Chapter 7Skeletal Tissues

Connective Tissues

Bones

Cartilage

Types of bones:

Long – (long) femur, humerous

Short - (cube/box) carpal, tarsal

Flat – (broad/thin) skull, scapulae

Irregular – (varies/groups) vertebrae› Sesamoid – single - patella

Parts of a long bone:

Diaphysis – shaft Epiphysis – end

› Metaphysis – between diaphysis and epiphysis

Articular cartilage – thin layer of hyline cartilage – shock

Medullary cavity – in diaphysis – yellow marrow

Endosteum – epithelial lining inside medullary canal of long bones

Bone tissue

Osseous Contains cells, fibers, extracellular

matrix, collagen Extracellular matrix is calcified and

more abundant in bones than any other tissue

Rigidity provides support and protection

Composition of bone matrix

Inorganic salts

Organic matrix

Inorganic salts:

Calcium, phosphate (hydroxyapatite)

Process of deposition – calcification

Other variables detectable – › sodium› Sulfate› Fluoride› Magnesium

MicroscopicBone density:

Organic matrix:

Collagen fibers, protein, and polysaccharides (ground substance)

Present for growth/ repair Connective tissue cells secrete gel-like

substance Chondroitin sulfate – (GAG –

glycosaminoglycan) repair and maintanance

These components allow for plastic-like resilience

Lab exercise:

Microscopic Structure of Bone

Compact Bone

Cancellous Bone

Types of Bone Cells

Compact Bone

Many cylinder-shaped structures – osteons (Haversian systems)

Allows for delivery system of nutrition/waste

Osteon structures

Lamellae – calcified matrix

Lacunae – “little lakes” contains tissue fluid

Canaliculi – canals running all directions

Haversian canal – lengthwise – blood/lymph vessels

Transverse canal

Volkmann’s canals are for communication – nerves and vessels that carry blood/lymph to the bone surface

Cancellous bone

Spongy – not compact

Trabeculae – needle-like spikes which allows for cellular exchange of nutrients and waste

See diagram pg. 194 which refers to the sandwich effect of the compact / cancellous bone

Types of bone cells

Osteoblast – formation

Osteoclast – reabsorption

Osteocyte – mature

Bone marrow

Soft, diffuse connective tissue

Also called myeloid tissue

Produces blood cells

Two types of marrow

Yellow – fat saturated – no blood cell production

Red – erythrocyte production

Bone marrow transplantation

Harvested from vertebra/hip

Donation via I.V.

Without rejection, the pt. may begin new growth within the marrow

Functions of bone

Support Protection Movement Mineral storage Hematopoiesis

Regulation of calcium levels

98% of calcium in bones

Regulation due to new growth and breakdown/reabsorption

Essential for clotting, nerve transmission, muscle contraction, thyroid hormone production

Hormone regulation

Parathyroid – bone remodeling, renal calcium absorption, stimulation of Vit D synthesis

Calcitonin – thyroid – decrease of circulating levels of calcium

Bone development

All structure in-utero begins as cartilage and fibrous structures

Cartilage is then replaced with calcified bone matrix

Osteogenesis Strength of bone comes from use Endochondral ossification – bone from

cartilage Intramembranous ossification – bone from

fibrous membrane

Epiphyseal plate

Between diaphysis and epiphysis

Continual osteoblast formation and matrix calcification until maturity

Epiphysial plate

Developmental

Maturity

Repair of fratures

Considerations – blood vessels, nerves, type of fracture

Fracture hematoma

Immobilization

Vitos – synthetic calcium matrix

Immobilization of fractures

Types

Cartilage - hyaline

Hyaline – glassy, grissle Most common

Covers artricular surface Chondral surface Tracheal rings Nose Bronchii

Elastic

External ear Epiglottis

Fibrocartilage

Small matrix, abundant fibrous material

Strong, rigid

Symphysis pubis Intervertebral disks Tendonous articulations

Cartilangeous growth

Interstitial

Appositional