Various Parts Of Reproductive Organs& Their Functions

Functions: Urination and Copulation

Penis

www.freelivedoctor.com

Functions: Transport urine & semen

Urethra

Bladder


Function: Maintain temperature of testes approx. 30 C below normal

body temp.

Scrotum



Function: Produce sperm and testosterone

Testis


Function: Produce Sperm

Testis

Seminiferous Tubules


Testis Cross Section

Interstitial Cells

Produce Testosterone


Function: Sperm storage and maturation

Epididymis


Function: Transport sperm to urethra

Vas Deferens


Function: Produce 60% of alkaline semen including fructose

to provide energy for sperm.

Seminal Vesicles

Ejaculatory Duct


Function: Produces up to 1/3 of the semen & includes nutrients &

enzymes to activate sperm.

Prostate


Function: Secretes mucous & alkaline buffers to neutralize acidic

conditions of urethra.

Cowper’s Gland


Function: Receives penis & semen and serves as birth canal & passage for menstrual flow.

Vaginawww.freelivedoctor.com

Function: Provides passageway for sperm, receives blastocyst, retains & nourishes fetus & expells fetus at term.

Uterus


Function: Cervical mucosa secretes mucous blocking cervical

canal entrance to uterus.

Cervix


Function: Uterine lining in which implantation occurs.

Endometrium


Function: Muscular contractions.

Myometrium


Function: Passageway for oocyte and site of fertilization.

Uterine Tubes


Function: Produce oocytes & the hormones estrogen and

progesterone. Ovaries


Function: Sweep ovarian surface to draw oocyte into ovarian tube.

Fimbriae


Mechanisms of Hormonal Action

• Direct Gene Activation– lipid soluble, steroid hormones– diffuse through cell membranes– bind to intracellular receptor– activated hormone receptor/complex binds with

gene, turning it on– gene transcribes mRNA– ribosomes use mRNA to synthesize enzymes to

stimulate cell activity or synthesize structural proteins to be excreted or used within the cell


Direct Gene ActivationSteroid Hormone

Receptor/hormone Complex


Direct Gene Activation

Receptor/hormone Complex

mRNA

Protein

Aldosterone Cortisol Testosterone Estrogen Progesterone Thyroxine


Mechanisms of Hormonal Action

• Second Messenger Systems– amino acid & protein based– cannot pass through cell membranes– bind to cell membrane receptors– activate G proteins in membrane to produce

cyclic AMP in cytoplasm– cyclic AMP acts as second messenger inside

cell activating protein kinases– protein kinases trigger cellular responses


Second Messenger Systems


Hormone Sources & Functions• Gonadotropin-releasing Hormone

(GnRH) :– Source: Hypothalamus

– Targets & Functions:• Females & Males - Anterior Pituitary

– Stimulates the production of Follicle Stimulating Hormone (FSH) & Leutinizing Hormone (LH)

– Regulates the release of FSH & LH by the anterior pituitary gland


Hormone Sources & Functions

• Follicle Stimulating Hormone:– Source: Anterior Pituitary

– Targets & Functions:• Females - Ovaries

– Stimulates follicle growth & maturation

– Stimulates estrogen production

• Males - Seminiferous Tubules– Promotes sperm production

(Spermatogenesis) by establishing testosterone receptors on tubules


Leutenizing Hormone:• Source: Anterior Pituitary

– Targets & Functions:• Females - Ovaries

– Stimulates primary oocyte to complete first meiotic division to become secondary oocyte

– Triggers ovulation of secondary oocyte

– Transforms ruptured follicle into corpus luteum

– Stimulates production of progesterone by corpus luteum

• Males - Seminiferous Tubules– Stimulates sperm production

(Spermatogenesis) by causing interstitial cells in testes to secrete testosterone

Corpus luteum


Estrogen:• Sources: Maturing Follicles & Corpus Luteum

– Targets & Functions:• Body in general

– Stimulates the development of female secondary sexual characteristics

• Breasts– Stimulates development of milk ducts and

sinuses (ampullae)

