparation to fuse w secondary oocyte

the "head" of the sperm

unpolymerized actin in acrosome of spermatozoon

• the process of converting profilactin into actin
• this helps spermatozoon penetrate the secondary oocyte

• fraternal
• occur when 2 oocystes are shed, usually one from each ovary

• occure when the zygote splits into two embryos in an early division
• identical twins

• fertilization doesn't occur
• This is POLYSPERMY... the idea that it's possible for more than one sperm to enter the oocyte

• there are at least 2:
• Block to polyspermy
• One is fast (which is very detailed), the other is slow (which involves the cortical reaction)

• corona radiata
• zona pellucida

• "radiant crown"
• made by granulosa cells from the follicle
• partially surround the ovulated secondary oocyte
• outer layer

• the inner layer surrounding the ovulated secondary oocyte sperm must penetrate
• is a thick, clear layer

• caused by the penetration of the oocyte by the 1st spermatozoon
• causes Ca++ to be released from cortical granules in the oocyte
• This lifts the zona pellucida off egg, making it impossible to pass
• Unless the zona pellucida is in close contact w oocyte, sperm can't penetrate

• When the sperm and egg unit
• Forms a diploid = zygote
• Is the moment which starts out developmental "clock"

• the embryo travels from uterine tube, where fertilization almost always occurs near distal end of tube, 
• Along the way, it continues the process of mitotic cell division

• results from the first division of the zygote, resulting in two symmetrical, equal cells
• *the splitting of the cell at this point will result in monozygotic twins forming

• next division of embryo, takes place on day 2
• produces 4 equal, almost identical cells

• the stage after four-cell embryo; seen at day 4
• when simple pattern of cell division is lost
• "raspberry"

• when the embryo forms a hollow, fluid filled ball
• seen about day 5

• happens about day 6
• blastocyst makes contact w endometrium of uterus
• Inner cell mass develops
• Problem: embryo is "foreign issue (half of genes not from mom)
• so involves evading mother's defense mechanisms (since dad's DNA is foreign)

develops when the point of contact btwn blastocyst and endometrium causes uterus to release chemical factors

• days 8 - 12
• Upon implantation, the blastocyst divides into three parts:
• ~trophoblast
• ~innercell mass→ embryonic disc
• ~yolk sac
• The endometrial lining becomes the decidua
• By day 12, embryo is completely covered by endometrial tissue

• Happens approx day 16
• the process by which an embryo folds in on itself to form 3 layers:
• ectoderm ~ becomes skin & nervous system
• mesoderm ~ becomes connective tissue, muscles and bones
• Endoderm ~ becomes gut tube

• When cancer occurs, it's named by tissue of origin
• Carcinoma refers to tissue from the ectoderm
• Sarcoma refers to the tissue from the mesoderm

• epidermis
• teeth
• jaws
• nervous system
• posterior pituitary
• **Every Tom & Joe Needs Pussy

• Somites
• Kidneys
• Heart
• Reproductive system
• Gonads
• **Sadly Kissing Happened Regularly, George

• Lungs 
• bladder
• Thyroid
• Liver
• Pancreas
• Lining of digestive tract
• **Please... Let The Bitch Lie Longer??

• Look like little "speed bumps" of the mesoderm, when form into:
• dermatome = dermis
• sclerotome = vertebrae
• myotome = skeletal muscles, appendicular skeleton

term used for the uterine lining during pregnancy

• represent a collaboration btwn mom & baby
• Deals with the fact that the embryo is different from mom's tissues (is foreign) and also convinces mom to feed and protect embryo
• The joint project is called the placenta

• a joint project btwn mother and baby
• is half embryonic tissue & half maternal
• Placenta will:
• provide food to embryo
• Provide oxygenated blood to embryo
• Protect embryo from invaders w maternal antibodies (only IgG antibodies can pass placental border)

With the development of lacunae (open spaces) which form immediately after implantation

• loops of blood vessels formed by embryonic tissue
• important as the first structures of developing embryo that can be biopsied to detect genetic defects of the embryo
• Since this is completely derived from embryonic tissue, and not maternal tissue, and chromosomal abnormalities can be fully attributed to embryo
• Most common detected is trisomy 21 (downs)

the circular "wall" around the entire embryonic project area

• chromosomal abnormalities, can occur during meiosis I or Meiosis II
• Recall w meiosis, all 4 chromatids r suppose to arrive in different daughter cells
• In nondisjunction, chromatids fail to separate and both go to the same cell: one gamete get two copies of chromatid 21
• Therefore, at fertilization, Dad contributes one copy, Mom contributes 2, so child ends up with 3 copies

