female reproductive systems

FEMALE REPRODUCTIVE ORGANS

OverviewOverview OvaryOvary Oviduct Oviduct UterusUterus Vagina Vagina BreastBreast

ComponentsComponents

Functions Functions

1.1. OvaryOvary

2.2. Oviduct Oviduct

3.3. Uterus Uterus

4.4. VaginaVagina

5.5. External genitaliaExternal genitalia

6.6. Breasts Breasts

ComponentsComponents

Functions Functions


Produce oocyteProduce oocyte (female gamete) (female gamete)

Hold a fertilized oocyteHold a fertilized oocyte during its complete during its complete development through embryonic and fetal stages until development through embryonic and fetal stages until

birthbirth

Produce hormonesProduce hormones that control organs of the that control organs of the reproductive system and have influences on other reproductive system and have influences on other

organs of the bodyorgans of the body


StructureStructure

OogenesisOogenesis

Ovarian Ovarian folliclesfollicles

OvulationOvulation

Corpus Corpus luteum luteum

& &

interstitial interstitial cellscells

1.1. Surface covered by Surface covered by simple squamous or cuboidal cells simple squamous or cuboidal cells – germinal epithelium– germinal epithelium (GE) (GE)

2.2. Under GE – Under GE – layer of dense connective tissue – tunica layer of dense connective tissue – tunica albuginea (TA)albuginea (TA)


StructureStructure

OogenesisOogenesis


OvulationOvulation


& &


3.3. Under TA – Under TA – cortex – follicles containing oocytescortex – follicles containing oocytes

4.4. Follicles embedded in Follicles embedded in stroma composed of stroma composed of characteristic spindle-shaped fibroblastscharacteristic spindle-shaped fibroblasts

5.5. Most internal part – Most internal part – medulla – rich vascular bedmedulla – rich vascular bed within within a loose connective tissue a loose connective tissue


StructureStructure

OogenesisOogenesis


OvulationOvulation


& &



StructureStructure

Oogenesis Oogenesis


OvulationOvulation


& &


11stst month of embryonic month of embryonic

life – life – migration of migration of

primordial germ cellsprimordial germ cells from from

yolk sac to ovaryyolk sac to ovary

Divide and transform Divide and transform

into oogoniainto oogonia

33rdrd month – month – oogonia oogonia

enter prophase of 1enter prophase of 1stst

meiosismeiosis but but stop at the stop at the

diplotene stagediplotene stage as as primary primary

oocytesoocytes – become – become

surrounded by flattened surrounded by flattened

follicular cellsfollicular cells


StructureStructure

OogenesisOogenesis


OvulationOvulation


& &


Consists of an oocyte Consists of an oocyte

surrounded by one or surrounded by one or

more layers of more layers of

follicular cells or follicular cells or

granulosa cellsgranulosa cells

Different stagesDifferent stages of of

maturation of folliclesmaturation of follicles

areare

1.1. PrimordialPrimordial

2.2. Unilaminar primaryUnilaminar primary

3.3. Multilaminar primaryMultilaminar primary

4.4. AntralAntral

5.5. Mature (Graafian)Mature (Graafian)


StructureStructure

OogenesisOogenesis


OvulationOvulation


& &


Primordial folliclePrimordial follicle

1.1. Formed during fetal lifeFormed during fetal life

2.2. Found in superficial Found in superficial

cortexcortex

3.3. A primary oocyte A primary oocyte

(spherical) with large (spherical) with large

nucleus and prominent nucleus and prominent

nucleolusnucleolus

4.4. Enveloped by a single Enveloped by a single

layer of flattened layer of flattened


5.5. Cells are in the first Cells are in the first

prophase of meiosisprophase of meiosis


StructureStructure

OogenesisOogenesis


OvulationOvulation


& &


Primary folliclePrimary follicle

UnilaminarUnilaminarMultilaminarMultilaminar

(preantral)(preantral)

