1. Lecture 6 Adipose tissue
بسم الله الرحمن الرحيم
Histology
Lecture 6 Adipose tissue

2. Adipose Tissue A kind of connective tissue with many adipocytes
Forms one of the largest “organs” of body
15-20% of body weight in men
20-25% of body weight in women
Over 2 times as much stored energy as glycogen
Subcutaneous adipose shapes body
Shock absorber in soles of feet and palms
Fills space between organs

3. Types of Adipose Tissue
Yellow, White or unilocular
cells with one large fat droplet in cytoplasm
Brown or multilocular
cells with numerous smaller lipid droplets in cytoplasm and many mitochondria

4. Unilocular Adipose Tissue
White to dark yellow depending on diet
Most common form in adults
Cells micron diameter
Nuclei eccentric and flattened
Lipid droplet has no membrane
Heavily vascularized
Cell number constant after early postnatal period

5. Unilocular Adipose Tissue

7. Histogenesis

8. Multilocular Adipose Tissue
Fat cells store fat in multiple droplets
Brown fat, color due to vascularization and many mitochondria, Central nucleus
Has a lobular organization like glands
Production of body heat by many mitochondria
In human neonate, produces heat

10. Brown or multilocular adipose tissue

11. Brown or multilocular adipose tissue

13. Histology Lecture 7 Cartilage and Bone

14. Cartilage It supports soft tissues (nose, ear, trachea)
A kind of connective tissue with very firm extracellular matrix
It supports soft tissues (nose, ear, trachea)
Responsible for development and growth of long bones
Joint

15. Different Forms of Cartilage
There is three different kinds of cartilage:
Hyaline cartilage (collagen type II)
Elastic: (elastic fibers,and collagen type II)
Fibrocartilage: (type I collagen)

16. Hyaline Cartilage
Collagen type II

17. Perichondrium Vascular sheath(dense irregular connective tissue)
Inner cellular layer (chondrogenic cells that undergo division and differentiate into chondroblasts)
Outer fibrous layer
Articular cartilage lacks perichondrium,

18. Hyaline Cartilage Glassy blue-grayish in color
In embryo it serves as skeleton
joint surfaces, epiphyseal plate, nose, larynx, trachea, bronchi, ends of ribs adjacent to sternum
Amorphous ground substance
Pericellular capsule (1-3 µm) just around the lacuna

19. Hyaline Cartilage
matrix
Chondrocyte
Isogenous groups of chondrocytes

21. Appositional growth

23. Cartilage Growth
Interstitial growth: mitotic division of existing chondrocytes forming isogenous groups which are produce matrix and enlarging cartilage from within
Appositional growth: differentiation of new chondroblasts from chondrogenic cells located in inner layer of perichondrium and adding matrix to periphery of cartilage

24. Interstitial growth

25. Elastic Cartilage
Location: auricle of ear, external auditory canal, eustachian tube, epiglottis, cuneiform cartilage of larynx
It is similar to hyaline cartilage, but with many branching elastic fibers
Yellow in colour and more opaque than hyaline cartilage
Chondrocytes are more abundant and larger but matrix is less than hyaline cartilage
Perichondrium is also rich in elastic fibers

26. Elastic cartilage
Elastic fibers
Large Chondrocytes

27. Fibrocartilage
Location: intervertebral disks, tendon and ligament attachments to bone, pubic symphysis, and articular disk
Usually merges with adjacent dense connective tissue
Fibrocartilage matrix is scant (rich in chondroitin and dermatan sulfate), and exhibit bundles of type I collagen which stain acidophilic
It has not perichondrium

28. Fibrocartilage
Chondrocyte
Matrix
Collagen bundle

29. Department of Histology
دكتر محمد هادي بهادري