Physiology

detection of ovulation causes

women who want to plan conception or practice contraception

methods to detect ovulation

transvaginal us, urinary LH, serum progesterone, BBT, cervical mucus, salivary ferning analysis

fertility window

3-5d before ovulation and continues approx 1-2d after ovulation

when to do urinary luteinizing hormone detection

35-44hr after ovulation, peak 10-12h after ovulation

highly sensitive urinary lh kits can be performed when

10th day of new cycle or 4 days before estimated ovulation day

outside vs during perivovulatory period, how is mucus?

outside is thick scant and viscous (by mucin), during is less and loose (under estrogen

rise of bbt results from

thermogenic effect of progesteorone

when is bbt in lower range

follicular phase, lowest point 1 d before ovulation

when does bbt rise and plateau

luteal phase

when should progesterone level be detected

7-10d before next period (day 21)

hormone production by placenta increases in proportion to _________, with the exception of

increase in placental mass, except hCG

peak concentration of hCG occurs

8-10w (but from 6th day until 20w)

how to detect hCG

blood or urine (w/ anti-hCG atb)

hCG

hormone secreted by syncytiotrophoblast cells, takes role of pituitary LH, maintaining pregnancy and supporting corpus luteum fxn

when does hCG conc decline

end of second trimester

cause of false + hCG tests

drugs

when is prolactin secreted

pregnant and lactating women

effects prolactin

released under inhibitory influence of dopamine, stimulates breast dev in puberty, alveolar and ductal dev of breasts in pregnancy

what hormone stimulates prolactin

estrogen

testes function

synthesis testosterone by interstitial leydig cells under LH, spermatogenesis by sertoli cells under FSH

testicular fxn can be tested by

semen analysis, blood testosterone levels (total or free androgen index)

attributes of sperm

total # spermatozoa, total fluid v, vitality, motility and morphology of spermatozoa, composition of seminal fluid

prep of sample collection of semen

2-3samples, min 2 days of sexual abstinence

_______ analysis involves liquefaction, culturing, wet slide, dilutions

semen

macro exam of semen

gray-white colour, translucent, able to liquefy, easily drawn into pipette, homogenous stickiness,

ph of semen reflects balance bw

alkaline seminal vesicular secretion and acidic prostatic secretion

micro exam of semen

mucus strands, sperm aggregation + agglutination/motility, presence of cells other than spermatozoa (epithelial, leukocytes, germ cells)

normal sperm micro appearance

oval shaped head, long flagellar tail, acrosomal cap at tip of head

how is sperm viability assessed

mixing specimen with eosin-nigrosin stain, living cells remain blueish white

seminal fluid fructose investigation

micro investigation of semen, using resorcinol test → orange colour when fructose present

male reproductive fxn

1. spermatogenesis
2. performance of male sexual act
3. regulation of fxns by hormones

anatomical elements of male reproductive system

gonads, sex accessory organs

sperm will be transported thru

from seminiferous tubules → epididymis → vas deferens → ampulla vas deferens → prostatic ducts → 2 seminal vesicles → ejaculatory duct → int urethra

urethra is supplied with mucus from

urethral glands (along entire length), bulbourethral Cowper glands (near urethral origin)

spermatogenesis during embryo formation

primordial germ cells migrate into testes → immature germ cells called spermatogonia (lie in seminiferous tubules)

spermatogenesis at puberty

spermatogonia undergo mitosis → sperm

steps of spermatogenesis from puberty

spermatogonia (sertoli cells): mitotic divisions → primary spermatocytes → meiotic divisions → haploid spermatids → spermiogenesis (flagella formed) → sperm

how long does spermatogenesis takde

64-74d

spermatogenesis occurs where and as a result of what stimulation?

seminiferous tubules, ant pituitary gonadotropic hormones

head of sperm is made of

nucleus, anterior 2/3 has acrosome (mainly formed of golgi) → w/ enzymes allowing sperm to enter ovum

enzymes of acrosome

hyaluronidase - digest proteoglycan filaments of tissues

proteolytic enzymes - digest proteins

components of flagellum

axoneme (central skeleton), thin cell membrane covering, mitochondria making up the body (w/ atp for movement)

hormones stimulating spermatogenesis

testosterone (division testicular germinal cells), LH (stimulates leydig cells to secrete testosterone), FSH (stimulates sertoli cells to convert spermatids to sperm), estrogens, GH (early division spermatogonia)

testosterone is secreted by

leydig cells

what hormones secreted by pituitary

lh, fsh, gh

estrogens are formed from testosterone by sertoli cells when

stimulated by fsh

where is sperm stored

epididymis, a little in vas deferens

what happens to sperm when they pass thru epididymis

capability of motility

semen is composed of sperm and fluid from

vas deferens, seminal vesicles, prostate, bulbourethral glands

fluid from semen contains

hormones, enzymes, nutrients

max life span of sperm once ejaculated in semen

24-48h

capacitation of spermatozoa

occurs on contact w. fluid from female genital tract, inhibitory factors washed away, excess chol at acrosome lost → permeable to Ca+ → flagellum changes from undulating to whiplash

