Bones pt 1

Where does bone formation occur when bones grow in diameter?

Surface of the bones

What gives bones their hardness and strength?

hydroxyapatite crystals

Each trabecula forms along

lines of stress

How many bones are in the human body?

206

What is the most common cell type in yellow bone marrow?

Adipocytes

This bone marking is characterized by being rounded or cupped so the bones can come together at a joint

Articulation

What are the three general classes of bone markings?

Articulations, projections, and holes

Once the chondrocytes die, what fills the remaining spaces?

Blood vessels

What is found in the central canals?

Blood vessels, nerves, and lymphatic vessels

What part of the body stores calcium?

Bones

What bones form by endochondral ossification?

Bones at the base of the skull and long bones

What are the three components of the skeletal system?

Bones, cartilages, and ligaments

What chemical inhibits osteoclast activity and stimulates calcium uptake by the bones, but also decreases reabsorption of calcium by the kidneys?

Calcitonin

What type of cell secretes the fibrocartilaginous matrix?

Chondrocytes

What word describes spongy bone?

Diploë

The process in which bone develops by replacing hyaline cartilage

Endochondral ossification

Which region of long bone is composed of thin compact bone and a thick layer of spongy bone?

Epiphysis

True or False: During bone formation, once the calli have been created, the osteoblasts start creating new compact bone to replace the broken bone.

False

True or False: Hyaline cartilage becomes new bone in endochondral ossification.

False

What physical characteristic do collagen fibers give bones?

Flexibility

What step of fracture repair does this describe?: broken blood vessels bring blood to area that clots and forms fracture hematoma

Hematoma formation

What are the steps our body takes to repair a fracture?

Hematoma formation, internal and external callus formation, bone formation, and bone remodeling

What cellular process takes place in red bone marrow?

Hematopoiesis

What specific tissue type forms the template for long bones?

Hyaline cartilage

What type of cartilage is epithyseal plates composed of?

Hyaline cartilage

Is this the result of hypocalcemia or hypercalcemia? lethargy, sluggish reflexes, constipation and loss of appetite, confusion, and in severe cases, coma.

Hypercalcemia

Is this the result of hypocalcemia or hypercalcemia? blood has difficulty coagulating, the heart may skip beats or stop beating altogether, muscles may have difficulty contracting, nerves may have difficulty functioning, and bones may become brittle.

Hypocalcemia

The condition characterized by abnormally low levels of calcium is called

Hypocalcemia

In long bones, where is cancellous bone located?

In the epiphyses

These are the general steps to flat bone formation, which is called what?: 1. Mesenchymal cells group into clusters, and ossification centers form. 2. Secreted osteoid traps osteoblasts, which then become osteocytes. 3. Trabecular matrix and periosteum form.

Intramembranous Ossification

Osteocytes are located in the ________ surrounded by osseous tissue.

Lacunae

What is found at the borders of adjacent lamellae?

Lacunae

What happens to the chondrocytes as a result of matrix mineralization and causes them to die?

Nutrient loss

What two bone cell types are incapable of mitosis?

Osteoblasts and osteocytes

During bone formation, what type of cells reabsorb the dead bone tissue?

Osteoclasts

What bone cell creates osteoblasts?

Osteogenic cells

What chemical stimulates osteoclast proliferation and resorption of bone by osteoclasts, promotes reabsorption of calcium from the urine by the kidneys, and stimulates the synthesis of vitamin D

PTH

In a state of hypocalcemia, which hormones would be released?

PTH and vitamin D

What is one sesamoid bone found in everybody?

Patella

What is the girdle located at the shoulder called?

Pectoral girdle

What is the girdle located at the hips called?

Pelvic girdle

This bone marking is characterized by an area that projects off the surface of the bone

Projection

This bone marking serves as the attachment point for tendons and ligaments

Projection

Which interstitial growth zone has chrondrocytes going through rapid mitosis?

Proliferative zone

Which interstitial growth zone looks like stacked coins?

Proliferative zone

What substance is located in the porous, cancellous (or spongy) bone inside the epithysis?

Red marrow

What are the four zones of the epiphyseal plate in interstitial growth? (In order from epiphysis to diaphysis)

Reserve zone, proliferation zone, maturation and hypertrophy zone, and calcified matrix zone

What is the purpose of calli?

Stabilize the fracture

What is the function of tendons?

