Adipose tissue

1. Connective Tissues (CT)
• Defined:
• Loose CT example
• Matrix
• Fibers & their functions
– Fibroblast cells
– Collagen
– Elastin
– Fibrillin
– Fibronectin

2. Connective Tissues (CT)

3. More Connective Tissues
• Dense
connective
tissue
– Tendons &
ligaments
– Collagen
dominates
Tendons and ligaments

4. More Connective Tissues
• Adipose connective tissue
– Adipocytes
– Fat vacuoles
• Blood
– Plasma matrix
– Free blood cells

5. More Connective Tissues
Adipose tissue

6. Supporting Connective Tissues
• Cartilage
– Light & flexible
– Trachea & ears
• Bone
– Calcified
– Rigid
• Connective Tissues Reviewed

7. Supporting Connective Tissues
Map of the components of connective tissue

8. Muscle Tissues
• Contractile
– Force
– Movement
• Excitable- they
conduct signals
• Types
– Cardiac
– Smooth
– Skeletal
Three types of muscles

9. Nervous Tissues
• Neurons send
signals
– Excitable
– Electrical
– Chemical
• Glial cells support
Model neuron

10. Cell Life, Death, and Replacement
• Necrosis
– Damaged cells die
– Disrupt/kill neighbors
• Apoptosis
– Normal cell replacement
– Programmed cell death
– Does not damage neighbors
• Stem cells
– Role in cell replacement
– Research uses and potential

11. A Specialty Connective Tissue
ADIPOSE TISSUE

12. Function of Adipose Tissue
• Largest repository of energy in the body
– Triglycerides
– 9.3kcal/g
• Contributes to thermal insulation
– Important for temperature regulation
• Fills spaces between structures/protects
– Between organs
– Aids fit of valves in heart
– Pads of fat protect heels, palms

13. How Fat is Used in Adipose Cell
• Fatty acid + glycerol move into cell from
capillary.
• Sympathetic stimulation (NE) and Ep from
adrenal gland stimulate adipose cell:
– Release fatty acid, glycerol
– Used as a source of energy
nor-epinephrine

14. Adipose Dynamics
capillary capillary
NE
FFA Glycerol
Glycerol
FFA
triglyceride
Ep
Glu
(insulin) LIVER
nucleus

15. Route of FFA to Adipose Tissue
• Capillary endothelium
• Basal lamina
• CT ground substance
• Adipocyte basal lamina
• Adipocyte plasma membrane
free fatty acid

16. Development of Fat Tissue

17. Distribution of Adipose Tissue
In a human newborn,
multilocular adipose tissue
constitutes 2—5% of the
body weight and is
distributed as shown.
The black areas indicate
multilocular adipose tissue;
shaded areas are a mixture
of multilocular and
unilocular adipose tissue.

18. Adipose Tissue
Unilocular
Multilocular
(Brown Fat)

19. Adipocytes

20. Cartilage

21. Functions of Cartilage Tissue
• Specialized CT in which the firm
consistency of the extracellular matrix
allows the tissue to bear mechanical
stresses without permanent distortion
• Supports soft tissues.
• Shock-absorbing because it is resilient.
• Smooth surface allows sliding against it.
• Essential for growth, development of bone.

22. Characteristics
• Chondrocytes (-blasts)
– Located in lacunae
• Extensive extra-cellular matrix
– Fibers, ground substance
– Collagen, hyaluronic acid, proteoglycans,
glycoproteins, elastic (in elastic cartilage)
– Macromolecules, water, fibers bind together
and give firm, flexible properties to tissue.
• No blood, nerve supply
• Low metabolic rate.

23. Perichondrium
• Dense CT that covers
cartilage (except
articular cartilage of
joints.)
• Contains blood, nerve
supply, lymphatics.
• Contains collagen
fibers, fibroblasts
Hyaline cartilage

24. Transition Perichondrium / Cartilage

25. Hyaline Cartilage

26. CARTILAGE (hyaline)
Found at ends of
bones,
nose, trachea, larynx
Bluish white color.
Strong, rubbery,
flexible tissue.

27. Chondrocytes in Lacunae

28. Influence of hormones
• GH, TH, testosterone accelerates synthesis of
glycosaminoglycans.
• Cortisone, estradiol inhibits synthesis.
• Growth depends mainly on GH (somatotroopin)
– Stimulates liver to produce somatomedin C
– Somatomedin C acts on cartilage cell, stimulating
growth

29. Growth of Cartilage
• Growth is attributable to two processes:
– Interstitial growth
• Mitotic division of preexisting chrondrocytes
• Synthesis of matrix
• Expands cartilage matrix from within
• Occurs in epiphyseal plates, articular cartilage
– Appositional growth
• Differentiation of perichondrial cells  chondroblasts
• Synthesis of matrix

30. Growth in the Epiphyseal Plate

31. Epiphyseal Plate (Interstitial Growth)

32. Appositional Growth

33. ELASTIC CARTILAGE
• Similar to hyaline cartilage but has elastic
fibers running in all directions in addition to
collagen.
• Found in auricle of ear, walls of external
auditory canals, eustachian tubes,
epiglottis, larynx
• Maintains shape, deforms but returns to
shape; flexibility of organ; strengths and
supports structures.
E ar

34. ELASTIC CARTILAGE

35. Elastic Cartilage
Elastic fibers (elastin)
Yellow color

36. Elastic Cartilage (Epiglottis)

37. • Fibrous Cartilage
Fibrocartilage
• is a form of connective tissue transitional between
dense connective tissue and hyaline cartilage.
• Chondrocytes may lie singly or in pairs, but most
often they form short rows between dense bundles of
collagen fibres. In contrast to other cartilage types,
collagen type I is dominant in fibrous cartilage.
• is typically found in relation to joints (forming intra-
articular lips, disks and menisci) and is the main
component of the intervertebral disks, symphysis
pubis.
• merges imperceptibly into the neighboring tissues,
typically tendons or articular hyaline cartilage. It is
difficult to define the perichondrium because of the
fibrous appearance of the cartilage and the gradual
transition to surrounding tissue types.

38. Fibrocartilage
Note the rows of
chondrocytes separated by
collagen fibers. Fibrocartilage
is frequently found in the
insertion of tendons on the
epiphyseal hyaline cartilage.

39. Fibrocartilage
Intervertebral disks
Nucleus pulposus is the jelly-like
substance in the middle of the spinal disc

40. Fibrocartilage