• Uterus– Stimulates proliferative phase of uterine

cycle

• Ovaries– Promotes oogenesis

• Anterior Pituitary– Stimulates burst-like release of LHwww.freelivedoctor.com

Progesterone:• Source: Corpus Luteum & Placenta

– Targets & Functions:• Females - Uterus

– Maintains thickened endometrium

– Stimulates nutrient release

– Quiets myometrium

Corpus luteum• Females - Breasts

– Stimulates development of alveoli for milk production

• Females - Anterior Pituitary– Inhibits production & release of FSH &

LHwww.freelivedoctor.com

Testosterone:• Sources: Interstitial Cells in Testes

– Targets & Functions:• Body in general

– Stimulates the development of male secondary sexual characteristics including:

» development of male genitalia

» male skeleton and muscle development

» male patterns for hair growth

» increased RBC production & higher metabolic rate

• Seminiferous tubules– Necessary for the completion of

spermatogenesis

• Anterior Pituitary– Moderate inhibition of pituitary and

hypothalamus www.freelivedoctor.com

Oxytocin:• Sources: Manufactured by hypothalamus. Stored &

released by Posterior Pituitary

– Targets & Functions:• Uterus

– Stimulates contraction of uterine myometrium causing lowering of fetus & labor

• Breasts– Stimulates contraction of milk ducts and

sinuses, releasing milk

Positive Feedback Mechanisms:

1. Childbirth - Stretching of uterus and cervix

2. Suckling - Milk letdown reflex


Prolactin:

• Source: Anterior Pituitary

– Targets & Functions:• Breasts

– Stimulates alveoli of breasts to produce milk

• Regulation– Release of prolactin by anterior pituitary

is regulated by hypothalamus production of Prolactin Releasing Hormone (PRH) & Prolactin Inhibiting Hormone (PIH)


Human Chorionic Gonadotropin:

• Source: Trophoblasts of blastocyst & Chorion

– Target & Functions:• Corpus Luteum

– Maintains corpus luteum & causes it to continue producing progesterone in the absence of LH through first four months of pregnancy till placenta produces sufficient estrogen & progesterone to maintain the pregnancy


Hormonal Regulation of Ovarian & Menstrual Cycles

1. Hypothalamus releases GnRH.

2. GnRH stimulates anterior pituitary to release FSH.

FSH

3. FSH stimulates a follicle to grow & produce estrogen.

Estrogen


Hormonal Regulation of Menstrual & Ovarian Cycles

FSHEstrogen

4. Rising levels of estrogen cause anterior pituitary to increase production & storage of LH.

LH

Estrogen



5. High estrogen causes LH to be released in a burst & the endometrium to thicken (proliferative phase).

6. High LH stimulates first meiotic division of primary oocyte.

FSHEstrogen

Estrogen

LH



7. High LH triggers ovulation.

FSHEstrogen

Estrogen

LH

8. High LH causes ruptured follicle to become a corpus luteum.



FSH

9. Corpus luteum produces progesterone.

Estrogen

Estrogen

LH

Progesterone

XX

10. Progesterone inhibits the production of FHS & LH by the anterior pituitary & stimulates secretory phase .



11. Diminishing levels of FSH & LH cause corpus luteum to deteriorate & produce less progesterone.

12. Dimishing levels of estrogen & progesterone cause inhibition of FSH & LH to end & thickened endometrium to slough (menses).

Estrogen

FSH

LH

ProgesteroneXX

X



FSH

13. Increasing levels of FSH cause a new cycle to begin.


Hormonal Regulation in Pregnancy

Normally dimishing levels of estrogen & progesterone from deterioration of the corpus luteum would cause thickened endometrium to slough (menses) which would terminating a pregnancy.