penis stimulation

somatic efferent and afferent via pudendal n

stimulation for male sex act

symp + parasymp

most importance source of sensory n signals for initiating male sexual act

glans penis, areas adjacent

male sex act results from

reflex mechanisms in sacral and lumbar spinal cord (by psychic or local stimulation)

penile erection is coordinated thru which stimulation

parasympathetic (increased flow)

androgens

testosterone, dihydrotestosterone, androstenedione

where are estrogens in males formed from

from testosterone and estradiol by sertoli cells, from testosterone and androstanediol by liver

what makes up 20% of mass of adult testes

leydig cells

when are leydig cells present in life

numerous in newborn male infant + after puberty

all androgens are synthesized from _____________ in what?

cholesterol or acetyl coa

testes and adrenal cortex

testosterone is bound in blood w/

sex hormone binding globulin (SHBG)

much of testosterone is converted within target tissue cells to

DHT

intracellular mechanism of action of testosterone

usually first converted to DHT → binds to nuclear protein and induces transcription → RNA increases → increased cell proteins

pattern of testosterone secretion during life

fetal life testes produce testosterone by chorionic gonadotropin from placenta, no testosterone until puberty by ant pituitary gonadotropics, decreases after 50y

testosterone begins to be made by fetal testes when

7th w

what causes differentiation into cells that secrete testosterone in fetus from genital ridgewhen→ testes

sex-determining region Y gene on male chromosome

when do testicles descend under testosterone

last 2-3m gestation

testosterone effects in puberty

laryngeal mucosa hypertrophy, hair growth (pubis, linea alba, face, chest, back), thick skin, increased rate sebaceous gland secretion, muscle mass, bone matrix, RBCs, Na+ reabsorption

control of sexual fxns in males and females begins w/

secretion GnRH by hypothalamus

GnRH stimulates what?

ant pituitary to secrete LH and FSH

_________ is a short peptide secreted by arcuate nuclei neurons of hypothalamus

GnRH

intensity of GnRH intermittent stimulus is determined by

frequency of cycles of secretion and quantity of GnRH released in each cycle

secretion rates of gonadotropes with GnRH

LH is cyclical w/ GnRH, FSH not reliant

testosterone and lh relation

secreted in direct proportional amounts to

what has inhibitory effect of ant pituitary secretion of lh

testosterone → decrease lh and fsh secretion → decreased testosterone

_______ binds to sertoli cells causing them to grow and secrete spermatogenic substances

fsh

what are necessary to initate spermatogenesis

fsh and testosterone

negartive feedback effect on FSH is by

inhibin (of sertoli cells)

phases of female reproductive fxns

* prep body for conception and pregnancy (producing haploid gametes - ova, site for fertilization and implantation)
* period of pregnancy

each ovary consists of

inner medulla (vessels), outer cortex (follicles, corpora lutea)

distal end of fallopian tubes

expands as infundibulum, w/ multiple fimbriae

activity of fallopian tubes cilia

facilitate ovum transport

a developing egg (____) differentiaties into a mature egg (_______) through oogenesis

oocyte, ovum

in fetal life the ovum is called

primordial follicle, surrounded by single layer granulosa cells

at birth ovum is called

primary oocyte

meiotic divisions of ovum at puberty

1 oocyte - large secondary oocyte + small polar body, each with 23 duplicated chromosomes → polar body disintegrates, ovum undergoes second meiosis arrested in metaphase

when does final step meiosis occur in in ovum (secondary oocyte)

if ovum is fertilized

During_____________, only 400 to 500 of the primordial follicles develop enough to expel their ova—one each month; the remainder degenerate

all the reproductive years of adult life, between about 13 and 46 years of age

3 hierarchies of hormones of female system

1. GnRH
2. ant pituitary - FSH + LH (in response to GnRH)
3. ovarian hormone - estrogen + progesterone (in response to LH + FSH)

monthly rhythmical changes in repro yrs of female

rates of secretions of female hormones, corresponding physical changes in sex organs → 1 ovum released from ovaries, endometrium preps for fertilized ovum implantation

events of ovarian cycle

1. folliculogenesis
2. ovulation
3. corpus luteum formation
4. atresia of corpus luteum

phases of ovarian cycle

1. follicular phase - after corpus luteum atresia, 12-14d until ovulation
2. luteal phase - @ ovulation, 12-14d until corpus luteum atresia

endometrial cycle events

1. menses
2. proliferative phase
3. secretory phase (differentiation endometrial epithelium into glandular)

ovarian cycle is completeley dependent on

gonadotropes LH and FSH

what happens to gonadotropic hormones at age 9-12y for women

pituitary secretes more → onset monthly sex cycles

FSH and LH stimulate follicle growth, producing what?

estradiol (by granulosa and int thecal cells)

as estradiol levels increase, what occurs in monthly ovarian cycle

proliferative phase of endometrium + preovulatory follicle develops in an ovary

ovarian follicle growth

preantral follicle→ antral follicle (vesicular or graafian)