ch07_answer_key_13edition.doc

8/13/2019 ch07_answer_key_13edition.doc

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Shier, Butler, and Lewis: Holes Human Anatomy and Physiology, 13thed. Chapter 7: Skeletal System

Chapter 7: Skeletal System

I. Introduction

1. Bones include active, living tissues: bone tissue, cartilage, dense connective

tissue, blood, and nervous tissue.

. Bones: support and protect so!t tissues, provide points o! attachment !or

muscles, house blood"producing cells, and store inorganic salts.

#. $he !our classes o! bone according to shape are long, short, !lat, and irregular.

%. &'amples o! long bones are !orearm and thigh bones.

(. Short bones are shaped like cubes.). &'amples o! short bones are wrist bones and ankle bones.

7. *lat bones are plate"like structures.

+. &'amples o! !lat bones are some skull bones, ribs, and scapulae.

. -rregular bones have a variety o! shapes.

1. &'amples o! irregular bones are vertebrae and some !acial bones.

11. /ound bones are also called sesamoid bones.

1. Sesamoid bones are small and nodular and embedded within tendons ad0acent

to 0oints.

1#. n e'ample o! a sesamoid bone is the patella.

II. Bone Structure

. 2arts o! a Long Bone

1. n e'panded end o! a long bone is called an epiphysis.

. n epiphysis articulates with another bone.

#. rticular cartilage is located on the articulating portion o! an epiphysis.

%. $he sha!t o! a long bone is called a diaphysis.

(. $he metaphysis is the widening part o! the bone between the diaphysis

and the epiphysis.

(. 2eriosteum is a tough, vascular, !ibrous membrane covering the

diaphysis o! a bone.


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). 2eriosteum !unctions to !orm and repair bone tissue.

7. 2rocesses provide sites !or attachments o! tendons or ligaments.

+. $he wall o! the diaphysis is composed o! compact bone.

. Compact bone has a continuous e'tracellular matri' with no gaps.

1. $he epiphyses are largely composed o! spongy bone.

11. Spongy bone consists o! bony plates called trabeculae.

1. bone usually has compact bone overlying spongy bone with the

relative amounts o! each varying in di!!erently shaped bones.

1#. semi"rigid tube with a hollow chamber called the medullary cavity

runs through the diaphysis.

1%. &ndosteum lines the medullary cavity and spaces o! spongy bone.

1(. &ndosteum contains bone"!orming cells.

1). $he tissue that !ills the spaces o! bone is called marrow.

17. $he two !orms o! marrow are red and yellow.

B. 3icroscopic Structure

1. -ntroduction

a. Bone cells are called osteocytes.

b. Lacunae are tiny chambers that contain osteocytes.

c. Lacunae !orm concentric canals around central canals.

d. 4steoctyes transport nutrients and wastes to and !rom nearby

cells.

e. Cellular processes o! osteocytes pass through canaliculi.

!. $he e'tracellular matri' o! bone is composed o! collagen and

inorganic salts.

. Compact Bones

a. n osteon is a cylinder"shaped unit o! compact bone.

b. $he substance o! compact bone is !ormed !rom many osteons

cemented together.

c. &ach central canal contains blood vessels and nerves.

d. 2er!orating canals connect central canals o! osteons.

e. 2er!orating canals contain larger blood vessels and nerves.


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#. Spongy Bone

a. Spongy bone is also composed o! osteocytes

and e'tracellular material.

b. 5nlike compact bone, the bone cells do not aggregate around

central canals.

c. -nstead the cells lie within trabeculae.

d. 4steocytes get nutrients !rom substances di!!using into

canaliculi that lead to the sur!ace o! trabeculae.

III. Bone Development and Growth

. -ntroduction

1. 2arts o! the skeleton begin to !orm during the !irst !ew weeks o!

prenatal development.

. Bony structures continue to grow until adulthood.

#. Bones !orm by replacing e'isting connective tissues.

%. -ntramembranous bones originate within sheetlike layers o! connective

tissue.

(. &ndochondral bones originate as masses o! cartilage that are later

replaced by bone tissue.

B. -ntramembranous Bones

1. &'amples o! intramembranous bones are the broad, !lat bones o! the

skull.

. 4steogenesis is bone development.

#. 6uring their development, membranelike layers o! relatively

undi!!erentiated connective tissue appear at the sites o! their !uture bones.

%. 6ense networks o! blood vessels supply the connective tissue layers.

(. 4steoblasts are bone"!orming cells.

). 4steoblasts deposit bony matri' around themselves.

7. Spongy bone can become compact bone as spaces !ill with bone

matri'.

