Skeletal Muscle

Front 1

The skeletal system is composed of what various tissues?

Back 1

i. Bone
ii. Cartilage
iii. Epithelium
iv. Fat
v. Neurons

Front 2

What is the framework of bones and cartilage?

Back 2

Skeletal Muscle

Front 3

What are the functions of skeletal muscle?

Back 3

i. Support- internal skeleton
ii. Protection
iii. Movement- in conjunction with muscle
iv. Mineral storage- calcium and phosphorus
v. Blood cell production- red and white blood cells
vi. Fat storage

Front 4

What is the introduction to bone tissue?

Back 4

i. A kind of connective tissue
ii. Crystals of inorganic calcium salts make it more rigid than other connective tissues
iii. Network of collagen fibers provides flexibility and strength

Front 5

What are the two types of bone tissue?

Back 5

i. Compact or dense bone tissue
ii. Spongy or cancellous bone tissue

Front 6

What does the compact or dense bone tissue contain?

Back 6

i. Contain few spaces
ii. Forms a layer over spongy bone
iii. Provides protection, support, and strength
iv. Has a concentric ring structure

Front 7

What does the spongy or cancellous bone tissue contain?

Back 7

i. Contains many large spaces
ii. Makes up most of the bone tissue of:
1. Skull bones and vertebrae
2. Epiphyses or tips of long bones
iii. Latitice works of thin bone plates are call trabeculae
iv. In some bones the spaces are filled with red marrow which produces blood cells
v. Spongy bone provides the greatest strength with the least weight

Front 8

What are the parts of the typical long bone?

Back 8

i. Diaphysis
ii. Epiphyses
iii. Metaphysis
iv. Medullary
v. Endosteum
vi. Articular cartilage
vii. Periosteum

Front 9

What is the Diaphsis?

Back 9

Shaft of the bone

Front 10

What is the Epiphyses?

Back 10

Tips of the bone.
~two types: proximal and distal

Front 11

What is the Metaphsis?

Back 11

Line or a plate between epiphyses and diaphysis
ii. Contains the epiphyses plate where bone growth occurs
1. Length and diameter

Front 12

What is the Medullary or marrow cavity?

Back 12

i. Space within the diaphysis
ii. Contains fatty yellow marrow in adults

Front 13

What is the Endosteum?

Back 13

Layer of osteoblasts living the marrow cavity and scattered osteoclasts

Front 14

What is articular cartilage?

Back 14

Thin layer of cartilage covering the epiphysis at a joint with another bone

Front 15

What is periosteum?

Back 15

i. Fibrous covering around the bone [where it is not covered by articular cartilage]
ii. Consists of :
1. Connective tissues containing blood vessels
2. Lymphatic vessels
3. Nerves
4. Cells that can become osteoblasts

Front 16

What are the parts of the microscopic anatomy?

Back 16

i. Osteon or Haversian System
ii. Central or Haversian Canal
iii. Perforating or Volmann's Canal
iv. Osteocytes (bone cells)
v. Circumferential Lamellae

Front 17

What is the Osteon or Haversian System?

Back 17

a. Structural unit of bone [building block]
b. Elongated cylinder parallel to bone’s long axis
c. Function as weight bearing pillars
i. Oriented in the direction of contraction
d. Osteon is a hollow tube of bone
i. Like rings on a tree
ii. Each ring is called a lamella
e. Collagen fibers in adjacent lamella run in opposite directions

Front 18

What is the central or Haversian canal?

Back 18

a. Canal that runs through the center of the osteon
b. Contains small blood vessels
c. Nerve fibers

Front 19

What are the Perforating or Volmann's canals?

Back 19

a. Lie at right angles to the central canal
b. Connect nerves and blood vessels in central canals with the rest of the body

Front 20

What are Osteocytes?

Back 20

a. Mature bone cells
b. Founds in lacunae at the junctions of the lamellae
c. Canaliculi [a little canal] connect lacunae

Front 21

What are circumferential lamellae?

Back 21

a. Located on the outside or surface of the shaft
b. Surround the osteons inside the bone
c. Like bark on a tree

Front 22

What are the parts of bone formation and growth?

Back 22

i. Ossification- bone formation
ii. Bones are continuously remodeled
iii. Bone regulation hormones
iv. Remodeling and mechanical factors

Front 23

What is Ossification?

Back 23

i. Embryo starts out with a “skeleton” cartilage and fibrous membranes shaped like bones
ii. Ossification begins week 6-7 after conception and continues throughout life and adulthood
iii. Embryonic connective tissue cells multiply and enlarge and form cartilage and bone
iv. Once a framework is made, calcification occurs
1. Calcium is deposited making the bone hard
v. In long bones:
1. Shaft ossifies first
2. Epiphyses ossify secondary
3. Epiphyseal plate between the shaft and ends remains cartilage
4. Permits growth of the bone shaft
5. When lengthening stops the epiphyseal plate becomes the epiphyseal line
6. Bones also increase in diameter during growth

Front 24

How are bones continuously remodeled?

Back 24

i. Bone tissue is re absorbed and replaced
1. Allows the bones and blood to exchange calcium
ii. Controlled by remodeling units
1. Osteoblasts- makes bone
2. Osteoclasts- degrades bone
iii. Diet must contain enough of :
1. Calcium
2. Phosphorus
3. Vitamin D

Front 25

What are bone regulation hormones?

Back 25

i. Growth hormones
1. Pituitary gland in the brain
2. Regulates general body growth
ii. Calcitonin
1. Thyroid gland in the throat
2. Promotes calcium deposition into bones
iii. Parathyroid hormone
1. Parathyroid glands in the throat
2. Promotes removal of calcium from the bones
iv. Hormonal control of remodeling
1. When blood concentration of CA2+ is too high
a. Rising blood levels of stimulate calcitonin release
b. Cacitonin stimulates the osteoblasts to deposit CA2+ into bones
c. CA2+ concentration of blood returns to the homeostatic level
2. When blood concentration of CA2+ is too low
a. Falling CA2+ levels stimulate parathyroid hormone release
b. Hormone stimulates osteoclasts to degrade the bone
c. CA2+ released into the blood
d. CA2+ levels in blood increase to the homeostatic levels

Front 26

What are the remodeling and mechanical factors?

Back 26

i. Functions to strengthen parts of the skeleton that are under stress
ii. How this occurs is still unknown
iii. Aging shifts the balance between organic matter and calcium in bones
iv. More inorganic salts and less organic matter
v. Causes less flexible and more brittle bones