Bs-Skeletal

Front 1

Vertebrates have an _____skeleton

Back 1

endoskeleton, as opposed to the chitinous (fibrous substance consisting of polysaccharides) exoskeleton of arthropods

Front 2

Five roles of the Vertebrate Skeletal System

Back 2

1) To support the body
2) Provide the framework for movement
3) Protect vital organs (brain, heart, etc)
4) Store calcium
5) The marrow of flat bones is the location of hematopoiesis, the synthesis of the formed elements of the blood (RBC's, WBC's, platelets)

Front 3

Two components of the Vertebrate Endoskeleton

Back 3

1) Axial Component: consists of skull, vertebral column, the rib cage
2) Appendicular Component: consists of all other bones

Front 4

Connective Tissue

Back 4

Definition: consists of cells and the materials they secrete
-all connective tissue cells are derived from a single progenitor cell (the fibroblast)
ex: bone

Front 5

Connective Tissues are derived from

Back 5

a single progenitor cell (the fibroblast: secretes fibrous material such as collagen, a fibrous protein)

Front 6

Fibroblast

Back 6

a single progenitor cell for connective tissue (bone)

the fibroblast: secretes fibrous material such as collagen, a fibrous protein

Front 7

Examples of fibrous extracellular protein

Back 7

1) Collagen: a strong fibrous protein
2) Elastin: provides rubber-like elasticity

Front 8

3 Fibroblast-derived cells

Back 8

1) Adipocytes: fat cells
2) Chondrocytes: cartilage cells
3) Osteocytes: bone cells

Front 9

2 Types of Connective Tissue

Back 9

1) Loose: includes adipose (fat) tissue and material located between cells throughout the body (extracellular matrix)
2) Dense: contain lots of collagen; including: bones, tendons, ligaments

Front 10

Main Ingredient of the Extracellular Matrix

Back 10

Proteoglycans: large macropolymers consisting of a protein core with many attached carbohydrate chains (glycosaminoglycans, GAGs), very hydrophilic (always surrounded by a large amount of water)

Front 11

Why does dehydration result in saggy skin?

Back 11

Because of decreased hydration of the extracellular matrix

Front 12

Basement membrane

Back 12

Definition: sheet of collagen that supports cell layers
-important example of loose connective tissue

Front 13

Hematopoiesis

Back 13

The development (via differentiation) of blood cells

Front 14

2 Primary Bone Shapes

Back 14

1) Flat- location of hematopoiesis, important for protection of organs
include: scapula, ribs, bones of the skull
2) Long- important for support and movement
include: bones of the limbs
*diaphysis: main shaft of long bone
*epiphysis: flared end of long bone

Front 15

2 Types of Bone Structure

Back 15

1) Compact: dense and hard bone
*diaphysis of long bones is a tube composed of compact bone
2) Spongy: porous bone, disorganized structure in which many spikes of bone surround marrow-containing cavities (spikes of bone: spicules or trabeculae)

-most bones: spongy bone surrounded by a layer of compact bone

Front 16

3 Types of Marrow

Back 16

1) Bone marrow: non-bony material found in the shafts of long bones and in the pores of spongy bones
2) Red marrow: found in spongy bone within flat bones, is the site of erythropoiesis (formation of RBCs); its activity increases in response to erythropoietin, a hormone made by kidney
3) Yellow marrow: found in the shafts of long bones, is filled with fat and is inactive

Front 17

Erythropoiesis

Back 17

formation of RBCs
-occurs in red marrow whose activity increases in response to erythropoietin, a hormone made by kidney

Front 18

2 Principal Ingredients of Bone

Back 18

1) Collagen
2) Hydroxyapatite: a solid material consisting of calcium phosphate crystals
-in bone synthesis, collagen is laid down in a highly ordered structure. then, hydroxyapatite crystals form around collagen framework, giving bone its characteristic strength and inflexibility