EstrogenProgesteroneX

X

X


Hormonal Regulation if Pregnancy Occurs

Blastocyst produces human Chorionic Gonadotropin (hCG) hormone which maintains corpus luteum in the absence of FSH & LH for the first trimester.

hCG

Eventually the placenta will produce sufficient estrogen & progesterone to sustain the pregnancy.


Mitosis

Interphase Prophase Metaphase


Mitosis

Anaphase Telophase Interphase

• Most cells of the body - growth, replacement, healing.

• No change in the number of chromosomes within each cell.

46

46


Meiosis

Interphase Prophase Metaphase

46


Meiosis

Anaphase Telophase Interphase

23

23

Reduction Division


Meiosis

23

23

23

23

23

23

• Only in gonads.

• Synapsis & shuffling of genetic information providing variation.

• Results in reduction of number of chromosomes by half (haploid).www.freelivedoctor.com

Mitosis/Meiosis Comparison46

46 46

46

23 23

23 23 23 23www.freelivedoctor.com

Gametogenesis:

• Spermatogenesis:– produces male gametes

(sperm)

– occurs in the seminiferous tubules of the testes

– involves meiosis

– occurs throughout life after puberty

– may produce 400,000,000 per day

• Oogenesis:– produces female

gametes (oocytes)

– occurs in the ovaries

– involves meiosis

– occurs after puberty until menopause

– humans normally produce one oocyte during each ovarian cycle

Process through which gametes are formed


Spermatogenesis

Spermatogonium (46)

Mitosis Daughter Cells (46)


Spermatogenesis

Spermatogonium (46)

MitosisDaughter Cells (46)

GrowthPrimary Spermatocyte (46)

Meiosis ISecondary Spermatocytes (23)


Spermatogenesis

Spermatogonium (46)




Spermatogonium

Meiosis IIEarly Spermatids (23)


Spermatogenesis

Spermatogonium (46)




Spermatogonium


SpermiogenesisLate Spermatids (23)


Spermatogenesis

Spermatogonium (46)




Spermatogonium


SpermiogenesisLate Spermatids (23)

Spermatozoa (23)

(Lumen)


Oogenesis

Oogonium (46)

Primary Oocyte (46)

(Mitosis)

Primary Oocyte (46)


Oogenesis

Oogonium (46)(Mitosis)

Secondary Oocyte (23)(Meiosis 1)

OvulationFertilizationPolar Body (23)

(Meiosis 2)

Primary Oocyte (46)


Definitions & Functions Relative to Reproduction

• Hypothalamus: – Produces GnRH which stimulates the

production of FSH & LH by the anterior pituitary gland initiating the ovarian cycle.

– Produces Oxytocin which is stored in the posterior pituitary gland.

• Posterior Pituitary:– Stores & releases hormone Oxytocin to

stimulate uterine contractions (Braxton Hicks) & the milk let-down reflex.



• Anterior Pituitary: – Produces hormone FSH which stimulates the

growth & maturation of a follicle, the production of estrogen in females and stimulates sperm production in males.

– Produces & stores hormone LH which causes first meiotic division of primary oocyte, stimulates ovulation, causes the development of and the production of progesterone by the corpus luteum

– Produces & stores hormone Prolactin which promotes lactation .



• Spermatogonium: – Primordial germ cell in seminiferous tubules

of testes from which sperm are produced.• Oogonium:

– Primordial germ cell in ovaries of fetus from which primary oocytes in follicles are produced.

• Follicle:– Sack-like structure in ovary containing an

oocyte surrounded by one or more layers of cells which produces the hormone estrogen.www.freelivedoctor.com


• Mitosis: – Process through which the nucleus of body cells divide to produce

identical daughter cells for maintenance, healing & growth.

• Meiosis:– Process through which gametes are formed

with half of the normal number of chromosomes for sexual reproduction.

• Ovum:– Functional female gamete which has

completed the first and second meiotic divisions to become haploid.



• Spermatozoan: – Haploid male gamete which has completed meiosis 1 & 2,

spermiogenesis & is capable of fertilizing a female secondary oocyte.

