Download Connective tissues (pages 99 – 105) – Anatomy Physiology

Connective tissues (pages 99 – 105) – Anatomy Physiology
Connective tissue most diverse tissue in body (Bone, blood, fat)
Three basic components:
1. Specialized cells
2. protein fibers
3. Fluid (GROUND substance)
Epithelial = mostly cells…but Connective tissue = mostly Extracellular matrix
NEVER exposed to outside environment
Many are highly vascular
Many have receptors for pain, pressure, and temp
FUNCTIONS include:
1. support and protection
2. transport of materials
3. storage of energy
4. defense of body
CLASSIFYING CONNECTIVE TISSUE
1. Connective tissue proper (tendons and ligaments…dense and loose)
2. Fluid connective tissue (blood and lymph)
3. Supportive connective tissue (cartilage – solid rubbery matrix and bone – solid
crystalline matrix)
Fluid connective tissue
1. Blood and Lymph = disconnected cells in a fluid matrix
a. Plasma = the watery matrix in blood
b. Red blood cells = ½ of blood volume
c. White blood cells = immune system component
d. Platelets – cell fragments for blood clotting
Plasma + Lymph + Interstitial fluid = MOST of Extracellular fluid in body
Connective tissue proper
VARIED cells: fibers, syrupy ground substance…some permanent, others for
defense.
1. CELLS
a. fibroblasts (most abundant)…permanent…for
PRODUCING connective tissue proper and ground sub.
b. Macrophages – scattered, phagocytize, some fixed ‘ macrophages others
free macrophages.
c. Fat cells (adipocytes) permanent…hold droplets of lipids,
nucleus to one side.
d. Mast cells – mobile and near blood vessels…fore defense and release
chemicals to begin defensive activities.
OTHERS…antibody producing white blood cells and
antibodies – proteins that destroy invaders.
2. FIBERS
a. Collagen – long, straight, unbranched
b. Elastic fibers – contain protein elastin…branched, wavy,
and stretchy.
c. Reticular fibers (reticulum)
3. Ground Substance
a. Spaces between cells and surrounds connective tissue fibers
b. Clear, colorless, like maple syrup consistency
c. SLOWS the movement of bacteria and pathogens
d. Loose – packing material of body
e. Dense – tough, strong, durable, connect bones and
muscles
4. Loose Connective tissue = AREOLAR tissue (little space)…least specialized.
a. provides space between muscles and skin…BLOOD flow
here
5. Adipose tissue – a loose connective tissue…loose connective is called adipose
when it becomes dominated by fat cells….
a. padding
b. shock absorption
c. heat loss
d. energy storage.
6. Dense connective tissue – MOSTLY collagen fibers and some fibrous
a. Tendons – cords to attach muscles to bones
b. Ligaments – cords to attach bone to bone
Supporting connective tissue = cartilage and bone
1. Cartilage – the matrix of this is a firm gel with embedded fibers
a. Chondrocytes the ONLY cell in cartilage matrix
b. Cartilage is Avascular (so chondrocytes get nutrients from
diffusion through matrix.
c. Vessels don’t grow because chondrocytes produce
chemicals that STOP their formation
d. because Avascular…repair is limited!!!! Don’t damage your cartilage!!!
e. Perichondrium = covering…peri = AROUND
2. TYPES OF CARTILAGE
a. Hyaline cartilage = most common…connects ribs to
sternum, passage of respiratory tract, covers opposing bone surfaces.
b. Elastic cartilage – lots of elastic fibers…the outer ear
(AURICLE or PINNA) and middle ear.
c. fibrocartilage – almost NO ground substance and mostly
collagen fibers….fibers densely woven for durability…between vertebra of
spinal cord, around an in some joints and tendons.
3. BONE = osseous tissue
a. Ground substance is very small
b. Matrix = mostly hard calcium compounds and flexible collagen fibers for
flexibility and strength.
c. Osteocytes = bone cells
d. Central space with osteocytes (in lacunae) surrounding it. Central space
has BLOOD VESSELS
e. NOT diffusion through matrix so nutrients get to blood vessels through
cytoplasmic extensions.
f. canaliculi (little canals) the network of cytoplasmic extensions in a
branching network.
g. periosteum – surrounds each bone with an outer and inner layer.
NOTE: bone is constantly being remodeled throughout life and complete
repairs can be made.
Lacunae = small pockets where connective tissue CELLS live
Tables and charts:
4.8 cells and fibers in connective tissue proper
1. reticular fiber
2. fixed macrophages
3. antibody producing cells
4. blood in vessels.
5. adipocytes,
6. ground substance
7. mast cells
8. elastic fibers
9. collagen fibers
10. free macrophage
11. fibroblast
12. stem cell
13. white blood cells
4.9 connective tissue proper loose and dense
1. Loose – under skin, digestive tract, between muscles and more
FOR cushions, support, movement, and defense against pathogens
2. Adipose – LOOSE – deep to skin, sides, butt, breasts, kidneys, around eyes
FOR padding, insulation, energy reserves
3. DENSE = between skeletal muscles, covers skeletal muscles, capsules of
internal organs
FOR firm attachment, reduces friction, stabilizes bone, prevents
Over expansion of bladder.
4.10 types of cartilage
1. Hyaline cartilage – between ribs and bones of sternum, covers bone surfaces,
forms part of nasal septum
FOR stiff but flexibility, reduces friction
2. Elastic cartilage – auricle of ear, epiglottis, and middle ear
FOR support but distortion without damage
3. Fibrocartilage – pads in knee joints, intervertebral discs
FOR resists compression, prevents bone to bone contact.
Table 4-3 comparison of cartilage and bone
Chara
Cartilage
Cells
Chondrocytes
Ground sub
Protein gel and water
Fibers
collagen, elastic
Reticular fiber
Vascularity
NO
Covering
Perichondrium
Strength
limited
Oxygen needed `
low
Nutrient delivery
diffusion
Repair
limited
Bone
Osteocytes
Little liquid and salts
collagen
LOTS
Periosteum
flexible
high
canaliculi
extensive