Front 19

Basic Unit of Compact Bone Structure

Back 19

Haversian system or osteon

Front 20

Microscopic Bone Structure

Back 20

-in the center of the *osteon=hole called a Haversian (or central) canal- contains blood, lymph vessels, & nerves
-lamellae: surround canal, concentric rings of bone
-canaliculi: tiny channels that branch out from the Haversian canal to spaces (*lacunae)
-osteocyte: in each lacuna, have long processes which extend down the *canaliculi to contact other *osteocytes through gap junctions

Front 21

Gap Junctions

Back 21

In bones, allows the *osteocytes to exchange nutrients and waste through an otherwise impermeable membrane

Front 22

Volkman's Canals

Back 22

Channels that run perpendicular to Haversian canals to connect *osteons

Front 23

Cartilage

Back 23

Strong but very flexible extracellular tissue secreted by cells called *chondrocytes

Front 24

3 Types of Cartilage

Back 24

1) Hyaline: strong and somewhat flexible cartilage
ex: larynx and trachea, joints (lined by hyaline cartilage known as articular cartilage)
2) Elastic: found in structures that require support & more flexibility than hyaline cartilage can provide; it contains elastin
3) Fibrous: very rigid and is found in places where strong support is needed
ex: pubic symphysis (anterior connection of the pelvis), intervertebral disks of the spinal column

Front 25

Unique fact about Cartilage

Back 25

Cartilage is not innervated and does not contain blood vessels (it's avascular)

Front 26

Epiphyseal plate

Back 26

A disk, observed between the diaphysis and the epiphysis during childhood
-cartilage is produced at this plate, epiphysis and diaphysis are forced apart
-@ puberty, androgens or estrogens cause the epiphyseal disk to ossify (& lengthening can no longer occur)

Front 27

Remodeling

Back 27

A process by which bone is continually degraded and remade

Front 28

Osteoblasts

Back 28

Cells which make bone by laying down collagen and hydrocyapatite
-synthesizes bone until surrounded by bone (space it is left in is *lacuna, and the osteoblast is now an osteocyte)

Front 29

Osteoclasts

Back 29

Cells that continually destroy bone by dissolving the hydroxyapatite crystals
-a large phagocytic cousin of the macrophage

Front 30

What is the result of an increased ratio of osteoclasts to osteoblasts?

Back 30

Liberation of calcium and phosphate into the bloodstream

Front 31

What is the result of an increased ratio of osteoblasts to osteoclasts?

Back 31

Retention of calcium and phosphate in the bones

Front 32

What do Calcitriol and PTH lead to?

Back 32

Lead to decreased levels of osteoblasts as opposed to osteoclasts and, thus, Ca2+ increases in serum

Front 33

Ligaments

Back 33

Connect bones to other bones

Front 34

Tendons

Back 34

Connect bones to muscles

Front 35

Joint

Back 35

The point where one bone meets another bone

Front 36

Synarthroses

Back 36

Immovable joints
-points where two bones are fused together

Front 37

Amphitroses

Back 37

Provide movability and a great deal of support
ex: vertebral joints

Front 38

Diarthroses

Back 38

Freely movable joints
ex: ball and socket (hip, shoulder), hinge (elbow)

Front 39

What are all movable joints supported by?

Back 39

Ligaments (a short band of tough, flexible , fibrous connective tissue that connects two bones or cartilages or holds together a joint)

Front 40

Synovial Fluid

Back 40

Lubricates movable joints
-kept within the joint by the synovial capsule

Front 41

Articular Cartilage

Back 41

-Composed of *hyaline cartilage, makes the surfaces of the two bones which contact each other perfectly smooth

Front 42

What is cartilage susceptible to?

Back 42

Damage, because it lacks blood vessels
-it is easily damaged by 1) Overuse and 2) Infection

Front 43

Arthritus

Back 43

Inflammation of the joints
-leads to destruction of the articular cartilage