Single layerSingle layer StratifiedStratified

ofof follicularfollicular

cuboidalcuboidal epitheliumepithelium

Zona pellucidaZona pellucida ( a thick ( a thick amorphous layer of amorphous layer of glycoproteinglycoprotein covering the covering the oocyte)oocyte)


StructureStructure

OogenesisOogenesis


OvulationOvulation


& &



StructureStructure

OogenesisOogenesis


OvulationOvulation


& &


Secondary follicleSecondary follicle

1.1. Increase in size Increase in size

and number of and number of

granulosa cellsgranulosa cells

2.2. Liquid Liquid (liquor (liquor

folliculi)folliculi) begins begins

to to accumulate accumulate

between between



StructureStructure

OogenesisOogenesis


OvulationOvulation


& &



3.3. Granulosa cells Granulosa cells

reorganize reorganize

themselves to themselves to form form

a larger cavity – a larger cavity – the the

antrumantrum


StructureStructure

OogenesisOogenesis


OvulationOvulation


& &



4.4. Some cells concentrate at a certain point on the Some cells concentrate at a certain point on the follicular wall – follicular wall – cumulus oophoruscumulus oophorus


StructureStructure

OogenesisOogenesis


OvulationOvulation


& &



5. A group of cells concentrate around the oocyte and 5. A group of cells concentrate around the oocyte and form the form the corona radiatacorona radiata


StructureStructure

OogenesisOogenesis


OvulationOvulation


& &



FibroblastsFibroblasts of the stroma of the stroma differentiate differentiate to form to form theca folliculitheca folliculi (TF) (TF)

Theca Theca ThecaTheca

InternaInterna ExternaExterna

Androste-Androste- FibroblastsFibroblasts

nedionenedione

AromataseAromatase (GC) (GC)

EstrogenEstrogen


StructureStructure

OogenesisOogenesis


OvulationOvulation


& &


Mature follicleMature follicle

1.1. During During each cycle one follicleeach cycle one follicle matures more than matures more than

othersothers

2.2. Protrudes from surface of ovary and can be Protrudes from surface of ovary and can be detected detected

by USGby USG

3.3. Follicular Follicular cavity increases in sizecavity increases in size and and oocyte adheres oocyte adheres

to the wallto the wall of the follicle of the follicle


StructureStructure

OogenesisOogenesis


OvulationOvulation


& &


1.1. Rupture of part of wall of mature follicle and Rupture of part of wall of mature follicle and

liberation of oocyteliberation of oocyte

2.2. Takes place around the 14Takes place around the 14thth day of menstrual cycle day of menstrual cycle

3.3. In human, usually 1 oocyte liberated by ovary during In human, usually 1 oocyte liberated by ovary during

each cycleeach cycle

4.4. Stimulus for ovulation is a surge of luteinizing Stimulus for ovulation is a surge of luteinizing

hormone (LH)hormone (LH) secreted by anterior pituitary secreted by anterior pituitary

5.5. The 1The 1stst meiotic division is completed just before meiotic division is completed just before

ovulationovulation – one of the secondary oocytes retain most – one of the secondary oocytes retain most

of the cytoplasm – the other becomes the 1of the cytoplasm – the other becomes the 1stst polar polar

bodybody

6.6. The oocyte and the 1The oocyte and the 1stst polar body, enclosed by zona polar body, enclosed by zona

pellucida, the corona radiata enter the oviductpellucida, the corona radiata enter the oviduct

(uterine tube)(uterine tube)


StructureStructure

OogenesisOogenesis


OvulationOvulation


& &


LH surgeLH surge

Blood flow through ovary Blood flow through ovary Plasma protein leakagePlasma protein leakage

EdemaEdema Local release of Local release of prostaglandinsprostaglandins, ,

histaminehistamine, , vasopressinvasopressin and and

collagenasecollagenase

Pressure Pressure Collagen degradation of Collagen degradation of of follicular of follicular tunica albuginea fluidtunica albuginea fluid

Ischemia & death of cellsIschemia & death of cells

Rupture of outer follicular wall and ovulationRupture of outer follicular wall and ovulation


