BIOL 2301- Chapter 6-4: Compact bone contains

The femur can withstand ____ to ____ times the body's weight without breaking.

10 to 15 times

_________ lamellae are found at the outer and inner surfaces of the bone, where they are covered by the periosteum and endosteum. These lamellae are produced during the growth of the bone.

Circumferential lamellae (circum-, around + ferre, to bear)

Compare the structures and functions of compact bone and spongy bone:

Compact bone consists of osteons (Haversian systems) with little space between them. Compact bone lies over spongy bone and makes up most of the diaphysis. It functions to protect, support, and resist stress. Spongy bone consists of trabeculae with numerous red marrow-filled spaces. Spongy bone makes up most of the structure of short, flat, and irregular bones and is also found at the epiphyses of long bones. Spongy bone functions in storing marrow and providing some support.

In spongy bone, osteons are present. True, False?

False

The matrix in spongy bone forms a fluid of supporting bundles of fibers called trabeculae (tra-BEK-ū-lē) true,false?

False, The matrix in spongy bone forms a MESHWORK of supporting bundles of fibers called trabeculae (tra-BEK-ū-lē)

Spongy bone can be found within the epiphyses of long bones, such as the________.

Femur

What do Interstitial lamellae do?

Interstitial lamellae fill in the spaces between the osteons in compact bone. These lamellae are remnants of osteons whose matrix components have been almost completely recycled by osteoclasts.

What are the three ways in which lamellae are organized in compact bone?

Lamellae are organized concentrically around an osteon, interstitially between osteons, and circumferentially around the entire bone.

The osteons in the diaphysis of a long bone are __________ to the long axis of the shaft. For this reason, the shaft does not bend, even when extreme forces are applied to either end. anterior distal parallel contra

Parallel

Spongy bone within the epiphyses of long bones and the interior of other large bones, contains ________ bone marrow, which forms _______ ________cells.

Red bone marrow, Red blood cells

In ___________ bone, lamellae are not arranged in osteons. No osteons are present. The matrix forms a meshwork of supporting bundles of fibers called trabeculae. These thin trabeculae branch, creating an open network. The trabeculae are oriented along stress lines and extensively cross-braced.

Spongy

Compact bone is thickest where_________ has been applied from a limited number of directions.

Stress

Give an example of how compact bone and spongy bone work together to support the body's weight:

The femur, or thigh bone, has a diaphysis (shaft) with walls of compact bone and epiphyses filled with spongy bone. The body weight is transferred to the femur at the hip joint. Because the hip joint is off center relative to the axis of the shaft, the body weight is distributed along the bone in a way that compresses the medial (inner) portion of the shaft and stretches the lateral (outer) portion.

Select the correct words for the following sentence: The (endosteum/or periosteum) covers the superficial layer of compact bone and is made up of (the fibrous and cellular layers/or osteoblasts, osteoclasts, and osteocytes).

The periosteum covers the superficial layer of compact bone and is made up of the fibrous and cellular layers.

What do perforating canals, aka Volkmann's (FŌLK-manz) canals, do?

They extend perpendicular to the surface. Blood vessels in these canals supply blood both to osteons deeper in the bone and to tissues of the medullary cavity.

In spongy bone, lamellae are not arranged in osteons. True,false?

True

Perforating (or Sharpey's) fibers is a method of attachment that bonds the tendons and ligaments into the general structure of the bone. This provides a much stronger attachment than would otherwise be possible. True/False?

True

There are no capillaries or venules in the matrix of spongy bone. True, false?

True

spongy bone is less dense than compact bone. True, False?

True

An extremely powerful pull on a tendon or ligament will usually ______ a _______rather than ________ the_____________ ___________ at the bone surface.

break a bone, snap the collagen fibers

The lamellae (thin plates) of each osteon form a series of nested cylinders around the ________ canal. In transverse section, these concentric lamellae create a targetlike pattern, with the central canal as the bull's-eye. Collagen fibers within each lamella form a spiral pattern that adds strength and resiliency.

central canal

The _______ canal aka __________ canal, contains one or more blood vessels (normally a capillary and a venule) that carry blood to and from the osteon. _________ canals generally run parallel to the surface of the bone.

central canal aka Haversian canal, Central

The ___________, an incomplete cellular layer, lines the medullary cavity. This layer is active during bone growth, repair, and remodeling. It covers the trabeculae of spongy bone and lines the inner surfaces of the central canals of compact bone.

endosteum

The ____________ (thin plates) of each osteon form a series of nested cylinders around the central canal.

lamellae

Bone matrix forms layers called Bone matrix forms layers called __________.

lamellae (lah-MEL-lē ; singular, lamella, a thin plate).

While spongy bone provides:

moderate support and stores marrow.

The endosteum consists of a simple flattened layer of ___________ cells that covers the bone matrix, generally without any intervening connective tissue fibers. Where the cellular layer is not complete, the matrix is exposed. At these exposed sites, osteoclasts and osteoblasts can remove or deposit matrix components.

osteogenic

At the microscopic level, the basic functional unit of mature compact bone is the ______________, aka ______________ system.

osteon (OS-tē-on) aka Haversian (ha-VER-jhun)

Compact bone contains ____________ ____________, and spongy bone contains _________.

parallel osteons, trabeculae

The fibers of the periosteum are interwoven with those of the tendons attached to the bone. As the bone grows, these tendon fibers are cemented into the circumferential lamellae by osteoblasts from the cellular layer of the periosteum. Collagen fibers incorporated into bone tissue from tendons and ligaments, as well as from the superficial periosteum, are called ________-(aka_________) fibers.

perforating (Sharpey's)

Except within joint cavities, the superficial layer of compact bone that covers all bones is wrapped by a __________________, a membrane with a fibrous outer layer and a cellular inner layer. The __________________ isolates the bone from surrounding tissues, provides a route for the blood vessels and nerves, and takes part in bone growth and repair.

periosteum (peri, around),

Bones have two kinds of coverings:______________ on the outside and __________ lining the inside.

periosteum, endosteum

Compact bone functions to:

protect, support, and resist stress.

Spongy bone is found where bones are not heavily _________ or where _______ originates from many directions.

stress

At a joint that permits significant amounts of movement, called a ____________ joint, the periosteum is continuous with the joint capsule.

synovial (si-NŌ-vē-ul)

A sample of long bone has lamellae, which are not arranged in osteons. Is the sample most likely taken from the epiphysis or diaphysis?

the presence of lamellae that are not arranged in osteons is indicative of spongy bone, which is located in an epiphysis.

Spongy bone can be found in the interior of other large bones such as the ________ and _________(a large bone of the pelvis).

the sternum and ilium

In an osteon, the osteocytes are arranged in concentric layers around a _________ canal, aka _______ canal.

vascular central canal, or Haversian (ha-VER-jhun) canal .