Bone Tissue

Front 1

How much weight does bone tissue makeup?

Back 1

18 percent of the human body

Front 2

how does the skeleton support the human body?

Back 2

The skeleton serves as a structural framework for the body by supporting soft tissues and providing attachment points for tendons of both skeletal muscles

Front 3

how does the skeleton provide protection to the human body?

Back 3

The skeleton protects the most important internal organs from injury. For example, cranial bones protect the brain, vertebrae protect the spinal cord, and the rib cage protects the heart and lungs

Front 4

How does the skeleton provide assistance in movement?

Back 4

most skeletal muscles attached to bones, when they can tract, they pull on bones to produce movement

Front 5

How does the skeleton provide mineral homeostasis?

Back 5

Bone tissues store several minerals, especially calcium and phosphorus, which contribute to the strength of bone. Bone tissues store is about 99% of the body's calcium. on demand, phone releases minerals into the blood to maintain critical mineral balances , homeostasis, and to distribute the minerals to other parts of the body.

Front 6

How does the skeleton help in blood cell production?

Back 6

Within certain phones, a connective tissue called red bone marrow produces red blood cells, white blood cells, and platelets aunt, a process called hemopoiesis. red bone marrow consists of developing blood cells, adipocytes, fibroblasts, and macrophages within a network of reticular fibers. It is present in developing bones of the fetus and in some adult bones, such as the hip bones, red, sternum, vertebrae, school, and ends of the bones of the humerus and fever. & a newborn, all the marrow is red and is involved in hemopoiesis. with increasing age, much of the bone marrow changes from red to yellow.

Front 7

What role does the skeleton play in triglyceride storage?

Back 7

Yellow bone marrow consists mainly of adipose cells, which store triglycerides. The stored triglycerides are a potential chemical energy reserve.

Front 8

Diaphysis - long bone

Back 8

The bone's shaft or body, the long, cylindrical, main portion of the bone

Front 9

Epiphyses - long bone

Back 9

The proximal and distal ends of the bone

Front 10

metaphyses - long bone

Back 10

The regions between the diaphysis and the epiphyses. In a growing bone, each metaphyses contains an epiphyseal plate, a layer of hyaline cartilage that allows the diaphysis of the bone to grow in length. when a bone pieces to grow in length and about ages 18 to 21, the cartilage in after this your epiphyseal plate is replaced by bone, the resulting bony structure is known as the epiphyseal line.

Front 11

What role does articular cartilage play in long bone?

Back 11

It is a thin layer of hyaline cartilage covering the part of the epiphyses where the bone forms an articulation or joint with another bone. Articular cartilage reduces friction and absorbs shock freely movable joints. Because articular cartilage lacks a perichondrium and lacks blood vessels, repair of damage is limited

Front 12

what role does the periosteum play in long bone?

Back 12

It is the tough connective tissue sheath and its associated blood supply that surrounds the bone surface wherever it is not covered by articular cartilage. It is composed of an outer fibrous layer of dense irregular connective tissue and an inner osteogenic layer that consists of cells. Some of the cells enabled bone to grow in thickness, but not in length. The periosteum also protects the bone, assist in fracture repair, helps nourish bone tissue, and served as an attachment point for ligaments and tendons. The periosteum is attached to the underlying bone by perforating fibers, or Sharpey's fibers, thick bundles of collagen that extend from the periosteum into the bone extracellular matrix.

Front 13

What role does the medullary cavity play in long bone?

Back 13

Also called the marrow cavity, it is a hollow, cylindrical space within the diaphysis that contains fatty yellow bone marrow and numerous blood vessels in adults. This cavity minimizes the weight of the bone by reducing the dense pony material where it is least need it. The long bones tubular design provides maximum strength with minimum weight.

Front 14

What role does the endosteum play and long bone ?

Back 14

It is a thin membrane that lines the medullary cavity. It contains a single layer of bone forming cells and a small amount of connective tissue.

Front 15

What kind of bone marrow does the medullary cavity contain?

