Histology of the breast

1. نمحرلاامسب
ميحرلا

2. The breast
By: P.D.Sanaa El-Sherbiny
Mansoura University

3. Structure of mammary
gland
•clavicle
•superficial fascia
•glandular tissue
•lactiferous duct
•lactiferous sinus
•areola
•nipple
•rib
•intercostal muscles
•pleura
•pleural cavity

4. Histological structure
•The breast is formed of compound tubulo-
alveolar glands covered by thin skin.

5. Mammary gland
•These are a pair of
compound tubulo-alveolar
glands to nourish new-
borns
•The histological structure
varies according to sex
,age & physiologic status

6. The covering skin shows:

•Areola: central pink area of skin,
deeply pigmented during
pregnancy
•Nipple:
–An elevation in the center of the areola
–It contains 15-25 opening of lactiferous
duct

7. 1.Stroma
–Interlobar septa: thick
• fibrous C.T. called “suspensory
ligaments of cooper”
–Interlobular septa
–Adipose C.T
–Loose C.T :contain fibroblasts ,lymph-
ocytes , plasma
cell & macrophages

8. 1.Parenchyma
–Contains duct system and secretory
units
In resting gland there is no secretory
units
–Duct system consists of:
4.Intralobular ducts: in the lobules ,lined
with 2 layers of cubical cells
5.Lactiferous ducts: results from union of
intralobular ducts, dilated to form
lactiferous sinuses , their proximal parts lined
with st.col .Epith.
6.Lactiferous sinuses and terminal parts are lined
with st. sq. epith.

9. During puberty
•Their development forms one of the 2ry sex
characters
•Increase in vol. of ducts with cell
proliferation
•accumulation of adipose tissue in the
inter lobar and interlobular C.T.
•All these changes are due to  in ovarian
hormones with minimal
appearance of alveoli at time of
ovulation where estrogen reaches peak there
is  in adipocytes  lipid acc.and   breast
in size

10. Resting non lactating glands

11. During pregnancy
•The glands undergo intense growth
due to proliferation of ducts +
production of secretory
tubules and alveoli
•The C.T. stroma and adipose tissue
decrease
•No visible signs of secretion except in
late pregnancy

12. Secretory alveoli
•Begin to appear at the 6
th
month of pregnancy
•They are lined with columnar epith.
•They are surrounded by myoepithelial cells
•They contain colostrum in late months of
•
Pregnancy ***Their mode
of secretion is
apocrine
•Mode of secretion.

13. Hormones controlling breast
enlargement
1-Ovarian hormones :Estrogen increases during
pregnancy acting on duct system
2-Progestrone by (corpus luteum ) 2-
placental hormons act on secretory alveoli
•Placental Hormones are :
progestrone ,placental mammotrophins
3-Anterior pituitary: growth h &prolactin h.
4-Suprarenal: glucocorticoids.

14. Lactating mammary gland
•Consists of compound tubulo-alveolar
•gland
1.Stroma is thin
2.Parenchyma is formed of duct system and alveoli
3.Alveoli are lined by columnar or cubical epith. Filled with
vacuolated milk secretion
4.Milk secretion is controlled by
5.Prolactin which stimulate alveolar cells secretion
6.Oxytocin: contraction of myo-epithelial Cells ,squeezes
alveoli cause milk ejection

16. In lactation
•Milk acc. In the lumen of secretory part
and ducts
•Cells. Milk containing lipid vacuoles and
also protein vacuoles
•Milk composition :
1.Lipid 4%
2.Protein 1.5%
3.Lactose 7%
•Colostrum : it contains less fat and
more proteins and rich in antibodies
(IgA)

17. Active lactating mammary gland

18. Lactating versus resting glands

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20. revision

21. Histological structure of the
skin
•Formed of
two layers:
•1- Epidermis
•2- Dermis

22. Types:1-THICK SKIN
•EPIDERMIS: IS THICK:0.8mm in palm ,1.4 mm
in sole.
•Contains 4 types of cells:
•1-keratinocytes (85% of cells)
•2-Melanocytes
•3-Langerhans cells
•4-Merkel cells
•ِArranged in five layers.

23. Layers of epidermis are
•Stratum basale
(germinativum)
•Stratum spinosum
•Stratum granulosum
•Stratum lucidum (may not
be present)
•Stratum corneum

24. Thin skin

25. SWEAT GLANDS
•Merocrine glands:
•Allover the body
•Secretory cells 2types
•Clear cells cubical rich in
glycogen granules.
•Dark with narrow basal part
with
•Apical glycoprotein granules
•Myoepithelialt cells
•Ducts lined by 2layers of cubical
cells
•Apocrine glands:
•Axilla,groin,pubic region
•Secretory part similar
•To mero. With
•Wider lumen
•Their ducts are lined
•With 2 layers of cubical cells
but open into hair follicles
•Secretion stim.by sex
•hormones

26. sweat glands
Two types of sweat glands
–Eccrine
•Not associated with hair follicle
•Duct segment
–less coiled, leads to epidermis
–Stratified cuboidal epithelium
•Secretory segment
–in deep dermis or hypodermis
–Secretory cells
–Myoepithelial cells lie between
secretory cells, contraction expels
sweat
–Apocrine
•Found in limited areas
•Empty into hair follicle

27. Structures of skin: hair follicle
•Invagination of epidermis
•Hair contains keratin and melanin
•Dermal papilla
–Connective tissue invagination
into bulb, has capillary network
•Matrix
–Germinative layer adjacent to
dermal papilla
–Also contains melanocytes
•Sebaceous gland
–Secretion empties into hair
follicle
•Arrector pili muscle
–Smooth muscle, inserts on hair
follicle and base of epidermis
bulb
(dermal papilla)

28. The hair is formed of
•Shaft: medulla, cortex and cuticle
•The hair follicle is formed of :
•Inner root sheath formed of:
•Cuticle ,Huxleys layer,Henles layer
•Outer root sheath: identical with
Malpighian
•Layer of epidermis
•Connective tissue sheath.

29. ECCRINE AND APOCRINE GANDS

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