StructureStructure

OogenesisOogenesis


OvulationOvulation

Corpus Corpus luteumluteum

& &


After ovulation, After ovulation,

granulosa cells and granulosa cells and

cells of theca interna cells of theca interna

form a temporary form a temporary

endocrine glandendocrine gland

GC cells increase in size GC cells increase in size

granulosa lutein cellsgranulosa lutein cells

Cells of theca interna Cells of theca interna

theca lutein cellstheca lutein cells

Embedded within the Embedded within the

cortexcortex


StructureStructure

OogenesisOogenesis


OvulationOvulation


& &


Release of follicular Release of follicular fluidfluid

collapse of follicular collapse of follicular wallwall

folded wallsfolded walls

Blood flows into cavity Blood flows into cavity and clotsand clots

Connective tissue Connective tissue invades cavityinvades cavity

Blood capillaries and Blood capillaries and lymphatics form a lymphatics form a rich rich vascular networkvascular network


StructureStructure

OogenesisOogenesis


OvulationOvulation


& &


Reorganization Reorganization

results from results from

stimulus by LHstimulus by LH

released before released before

ovulationovulation

Secrete Secrete

progesterone and progesterone and

estrogenestrogen

Programmed to Programmed to

secrete for 12-14 secrete for 12-14

daysdays


StructureStructure

OogenesisOogenesis


OvulationOvulation


& &


If no pregnancy, If no pregnancy, cells cells

degenerate by degenerate by

apoptosisapoptosis, phagocytosed , phagocytosed

by macrophagesby macrophages

Fibroblasts invadeFibroblasts invade

produce a scar of produce a scar of

dense connective dense connective

tissue tissue

corpus albicanscorpus albicans

If pregnancy – If pregnancy – HCG HCG

maintains the CLmaintains the CL – –

persists persists for 4-5 monthsfor 4-5 months - -

degenerates – degenerates – corpus corpus

albicansalbicans


StructureStructure

OogenesisOogenesis


OvulationOvulation


& &


Pituitary Pituitary

hormones hormones

control most control most

ovarian ovarian

functionsfunctions


StructureStructure

OogenesisOogenesis


OvulationOvulation


& &


Follicular atresiaFollicular atresia

Cessation of mitosisCessation of mitosis of GC of GC

Detachment of GC from basal laminaDetachment of GC from basal lamina

Death of oocyteDeath of oocyte

PhagocytosisPhagocytosis of the debris by macrophages of the debris by macrophages

Interstitial cellsInterstitial cells

Persistent theca interna cellsPersistent theca interna cells following atresia following atresia

Present from childhood through menopausePresent from childhood through menopause

Active steroid secretingActive steroid secreting cells, stimulated by LH cells, stimulated by LH


StructureStructure

OogenesisOogenesis


OvulationOvulation


& &


Follicular atresiaFollicular atresia

OverviewOverview OvaryOvary OviductOviduct UterusUterus Vagina Vagina BreastBreast

Parts Parts

StructureStructure

Function Function

4 parts4 parts

• InfundibulumInfundibulum

• AmpullaAmpulla

• IsthmusIsthmus

• Pars uterina tubaePars uterina tubae

(intramural part)(intramural part)

2 ostia2 ostia

• Uterine ostiumUterine ostium

• Pelvic or Pelvic or

abdominal ostiumabdominal ostium

(Fimbriae)(Fimbriae)


PartsParts

StructureStructure

Function Function

Layers Layers

1.1. MucosaMucosa

a.a. Longitudinal foldsLongitudinal folds

most numerous in most numerous in

ampullaampulla

b.b. Simple columnar Simple columnar

epitheliumepithelium

c.c. 3 types of cells3 types of cells

i.i. CiliatedCiliated

ii.ii. SecretorySecretory

iii.iii. IntercalaryIntercalary

d.d. Lamina propriaLamina propria

composed of loose composed of loose

connective tissueconnective tissue


PartsParts

StructureStructure

Function Function


PartsParts

StructureStructure

Function Function

Layers

2. Thick muscularis

- Outer longitudinal

and inner circular

- Intramural part,

innermost

longitudinal layer

- Circular muscle

abundant at

isthmus –

anatomical

sphincter

3. Serosa (visceral

peritoneum)


PartsParts

StructureStructure

Function Function

At ovulation, oviduct exhibits At ovulation, oviduct exhibits active movementactive movement..

