Chapter 6: The Skeletal System - Bone Tissue Flashcards
Chapter 6: The Skeletal System - Bone Tissue
The skeletal system has 6 important functions they are?
Support, Protection, Assistance in movement, Mineral homeostasis, Blood cell production, and Triglyceride storage.
The two major tissues of the Skeletal System are?
Bone (osseous tissue) and cartilage.
Bone is found in the body in what two different arrangements?
Compact bone and Spongy bone
Compact bone is good at providing?
protection and support.
Spongy bone is lightweight and
provides?
tissue support
Spongy forms much of the epiphysis and?
the internal cavity of long bones.
Bone is a highly _____ C.T. with a hard, mineralized extracellular matrix.
vascularized
Cartilage is a poorly _____ C.T. with a matrix composed of chondroitin sulfate and various fibers.
vascularized
Fiber types distinguish ____
cartilage from _____ or
____ cartilage.
hyaline, fibrocartilage, or elastic.
What cartilage is the thin layer of hyaline cartilage covering the epiphysis of long bones?
Articular
What cartilage is found where the bone forms an
articular (joint) surface (where one bone moves against another bone)?
Articular
What is a tough sheath of dense, irregular connective tissue on the outside of the bone?
The periosteum
The periosteum contains _____ that help the bone grow in thickness, but not in length.
osteoblasts
What assists with fracture repair and serves as an attachment point for tendons and ligaments?
The periosteum
What is a space within the diaphysis of long bones that contains fatty yellow bone marrow in adults?
medullary cavity
What is a membrane that
lines the medullary cavity?
endosteum
What is composed of
osteoclasts, osteoblasts, and
connective tissue?
endosteum
What is a dense irregular connective tissue membrane that surrounds cartilage?
perichondrium
What are cells that
form cartilage?
Chondrocytes
Four types of cells are present in bone tissue they are?
Osteogenic, Osteoblast , Osteocytes , and Osteoclast.
What are bone building cells? They synthesize and secrete collagen fibers and other organic components.
Osteoblasts
What are mature osteoblasts (maintenance).
Osteocytes
What are large bone breakdown cells and are derived from the fusion of 50 monocytes?
Osteoclasts
As white blood cells, osteoclasts migrated from the bone marrow to become ____ ____ in the substance of the bone.
“fixed macrophages”
Besides bone and cartilage, the skeletal system contains other important tissues. They are?
Epithelium, Nerves, Red marrow, and Yellow marrow.
Bone is ___% water, ____% organic proteins, ___% mineral salts (hydroxyapatite crystals).
25, 25, and 50
What fibers provide flexibility and tensile strength?
Collagen (Organic constituents)
The ____ in the arm is a typical long bone.
humerus
What is the shaft or
body of a long bone?
diaphysis
What forms the distal
and proximal ends of a
long bone?
epiphyses
What are the areas
where the epiphyses and
diaphysis join?
metaphyses
In adolescents, through the end of active growth, the epiphysis of the long bones contains hyaline cartilage and forms an?
“epiphyseal growth plate”.
The epiphyseal growth plate is always actively dividing and causing the bone to?
elongate from each end.
In adults, the epiphyseal cartilage is no longer present and elongation of bones has stopped. The epiphyseal growth plate becomes an \_\_\_\_ \_\_\_\_ as growing cartilage is replaced by calcified bone.
“epiphyseal line”,
Interstitial lamellae
between osteons are left
over fragments of older?
osteons
What encircles the bone beneath the periosteum?
Outer circumferential lamellae
What encircles the medullary
cavity?
Inner circumferential lamellae
What are small spaces
between the lamellae which
house osteocytes?
Lacunae
What are small channels filled with extracellular fluid connecting the lacunae?
Canaliculi
Blood and lymphatic vessels
are found in the osteon’s?
Central canal.
What allows transit of
Blood and lymphatic vessels to the outer cortex of the bone?
Perforating (Volkmann’s)canals
Spongy bone lacks osteons. Instead, lamellae are arranged in a lattice of thin columns called?
trabeculae.
What spongy bone tissue supports and protects the red bone marrow and are oriented along lines of stress?
Trabeculae
Hematopoiesis (blood cell production) occurs in?
spongy bone.
Within each trabecula of spongy bone are?
lacunae
As in compact bone, lacunae contain osteocytes that nourish the mature bone tissue from the blood circulating through the?
trabeculae.
The interior of long bones is made up primarily of? This lessens overall bone weight.
spongy bone.
Bone is richly supplied with blood; ____ arteries and veins supply the periosteum and compact bone.
Periosteal
What is rich in sensory nerves and is sensitive to tearing or tension?
The periosteum
____ or ____ is the process of forming new bone.
Ossification or osteogenesis
Bone formation occurs in four situations. They are?
Formation of bone in an embryo, Growth of bones until adulthood, Remodeling of bone, and Repair of fractures
Osteogenesis occurs by two different methods, beginning about the 6th week of embryonic development. The two methods are?
Intra-membranous ossification and Endochondral ossification
What Osteogenesis method produces spongy bone?