+. s development continues, osteoblasts may become surrounded by

matri'.


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. &'tracellular matri' enclosing the processes o! osteoblasts gives rise to

canaliculi.

1. 4nce isolated, osteoblasts become osteocytes.

11. 2eriosteum comes !rom cells o! the undi!!erentiated connective tissue

that persist outside o! the developing bone.

1. Compact bone is !ormed by osteoblasts on the inside o! periosteum.

1#. -ntramembranous ossi!ication is the process o! replacing connective

tissue to !orm an intramembranous bone.

C. &ndochondral Bones

1. 3ost o! the bones o! the skeleton are endochondral bones.

. &ndochondral bones develop as masses o! hyaline cartilage.

#. &ventually the cartilage decomposes.

%. s the cartilage decomposes, a periosteum !orms !rom connective

tissue that encircles the developing structure.

(. Blood vessels and undi!!erentiated connective tissue cells invade the

disintegrating tissue.

). Some o! the cells di!!erentiate into osteoblasts.

7. 4steoblasts !orm spongy bone in the spaces previously housed by

cartilage.

+. &ndochondral ossi!ication is the process o! !orming an endochondral

bone by the replacement o! hyaline cartilage.

. $he primary ossi!ication center is an area in the diaphysis o! a long

bone in which the bony tissues begin to replace hyaline cartilage.

1. Secondary ossi!ication centers appear in epiphyses.

11. $he epiphyseal plate is a band o! cartilage between the primary and

secondary ossi!ication centers.

6. rowth at the &piphyseal 2late

1. -n a long bone, the diaphysis is separated !rom the epiphysis by an

epiphyseal plate.

. $he cartilaginous cells !orm !our layers.


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1. $hroughout li!e, osteoclasts resorb bone tissue and osteoblasts replace

bone.

. bout # to ( o! bone calcium is e'changed each year.

*. *actors !!ecting Bone 6evelopment, rowth, and /epair

1. *actors that a!!ect bone development, growth, and repair include

nutrition, e'posure to sunlight, hormonal secretions, and physical e'ercise.

. ;itamin 6 is necessary !or proper absorption o! calcium.

#. Lack o! vitamin 6 can lead to the diseases rickets and osteomalacia.

%. ;itamin is necessary !or osteoblast and osteoclast activity during

normal development.

(. ;itamin C is re


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. $he bones o! lower limbs, pelvis, and vertebral column support the

body=s weight.

#. $he bones o! the skull protect the eyes, ears, and brain.

%. $he bones o! the thora' protect the heart and lungs.

(. Bones o! the pelvic girdle protect lower abdominal and internal

reproductive organs.

B. Blood Cell *ormation

1. 9ematopoiesis is blood cell !ormation.

. Blood cell !ormation begins in the yolk sac.

#. Later in development, blood cells are made in the liver, the spleen, and

red bone marrow.

%. 3arrow is a so!t, netlike mass o! connective tissue within the

medullary cavities o! long bones, in the irregular spaces o! spongy bone,

and in the larger central canals o! compact bone tissue.

(. /ed marrow !unctions in the !ormation o! red blood cells, white blood

cells, and platelets.

). /ed marrow occupies the cavities o! most bones in an in!ant.

7. >ith increasing age, yellow marrow replaces red marrow.

+. ?ellow marrow stores !at.

. -n an adult, red marrow is primarily !ound in the spongy bone o! the

skull, ribs, sternum, clavicles, vertebrae, and hipbones.

C. -norganic Salt Storage

1. &'tracellular matri' o! bone tissue includes collagen and inorganic

mineral salts.

. $he salts account !or about 7 o! the e'tracellular matri' by weight.

#. 9ydro'yapatites are tiny crystals o! calcium phosphate.

%. $he body rehen blood calcium is low, parathyroid hormone stimulates

osteoclasts to break down bone tissue to release calcium salts.


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). ;ery high blood calcium levels inhibit osteoclast activity.

7. Calcitonin stimulates osteoblasts to !orm bones.

+. Bone tissue contains lesser amounts o! magnesium, sodium, potassium

and carbonate ions.

V. Skeletal r!ani"ation

. @umber o! Bones

1. $he number o! bones in a human skeleton is around ).

. *lat bones o! the skull are tightly 0oined by sutures.

B. 6ivisions o! the Skeleton

1. $wo ma0or portions o! the skeleton are a'ial and appendicular.

. $he a'ial skeleton contains skull bones, middle ear bones, the hyoid

bone, vertebral column bones, and thoracic cage bones.

#. $he skull is composed o! + cranial bones and 1% !acial bones.