• Resulting embryo can be
• XXX, XXY, XO, or YO
• YO embryos do not survive

• maternal circulation ⇛
• maternal endometrial arteriole ⇛
• fetal blood vessels in chorionic villi ⇛
• umbilical vein (IS OXYGENATED BLOOD) ⇛
• embryo ⇛
• umbilical artery (IS DEOXYGENATED BLOOD) ⇛
• fetal blood vessels in chorionic villi ⇛
• maternal endometrial venule

The initial clustering of embryonic cells from which a part or an organ develops

• The time when individual organs start to develop from precursor tissues found in the appropriate layer
• begins once gastrulation has occurred & 3 embryonic layers are formed
• Day 20-28

• a prominent feature of the dorsal surface of embryo, forming a distinct groove
• The lips of this groove meet to form a neural tube, which will twist and fold to form the brain

• time when systems are sensitive & can be harmed by teratogens
• when a system can be changed
• during the embryonic period

• substances that can cause birth defects
• Ex:
• rubella ("german measles")
• toxoplasma (cat feces)
• radiation
• cytomegalovirus

• defined as fertilization to 8 weeks
• After this time, the fate of most organ systems is set

• 9 weeks to 40 weeks
• There is growth and development, but most of fetal period involves the organs carrying out developmental plan set out during the embryonic period

• hCG (human chorionic gonadotropin)
• relaxin
• hCS (human chorionic somatomammotropin)
• CRH (corticotropin-releasing hormone)

• human chorionic gonadotropin - hormone released by placenta
• released by chorionic membrane, acts on gonads
• Supports the function of the corpus luteum, keeping it "alive" for about 3 more months
• Basis for home pregnancy testing

hormone released by placenta that helps at childbirth by making pubic symphysis more flexible, and aiding in dilation of cervix during labor

• human chorionic somatomammotropin - hormone released from the placenta
• alters maternal metabolism, increasing protein synthesis to enhance growth
• decreasing glucose use and increasing fatty acid use for ATP

• corticotropin-releasing hormone - released from placenta
• establishes the time of birth and increases cortisol secretion from the adrenal cortex

• Spike of hCG is earliest, peaking btwn 8-10 wks
• Slow rise in progesterone and estrogens from maintenance of corpus luteum:
• levels of estrogens rise steadily through pregnancy
• levels of progesterone rise steadily, but begin to drop slightly at end of pregnancy

• increased blood flow to placenta (duh)
• ⇧ stroke volume
• ⇧ cardiac output
• ⇧ heart rate
• ⇧ blood volume

• compression of inferior vena cava, leading to edema in legs and varicose veins
• compression of renal artery may lead to renal hypertension

• ⇧ tidal volume
• ⇧ ventilation
• ⇧ total oxygen consumption

⇩ expiratory reserve volume

dyspnea possible

increased urination due to fetus sitting on bladder, duh

increased glomerular filtration rate

• pre-eclampsia
• cardial signs are rapid rise in BP to hypertensive levels & proteinuria

• Life-threatening condition
• Hemolytic anemia, Elevated Liver enzymes, Low Platelet count

• dilation stage
• expulsion stage
• placental stage

• From onset of labor to dilation of cervix
• Lasts about 6-12 hours
• regular contractions
• Usually rupturing of amniotic sac
• Ends w complete diation 

The estrogen/progesterone ratio, increased maternal oxytocin release, and increased fetal oxytocin release probably play a key role in initiating parturition

• can last 10 minutes to several hours
• begins w dilation of cervix, ends with delivery

• The final stage to labor
• can last 5 to 30 minutes
• Ends w expulsion of placenta
• Powerful uterine contractions expel placenta and help control bleeding

• Is rare example of positive feedback loop
• Input: stretching of cervix sends sensory info to brain
• Processing & output: brain interprets signal, releases oxytocin from posterior pituitary
• Oxytocin causes uterus to contract more forcefully
• This pushes baby further into cervix, increasing stretch
• Delivery of baby stops feedback loop
• *Synthetic oxytocin (Pitocin) can be used to stimulate this homeostatic loop

• another positive feedback loop associated with childbirth
• allows newborn to suckle
• Only involves releasing stored milk

• Input: baby sucks nipple
• Processing & output: hypothalamus and posterior pituitary 
• Releases oxytocin which stimulates "milk let-down reflex"
• Cycle continues until baby stops suckling

• are modified sudoriferous (sweat) glands which produce milk
• Alveolar glands w/in fat tissue of breast are surrounded by myoepithelial cells, which contract in response to oxytocin
• This ejects milk from alveoli

• Bulk of breast is adipose tissue, embedded within are alveolar glands
• 15-20 lobes per breast, separated by fat tissue
• lobes have lobules that contain alveoli

• also referred to as suspensory ligaments
• maintains structure of breast
• become stretched throughout life

• from a single, unprotected act 2-4%
• Peak probability of conception if at days 12-14
• Sperm survive 3 days, so intercourse slightly after ovulation has higher probability of conception than intercourse after ovulation