Page 188 - Atlas of Histology with Functional Correlations
P. 188
Fibrocytes
Smaller than fibroblasts
Inactive or resting connective tissue cells
White Adipose (Fat) Cells
Most common type of adipose tissue with wide distribution
Occur singly or in groups and exhibit single or unilocular lipid droplet
When adipose cells predominate, the connective tissue is adipose tissue
Store fat (lipid) as a single large droplet, primarily as triglycerides
Lipids derived from intestinal lipoproteins and low lipid lipoproteins from
liver
Appear as empty cells because lipid is dissolved during tissue preparation
Distributed throughout the body, serves as insulation, and forms fat pads for
organ protection
Highly vascularized owing to high metabolic activity
Exhibit receptors for hormones that influence accumulation and release of
lipid
Sole source of hormone leptin that increases lipid metabolism and regulates
appetite and food intake
Brown Adipose Cells
Exhibits more limited distribution
Cells smaller than white adipose cells; store fat as multiple lipid droplets
(multilocular)
Best developed in hibernating animals and newborn individuals
In newborns or animals emerging from hibernation, generates body heat
Norepinephrine from sympathetic nervous system promotes hydrolysis of
lipids
As an adaptation to cold environment, cell numbers and tissue increase
Macrophages
Most numerous in loose connective tissue
Ingest bacteria, dead cells, cell debris, and foreign matter
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