A+P CH 7

How does a long bone grow in width?

Osteoblasts deposit new bone under the periosteum of the diaphysis.

distinguish between the functions of the red marrow and yellow marrow.

Red marrow produces blood cells, and yellow marrow stores fat

condyle

Rounded process that usually articulates with another bone

fontanel

Soft spot in the skull where membranes cover the space between bones

During endochondral ossification, how are spongy and compact bone deposited?

Spongy bone is formed first and compact bone is deposited between the spongy bone and the periosteum.

How does the integumentary system interact with the skeletal system?

The integumentary system functions in the activation of vitamin D.

Grooves and openings on/through a bone form passageways for ______ and ______.

blood vessels and nerves

Ramus

branch or similar extension

When the blood calcium levels are high, the hormone _________ stimulates __________(cells) to form bone tissue in order to lower blood calcium levels.

calcitonin, osteoblasts

sinus

cavity within a bone

As endochondral ossification begins, where does bone tissue first begin to replace hyaline cartilage?

center of diaphysis

each ________ contains blood vessels and nerves surrounded by loose connective tissue. Blood in these vessels nourishes bone cells associated with the central canal via gap junctions between osteocytes

central canal

Which bones compose the pectoral girdle?

clavicle and scapula

fissure

cleft or groove

The anatomical name for the tailbone, located at the end of the vertebral column, is the

coccyx

A thin membrane containing bone-forming cells, called _________ lines the medullary cavity as well as spaces within spongy bone.

endosteum

The inside of the diaphysis of a long bone is lined with a thin layer of cells called the

endosteum

head

enlargement on the end of a bone

The junction between the diaphysis and epiphysis is called the ______.

epiphyseal plate

What is the name of the structure located between the primary and secondary ossification centers?

epiphyseal plate

The femur is an example of a long bone. It has two expanded portions at each end: the proximal and distal ________

epiphyses

At the end of each long bone is an expanded portion called an _______, which articulates (or forms a joint) with another bone

epiphysis

A ________ fracture is an incomplete longitudinal break

fissured

_______ bones are platelike structures with broad surfaces, such as the ribs, scapulae, and some bones of the skull

flat

How do intramembranous bones form?

from sheetlike layers of unspecialized connective tissue

sulcus

furrow or groove

The _________ fracture is incomplete, and the break occurs on the convex surface of the bend in the bone

greenstick

The process of blood cell formation, called _____________, or hemopoiesis, begins in the yolk sac which lies outside the embryo. Later in development, blood cells are manufactured by the liver and spleen, and still later, they form in the bone marrow

hematopoiesis

In an adult, what is the primary location for red marrow?

hip bones

Which is a factor that directly influences bone development, growth, and repair?

hormones

What is a function of the skeletal system?

house blood-producing cells

What bones are found in the upper limb?

humerus, ulna, radius

Endochondral bones are formed from models made of _________ cartilage

hyaline

Where one bone articulates with another, a layer of tissue called ______ protects the underlying bone. This layer is also called ______.

hyaline cartilage, articular cartilage

In endochondral ossification, as masses of ______ cartilage breaks down, ______ deposit bone in the spaces created.

hyaline; osteoblasts

The extracellular matrix of bone tissue includes collagen as well as abundant inorganic salts which are found in the form of a mineral called ______.

hydroxyapatite

The muscles that help move the tongue are attached to the __________ bone. This bone does not articulate with any other bone.

hyoid

Where is the medullary cavity of a long bone found?

in the diaphysis

Osteoclasts secrete acid to dissolve the ______ components of bone and use lysosomal enzymes to digest the ______ components of bone.

inorganic, organic

suture

interlocking line of union between bones

Flat bones in the skull develop through a process called ______ ossification

intramembranous

Flat bones, such as bones of the skull, that develop from sheetlike layers of connective tissue, are called ______.