Back 15

The medullary cavity of the diaphysis contains yellow bone marrow an adult

Front 16

What are the six functions of bone tissue?

Back 16

1. Support soft tissue and provides attachment for skeletal muscles

2. Protects internal organ

3. Assist in movement, along with skeletal muscle

4. Stores and releases minerals

5. Contains red bone marrow, which produces blood cells

6. Contains yellow bone marrow, which stores triglycerides

Front 17

Osteogenic cells

Back 17

Unspecialized bone stem cells derived from mesenchyme, the kiss you from which almost all connective tissues are formed. They are the only bone cells to undergo cell division, the resulting cells develop into osteoblasts. Osteogenic cells are found along the inner portion of the periosteum, in the endosteum, and in the canals with in the bone that contains blood vessels.

Front 18

Osteoblast

Back 18

These are bone building cells. They synthesize and secrete collagen fibers and other organic components needed to build the extracellular matrix of bone tissue, and they initiate calcification. As osteoblast surround themselves with extracellular matrix, they become trapped in their secretions and become osteocytes

Front 19

Osteocytes

Back 19

Mature bone cells, are the main cells in bone tissue and maintain its daily metabolism, such as the exchange of nutrients and wastes with the blood. Like osteoblasts, osteocytes do not undergo cell division

Front 20

Osteoclasts

Back 20

These are huge cells derived from the fusion of as many as 50 monocytes, a type of white blood cell, and are concentrated in the endosteum. on the side of the cell that faces the bone surface, the osteoclast's plasma membrane is deeply folded into a ruffled border. Here the cell releases powerful lysosomal enzymes and acids to digest the protein in mineral components of the underlying extracellular bone matrix.

Front 21

Resorption

Back 21

Be part of the normal development, maintenance, and repair of bone

Front 22

Compact bone tissue

Back 22

Contains few spaces and is the strongest form of bone tissue. It is found beneath the periosteum of all bones and makes up the bulk of the diaphyses of long bone. Compact bone tissue provides protection and support and resists the stresses produced by weight and movement

Front 23

Osteons or Haversian system

Back 23

Compact bone tissue is composed of these repeating structural units. Each osteon consists of concentric lamellae arranged around a central Haversian canal. resembling the gross rings of a tree, the concentric lamellae are circular plates of mineralized extracellular matrix of increasing diameter, surrounding a small network of blood vessels, lymphatics, and nerves located in the central canal. These tubelike unit of bone generally form a series of parallel cylinders that, in long bones, tend to run parallel to the long axis of the bone.

Front 24

Lacunae

Back 24

Between the concentric lamellae are small spaces called lacunae , which contain osteocyte

Front 25

Canaliculi

Back 25

Tiny structures that radiate in all directions from the lacunae , they are filled with extracellular fluid. Inside the canaliculi are slender fingerlike processes of osteocytes period neighboring osteocytes communicate via gap junctions. The canaliculi connect lacunae with one another and with the central canals, for me an intricate, miniature system of interconnected canals throughout the bone. This system provides many routes for nutrients and oxygen to reach the osteocytes and for the removal of waste.

Front 26

interstitial lamellae

Back 26

The area between neighboring osteons, nice also have lacunae with osteocytes in canaliculi. Interstitial lamellae are fragments of older osteons that have been partially destroyed during bone rebuilding or growth.

Front 27

Perforating canals

Back 27

Canal that allow blood vessels, lymphatic vessels, and nerves from the periosteum to penetrate the compact bone. The vessels and nerves of the perforating canals connect with those of the medullary cavity, periosteum, and central canal

Front 28

Circumferential lamellae

Back 28

Lamellae that are arranged around the entire outer and inner circumference of the shaft of a long bone. They developed during initial bone formation. - circumferential lamellae directly to the periosteum are called outer circumferential lamellae. they are connected to the periosteum by perforating sharpies fibers. The circumferential lamellae that lines the medullary cavity are called inner circumferential lamellae

Front 29

Spongy bone tissue

Back 29

Trabecular or cancellous bone tissue, does not contain osteon. Spongy bone tissue is always located in the interior of a bone, protected by a covering of compact bone.