The funnel-shaped extremity (fringed with The funnel-shaped extremity (fringed with

numerous numerous fimbriaefimbriae) comes very close to surface of ) comes very close to surface of

ovary.ovary.

This This favors the transportfavors the transport of oocyte into the tube. of oocyte into the tube.

Promoted by Promoted by muscle contraction and activity of muscle contraction and activity of

ciliated cellsciliated cells, oocyte traverses the tube., oocyte traverses the tube.

Secretion of the epithelium has Secretion of the epithelium has nutrient and nutrient and

protective functions for the oocyteprotective functions for the oocyte..

The secretion also The secretion also promotes capacitationpromotes capacitation of the of the

spermatozoa.spermatozoa.

FertilizationFertilization usually occurs at ampulla. usually occurs at ampulla.


StructureStructure

MyometriumMyometrium

EndometriumEndometrium

CycleCycle

Proliferative Proliferative phasephase

Secretory Secretory phasephase

Menstrual Menstrual phase phase

Cervix Cervix

PartsParts

1.1. FundusFundus

2.2. BodyBody

3.3. CervixCervix

Layers of the wallLayers of the wall

1.1. PerimetriumPerimetrium

a.a. Serosa (mesothelium)Serosa (mesothelium)

b.b. Adventitia (connective tissue)Adventitia (connective tissue)

2.2. MyometriumMyometrium

3.3. Endometrium Endometrium

StructureStructure



CycleCycle




Cervix Cervix


Bundles of smooth musclesBundles of smooth muscles

4 layers4 layers

11stst and 4 and 4thth layers – longitudinal layers – longitudinal

Middle layersMiddle layers – circular – – circular – stratum vascularestratum vasculare

Endometrial vessels pass through inner layer – stops Endometrial vessels pass through inner layer – stops

uterine bleeding on contraction – uterine bleeding on contraction – living ligature of living ligature of

uterusuterus

During puberty, During puberty, growth of the myometrium is growth of the myometrium is

stimulated by estrogenstimulated by estrogen

During pregnancy, During pregnancy, hypertrophyhypertrophy ( (increase in cell size – increase in cell size –

placental estrogenplacental estrogen) and ) and hyperplasiahyperplasia ( (increase in cell increase in cell

number – mitosis of undifferentiated mesenchymal number – mitosis of undifferentiated mesenchymal

cellscells) of myometrium ) of myometrium

StructureStructure



CycleCycle




Cervix Cervix


EpitheliumEpithelium

Simple columnarSimple columnar cells cells

Ciliated Ciliated mostly before reproductive age groupmostly before reproductive age group

Lamina propriaLamina propria

Simple tubular glandsSimple tubular glands lined with simple columnar lined with simple columnar


Connective tissueConnective tissue

FibroblastsFibroblasts

Collagen type III fibresCollagen type III fibres

Abundant ground substance Abundant ground substance

StructureStructure



CycleCycle




Cervix Cervix


Zona basalisZona basalis

- Deepest one adjacent to myometriumDeepest one adjacent to myometrium

- Contains lamina propriaContains lamina propria

- Beginning of uterine glandsBeginning of uterine glands

- Supplied by Supplied by straight arteriesstraight arteries (branch from (branch from

arcuate arteries)arcuate arteries)

Zona functionalisZona functionalis

- Remaining of the lamina propria and glandsRemaining of the lamina propria and glands

- Surface epitheliumSurface epithelium

- Supplied by Supplied by spiral arteriesspiral arteries (branch from (branch from

arcuate arteries)arcuate arteries)

