L5: Skeletomuscular System

The five main anatomical components of the musculoskeletal system:

1. Muscle

2. Bone

3. Tendons

4. Ligaments

5. Cartilage

• Ligaments and tendons are examples of _____________ tissue while

• Cartilage and bones are an example of ________________ tissue

dense regular connective - supportive connective

Supportive connective tissues have a ____________ matrix.

dense, solid

Cartilage is vascular/avascular and has ________ residing in lacunae which produce _________

avascular - chondrocytes - collagen + ECF

Cartilage surface is covered by a ______________, which is a __________________ tissue

perichondrium - dense fibrous connective

Collagen’s three subtypes:

1. __________: proteoglycans

   1. e.g. _____________

2. __________: proteoglycans + elastin

   1. e.g. _____________

3. __________: proteoglycans + collagen

   1. e.g. _____________

1. hyaline - joints

2. elastic - ear

3. Fibrocartilage - intervertebral discs

Bone tissue is vascular/avascular and filled with _____________. They have lacunae which house ___________.

vascular - bone marrow - osteocytes

Compact bone is organized into _____________ separated by layers of __________. It _______ force.

concentric rings - matrix - resists

Spongy bone is organized into ___________ within ___________. It ________ force

trabeculae - bone marrow - distributes

Bone tissue cell that produces other bone cells + location

osteogenic cells - endosium

Bone cells that maintain bone matrix:

Osteocytes - moved down form osteoblasts

Bone cells that produce bone matrix + location

Osteoblasts - periosteum

Bone cell that dissolves bone matrix + location

Osteoclasts - medullary cavity

Why is it important that bone can be remodeled by cellular activity?

mineral reservoir: t can store or release minerals as needed

When calcium levels are high, __________ cells will __________.

If they are low, ______ cells will _____________.

• High: osteoblasts - make new bone matrix

• Low: osteoclasts - break down bone to release calcium and phosphate ions

Cartilage can grow through ____________ as well as __________ during childhood.

differentiation - cell division

Interstitial cartilage growth involves the ____________ of ___________ cells. Cells are pushed apart by: ___________.

proliferation - chondrocyte - new matrix secreted

_________ cartilage growth is growth by differentiation:

• _______ to ___________

• ___________ secrete ___________

• ___________ to _____________

appositional

• stem/mesenchymal cells - chondroblasts

• chondroblasts - new matrix

• chondroblasts - chondrocytes

Endochondral growth is the growth of ________ by the _________ of _________ . It only occurs during childhood and begins as __________ in utero.

bone - ossification - cartilage - hyalin cartilage

• Endochondral growth starts with ossification at the _________ then the _________.

• ___________ grow by _______ _______ until they ossify at puberty.

• shaft - epiphyses

• epiphysial plates - interstitial division

• Bones lengthen at the ____________. Chondrocytes divide then _______, causing the matrix to ________.

• Then _______ will secrete _________ and _________ will occur.

• epiphyseal - die - calcify

• osteoblasts - bone matrix - ossification

Intramembranous ossification is the direct conversion of __________ _________ cells in _______ ______ connective tissue into __________.

embryonic mesenchymal - dense proper - osteoblasts

_______ and _______ bones are examples of bones made through intramembranous bones.

dermal - sesamoid

Bone can grow by _______ growth, as well as __________ growth & __________ during embryonic development and childhood.

appositional - endochondral - intramembranous ossification

• The diameter of a bone increases with ___________ growth at the inner layer of the ___________ with the activity of ___________.

• As the bone diameter increases, (cell + activity), will cause the _________ to expand.

• appositional - pericardium - osteoblasts

• osteoclasts break down bone matrix - medullary cavity

Synovial joints are part of the __________ functional category.

Diarthrosis (free movement)

Synovial joints have _______ cartilage, a sub-type of ________ cartilage.

articular - hyaline

Bone repairs itself through ____________ of cells, starting with ________ → __________ → _________. Calluses are formed by __________

extra proliferation

cartilage → spongy bone → compact bone

secreting chondrocytes

Cartilage can only repair itself through __________ only for _____ and ______ cartilage and not ________ cartilage because __________.

appositional growth - fibro/elastic cartilage - articular - it has no perichondrium (contains stem cells)

Osteoarthritis is caused by damage to the ______________. This increases _________ which leads to inflammation and more ______________

articular cartilage - friction - pressure on remaining cartilage.