Front 30

Trabeculae

Back 30

The arrangement of lamellae in a irregular pattern of thin columns and make up spongy bone tissue

Front 31

What is in between the trabeculae?

Back 31

Spaces that are visible to the unaided eye, they are filled with red bone marrow in bones that produces blood cells, and yellow bone marrow in other bones. Both types of bone marrow contain numerous small blood vessels that provide nourishment to the osteocyte. Each trabeculae consist of concentric lamellae, osteocytes that lie in lacunae, and canaliculi that radiate outward from the lacunae

Front 32

Name two ways that spongy bone tissue and compact bone tissue are different

Back 32

1. Spongy bone tissue is light, which reduces the overall weight of a bone. This reduction in weight allows the bone to move more readily when pulled by skeletal muscle.

2. The trabeculae of spongy bone tissue support and protect red bone marrow. Spongy bone in the hip bone, ribs, sternum, vertebrae, and the proximal end of the humerus and femur is the only site where red bone marrow is stored and, thus, this site where hemopoiesis occurs in adults

Front 33

periosteal arteries

Back 33

Small arteries accompanied by nerves, enter the diaphysis through many perforating canals and supply the periosteum and outer part of the compact bone

Front 34

Nutrient artery

Back 34

It is located near the center of the diaphysis and passes through a hole in the compact bone called the nutrient foramen. on entering the medullary cavity, the nutrient artery divided into proximal and distal branches that course towards each end of the bone. These branches supply both the inner part of compact bone tissue of the diaphysis and a spongy bone tissue and red bone marrow as far as the epiphyseal plates.

Front 35

Metaphyseal arteries

Back 35

Supply the ends of long bones and arise from the arteries that supply the associated joint. enter the metaphysis of a long bone and together with the nutrient artery, supply the red bone marrow and bone tissue to the metaphysis.

Front 36

Epiphyseal arteries

Back 36

Supplied the end of long bones and arise from arteries that supply the associated joint. These enter the at the epiphysis of a long bone is supplied the red bone marrow and bone tissue epiphyses

Front 37

What are the three types of veins that carry blood away from long bones?

Back 37

1. One or two nutrient veins on company the nutrient artery and exit through the diaphysis

2. Numerous epiphyseal veins and metaphyseal veins accompany their respective arteries and exit through the epiphyses

3. Many small periosteum veins accompany their respective artery and exit through the periosteum

Front 38

Ossification or osteogenesis

Back 38

The process by which bones form. Bone formation occurs in four principal situations -

1. The initial formation of bones in an embryo and fetus

2. The growth of bones during infancy, childhood, and adolescence until their adult sizes are reached

3. The remodeling of bone

4. The repair of fractures throughout life

Front 39

Intramembranous ossification

Back 39

bone forms directly within mesenchyme , which is arranged in sheet like layers that resemble membranes

Front 40

Endochondral ossification

Back 40

bone forms within hyaline cartilage that develops from mesenchyme

Front 41

Describe the development of the ossification center in the intramembranous ossification process.

Back 41

At the site where the bone will develop, specific chemical messages cause the mesenchymal cells to cluster together and differentiate, first into osteogenic cells and then into osteoblasts. The sight of such a cluster is called ossification center. Osteoblasts secrete the organic extracellular matrix of bone until they are surrounded by it.

Front 42

Describe the calcification process in intramembranous ossification.

Back 42

Next the secretion of the extracellular matrix tops, and the cells, now called osteocyte, lie in lancunae and extend their narrow cytoplasmic processes into canaliculi that radiates in all directions. Within a few days, calcium and other mineral salts are deposited in the extracellular matrix hardens or calcifies

Front 43

Describe the formation of trabeculae in intramembranous ossification.

