Ch. 6 Gross Anatomy of Bone

another name for spongy bone

trabeculae (trah-bek'u-le; "little beams").

in living bones, the open spaces between trabeculae are filled with
__________________________________________.

red or yellow bone marrow

What is a Diaphysis

A tubular diaphysis, or shaft, forms the long axis of the bone.

Describe the construction of the diaphysis

It is constructed of a relatively thick collar of compact bone that surrounds a central medullary cavity

What's a medullary cavity?

it's a narrow cavity, that contains no bone tissue. Instead, the medullary cavity contains yellow marrow (fat) in adults and so is called the yellow marrow cavity.

What's often between the marrow and the compact bone?

there is often a thin layer of spongy bone.

What's the epiphyses?

The epiphyses (e-pif'i-sez; singular: epiphysis) are
the bone ends (epi = upon).

describe the composition of the epiphyses

An outer shell of compact bone forms the epiphysis exterior and the interior contains spongy bone. A thin layer of articular (hyaline) cartilage covers the joint surface of each epiphysis, cushioning the opposing bone ends during movement and absorbing stress.

What's the thing between the diaphysis and each epiphysis of an adult long
bone? Why is it there?

an epiphyseal line, a remnant of the epiphyseal plate

What's an epiphyseal plate?

The epiphyseal plate, commonly called the growth plate,
is a disc of hyaline cartilage that grows during childhood to
lengthen the bone.

What's a metaphysis?

The flared portion of the bone where the
diaphysis and epiphysis meet, whether it is the epiphyseal plate
or line, is called the ,metaphysis (meta = between).

What is the outer fibrous layer of the periosteum made of?

Dense irregular connective tissue

what's a periosteum?

A glistening white, double-layered membrane that covers the external surface of the entire bone except the
joint surfaces.

true of false: the periosteum covers the joint surfaces

false, the periosteum covers the external surface of the entire bone except the joint surfaces.

what is the outer fibrous layer of the periosteum made of?

dense irregular connective tissue

What type of cells are found in the inner osteogenic layer of the periosteum?

Osteoprogenitor cells, osteoclasts, and osteoblasts

What are osteoprogenitor cells? what do they do?

They are primitive stem cells that give rise to most bone cells

What are osteoclasts?

Bone-destroying cells

what are osteoblasts?

bone forming cells

what are Perforating fibers? what do they do?

Perforating fibers are bundles of collagen fibers that extend into the bone matrix and function to secure the periosteum to the underlying bone

Why are broken bones painful and bleed profusely?

Because the periosteum is richly supplied with nerve fibers and blood vessels

What secures the periosteum to the underlying bone?

Perforating fibers - bundles of collagen fibers that extend into the bone matrix

What do the perforating fibers in the periosteum provide anchoring points for?

Tendons and ligaments

At what points are the perforating fibers exceptionally dense?

perforating fibers are exceptionally dense at the periosteum's anchoring points for tendons and ligaments

What covers internal bone surfaces?

endosteum

What all does the endosteum cover?

The endosteum covers the trabeculae of spongy bone and lines the canals that pass through the compact bone

The endosteum contains the same cell types as the _____________________________

inner layer of the periosteum

The main vessels serving the diaphysis are a ______________ and a __________________. Together these run through a hole in the wall of the diaphysis, the __________________________.

The main vessels serving the diaphysis are a nutrient artery and a nutrient vein. Together these run through a hole in the wall of the diaphysis, the nutrient foramen (fo-ra'men; "opening").

Describe how the nutrient artery runs and what it supplies

The nutrient artery runs inward to supply the bone marrow and the spongy bone. Branches then extend outward to supply the compact bone.

What supplies each epiphysis?

Several epiphyseal arteries and veins serve each epiphysis in the same way as the nutrient arteries and veins do the diaphysis

_____________ accompany blood vessels through the nutrient foramen into the bone.

Nerves

Hematopoietic (blood-forming) tissue is also called __________________

red marrow

true or false: adult bones contain fat that extends all the way into the epiphyses

true, In adults, much of the red marrow, particularly in long bones, has been replaced by yellow marrow. In most adult long bones, the fat-containing yellow marrow extends well into the epiphysis

true or false: epiphyses and diaphysis are universal terms to all bone types

false, the terms are specific to long bone

true or false: red marrow in adults is mostly found in the spongy bone cavities of long bones

false. Little red marrow is present in the spongy bone cavities. As a result, red marrow in adults is only found in the cavities between trabeculae of spongy bones in:
• The flat bones of the skull, as well as the sternum, ribs, clavicles,
scapulae, hip bones, and vertebrae
• The heads of the femur (thigh bone) and humerus (long bone
of the arm)

When clinicians suspect problems with the blood-forming tissue, they obtain red marrow samples from _________ because ____________________

the spongy bone of flat bones (such as the sternum) and in some irregular bones (such as the hip bone) because they are much more active in hematopoiesis

true or false: yellow marrow in the medullary cavity can revert to red marrow if a person becomes very anemic (has low oxygen-carrying capacity) and needs more red blood cells

True

What are the 3 categories of bony markings

projections, surfaces, depressions/openings

Projections are _______________

sites of muscle and ligament attachment

surfaces form ______

joints

depressions and openings are for _________

blood vessels and nerves