Lesson 6 - TISSUES PART 2 Flashcards
what are the 3 basic characteristics of connective tissue ?
- specialized cells (more than 1 cell type present)
- solid extracellular protein fibers
- fluid extracellular ground substance
is important not only fills space between cells, but also slow pathogen movement
ground substance
the extracellular components of connective tissue
fibers and ground substance
the extracellular components of connective tissue make up the ____
matrix
majority of connective tissue volume
determines specialized function
the extracellular components of conn. tissue that make up the matrix
FUNCTIONS OF CONNECTIVE TISSUE
FUNCTIONS OF CONNECTIVE TISSUE
- establishing a structural framework for the body
- transporting fluids and dissolved materials
- protecting delicate organs
- supporting, surrounding, and interconnecting other types of tissue
- storing energy reserves, especially in the form of triglycerides
- defending the body from invading microorganisms
3 general categories of connective tissue
- connective tissue proper
- fluid connective tissues
- supporting connective tissues
functions to connect and protect
ex: tendons and adipose tissue
connective tissue proper
functions in transportation
ex: blood and lymph
fluid connective tissue
provides structural strength
ex: cartilage and bone
supporting connective tissues
connective tissue proper cell populations
- fibroblasts
- fibrocytes
- adipocytes
- mesenchymal cells
- macrophages
- mast cells
- lymphocytes
- microphages
- melanocytes
the most abundant cell type in connective tissue
fibroblasts
found in all connective tissue proper
fibroblasts
secrete proteins and hyaluronan (cellular cement)
fibroblasts
the second most abundant cell type - develops from fibroblasts
fibrocytes
found in all connective tissue proper
fibrocytes
maintain the fibers of connective tissue proper
fibrocytes
also known as adipose cells
adipocytes
fat cells
adipocytes
each cell stores a single, large fat droplet
adipocytes
functions as energy reserve and cushions tissues/organs
adipocytes
found in many connective tissue
mesenchymal cells
stem cells are part of mesenchymal cells
true
cells that respond to injury or infection
stem cells
differentiate into fibroblasts, macrophages, or other connective tissue cells in response to injury or infection
stem cells
large, amoeba-like cells of the immune system
macrophages
eat pathogens and damaged cells
macrophages
two classes of macrophages:
fixed and free
stay in tissue, frontline defense, reinforced by free macrophages and other cells
fixed macrophages
migrate through tissue
free macrophages
stimulate inflammation after injury or infection
mast cells
release histamine (dilates blood vessels) to stimulate local inflammation and heparin (anticoagulant) to prevent blood clots in areas of slow blood flow
mast cells
basophils are leukocytes (white blood cells) that also contain histamine and heparin (mast cells)
true
specialized immune cells in lymphatic (lymphoid) system
lymphocytes
ex: some lymphocytes may develop into plasma cells (plasmocytes) that produce antibodies
true
vaccines stimulate some lymphocytes to become plasma cells which produces antibody proteins that circulate in blood (lymphocytes)
true
neutrophils and eosinophils
microphages
phagocytic white blood cells
microphages
moves through connective tissue in small numbers
microphages
respond to signals from macrophages and mast cells and signals from site of infection
microphages
synthesize and store the brown pigment melanin (gives tissue a dark color)
melanocytes
located in the eye and the dermis of the skin
melanocytes
embryonic connective tissue
Mesenchyme
the first connective tissue in embryos
embryonic connective tissue
gives rise to all other connective tissues
embryonic connective tissue
are not found in adults
BUT
many adult connective tissues do have mesenchymal stem cells for tissue repair
embryonic connective tissue
loose connective tissue found in many parts of embryo, including the umbilical cord
(not found in adults)
mucous connective tissue (Wharton’s jelly)
contains many adipocytes (fat cells)
adipose tissue
incapable of dividing in adults
adipose tissue
mesenchymal cells around adipose tissue can divide and differentiate into adipocytes if there is chronic elevation of circulating lipids
true
shrinks when nutrients are scarce, cell doesn’t die, can regain size when nutrients plentiful
adipose tissue
2 types of adipose tissue
white fat
brown fat
most common
stores fat
absorbs shock
slows heat loss (insulation)
white fat
more vascularized, widespread in fetus and infants, only small amounts in adults
brown fat
adipocytes have many mitochondria
brown fat
when stimulated by nervous system, fat breakdown accelerates, releasing energy as heat
brown fat
surrounding tissues absorbs heat to quickly warm circulating blood
brown fat
