HHIS221: HUMAN HISTOLOGY
Lesson 4 | Specialized Connective Tissue
2) Brown Adipose Tissue
● Comprises up to 5% of the newborn’s body weight but
Topic Outline:
● Specialized Connective Tissue smaller amounts in adults.
● Adipose Tissue ● Contain primarily many small lipid droplets (they are
● Cartilage multilocular) in cytoplasm containing many
● Bone mitochondria and a central nucleus
● This tissue is rich in mitochondria and specialized for
Specialized Connective Tissue generation of heat; it plays a part in body temperature
● include a number of different tissues with specialized cells regulation
and unique ground substance. ● characterized by expression of a unique uncoupling
I. ADIPOSE TISSUE protein, UCP1 or Thermogenin. This protein, in
II. CARTILAGE association with several other modulating factors,
III. BONES serves to uncouple mitochondrial metabolism from
IV. BLOOD production of ATP to produce heat.
I. Adipose Tissue
● Connective tissue in which fat-storing cells or adipocytes II. Cartilage
predominate ● A tough, resilient type of connective tissue that
● normally represents 15%-20% of the body weight in men, structurally supports certain soft tissues; and provides
and >20% in women cushioned, low-friction surfaces in joints.
● Adipocytes ● All types of cartilage lack vascular supplies and
➔ are very large cells derived from mesenchyme and chondrocytes receive nutrients by diffusion from
specialized for energy storage in lipid droplet(s) with capillaries in surrounding connective tissue (with the help
triglycerides of the perichondrium)
➔ are supported by reticular fibers, with connective ● Cartilage ECM typically includes collagen as well as
tissue septa dividing the tissue into lobules of various abundant proteoglycans, notably aggrecan, which bind a
sizes large amount of water
Two Types of Adipose Tissue ● Cells of cartilage, chondrocytes
1) White Adipose Tissue ➔ synthesize and maintain all ECM components and are
● Adipocytes of white fat are typically very large cells, located in the lacunae.
ranging in diameter from 50 to 150 μm. ● Perichondrium
● Cells contain primarily one large lipid droplet (they are ➔ is a sheath of dense connective tissue that surrounds
unilocular), causing the nucleus and remaining cartilage in most places, forming an interface between
cytoplasm to be pushed against the plasmalemma. – the cartilage and the tissues supported by the
ghost like cell cartilage
● comprises up to 20% of total body weight in normal ➔ harbors the blood supply serving the cartilage and a
(target weight) well-nourished male adults and up to small neural component
25% in females but can reach more than 50% in Three Major Forms of Cartilage
obesity. It is distributed throughout the body, 1) Hyaline Cartilage
particularly in the deep layers of the skin ● the most common of the three types, is homogeneous
● Specialized for relatively long-term energy storage and semitransparent in the fresh state.
● White adipocytes can store triglycerides derived from ● rich in type II collagen and aggrecan complexes with
three sources: bound water.
– Dietary fats brought to the cells via the circulation ● The ECM of hyaline cartilage is homogenous and
as chylomicrons glassy, has less collagen and more proteoglycan
– Lipids synthesized in the liver and transported in immediately around the lacunae, producing slight
blood with very low-density lipoproteins (VLDLs) staining differences in this territorial matrix.
– Free fatty acids and glycerol synthesized by the ● Chondrocytes occur singly or in small, mitotically
adipocyte derived isogenous groups
● Perichondrium is usually present, but not at the
hyaline cartilage of articular surfaces or the epiphyses
of growing long bones.
1
Lesson 4 | Specialized Connective Tissue
2) Brown Adipose Tissue
● Comprises up to 5% of the newborn’s body weight but
Topic Outline:
● Specialized Connective Tissue smaller amounts in adults.
● Adipose Tissue ● Contain primarily many small lipid droplets (they are
● Cartilage multilocular) in cytoplasm containing many
● Bone mitochondria and a central nucleus
● This tissue is rich in mitochondria and specialized for
Specialized Connective Tissue generation of heat; it plays a part in body temperature
● include a number of different tissues with specialized cells regulation
and unique ground substance. ● characterized by expression of a unique uncoupling
I. ADIPOSE TISSUE protein, UCP1 or Thermogenin. This protein, in
II. CARTILAGE association with several other modulating factors,
III. BONES serves to uncouple mitochondrial metabolism from
IV. BLOOD production of ATP to produce heat.
I. Adipose Tissue
● Connective tissue in which fat-storing cells or adipocytes II. Cartilage
predominate ● A tough, resilient type of connective tissue that
● normally represents 15%-20% of the body weight in men, structurally supports certain soft tissues; and provides
and >20% in women cushioned, low-friction surfaces in joints.
● Adipocytes ● All types of cartilage lack vascular supplies and
➔ are very large cells derived from mesenchyme and chondrocytes receive nutrients by diffusion from
specialized for energy storage in lipid droplet(s) with capillaries in surrounding connective tissue (with the help
triglycerides of the perichondrium)
➔ are supported by reticular fibers, with connective ● Cartilage ECM typically includes collagen as well as
tissue septa dividing the tissue into lobules of various abundant proteoglycans, notably aggrecan, which bind a
sizes large amount of water
Two Types of Adipose Tissue ● Cells of cartilage, chondrocytes
1) White Adipose Tissue ➔ synthesize and maintain all ECM components and are
● Adipocytes of white fat are typically very large cells, located in the lacunae.
ranging in diameter from 50 to 150 μm. ● Perichondrium
● Cells contain primarily one large lipid droplet (they are ➔ is a sheath of dense connective tissue that surrounds
unilocular), causing the nucleus and remaining cartilage in most places, forming an interface between
cytoplasm to be pushed against the plasmalemma. – the cartilage and the tissues supported by the
ghost like cell cartilage
● comprises up to 20% of total body weight in normal ➔ harbors the blood supply serving the cartilage and a
(target weight) well-nourished male adults and up to small neural component
25% in females but can reach more than 50% in Three Major Forms of Cartilage
obesity. It is distributed throughout the body, 1) Hyaline Cartilage
particularly in the deep layers of the skin ● the most common of the three types, is homogeneous
● Specialized for relatively long-term energy storage and semitransparent in the fresh state.
● White adipocytes can store triglycerides derived from ● rich in type II collagen and aggrecan complexes with
three sources: bound water.
– Dietary fats brought to the cells via the circulation ● The ECM of hyaline cartilage is homogenous and
as chylomicrons glassy, has less collagen and more proteoglycan
– Lipids synthesized in the liver and transported in immediately around the lacunae, producing slight
blood with very low-density lipoproteins (VLDLs) staining differences in this territorial matrix.
– Free fatty acids and glycerol synthesized by the ● Chondrocytes occur singly or in small, mitotically
adipocyte derived isogenous groups
● Perichondrium is usually present, but not at the
hyaline cartilage of articular surfaces or the epiphyses
of growing long bones.
1
