Chapter 6: Bone Tissue and the Skeletal System

epiphysis

Each ________ meets the diaphysis at the metaphysis, the narrow area that contains the epiphyseal plate (growth plate), a layer of hyaline (transparent) cartilage in a growing bone.

somemotion

Provide stability, support, while allowing for ________.

nutrient foramen

The arteries enter through the ________ (plural= foramina), small openings in the diaphysis.

long cytoplasmic processes

They can communicate with each other and receive nutrients via ________ that extend through canaliculi (singular= canaliculus), channels within the bone matrix.

Blood vessels

________ and nerves enter the bone through the nutrient foramen.

proliferation

Stimulates osteoclast ________ and resorption of bone by osteoclasts; promotesreabsorption of calcium by kidney tubules; indirectly increases calcium absorption by small intestine.

inflammation

Reduces ________ that may interfere with osteoblast function.

synthesis of bone

Stimulates bone growth and promotes ________ matrix.

Increases length of long bones

________, enhances mineralization, and improves bone density.

hard compact bone

The walls of the diaphysis are composed of dense and ________.

**Bone**

or osseous tissue, is a hard, dense connective tissue that forms most of the adult skeleton, the support structure of the body.

**skeletal system**

is the body system composed of bones and cartilage

**Yellow marrow**

contains adipose tissue; the triglycerides stored in the adipocytes of the tissue can serve as a source of energy. 

**Red marrow**

is where **hematopoiesis**—the production of blood cells—takes place.

A long bone has two parts

the diaphysis and the epiphysis

The outer surface of the bone is covered with a fibrous membrane called the periosteum (peri

= "around" or "surrounding")

Fractures

Bone Repair

Calcium Homeostasis

Interactions of the Skeletal System and Other Organ Systems

Hypo

or hypercalcemia occurs when this level is not maintained

**long bone**

is one that is cylindrical in shape, being longer than it is wide.

**short bone**

is one that is cube-like in shape, being approximately equal in length, width, and thickness.

**flat bone**

* is somewhat of a misnomer because, although a flat bone is typically thin, it is also often curved.

irregular bone

is one that does not have any easily characterized shape and therefore does not fit any other classification.

**sesamoid bone**

is a small, round bone that, as the name suggests, is shaped like a sesame seed.

**diaphysis and epiphysis**

A long bone has two parts 

**medullary cavity**

The hollow region in the diaphysis is called the **___** which is filled with yellow marrow. 

**compact bone**

* The walls of the diaphysis are composed of dense and hard

**endosteum**

The medullary cavity has a delicate membranous lining called the

**articulation**

is where two bone surfaces come together (articulus = “joint”).

**projectio**n

is an area of a bone that projects above the surface of the bone.

**hole**

is an opening or groove in the bone that allows blood vessels and nerves to enter the bone.

**osteoblast**

is the bone cell responsible for forming new bone and is found in the growing portions of bone, including the periosteum and endosteum.

**lacuna**

Each osteocyte is located in a space called a

**osteocyte**

the primary cell of mature bone and the most common type of bone cell.

**osteon**

The microscopic structural unit of compact bone is called an

**spongy bone**

also known as *cancellous bon*e

**trabeculae**

the lacunae and osteocytes are found in a lattice-like network of matrix spikes called__ (singular = trabecula).

**nutrient foramen**

The arteries enter through the **___** (plural = foramina), small openings in the diaphysis.

**intramembranous ossification**

, compact and spongy bone develops directly from sheets of mesenchymal (undifferentiated) connective tissue.

**ossification center**

Although they will ultimately be spread out by the formation of bone tissue, early osteoblasts appear in a cluster called an

**reserve zone**

is the region closest to the epiphyseal end of the plate and contains small chondrocytes within the matrix.

**proliferative zone**

is the next layer toward the diaphysis and contains stacks of slightly larger chondrocytes.

**zone of calcified matrix**

Most of the chondrocytes in the **___** the zone closest to the diaphysis, are dead because the matrix around them has calcified.

**epiphyseal line**

All that remains of the epiphyseal plate is the

**fracture**

is a broken bone

**closed reduction**

When a broken bone is manipulated and set into its natural position without surgery, the procedure is called a

**Open reduction**

requires surgery to expose the fracture and reset the bone.

**fracture hematoma**

The blood begins to clot, and about six to eight hours after the fracture, the clotting blood has formed a

**Hypocalcemia**

a condition characterized by abnormally low levels of calcium, can have an adverse effect on a number of different body systems including circulation, muscles, nerves, and bone.

**hypercalcemia**

a condition characterized by abnormally high levels of calcium, the nervous system is underactive, which results in lethargy, sluggish reflexes, constipation and loss of appetite, confusion, and in severe cases, coma.