intramembranous bones

Bones that develop within sheets of connective tissue are called ________ bones, while bones that develop from masses of hyaline cartilage are called _________ bones

intramembranous, endochondral

_________ bones have a variety of shapes, and most are connected to several other bones. Examples include the vertebrae that compose the backbone, and many facial bones

irregular

tubercle

knoblike process

tuberosity

knoblike process usually larger than a tubercle

In compact bone, the osteocytes and layers extracellular matrix called __________ are concentrically located clustered around a central canal (haversian canal) forming a cylinder-shaped unit called an osteon, also called a Haversian system

lamellae

The basic cylinder-shaped unit of a compact bone consists of a central canal and several layers of extracellular matrix called _____________ which are clustered around the central canal.

lamellae

The bony matrix of compact bone is organized into concentric layers of extracellular matrix called ______ that encircle central canals.

lamellae

_____ bones have long longitudinal axes and expanded ends. Examples include the forearm and thigh bones

long

Parathyroid hormone is released when blood calcium levels are ______. This hormone stimulates ______ to break down bone releasing calcium into the blood.

low; osteoclasts

The rigidity of compact bone comes from the arrangement of osteocytes in concentric circles around a central canal, forming a structural unit known as a(n)

osteon

The lamellae in compact bone are arranged in cylinder-shaped units called ______.

osteons

A disorder of the bones that is similar to osteoporosis, only milder, is ______.

osteopenia

In ________________ bone mass declines, bones easily fracture, and may spontaneously break because they no longer can support body weight.

osteoporosis

What connects the upper limb to the axial skeleton and aids in upper limb movement?

pectoral girdle

Central canals extend longitudinally through bone tissue, and transverse _________ connect the central canals.

perforating canals (Volkmann's canals)

A bone is enclosed by a tough, vascular covering of dense connective tissue called the ___________, except for the articular cartilage on its ends. It's firmly attached to the bone, its fibers are continuous with connected ligaments and tendons, and it helps to form and repair bone tissues

periosteum

In intramembranous ossification, mesenchyme tissue that persists outside the developing bone gives rise to the ______.

periosteum

What bones are found in the lower limb?

phalanges fibula tarsals femur tibia

What are bony projections that allow for attachment of ligaments and tendons called?

processes

process

prominent projection on a bone

In ________ marrow, red blood cells (erythrocytes), white blood cells (leukocytes), and blood platelets form. The color comes from the red, oxygen-carrying pigment hemoglobin in red blood cells

red

the two types of marrow are

red and yellow

During a bone marrow transplant, cells are retrieved from ______ bone marrow located in ______ bone of a donor.

red; spongy

fossa

relatively deep pit or depression

trochanter

relatively large process

The total mass of bone tissue in a healthy adult skeleton ______.

remains nearly constant

The thoracic cage consists of twelve pairs of _______ and one ________

ribs, sternum

The lack of vitamin D results in soft and deforming bones. In children, this condition is called _____________ and in adults, this condition is called ____________

rickets, osteomalacia

The large triangle-shaped bone at the distal end of the vertebral column that is actually five bones fused into one is called the

sacrum

Indicate the bones of the appendicular skeleton.

scapula fibula tarsals patella clavicle ulna phalanges

The pectoral girdle consists of two ______ and two ____________

scapula, clavicles

Regions of the epiphyses, where cartilage slowly breaks down and spongy bone form in all directions, are called

secondary ossification centers

A special type of short bone is a _________ bone, or round bone. This type of bone is usually small and nodular and embedded in a tendon adjacent to a joint, where the tendon is compressed. The kneecap is an example of this

sesamoid

______ bones have equal widths and lengths. Examples would be the wrists and ankles

short

In a closed bone fracture, the ______ is unbroken. In a compound fracture, it is broken

skin

What bones belong to the axial skeleton?

skull vertebrae sacrum ribs

facet

small, nearly flat surface

A _________ fracture is caused by excessive twisting of a bone

spiral

The epiphyses are largely composed of __________, also called cancellous bone, with thin layers of compact bone on their surfaces.

spongy bone

What are the four major functions of a bone, an organ of the skeletal system?

support and protection storage of inorganic salts attachment for muscles blood cell formation

The skull is made of two parts:

the cranium and the facial bones

What is ossification?

the formation of bone

What are the living tissues found in bones?

they include bone tissue, blood, nerves, and cartilage, and other connective tissues

What are trabeculae?

thin, bony plates in spongy bone

spine

thornlike projection

fovea

tiny pit or depression

Spongy bone consists of many branching bony plates called __________, which help to reduce a bone's weight

trabeculae

A ________ fracture is complete, and the break occurs at the right angle to the axis of the bone

transverse

True or false: When the ossification center of the diaphysis and epiphysis meet and the epiphyseal plates ossify, lengthening of the bone is no longer possible.

true

In order for a long bone to grow in width (thickness), new bone is deposited ______ while the bone is eroded ______.

under the periosteum; in the medullary cavity

Indicate the statements that are true about intramembranous ossification.