They attach muscles to bone

True or False: Calcium is a chemical element that cannot be produced by any biological processes.

True

True or False: It is important for bone cells to subtly reshape the bone.

True

What chemical is important for calcium absorption?

Vitamin D

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

a hole

What tissue makes up yellow bone marrow?

adipose tissue

What type of growth is necessary for bones to grow in width?

appositional growth

The layer of hyaline cartilage that covers surfaces of bone that form joints with other bones is called

articular cartilage

During appositional growth, where do osteoblasts create new bone tissue?

beneath the periosteum

What step of fracture repair does this describe?: replacement of cartilage by trabecular bone through endochondral ossification

bone formation

The endosteum is the location of

bone forming cells

Eroded lacunae in the zone of maturation and hypertrophy cause the cartilaginous matrix to

calcify

In a state of hypercalcemia, which hormone would be released?

calcitonin

What two minerals create hydroxyapatite?

calcium phosphate and calcium carbonate

What is the function of osteoblasts?

create new bone

__________ are canals that radiate perpendicular to the lamellae and contain processes of osteocytes, which allows them to transport nutrients and remove waste products..

canaliculi

Osteocytes communicate to other cells and receive nutrients through

canaliculi channels

Where do cannaliculi connect?

cannaliculi and central canal

Running down the center of each osteon is what canal?

central (Haversion) canal

What type of cells create external calli?

chondrocytes and osteoblasts

Having a cast on your broken arm is an example of

closed reduction

What do platelets do?

clot blood

Osteoblasts synthesize and secrete what?

collagen and calcium salts

What fiber type is present in the bone matrix?

collagen fibers

What gives bone its flexibility?

collagen fibers

What are the two types of bone tissue? (the third one is subchondral tissue, which is located underneath cartilage)

compact and cancellous

What always surrounds cancellous bone?

compact bone

These are the general steps to long bone formation, which is called what?: 1. Mesenchymal cells differentiate into chondrocytes. 2. The cartilage model of the future bony skeleton and the perichondrium form. 3. Capillaries penetrate cartilage. Perichondrium transforms into periosteum. Periosteal collar develops. Primary ossification center develops. 4. Cartilage and chondrocytes continue to grow at ends of the bone. 5. Secondary ossification centers develop. (f) Cartilage remains at epiphyseal (growth) plate and at joint surface as articular cartilage.

endochondral ossification

The delicate membranous lining of the medullary cavity is called the

endosteum

Where are the chondrocytes that form the internal callus?

endosteum

Where are osteogenic cells found?

endosteum, periosteum, and central canals

The following functions belong to which location in the bones? bone growth, repair, and remodeling

endostreum

What do osteocytes secrete during normal processes (not ossification)?

enzymes

Once one has reached maximum size in adolecense/early adulthood, the epiphyseal plate becomes the

epiphyseal line

What is the growth plate in the metaphysis called?

epiphyseal plate

Where are the secondary ossification centers located in endochondral ossification?

epiphyses

Internal calli are composed of what type of tissue?

fibrocartilage

Which bones form through the process of intramembranous ossification?

flat bones of the face, most of the cranial bones, and the clavicles (collarbones)

When blood vessels are torn by a fracture they form a

fracture hematoma

The appendicular skeleton is divided into which two groups?

girdles and limbs

What is the process of creating blood cells?

hematopoiesis

What controls bone growth?

hormones

External calli are composed of what type of tissue?

hyaline cartilage

What are inorganic salt crystals called?

hydroxyapatite

What is formed by calcium phosphate and calcium carbonate and incorporates other inorganic salts like magnesium hydroxide, fluoride, and sulfate as it crystallizes?

hydroxyapatite

The condition characterized by abnormally high levels of calcium is called

hypercalcemia

What adheres to collagen fibers?

inorganic salt crystals

What step of fracture repair does this describe?: secretion of fibrocartilage matrix to create internal callus, and secretion of hyaline cartilage and bone to create external callus

internal and external callus formation

These steps result in the lengthening of the bone. This process is called what?: 1. Chondrocytes in the reserve zone undergo mitosis in the proliferative zone. 2. Chondrocytes enlarge and mature in the zone of maturation and hypertrophy. 3. Most chondrocytes in the zone of calcified matrix die as a result of the calcification of the surrounding matrix. 4. New bone is formed as osteoblasts and capillaries invade the calcified tissue.