Back 43

As the bone extracellular matrix forms, it develops into trabeculae that fuse with one another to form spongy bone around the network of blood vessels in the tissue. Connective tissue that is associated with the blood vessels in the trabecule differentiates into red bone marrow

Front 44

Describe the development of the periosteum in intramembranous ossification.

Back 44

In conjunction with the formation of trabeculae, the mesenchyme condenses at the periphery of the bone and develops into the periosteum. Eventually, a thin layer of compact bone replaces the surface layers of the spongy bone, but spongy bone remains in the center. Much of the newly-formed bone is remodeled comet destroyed and reformed, as the bone is transformed into its adult size and shape.

Front 45

Describe the development of the cartilage model and endochondral ossification.

Back 45

At the site where the bone is going to form, specific chemical messages cause the mesenchymal cells to crowd together in general shape of a future bone, and then develop into chondroblasts. The chondroblasts secrete cartilage extracellular matrix, producing a cartilage model consisting of hyaline cartilage. A covering called me perichondrium develops around the cartilage model.

Front 46

describe the growth of the cartilage model and endochondral ossification.

Back 46

Once chondroblasts become deeply buried in the cartilage extracellular matrix, they are called chondrocytes. The cartilage model grows in length by continual cell division of chondrocytes, accompanied by further secretion of the cartilage extracellular matrix. This type of gross, called interstitial growth, results in an increase in length. In contrast growth of the cartilage in thickness is due mainly to the deposition of extracellular material on the cartilage surface of the model by new chondroblasts that developed from the perichondrium.

Front 47

Oppositional, or exogenous, growth

Back 47

Growth of the cartilage in thickness due mainly to the deposition of extracellular matrix material on the cartilage surface of the model by new chondroblasts develop from the perichondrium

Front 48

Describe the development of the primary ossification center in endochondral ossification.

Back 48

Primary ossification precedes any word from the external surface of the bone. A nutrient are very penetrate the perichondrium calcifying cartilage model through a nutrient for a min in the middle region of the cartilage model , stimulating osteogenic cells in the perichondrium to differentiate into osteoblasts. Once the perichondrium starts to form the phone, it is known as the periosteum. Near the middle of the model, periosteal capillaries grow into the disintegrating calcified cartilage inducing gross of a primary off vacation center, a region where bone tissue will replace most of the cartilage. Osteoblast then begin to deposit bone extracellular matrix over the remnants of calcified cartilage, forming spongy bone trabeculae. primary ossification spreads from central location towards both ends of the cartilage model

Front 49

Describe the development of the medullary cavity in endochondral ossification.

Back 49

as the primary off vacation center growth toward the end of the bone, osteoclasts break down some of the newly-formed spongy bone trabeculae. This activity we have a cavity, the medullary cavity, and the diaphysis. Eventually most of the wall of the diaphysis is replaced by compact bone

Front 50

Describe the development of the secondary ossification centers in endochondral ossification.

Back 50

when branches of the epiphyseal artery enter the epiphyses, secondary ossification centers develop, usually around the time of birth. Bone formation is similar to what occurs and primary off vacations centres. However the secondary ossification center is spongy bone remains in the interior of the epiphyses. in contrast to primary ossification, secondary ossification Christine outward from the center of the epiphysis toward the outer surface of the bone.

Front 51

describe the formation of articular cartilage and the epiphyseal growth plate in endochondral ossification.

Back 51

The hyaline cartilage that covers the epiphyses becomes the articular cartilage. Prior to adulthood, hyaline cartilage remains between the diaphysis and epiphysis as the epiphyseal plate, the region responsible for the lengthwise growth of long bones

Front 52

What are the two major events in the growth of long bones lengthwise?

Back 52

1. Interstitial growth of cartilage on the epiphyseal side of the epiphyseal plate

2 . replacement of cartilage on the diaphyseal side of the epiphyseal plate with bone by endochondral ossification

Front 53

What are the 4 zones of the epiphyseal plate?