-Osteoblasts deposit new bone along blood vessels. -Skull bones are formed via intramembranous ossification. -It occurs between flat sheets of connective tissue.

How might a bone marrow transplant recipient get cells necessary for blood cell formation?

-Retrieval of red marrow cells from donor's spongy bone. -Stem cells from the umbilical cord of a newborn. -Stem cells separated out of the donor's blood

What are the three roles of calcium in the body?

-a component of bony matrix -plays a role in muscle contraction -important in blood clot formation

Ch 5 review

-bone cells called osteocytes are in tiny, bony chambers called lacunae -osteocytes exchange substances with nearby cells by means of cellular processes passing through canaliculi -The extracellular matrix of bone tissue is largely collagen and inorganic salts -collagen gives bones their strength and resilience, and inorganic salts make them hard and resistant to crushing

In a bone, where can bone marrow be found?

-central canals of compact bone -medullary cavity -irregular spaces in spongy bone

What two bones contain significant amounts of red bone marrow in an adult?

-hip bones -sternum (breastbone)

What are examples of bones that form through intramembranous ossification?

-mandible (jaw bone) -sternum -flat bones of the skull

epiphyseal plate layer characteristics:

1. Zone of resting cartilage -layer closest to the epiphysis 2. Zone of proliferating cartilage -young cells undergo mitosis 3. Zone of hypertrophic cartilage -cartilage cells enlarging while osteoblasts deposit bone matrix 4. Zone of calcified cartilage -composed of dead cartilage cells encased in bone matrix

Match each bone marking with the correct description.

1. condyle -> rounded process 2. fontanel -> soft spot in the fetal skull 3. foramen -> opening through a bone 4. head -> enlargement on the end of a bone 5. spine -> thornlike projection 6. tuberosity -> swelling (knoblike) on the bone, knoblike process usually larger than a tubercle 7. Tubercle -> small knoblike process 8. trochanter -> relatively large process 9. suture -> interlocking line of union between bones

list the five major parts of a long bone

1. diaphysis (shaft) 2. epiphyses (expanded ends) 3. periosteum (outer covering) 4. endosteum (inner lining) 5. medullary cavity

Place in order the sequence of events during the process of healing of fractures, starting at the top.

1. hematoma formation 2. fibrocartilage formation 3. bony callus formation 4. bone remodeling by osteoclasts

Place the following steps of endochondral ossification in order as they would occur, starting at the top.

1. hyaline cartilage model forms 2. cartilage tissue breaks down 3. osteoblasts form spongy and compact bone 4. osteoblasts become osteocytes

What are the four layers of the epiphyseal plate?

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

How many pairs of ribs make up the thoracic cage?

12

How many bones are in the human body (if we ignore variations due to sutural and sesamoid bones)?

206

epicondyle

A projection situated above a condyle

meatus

A tube like passage within a bone

Where is the sacrum located?

At the end of the vertebral column in the pelvis.

List the substances normally stored in bone tissue

Bone tissue stores calcium and phosphorus, and small amounts of magnesium, sodium, potassium, and carbonate ions. Harmful metals, if ingested, such as lead, radium and strontium, are also stored in the bones.

explain how bones are classified by shape

Bones are classified by shape as long, short, flat, or irregular. Long bones are long and narrow, with expanded ends. Short bones are about equal in length and width. A sesamoid, or round, bone is a type of short bone that is small and rounded. Flat bones have broad surfaces and a platelike shape. Irregular bones have various shapes.

What are the general functions of bones?