%. $he hyoid bone supports the tongue and is an attachment !or certain

muscles that help move the tongue.

(. $he hyoid bone is located in the neck between the lower 0aw and the

laryn'.

). $he vertebral column consists o! vertebrae, a sacrum, and coccy'.

7. $he distal end o! the column is !ormed by the sacrum and the coccy'.

+. $he coccy' is also called the tailbone.

. $he thoracic cage is composed o! 1 pairs o! ribs and the sternum.

1. $he appendicular skeleton consists o! bones o! the pectoral girdle,

upper limbs, pelvic girdle, and lower limbs.

11. $he pectoral girdle is !ormed by scapulae and clavicles.

1. $he pectoral girdle connects the bones o! the upper limbs to the a'ial

skeleton.

1#. $he pectoral girdle aids in upper limb movements.

1%. &ach upper limb consists o! a humerus, radius, ulna, carpals,

metacarpals, and phalanges.

1(. $he humerus, radius, and ulna articulate at the elbow.

1). $he wrist bones are called carpals.


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17. $he bones o! the palm are called metacarpals.

1+. Bones in the !ingers are called phalanges.

1. $he pelvic girdle is !ormed by two co'al bones.

. $he pelvic girdle connects the bones o! the lower limbs to the a'ial

skeleton and with the sacrum and coccy'.

1. $he pelvic girdle, sacrum, and coccy' !orm the pelvis.

. &ach lower limb consists o! a !emur, tibia, !ibula, patella, tarsals,

metatarsals, and phalanges.

#. $he !emur and tibia articulate with each other at the knee.

%. $he kneecap is called the patella.

(. $he anklebones are tarsals.

). $he bones o! the instep o! the !oot are called metatarsals.

7. Bones o! the toes are called phalanges.

VI. Skull #$II. %ower %im&

. -ntroduction

1. human skull usually consists o! bones.

. $he moveable bone in the skull is the mandible.

#. Some cranial and skull bones together !orm the orbit o! the eye.

B. Cranium

1. $he cranium encloses and protects the brain.

. $he sur!ace o! the cranium provides attachments !or muscles that make

chewing and movements o! the head possible.

#. Sinuses are air"!illed cavities in cranial bones.

%. Sinuses reduce the weight o! the skull and increase the intensity o! the

voice by serving as resonant sound chambers.

(. $he eight bones o! the cranium are 1 !rontal bone, parietal bones, 1

occipital bone, temporal bones, 1 sphenoid bone and 1 ethmoid bone.

). $he !rontal bone !orms the anterior portion o! the skull above the eyes,

the roo! o! the nasal cavity and the roo!s o! the orbits.

7. $he supraorbital !oramen is on the upper margin o! each orbit and

allows blood vessels and nerves to pass to tissues o! the head.


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+. $he sinuses o! the !rontal bone are called !rontal sinuses.

. $he two halves o! the !rontal bone !use together by the !i!th or si'th

year o! li!e.

1. 4ne parietal bone is located on each side o! the skull behind the

!rontal bone.

11. $ogether the parietal bones !orm the sides and roo! o! the cranium.

1. $he sagittal suture !uses the parietal bones.

1#. $he coronal suture !uses the parietal bones to !rontal bones.

1%. $he occipital bone 0oins the parietal bones along the lambdoidal

suture.

1(. $he occipital bone !orms the back o! the skull and the base o! the

cranium.

1). $he !oramen magnum is a large opening in the occipital bone through

which the brain and spinal cord 0oin.

17. 4ccipital condyles are located on each side o! the !oramen magnum.

1+. 4ccipital condyles articulate with the !irst cervical vertebra.

1. temporal bone on each side o! the skull 0oins the parietal bone along

a s


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7. $he 8ygomatic process pro0ects anteriorly !rom the temporal bone and

0oins the 8ygomatic bone.

+. $he sphenoid bone helps !orm the anterior portion o! the cranium.

. $he sella turcica is an indention in the middle o! the sphenoid bone

and holds the pituitary gland.

#. $he sinuses o! the sphenoid bone are called sphenoidal sinuses.

#1. $he ethmoid bone is located in !ront o! the sphenoid bone.

#. -t consists o! two masses 0oined by cribri!orm plates.

##. $he cribri!orm plates !orm the roo! o! the nasal cavity.

#%. @erves associated with smell pass through ol!actory !oramina.

#(. 2ortions o! the ethmoid bone also !orm sections o! the cranial !loor,

orbital walls, and nasal cavity walls.

#). perpendicular plate pro0ects downward !rom the cribi!orm plates to

!orm most o! the nasal septum.