- Undergoes profound changes and shed Undergoes profound changes and shed

during menstrual cycles during menstrual cycles

StructureStructure



CycleCycle




Cervix Cervix


Menstrual cycleMenstrual cycle – – cyclic structural modifications of cyclic structural modifications of

the endometriumthe endometrium influenced by ovarian hormones influenced by ovarian hormones

under the stimulus of anterior pituitary gland after under the stimulus of anterior pituitary gland after

pubertypuberty

DurationDuration – 28 days (average) – 28 days (average)

Menstruation Menstruation – monthly discharge per vagina – monthly discharge per vagina

consisting of consisting of degenerated endothelium mixed with degenerated endothelium mixed with

bloodblood from ruptures vessels from ruptures vessels

DurationDuration – 3-4 days (average) – 3-4 days (average)

MenarcheMenarche – – initiation of menstruationinitiation of menstruation (age 12-15 (age 12-15

years)years)

MenopauseMenopause – – cessation of menstruationcessation of menstruation (age 45-50 (age 45-50

years) years)

StructureStructure



CycleCycle




Cervix Cervix


Menstrual cycleMenstrual cycle – begins on the day when menstrual – begins on the day when menstrual

bleeding appears (Day 1)bleeding appears (Day 1)

Phases of the cyclePhases of the cycle

Proliferative phaseProliferative phase ( variable duration, ( variable duration,

approximately 10 days)approximately 10 days)

Secretory phaseSecretory phase (begins at ovulation and lasts (begins at ovulation and lasts

about 14 days)about 14 days)

Menstrual phaseMenstrual phase (duration 3-4 days on average) (duration 3-4 days on average)

StructureStructure



CycleCycle




Cervix Cervix


FSH stimulates rapid growth of ovarian folliclesFSH stimulates rapid growth of ovarian follicles

Dominant follicles reach preovulatory stageDominant follicles reach preovulatory stage

Estrogen is the dominant ovarian hormoneEstrogen is the dominant ovarian hormone

Endometrial changesEndometrial changes::

- Cell proliferationCell proliferation (0.5mm-3mm) (0.5mm-3mm)

- Covered by simple columnar epitheliumCovered by simple columnar epithelium

- Glands are straight tubules with narrow lumensGlands are straight tubules with narrow lumens

- Cells accumulate more RERCells accumulate more RER

- Golgi complex increase in size Golgi complex increase in size

StructureStructure



CycleCycle




Cervix Cervix


Endometrial Endometrial

changeschanges

Cell proliferationCell proliferation

(0.5mm-3mm)(0.5mm-3mm)

Covered by simple Covered by simple

columnar epitheliumcolumnar epithelium

Glands are straight Glands are straight

tubules with narrow tubules with narrow

lumenslumens

Cells accumulate Cells accumulate

more RERmore RER

Golgi complex Golgi complex

increase in sizeincrease in size

StructureStructure



CycleCycle




Cervix Cervix


1.1. Peak of LHPeak of LH

2.2. Ovulation Ovulation / development of CL / degeneration / development of CL / degeneration

of CL (in absence of pregnancy)of CL (in absence of pregnancy)

3.3. ProgesteroneProgesterone is the dominant hormone is the dominant hormone

(production ceases in absence of pregnancy)(production ceases in absence of pregnancy)

4.4. Endometrial changesEndometrial changes::

Maximum thicknessMaximum thickness (5 mm) (5 mm)

Glands become highly coiledGlands become highly coiled

Glandular epithelial cells begin to Glandular epithelial cells begin to

accumulate glycogenaccumulate glycogen

Glycoprotein secretory products dilate Glycoprotein secretory products dilate

the lumen of the glandsthe lumen of the glands

5.5. Implantation of embryoImplantation of embryo at this stage at this stage

StructureStructure



CycleCycle




Cervix Cervix


Endometrial changes:Endometrial changes:

Maximum thicknessMaximum thickness

(5 mm) (5 mm)