interstitial growth

Compact and spongy bone develops directly from sheets of mesenchymal (undifferentiated) connective tissue during

intramembranous ossification

Why aren't bones composed of only compact bone?

it would be too heavy

In cancellous bone, where are osteocytes located?

lacunae

Layers (rings) of calcified matrix that surround the central canal are

lamellae (singular = lamella)

During appositional growth, osteoclasts reabsorb old bone in the

medullary cavity

From which tissue type do flat bones form?

mesenchymal (undifferentiated) connective tissue

What forms osteogenic cells?

mesenchymal cells

Where does each epiphysis meet the diaphysis?

metaphysis

What is the name of the process of increasing the diameter of the diaphysis and medullary cavities?

modeling

When the doctor preforms surgery to reset a broken bone, it is called

open reduction

What type of tissue composes the epiphyseal line?

osseous tissue

In intramembranous ossification, early osteoblasts appear in a cluster called an

ossification center

What are the four types of cells found in osseous tissue?

osteoblasts, osteocytes, osteogenic cells, and osteoclasts.

What bone cell is derived from monocytes and macrophages (two types of white blood cells)?

osteoclasts

What bone cells break down bone?

osteoclasts

Mature bones are made of a calcified matrix, what type of bone cell exists within the calcified matrix

osteocyte

Once the matrix surrounding the osteoblast calcifies, it becomes what?

osteocyte

What is the most common type of bone cell?

osteocyte

What do lacunae contain?

osteocytes

When blood vessels invade the previously cartilaginous space, what type of cells do they bring with them?

osteogenic cells

During intramembranous ossification, osteoblasts secrete _____________ to create an uncalcified matrix

osteoid

The functional unit of compact bone tissue is the

osteon

Where is PTH produced?

parathyroid gland

PTH stands for

parathyroid hormone

Vessels and nerves branch off at right angles through what canal?

perforating canal

In endochondral ossification, what is the membrane that covers the cartilage and will be the future periosteum called?

perichondrium

Where are the chondrocytes that form the external callus?

periosteal

During ossification, osteoblasts congregate around the cartilage of the diaphysis to form the

periosteal collar

The membrane that covers the outside of a bone is the

periosteum

Where are osteoblasts found?

periosteum and endosteum

Where are immature osteogenic cells found?

periosteum and marrow

What three cell types are made in red bone marrow?

red and white blood cells and platelets

During intramembranous ossification, the trabecular bone crowds nearby blood vessels to form

red marrow

What fills the space around and between trabeculae?

red marrow

After the fractured bone is repaired, it undergoes

remodeling

What step of fracture repair does this describe?: return to normal of bone shape and thickness

remodeling

What is the interstitial growth zone closest to the epiphyseal end of the plate and contains small chondrocytes within the matrix?

reserve zone

Which interstitial growth zone of chrondrocytes serve the function of securing the epiphyseal plate to the osseous tissue of the epiphysis?

reserve zone

Where is vitamin D produced?

skin

During bone formation, osteoblasts create

spongy bone

What are the five functions of the skeletal system?

supports the body, facilitates movement, protects internal organs, produces blood cells (hematopoiesis), mineral storage

Where are sesamoid bones found?

tendons

Where is the primary ossification center in endochondral ossification?

the (future) medullary cavity

In which interstitial growth zone do chondrocytes die?

the calcified matrix zone

Which interstitial growth zone borders the ossification zone within the medullary cavity?

the calcified matrix zone

In flat bones, where is cancellous bone located?

the center

During endochondral ossification, the blood vessels invade the previously cartilaginous space to create what cavity?

the medullary cavity

Where is the human when intramembranous ossification starts?

the womb

What is the function of ligaments?

they connect bones to each other

Once chondrocytes lose access to nutrients, what happens to them?

they die

What happens to chondrocytes when the matrix around them calcify?

they die

As a result of enlarged chondrocytes, what happens to the lacunae?

they erode and become larger

Where is calcitonin produced?

thyroid gland

What are the hard, bony branches within spongy bone called?

trabeculae

Spongy bone, cancellous bone, or

trabecular bone

During intramembranous ossification, osteoid secreted around the capillaries results in a

trabecular matrix

In yellow bone marrow's adipose tissue, the adipocytes store what molecule?

triglycerides

Which interstitial growth zone has enlarged chrondrocytes?

zone of maturation and hypertrophy