#7. Scroll"shaped plates called superior and middle nasal conchae pro0ect

inward !rom the lateral portions o! the ethmoid bone.

#+. $he lateral portions o! the ethmoid bone contain many small air

spaces called ethmoidal sinuses.

#. $he crista galli is triangular process that pro0ects upward and is

located between cribri!orm plates.

%. $he crista galli is attached to membranes that enclose the brain.

C. *acial Skeleton

1. $he !acial skeleton consists o! 1# immovable bones and a movable

lower 0aw bone.

. $he !acial bones provide sites o! attachment !or muscles that move the

0aw and control !acial e'pression.

#. $he ma'illary bones !orm the upper 0aw.

%. 2ortions o! the ma'illary bones also comprise the anterior roo! o! the

mouth, the !loors o! the orbits, and sides and !loor o! the nasal cavity.

(. $he ma'illary bones also contain sockets !or the upper teeth.

). -nside the ma'illae, lateral to the nasal cavity are ma'illary sinuses.


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7. $he ma'illary sinuses e'tend !rom the !loor o! the orbits to the roots o!

the upper teeth.

+. 6uring development, portions o! the ma'illary bones called palatine

processes grow together and !orm the anterior section o! the hard palate.

. $he alveolar arch is a horseshoe shaped collection o! alveolar

processes.

1. $eeth occupy cavities in this arch.

11. $he palatine bones are L shaped.

1. $he palatine bones are located behind the ma'illae.

1#. $he hori8ontal portions o! the palatine bones !orm the posterior

section o! the hard palate and the !loor o! the nasal cavity.

1%. $he perpendicular portions o! the palatine bones help !orm the lateral

walls o! the nasal cavity.

1(. Aygomatic bones are responsible !or the prominences o! the cheeks

below and to the sides o! the eyes.

1). &ach 8ygomatic bone has a temporal process that e'tends posteriorly

to 0oin the temporal bone.

17. Lacrimal bones are located in the medial wall o! each orbit.

1+. $he nasal bones !orm the bridge o! the nose.

1. $he nasal bones are attachments !or the cartilaginous tissues that !orm

the shape o! the nose.

. $he vomer is located along the midline within the nasal cavity.

1. 2osteriorly the vomer 0oins the perpendicular plate o! the ethmoid

bone.

. $he nasal septum is !ormed !rom the vomer and perpendicular plate o!

the ethmoid.

#. $he in!erior nasal conchae are attached to the lateral walls o! the nasal

cavity.

%. Like the ethmoidal conchae, the in!erior conchae support mucous

membranes within the nasal cavity.

(. $he mandible is shaped like a horseshoe.


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). $he !lat pro0ections at the ends o! a mandible are rami.

7. $he rami are divided into a mandiblar condyle and a coronoid

process.

+. $he mandibular condyles articulate with the temporal bones.

. $he coronoid processes provide attachment sites !or muscles used in

chewing.

#. $he alveolar border is a curved bar o! bone on the superior border o!

the mandible and it contains the sockets o! the lower teeth.

#1. 3andibular !oramens are located near the center o! each ramus.

#. Blood vessels and nerves run through mandibular !oramens.

##. $he mental !oramen is an opening near the point o! the 0aw.

6. -n!antile Skull

1. t birth, the skull is incompletely developed with !ibrous membranes

connecting the cranial bones.

. *ontanels are membranous areas o! an in!antile skull.

#. *ontanels permit some movement between the bones so that the

developing skull is partially compressible and can slightly change shape.

%. &ventually !ontanels close and cranial bones grow together.

&. ;ertebral Column

1. $he vertebral column e'tends !rom the skull to the pelvis and !orms the

vertical a'is o! the skeleton.

. $he vertebral column is composed o! vertebrae that are separated by

intervertebral discs.

#. $he vertebral column supports the head and the trunk o! the body.

%. $he vertebral column protects the spinal cord.

(. $he spinal cord passes through a vertebral canal.

). n in!ant has ## separate bones in the vertebral column.

7. $he sacrum is !ormed by !ive !used vertebrae.

+. $he coccy' is !ormed by !our !used vertebrae.

. n adult vertebral column has ) bones.


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1. $he !our curvatures o! the vertebral column are thoracic, sacral,

cervical, and lumbar.

11. $he cervical curvature develops when a baby begins to hold up its

head.

1. $he lumbar curvature develops when a child begins to stand.

*. $ypical ;ertebra

1. $he body o! a vertebra !orms the thick, anterior portion o! the bone.

. $he intervertebral discs are !astened to the upper and lower sur!aces o!

the vertebral bodies.

