BIO 141 ch 7

What are the zones of an epiphyseal place in their correct order:

1. Zone of resting cartilage 2. Zone of proliferating cartilage 3. Zone of hypertrophic cartilage 4. Zone of calcified cartilage 5. Zone of ossification

Interstitial growth of cartilage

Chondroctye in lacuna undergoes mitosis, then two cells occupy one lacuna, and lastly two cells in one lacuna begin to produce new matrix

Central canals of osteons:

Contain blood vessels, have a cylindrical channel, and contain nerves

How does cartilage receive its nutrients?

Diffusion through the matrix.

Which bones are produced by intramembranous ossification?

Flat bones of the skull

Microscopic arrangement of spongy bone

It contains lacunae and canaliculi, contains no osteons, and it contains parallel lamellae.

Compact bone

It is solid and relatively dense

Bone remodeling:

It occurs at the periosteal and endosteal surfaces of a bone, can be stimulated by stress of a bone, and helps maintain calcium and phosphate levels in body fluids

Canaliculi:

Nutrients pass through them, they contain osteocyte cytoplasmic extensions, and extend from lacunae to lacunae

A tough fibrous layer covering the outer surface of a long bone is called:

Periosteum

Hemopoiesis

Process of blood cell production

Osteoprogenitor cells

Produce a cell that becomes an osteoblast and are stem cells

Calcium is required for:

Stimulation of the heart, blood clotting, and initiation of muscle contraction

Central canals of osteons

They contain blood vessels, contain nerves, and are a cylindrical channel

T/F by age 25, most epiphyseal plates have ossified and lengthwise bone growth has stopped

True

Epiphyseal line

a think line of compact bone in the epipysis of a mature bone

Periosteum

a tough fibrous layer covering the outer surface of a long bone

Endosteum

an incomplete layer of cells that lines the medullary cavity of a bone

Growth along the periphery of cartilage is called the

appositional growth

Long bones include

bones of the fingers, bones of the toes, thigh bone, bones of the palm

Which organs are protected by bones?

brain, heart, lungs, reproductive organs

The two primary hormones that regulate blood calcium are:

calcitriol and parathyroid hormone

Tiny channels that connect lacunae to other lacunae in an osteon are called

canaliculi

The cylindrical channel that lies in the center of the osteon is the

central canal

The cells that produce the matrix of cartilage are called

chondroblasts

An osteon is the basic functional and structural microscopic unit of mature

compact bone

Flat bones have surfaces composed of__ with internally placed __ bone.

compact, spongy

Bone connective tissue

contains osteoblasts and osteocytes

endosteum

contains osteoclasts, medullary cavities, active during bone repair, and contains osteoblasts

Functions of cartilage

covers the ends of long bones, provides a model for the formation of bones, and supports soft tissues

Periosteum do:

covers the outer surface of the diaphysis of a long bone, composed of dense irregular connective tissue, helps to heal bone fractures, and functions to anchor blood vessels to the surface of bones

Ligaments and tendons are made of:

dense regular connective tissue

Diaphysis

elongated cylindrical shaft of a long bone

Bone remodeling begins during

embryologic development

The bones of the upper and lower limbs are produced through

endochondral ossification

An incomplete layer of cells that lines the medullary cavity of a bone is called the

endosteum

The region of cartilage between the diaphysis and an epiphysis of a long bone during endochondral ossification is called the

epiphyseal plate

T/F Bone has a poor supply of blood vessels

false

T/F Mature cartilage is well vascularized

false

Articular cartilage

functions to reduce friction in joints, composed of hyaline cartilage, and covers epiphysis

During bone development, the liver releases somatomedin in response to

growth hormone

Short bones

have a length equal to their width

The function of parathyroid hormone is to

increase blood calcium levels

A long bone's growth in length is called

interstitial growth

Calcitonin

is produced by the thyrold gland and has the greatest effect on children's blood calcium levels

Chondrocytes occupy small spaces called

lacunae

in intramembranous ossification, what replaces woven bone?

lamellar bone

Osteocytes

maintain bone matrix, reside in lacunae, and detect mechanical stress on the bone

Bones produced through intramembranous ossification

maxilla, flat bones of the skull, and mandible

The cylindrical space within the diaphysis of a long bone is called the

medullary cavity

The region of a mature bone b/w the diaphysis and epiphysis is the:

metaphysis

The region of a mature bone between the diaphysis and epiphysis is the

metaphysis

Another term for bone tissue is the

osseous connective tissue

the formation & development of bone is

ossification

When osteoblasts become entrapped in the matrix they produce, they become cells called

osteocytes

The release of

parathyroid hormone increases blood calcium levels

Osteoclasts are

phagocytic, have ruffled borders, and reabsorb bone matrix

The region in the diaphysis of a long bone where bone replaces cartilage through endochondral ossification is called the

primary ossification center: it is the first major center of bone formation

Functions of bone

protection, blood cell formation, support, and mineral storage

The epiphysis of a long bone closest to the body trunk is the

proximal epiphysis

In the structure of the epiphyseal plate, the zone farthest away from the medullary cavity of the diaphysis of a long bone is the zone of

resting cartilage

In endochondral ossification-

secondary ossification centers from in the epiphyses of long bones

Groups of bones serve as an attachment site for

skeletal muscles

Compact bones are:

solid and relatively dense

Ex's of short bones

some bones of the foot, bones of the wrist

Cancellous and trabecular bone is called

spongy bone

Flat bones:

sternum, bones of the roof of the skull, and shoulder blade bones

A major role of thryoid hormone in bone remodeling is to:

stimulate bone growth by influencing the basal metabolic rate of bone cells

Aging of the skeletal system:

tensile strength of bone decreases & ability to produce the organic portion of bone matrix decreases

In intramembranous ossification, newly formed bone that is immature and not well organized is called

woven bone