• Fertilization:– Process through which haploid male &

female gametes fuse to form a diploid zygote.

• Polar Bodies:– Nonfunctional haploid female cells with little

to no cytoplasm produced in meiosis.www.freelivedoctor.com


• Hormone: – Chemical messenger which is used to regulate

reproductive cycles and activities.

• Semen:– Mixture of sperm and fluids from male

reproductive glands which supplies energy, neutralizes acidic conditions in the reproductive tracts and activates sperm.

• Hyaluronidase:– Enzyme in acrosome of sperm that enables

sperm nucleus to enter the female gamete.www.freelivedoctor.com

Bone Formation

Preembryonic Development


Definitions & Functions

• Zygote:– A fertilized ovum which is diploid.

• Cleavage Divisions:– Mitotic divisions of the zygote to increase the

number and surface area of cells in a preembryo (2 cell, 4 cell, 8 cell, etc.)

• Morula:– A berry shaped cluster of preembryonic cells

produced from cleavage divisions .www.freelivedoctor.com

Definitions & Functions• Blastocyst:

– A fluid filled sphere of cells formed from the morula which implants in the endometrium.

• Trophoblast:– One of the cells making up the outer wall

of the blastocyst which will form the chorion.

• Inner Cell Mass:– A group of cells inside of the blastocyst

from which the three primary germ layers will develop.


Definitions & Functions• Chorionic Villi:

– Finger-like growths of the trophoblasts into the endometrium to form the placenta.


Definitions & Functions• Chorion:

– Outermost embryonic membrane which forms the placenta & produces human chorionic gonadotropin.


Definitions & Functions• Amnion:

– Membrane which surrounds embryo to form the amniotic cavity & produces amniotic fluid.


Definitions & Functions• Amnionic Fluid:

– Protects fetus from trauma & permits free movement without adhesion.


Definitions & Functions• Yolk Sack:

– Provides initial nutrients, supplies earliest RBCs and seeds the gonads with primordial germ cells.


Gastrulation

• Preembryo becomes embryo as three primary germ layers form.

Prembryo Embryo


Ectoderm Derivatives

• Brain, spinal cord, nerves

• Cornea & lens of eyes

• Outer skin & accessory structures– hair– nails

• Enamel of teeth

• Linings of nasal & oral cavities & anal canal


Endoderm Derivatives

• Epithelial lining of digestive tract

• Liver and pancreas

• Epithelial lining of respiratory tract & tonsils

• Epithelial lining of reproductive ducts & glands

• Thyroid, parathyroid & thymus glands

• Epithelial lining of bladder & urethrawww.freelivedoctor.com

Mesoderm Derivatives• Muscle: skeletal, cardiac & smooth

• Connective tissues: cartilage, bone, adipose

• Bone marrow, blood & lymphatic tissues

• Endothelial linings of blood & lymphatic vessels

• Visceral peritoneum of organs in ventral cavity

• Fibrous & vascular tunics of eyes

• Organs of urogenital system: kidneys, gonads & reproductive ductswww.freelivedoctor.com

Placental Function

O2Glucose VitaminsMinerals


Placental Function

Alcohol


Fetal Alcohol Syndrome

• Prenatal & postnatal growth retardation

• CNS involvement:– neurological abnormalities– developmental delays

• Alcohol related birth defects

• Mental retardation

• Speech & hearing impairment

• Learning, attention & memory deficitswww.freelivedoctor.com

Placental Function

CO2WastesUrea


Placental Function - Smoking

CO2

O2

CO

Nicotine


Smoking During Pregnancy• Increases risk of ectopic pregnancy

• Doubles risk of placenta previa & abruptio placenta

• Slows fetal development

• Doubles risk of low birthweight babies

• Increases risk of preterm deliveries

• Increases risk of cleft palate & lip

• Doubles risk of sudden infant death syndrome (SIDS)


Drug Use

Antibiotics Nicotine

Crackwww.freelivedoctor.com

Irradiation• High-energy

– X-rays– Gamma rays

• Penetrate deeply into tissues causing ionization of molecules.