Back 53

1. Zone of resting cartilage

2. Zone of proliferating cartilage

3. Zone of hypertrophic cartilage

4. Zone of calcified cartilage

Front 54

Zone of resting cartilage

Back 54

This player is nearest the epiphysis and consists of small, scattered chondrocytes. The term, resting, is used because the cells do not function in bone growth. Rather, the anchor the epiphyseal plate to the epiphysis of the bone.

Front 55

Zone of proliferating cartilage

Back 55

Slightly larger chondrocytes in this zone our range like stacks of coins. These chondrocytes undergo interstitial growth as they divided into create extracellular matrix. The chondrocytes in this zone divide to replace those that died at that diaphyseal side of the epiphyseal plate.

Front 56

Zone of hypertrophic cartilage

Back 56

This layer consists of large, maturing chondrocytes arranged in columns.

Front 57

Zone of calcified cartilage

Back 57

The final zone of the eposide seal plate is only a few cells thick and consists mostly of chondrocytes that are dead because the extracellular killer matrix around then have calcified. Osteoclast dissolve the calcified cartilage, and osteoblasts and capillaries from the diaphysis invade the area. The osteoblasts way down bone extracellular matrix, replacing the calcified cartilage by the process of endochondral ossification. Recall that endochondral ossification is the replacement of cartilage with bone. As a result, the zone of calcified cartilage becomes the new diaphysis that is firmly cemented to the rest of the diaphysis of the bone.

Front 58

epiphyseal line

Back 58

When epiphyseal cartilage stops dividing and bone replaces all remaining cartilage the epiphyseal plate fades, leaving a bony structure

Front 59

Fracture

Back 59

Any break in a bone. Fractures are named according to their severity, the shape or position of the fraction line, or even the physician first described them.

Front 60

Open or compound fracture

Back 60

The broken in the bone protruding through the skin.

Front 61

Comminuted fracture

Back 61

The bone is splintered, crushed, or broken into pieces at the site of impact, the smaller bone fragmentslie between the two main fragments

Front 62

Greenstick fracture

Back 62

A partial fracture of which one side of the bone is broken in the other side bends: somewhere to the way a green twig brakes on one side while the other side stay as hole, but then, occur only in children, whose bones are not fully ossified and contain more organic material in an inorganic materialawesome 5 and contain more organic material then in organic pictures

Front 63

Pott fracture

Back 63

Fracture of the distal end of the lateral leg bone fibula, with serious injury of the distal tibial articulation

Front 64

Colles fracture

Back 64

Fracture of the distal end of the lateral forearm bone radius, in which the distal fragment is displaced posteriorly

Front 65

Stress fracture

Back 65

A series of microscopic fissures in bone that forms without any evidence of injury to other tissue

Front 66

Impacted fracture

Back 66

One and the fractured bone is forcefully driven into the interior of the other

Front 67

Reduction of a fracture

Back 67

Aligning the fractured ends, commonly referred to as setting a fracture

Front 68

What are the four steps of repairing a bone fracture?

Back 68

1. Formation of fracture hematoma

2. Fibrocartilaginous callus formation

3. Bony callus formation

4. Bone remodeling

Front 69

Describe the formation of a fracture hematoma in bone repair

Back 69

Blood vessels crossing the fracture line are broken. As blood leaks from the torn ends of the vessels, a massive blood forms around the side of the fracture. This massive blood, called a fracture hematoma usually forms 6 to 8 hours after the injury. Because the circulation of blood stops at the site where the fracture hematoma forms nearby bone cells die. Swelling and inflammation occurs in response to dad both cells, producing additional cellular debris. Phagocytes and osteoclasts begin to remove the dead or damaged tissue and end around the fracture hematoma. This stage may last up to several weeks.