Intra-membranous ossification
What Osteogenesis method forms both compact and spongy bone?
Endochondral ossification
What is a process whereby cartilage is replaced by bone?
Endochondral ossification
What Osteogenesis method is used in forming the flat bones of the skull, mandible, and clavicle?
Intra-membranous ossification
Bone forms from ____ cells that develop within a membrane – without going through a cartilage stage
mesenchymal
Intra-membranous ossification occurs in what four steps?
Development of the ossification center, Calcification, Formation of Trabeculae, and development of the periosteum.
Endochondral ossification occurs in what six steps?
Development of the cartilage model, Growth of the cartilage model, Development of the medullary cavity, Development of the secondary ossification center, and formation of articular cartilage and the epiphyseal plate.
Ossification contributing to bone length is usually complete by ___-___ years of age.
18-21
Bones can still continue to thicken and are capable of repair even after the ____ ____ plates have closed.
epiphyseal growth
The epiphyseal plate becomes the epiphyseal ____ when the bone matures.
Line
Mesenchyme (stem) bone cells mature into?
Osteogenic bone cells
Osteogenic bone cells mature into?
Osteoblast bone cells (Building)
Osteoblast bone cells mature into?
Osteocytes (maintenance)
What product is derived from the breaking down of bone by Osteoclast?
Calcium
Calcium is important for neural communication and?
Muscle contraction, bone formation, neural communication
Osteoblast and Osteoclast communicate with each other to provide what?
Bone remodeling
Human growth hormone is one of the body’s many anabolic hormones. Among other things, its secretion will stimulate bone growth, muscle growth, loss of fat, and?
increased glucose output in the liver.
In bone remodeling, do Osteoblast reduce or increase the amount of calcium in the blood?
Reduce
In bone remodeling, is calcitonin associated with Osteoblast or Osteoclast?
Osteoblast
In bone remodeling, is the increase of calcium is associated with Osteoblast or Osteoclast?
Osteoclast
In bone remodeling, the Parathyroid hormone (PTH) is associated with Osteoblast or Osteoclast?
Osteoclast
Vitamin A stimulates activity of?
osteoblasts.
Vitamin C is needed for synthesis of?
collagen
What vitamin is essential to healthy bones because it promotes the absorption of calcium from foods in the gastrointestinal tract into the blood?
Vitamin D
Vitamins K and B12 are needed for synthesis of?
bone proteins.
What are key contributors to normal bone metabolism?
Hormones
During childhood, the hormones most important to bone growth are ___ and growth factors called?
human growth hormone (hGH),
IGFs (produced by the liver).
Thyroid hormones and ____ also promote bone growth by stimulating osteoblasts and protein synthesis.
insulin
The sex hormones ____ and ____ cause a dramatic effect on bone growth, such as the sudden “growth spurt” that occurs during the teenage years.
(estrogen and testosterone)
Parathyroid hormone (PTH) and ____ are critical for balancing the levels of calcium and phosphorus between blood and bone.
calcitonin
Vitamin D is needed for absorption of the Ca2+ (Calicum) and ____ ions from the small intestine, and reabsorption of those same ions in the kidneys.
(Phosphate) PO4–
What kind of fracture occurs when one side of the bone breaks and the other side bends?
Greenstick
What kind of fracture occurs when one end of the fractured bone is forcefully driven into the interior of the other?
Impacted
What kind of fracture occurs when the bone is splintered, crushed, or broken into pieces at the site of impact, and smaller bone fragments lie between the two main fragments?
Comminuted
What kind of fracture occurs when the broken ends of the bone protrude through the skin ?
Open (Compound)
What kind of fracture occurs when the broken ends of the bone do not break the skin?
Closed (Simple)
What kind of fracture occurs in the distal end of the lateral leg bone (fibula), with serious injury of the distal tibial articulation?
Pott
What kind of fracture occurs when the distal end of the lateral forearm bone (radius) in which the distal fragment is displaced posteriorly?
Colles’
A Pathological fracture is caused from?
Usually from a cancerous process or severe chronic disease
A compression fracture is caused by?
produced by extreme forces such as in trauma
Stress fracture is produced from?
Repeated strenuous activities such as running
Once a bone is fractured, repair proceeds in a predictable pattern. The first step, which occurs 6-8 hours after injury, is the formation of a?
fracture hematoma as a result of blood vessels breaking in
the periosteum and in osteons.
The second and third steps of bone repair involve the formation of a?
Bone callus (takes a few weeks, to as many as six months).
The fourth step of bone repair is?
Bone remodeling.
A decrease in bone mass occurs as the level of sex hormones diminishes during what age?
middle age (especially in women after menopause).
There are two principal effects of aging on bone tissue. They are?
Loss of bone mass, and Brittleness
Osteoporosis is a condition where bone resorption outpaces?
Bone deposition, Often due to depletion of calcium from the body or inadequate intake
Starting from the diaphysis and proceeding to the epiphysis list the zones of interstitial growth.
Calcified Cartlidge, Hypertrophic Cartlidge, Proliferating Cartlidge and Resting Cartlidge.