Glands become highly Glands become highly

coiledcoiled

Glandular epithelial Glandular epithelial

cells begin to cells begin to

accumulate glycogenaccumulate glycogen

Glycoprotein secretory Glycoprotein secretory

productsproducts dilate the dilate the

lumen of the glandslumen of the glands

StructureStructure



CycleCycle



Menstrual Menstrual phasephase

Cervix Cervix


In absence of pregnancy, In absence of pregnancy, CL ceases to function 10-12 CL ceases to function 10-12

days after ovulationdays after ovulation

Levels of Levels of progesterone and estrogen in blood fallsprogesterone and estrogen in blood falls

rapidlyrapidly

Several cycles of Several cycles of contraction of spiral arteriescontraction of spiral arteries, closing , closing

off blood flowoff blood flow

Ischemic necrosisIschemic necrosis of vessel walls and functionalis layer of vessel walls and functionalis layer

of endometriumof endometrium

Rupture of blood vesselsRupture of blood vessels and bleeding and bleeding

Endometrium reduced to a thin layerEndometrium reduced to a thin layer

StructureStructure



CycleCycle




CervixCervix


Differs from the rest of the uterus inDiffers from the rest of the uterus in

a.a. Mucus secreting Mucus secreting simple columnar epitheliumsimple columnar epithelium

b.b. Extensively Extensively branched glandsbranched glands

c.c. Mucosa Mucosa does not undergo remarkable changes does not undergo remarkable changes

during the menstrual cycleduring the menstrual cycle and does not and does not

desquamate during menstruationdesquamate during menstruation

d.d. External aspect that bulges into lumen of vagina External aspect that bulges into lumen of vagina

is covered with stratified squamous epitheliumis covered with stratified squamous epithelium

e.e. Mainly (85%) Mainly (85%) dense connective tissuedense connective tissue

f.f. Fewer Fewer smooth musclesmooth muscle cells cells

OverviewOverview OvaryOvary Oviduct Oviduct UterusUterus VaginaVagina BreastBreast

StructureStructure

Mucosa Mucosa

a.a. Devoid of glandsDevoid of glands

b.b. Stratified squamousStratified squamous


c.c. Cells may contain a Cells may contain a

small amount of small amount of

keratohyalinkeratohyalin

d.d. Intense Intense keratinization keratinization

does not occurdoes not occur


StructureStructure

Mucosa Mucosa

e.e. Synthesizes and Synthesizes and

accumulates a accumulates a large large

amount of glycogenamount of glycogen, ,

under estrogen under estrogen

stimulationstimulation

f.f. Bacteria metabolize Bacteria metabolize

glycogen to form lactic glycogen to form lactic

acid – acid – low pHlow pH


StructureStructure

Lamina propriaLamina propria

• Loose connective Loose connective

tissuetissue

• Rich in elastic Rich in elastic

fibresfibres

• Lymphocytes and Lymphocytes and

neutrophilsneutrophils in in

large quantitieslarge quantities

• Devoid of sensory Devoid of sensory

nerve endingsnerve endings, few , few

pain receptorspain receptors


StructureStructure

Muscle layerMuscle layer

- Longitudinal bundlesLongitudinal bundles

- Some circular Some circular

bundles (inner)bundles (inner)

AdventitiaAdventitia

- Dense connective Dense connective

tissuetissue

- Rich in elastic fibresRich in elastic fibres

- Extensive venous Extensive venous

plexus, nerve plexus, nerve

bundlesbundles


StructureStructure

DevelopmentDevelopment

PregnancyPregnancy

&&

LactationLactation

Post-Post-lactational lactational regressionregression

15-25 lobes of 15-25 lobes of

compound alveolarcompound alveolar

type of glandtype of gland

Each lobe separated Each lobe separated

from others by from others by dense dense

connective tissueconnective tissue and and

much much adipose tissueadipose tissue

Each lobe drained by Each lobe drained by

one one lactiferous ductlactiferous duct

Each lactiferous duct Each lactiferous duct

emerge independently emerge independently

in the nipplein the nipple


StructureStructure


PregnancyPregnancy

&&

LactationLactation


Before pubertyBefore puberty: :

lactiferous sinus and lactiferous sinus and

lactiferous ductslactiferous ducts

In girls In girls during pubertyduring puberty

– breasts enlarge – – breasts enlarge –

accumulation of accumulation of

adipose tissue and adipose tissue and

connective tissueconnective tissue, ,

increased increased growth and growth and

branching of branching of

lactiferous ductslactiferous ducts

(estrogenic)(estrogenic)