• May directly or indirectly affect the genetic material resulting in point mutations (affecting a single base).

• May break chromosomes causing deletions or translocation of genetic information.


Placenta abruptio

• Any amount of placental separation prior to delivery.

• Causes & Risk Factors:– Abdominal trauma– Hypertension during pregnancy– Diabetes mellitus – Cigarette smoking– Alcohol use during pregnancy


Placenta previa

• Placental growth across or adjacent to opening of cervical canal in the uterus.

• Risk Factors:– The number of prior pregnancies– Multiple pregnancies (twins/triplets)– Prior C-section where scar is close to cervix

• Symptoms:– Spotting during 1st & 2nd trimesters– Sudden, painless & profuse vaginal bleeding


Ectopic Pregnancy• Implantation of blastocyst anywhere other than

within the uterus.• Causes & Risk Factors:

– Physical blockage of uterine tube.– Scarring of uterine tube by prior tubal

infection (pelvic inflamatory disease).– Pregnancy following tubal ligation reversal

or despite oral contraceptive use.• Symptoms:

– Lower abdominal or pelvic pain.– Mild cramping on one side of pelvis.– Abnormal vaginal bleeding (spotting).www.freelivedoctor.com

Gonorrhea• Bacterial Pathogen: Neisseria gonorrhoeae

• Transmission: Sexual contact with infected person or contact with bacteria in the birth canal of an infected mother.www.freelivedoctor.com

Gonorrhea• Pathology: Inflammation of skin & mucous membranes of

urinary & reproductive organs.

• Females: Painful urination, abdominal pain, pelvic inflammatory disease, & sterility.

• Males: Painful urination with purulent discharge & possible sterility.www.freelivedoctor.com

Gonorrhea• Babies: Contract bacteria in birth canal of infected mother.

• Congenital Effects: Conjunctivitis & blindness.

• Treatment: Ceftriaxone & Tetracycline– Silver Nitrate in eyes of infantswww.freelivedoctor.com

Syphilis• Bacterial Pathogen: Treponema pallidum

• Transmission: Sexual & transplacental contact. www.freelivedoctor.com

Primary Syphilis• Incubation period - 21 days (average)

• Painless chancre (lesion) where bacteria enter mucous membranes or skin.

• Spontaneously heals after 3 to 8 weeks.www.freelivedoctor.com

Secondary Syphilis• Fever, influenza-like symptoms, swollen lymph nodes & skin rash.

• Without treatment, these symptoms may last several weeks & disappear or death may occur.www.freelivedoctor.com

Tertiary Syphilis• Involvement of the skin, cardiovascular and nervous systems.

• Gummas develop in infected tissues.

• Treatment of Choice: Penicillin.www.freelivedoctor.com

Congenital Syphilis• Transplacental transmission.

• Stillborn, infective skin lesions, deafness, impaired vision, Hutchison’s teeth, & skeletal deformities . www.freelivedoctor.com

Chlamydia• Most prevalent STD in US.• Bacterial Pathogen: Chlamydia trachomatis

• Pathology: Nongonococcal urethritis resulting in serious reproductive tract complications (up to 80% asymptomatic)– pelvic inflamatory disease– infertility– ectopic pregnancy

• Babies infected in birth canal– chlamydial opthalmia & pneumonia

• Treatment: Tetracyclinewww.freelivedoctor.com

Genital Herpes• Pathogen: Herpes Simplex Virus - Type 2

• Transmission by secretions from lesions.

• Crops of vesicular lesions occur on & around genitalia.

• Lesions are recurrent (as often as 4 weeks) & lead to painful ulcerations.

• Associated with higher than normal cervical cancer with a 50% mortality rate in infected women.

• Transplacental transmission to fetus.

• Treatment: Acyclovire to reduce symptoms.www.freelivedoctor.com

Documents

Various Parts Of Reproductive Organs& Their Functions