Front 70

Describe fibrocartilaginous callus formation in bone repair

Back 70

Fibroblasts from the periosteum invade the fracture site and produce collagen fibers. In addition, cells from the periosteum develop inta chondroblasts and begin to reduce fibrocartilage in this region. These events lead to the development of a 50 cartilaginous Calais, a mass of repair tissue consisting of collagen fibers and cartilage that bridge the broken ends of the bone. Formation of the fibrocartilaginous callus takes about 3 weeks

Front 71

Describe bony callus formation in bone repair

Back 71

In areas closer to well vascularized healthy bone tissue, osteogenic cells develop and osteoclasts, which begins for do spongy bone trabeculae. The trabeculae join living and dead portions of the original bone fragments. In time, the fibro cartilage is converted into spongy bone, and the callus is then referred to as a bony Callas. The bony callus lasts about 3 to 4 months.

Front 72

Describe bone remodeling in bone repair

Back 72

The final phase of fracture repair is bone remodeling of the callus. dead portions of the original fragments of broken bone are gradually reabsorbed by osteoclasts. compact bone replaces spongy bone around the periphery of the fracture. Sometimes, the repair process is so throw that the fracture line is undetectable, even by radiograph. However, a thickened area on the surface of the bone remains as evidence of a healed fracture.

Front 73

Describe the process by which parathyroid hormone regulates the calcium ion level in homeostasis.

Back 73

PTH secretion operates via a negative feedback system:

1. Some stimulus causes the blood calcium levels to decrease

2. Parathyroid gland cells detect a change and increase their production of AMP

3. The PTH gene detects the increase in AMP

4. PTH Santa synthesis speeds up and PTH is released into the blood

5. The presence of the PTH increases the activity of osteoclasts, which break down bone, releasing calcium into the system

Front 74

How does calcium and phosphorus impact bone

Back 74

Make bone extracellular matrix hard

Front 75

How does magnesium impacts the bone

Back 75

Helps form bone extracellular matrix

Front 76

How does fluoride impact bone

Back 76

Help strengthen bone extracellular matrix

Front 77

How does manganese impact bone

Back 77

Activates enzymes involved in synthesis of bone extracellular matrix.

Front 78

How does vitamin A Impact bone ?

Back 78

Needed for the activity of osteoblasts during the remodeling of bone: deficiency stunts bone growth: toxic in high doses

Front 79

How does vitamin C impact bones?

Back 79

Needed for synthesis of collagen, the main phone protein: deficiency leads to decreased collagen production, which slows down bone growth and delays repair of broken bone

Front 80

How does vitamin D impact bone?

Back 80

Active form, calcitriol, is produced by the kidneys: helps build bone by increasing absorption of calcium from gastrointestinal tract into blood: deficiency causes faulty calcification and slows down bone growth: may reduce the risk of osteoporosis but is toxic if taken in high doses

Front 81

how does vitamins K and b12 compact bone?

Back 81

Needed for synthesis of bone proteins : deficiency leads to abnormal protein production in bone extracellular matrix and decreased bone density

Front 82

How does human growth hormone impact

Back 82

Secreted by the anterior lobe of the pituitary gland, promote general growth of all body tissues, including bone, mainly by stimulating production of insulin-like growth factors

Front 83

how do fibroids hormones impact bone?

Back 83

Secreted by the pancreas: promote normal bone growth by increasing the synthesis of bone protein

Front 84

How does sex hormones impact bone?

Back 84

Secreted by the ovaries and women in by the testes and Men, stimulates osteoblasts and promote the sudden growth spurts that occur in the teenage years. Shut down growth of the epiphyseal plate around age 18 to 21. this causes lengthwise growth of the bone to end, and contribute to the bone remodeling during adulthood by falling bone reabsorption by osteoclast and promoting bone deposition by osteoblast

Front 85

How does parathyroid hormone impact bone?

Back 85

Succeeded by the parathyroid gland, it promotes bone reabsorption by osteoclasts, enhances recovery of calcium ions from urine, and promote the formation of the active form of vitamin D, calcitriol

Front 86

describe how calcitonin impacts bone

Back 86

Secreted by the thyroid gland, it inhibits bone reabsorption by osteoclast