StructureStructure


PregnancyPregnancy

&&

LactationLactation


Adult womenAdult women – – lobes lobes

develop at the tips of develop at the tips of

the smallest ductsthe smallest ducts

embedded in loose embedded in loose

connective tissueconnective tissue

A lobe consists of A lobe consists of

several ducts that several ducts that

empty into one empty into one

terminal ductterminal duct


StructureStructure


PregnancyPregnancy

&&

LactationLactation


Near the opening of nipple, Near the opening of nipple,

the the lactiferous ducts dilate lactiferous ducts dilate

to form lactiferous sinusesto form lactiferous sinuses

lined by stratified lined by stratified

squamous epithelium at squamous epithelium at

their external openings their external openings

that changes to stratified that changes to stratified

columnar or cuboidal columnar or cuboidal

proximallyproximally..

Lining of Lining of lactiferous ducts lactiferous ducts

and terminal ducts is and terminal ducts is

formed of simple cuboidal formed of simple cuboidal

epitheliumepithelium with closely with closely

packed packed myoepithelial cellsmyoepithelial cells..


StructureStructure


PregnancyPregnancy

&&

LactationLactation


Connective tissue surrounding alveoli Connective tissue surrounding alveoli contains many contains many lymphocytes and plasma cellslymphocytes and plasma cells (increase at end of pregnancy – (increase at end of pregnancy – secrete IgAsecrete IgA))

NippleNipple – externally covered by – externally covered by keratinized keratinized stratified squamous epitheliumstratified squamous epithelium

Abundant sensory nerve endingsAbundant sensory nerve endings

AreolaAreola – skin around – skin around

the nipple – the nipple –

darkens during darkens during

pregnancypregnancy


StructureStructure


PregnancyPregnancy

&&

LactationLactation


PregnancyPregnancy

1.1. Undergo Undergo intense growth intense growth

under influence of estrogen, under influence of estrogen,

progesterone, prolactin and progesterone, prolactin and

HPLHPL

2.2. Proliferation of alveoliProliferation of alveoli at the at the

ends of terminal ductsends of terminal ducts

3.3. Fat droplets and secretory Fat droplets and secretory

vacuoles (containing milk vacuoles (containing milk

protein)protein) seen in cytoplasm of seen in cytoplasm of

alveolar cellsalveolar cells

4.4. Stellate myoepithelial cells Stellate myoepithelial cells

foundfound


StructureStructure


PregnancyPregnancy

&&

LactationLactation


LactationLactation

1.1. Milk is produced by Milk is produced by

epithelial cells of alveoliepithelial cells of alveoli

2.2. Accumulate in their Accumulate in their

lumen and ductslumen and ducts

3.3. Secretory cells become Secretory cells become

low cuboidallow cuboidal

4.4. Cytoplasm contains Cytoplasm contains

spherical triglyceride spherical triglyceride

dropletsdroplets

5.5. Large number of Large number of

membrane-bound membrane-bound

vacuoles containing milk vacuoles containing milk

proteins (casein, proteins (casein, α- α-

lactalbumin, IgA)lactalbumin, IgA)


StructureStructure


PregnancyPregnancy

&&

LactationLactation


WeaningWeaning (cessation of breast-feeding) (cessation of breast-feeding)

Alveoli undergo degeneration through apoptosisAlveoli undergo degeneration through apoptosis

Sloughing of whole cellsSloughing of whole cells

Autophagy of cellular componentsAutophagy of cellular components

Dead cells and debris removed by macrophagesDead cells and debris removed by macrophages

BEST OF LUCKBEST OF LUCK

female reproductive systems

Health & Medicine