adipose & cartilage

White Adipocytes

Fat cells characterized by a single large fat droplet, primarily involved in energy storage.

Brown Adipocytes

Fat cells with multiple small fat droplets, primarily responsible for heat production.

adipocytes

store and synthesise triglycerides, secretes leptin

Leptin

An endocrine hormone secreted by adipocytes that signals satiety to the hypothalamus.

Ghrelin

A hormone that stimulates appetite and promotes eating as a method of short term regulation

Peptide YY

An appetite-suppressing hormone that signals the body to stop eating.

Chylomicrons

Lipoproteins that transport dietary fats from the intestines to other locations in the body.

Very Low-Density Lipoproteins (VLDL)

Lipoproteins that transport fats from the liver to tissues.

Lipase

breaks down triglycerides into fatty acids for energy mobilization.

White Adipose Characteristics

Unilocular structure, energy storage, and displaced nucleus and cytoplasm.

Brown Adipose Characteristics

Multilocular structure, central nuclei, and numerous mitochondria for heat production.

Cartilage

A specialized connective tissue with a firm but pliable extracellular matrix that withstands mechanical stress.

Chondroblasts

Cells that produce the extracellular matrix in cartilage; become chondrocytes when surrounded by matrix.

Chondrocytes

Mature cartilage cells that reside in lacunae and maintain the cartilage matrix.

Hyaline Cartilage

The most common type of cartilage, characterized by a homogenous matrix and primarily type II collagen.

Elastic Cartilage

Contains elastic fibers, does not calcify, and is found in structures like the ear and epiglottis.

Fibrocartilage

Contains abundant type I collagen, acts as a shock absorber, and is found in high-stress areas like intervertebral discs, no perichondrium

Interstitial Growth

A type of cartilage growth where chondrocytes divide and secrete new matrix from within

Appositional Growth

A type of cartilage growth where new layers of matrix are added to the surface.

Perichondrium

A dense connective tissue layer surrounding cartilage, involved in growth and repair.

Epiphyseal Growth Plate

Cartilage present at the ends of long bones during growth, later ossified when growth ceases.

why is repair limited

cartilage is avascular and aging can lead to calcification of cartilage and reduced repair capacity.

fat mobilisation

chylomicrons and VLDLs are broken down into fatty acids and taken into adipocytes where reorganisation into triglycerides occur, they are then stored in fat droplets

insulin

moves glucose out of bloodstream and into cells

layers of perichondrium

fibrous outer layer which contains fibroblasts that produce chondroblasts

inner layer has progenitor cells that make new cartilage