Bones provide shape to body parts, support the body weight, protect organs against injury, interact with muscles to allow movement, produce blood cells, and store inorganic salts

describe the microscopic structure of compact bone

Compact bone consists of densely packed, microscopic cylinders called osteons. Each osteon contains osteocytes and extracellular matrix deposited in rings (lamellae) around a central canal. Blood vessels and nerves occupy the central canal. Osteocytes live within tiny chambers called lacunae; they communicate and share nutrients with other osteocytes through canaliculi.

How do compact bone and spongy bone differ in structure?

Compact bone is dense and solid, and its matrix doesn't have any gaps. It consists of microscopic cylinders called osteons, which contain matrix and osteocytes deposited around central canals. Spongy bone contains osteocytes and matrix, but the tissue is loosely arranged in branching bony plates called trabeculae

compact vs spongy bone

Compact: -also called cortical bone -made of tightly packed tissue -continuous extracellular matrix with no gaps Spongy: -contains trabeculae -also contains cancellous bone -contains many irregular spaces

True or false: Most bones of the skeleton are intramembranous bones.

False

Explain the regulation of the concentration of blood calcium

If blood calcium levels drop, parathyroid hormone stimulates osteoclasts to break down bone and release calcium. If blood calcium levels rise, calcitonin (from the thyroid gland) stimulates osteoblasts to deposit calcium in the bones

foramen

Opening through a bone that usually is a passageway for blood vessels, nerves, or ligaments

What are the characteristics of an epiphyseal plate?

It is responsible for the growth in length of long bones. It separates the diaphysis and the epiphysis of long bones. It consists of cartilaginous cells.

Bone classifications

Long, short,flat, round, irregular

_________ is a soft, net-like mass of connective tissue in the medullary cavities of long bones, in the irregular spaces of spongy bones, and in the larger central canals of compact bone tissue

Marrow

________ canals contain larger blood vessels and nerves by which the smaller blood vessels and nerve fibers in central canals communicate with the surface of bone and the medullary cavity

Perforating

What is the role of vitamin D in bone development?

Vitamin D increases calcium absorption in the small intestine and thus helps maintain the calcium concentrations necessary to build the bone matrix.

The ________ skeleton is composed of the bones of the upper and lower limbs, and the bones that connect them to the axial skeleton

appendicular

The periosteum is located ______ and plays a role in ______.

around bones; bone growth and repair

The outer surface of the articulating portion of the epiphysis is coated with a layer of hyaline cartilage called ___________.

articular cartilage

The _________ skeleton consists of the bony and cartilaginous parts that support and protect the organs of the head, neck, and trunk

axial

A _____________ fracture is complete and fragments the bone

comminuted

The wall of diaphysis is mainly composed of tightly compact tissue called ____________, also called cortical bone. It has a continuous extracellular matrix with no gaps.

compact bone

Where is the spongy bone typically found?

deep to compact bone

The middle portion of a long bone, between the epiphyses, is called the

diaphysis

The shaft of the bone is called the __________

diaphysis

During the process of endochondral ossification, a primary ossification center appears in the ______, whereas secondary ossification centers appear in the ______.

diaphysis; epiphyses

What fills the spaces within the spongy bone and the medullary cavity?

marrow

a specialized type of soft connective tissue called __________ fills the spongy bone spaces and the medullary cavity.

marrow

compact bones in the diaphysis of a long bone forms a tube with a hollow chamber called the _____________ that's continuous with the spaces of the spongy bone.

medullary cavity

Which of the statements following accurately describes osteoblasts?

mesenchymal cells that have differentiated into bone-forming cells

During intramembranous ossification, a layer of ______ becomes the periosteum on the outside of the bone.

mesenchyme

The _________ is the widening part of the bone between the diaphysis and epiphysis

metaphysis

linea

narrow ridge

crest (krest)

narrow, ridgelike projection

Select three factors that affect bone development, growth, and repair

nutrition hormones physical exercise

An _________ fracture occurs at an angle other than a right angle to the axis of the bone

oblique

During ossification, ______ deposit bony matrix around themselves, ultimately surrounding themselves with bone. Once surrounded by bone, these cells are called ______.

osteoblasts; osteocytes

Which of the following are found in an osteon?

osteocytes central canal