#. $he discs cushion and so!ten the !orces caused by walking and 0umping

movements.

%. nterior longitudinal ligaments 0oin the bodies o! ad0acent vertebrae on

their anterior sur!aces.

(. 2osterior longitudinal ligaments 0oin the bodies o! ad0acent vertebrae

on their posterior sur!aces.

). 2edicles are two short stalks that pro0ect posteriorly !rom each

vertebral body.

7. Laminae are two plates that arise !rom the pedicles and !use in the back

to become spinous processes.

+. vertebral arch is !ormed by the pedicles, laminae, and spinous

processes.

. Spinous processes are structures !ormed by the !usion o! two laminae.

1. transverse process pro0ects laterally and posteriorly.

11. Superior and in!erior articulating processes pro0ect upward and

downward !rom each vertebral arch.

1. -ntervertebral !oramina provide passageways !or spinal nerves.

. Cervical ;ertebra

1. $here are 7 cervical vertebrae.

. $he transverse processes o! cervical vertebrae are distinctive because

they have transverse !oramina.


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#. $he spinous processes o! the second through the si'th cervical

vertebrae are bi!id.

%. $he vertebra prominens is the spinous process o! the 7thcervical

vertebra.

(. $he atlas is the 1stcervical vertebra.

). $he atlas supports the head.

7. $he !acets o! the atlas articulate with occipital condyles.

+. $he a'is is the second cervical vertebra.

. $he dens is a process that pro0ects upward and lies in the ring o! the

atlas.

1. s the head is turned !rom side to side, the atlas pivots around the

dens.

9. $horacic ;ertebra

1. $here are 1 thoracic vertebrae.

. $he !acets o! thoracic vertebrae articulate with ribs.

#. $he bodies o! thoracic vertebrae are adapted to bear increasing loads o!

body weight.

-. Lumbar ;ertebra

1. $here are ( lumbar vertebrae and they are located in the small o! the

back.

. $he bodies o! lumbar vertebrae are larger and stronger than the

superior vertebrae.

#. $he transverse processes o! lumbar vertebrae pro0ect posteriorly and

the spinous processes are thick, short, and nearly hori8ontal.

. Sacrum

1. $he sacrum is triangular in shape.

. $he median sacral crest is a ridge o! tubercles where the spinous

process o! sacral vertebrae !used together.

#. 2osterior sacral !oramina are rows o! openings located to the sides o!

the tubercles.


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%. $he sacrum is wedged between the co'ae and is united to them at its

articular sur!aces.

(. $he sacrum !orms the posterior wall o! the pelvic cavity.

). $he sacral promontory is upper anterior margin o! the sacrum.

7. nterior sacral !oramina provide passageways !or nerves and blood

vessels.

. Coccy'

1. $he coccy' is the lowest part o! vertebral column.

. Sitting presses on the coccy', and it moves !orward, acting like a shock

absorber.

L. $horacic Cage

1. $he thoracic cage includes the ribs, thoracic vertebrae, the sternum, and

the costal cartilages that attach the ribs to the sternum.

. $he thoracic cage supports the shoulder girdle and upper limb and

protects the viscera in the thoracic and upper abdominal cavities.

3. /ibs

1. $he usual number o! ribs is %.

. $he true ribs are the !irst 7 pairs o! ribs.

#. $he !alse ribs are the last !ive pairs o! ribs.

%. *loating ribs are the last two pairs o! !alse ribs.

(. typical rib has a long, slender sha!t.

). $he head o! a rib is an enlarged portion o! a rib at its posterior end.

7. $he head o! a rib articulates with a !acet on the body o! its own

vertebra and with the body o! the ne't higher vertebra.

+. tubercle o! a rib articulates with the transverse process o! the

vertebra.

. Costal cartilages are composed o! hyaline cartilage.

1. Costal cartilages are attached to the anterior ends o! a rib.

@. Sternum

1. $he sternum is located along the midline in the anterior portion o! the

thoracic cage.


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. $he three parts o! the sternum are manubrium, body, and 'iphoid

process.

#. $he 'iphoid process pro0ects downward.

%. $he manubrium articulates with clavicles.

(. $he manubrium and body articulate with ribs.

4. 2ectoral irdle

1. $he !our parts o! the pectoral girdle are two clavicles and two scapulae.

. $he pectoral girdle supports the upper limbs and is an attachment !or

several muscles that move the arm.

2. Clavicles

1. clavicle has an S shape.

. Clavicles run between the sternum and the shoulders.

#. $he sternal ends o! the clavicles articulate with the manubrium.

%. $he acromial ends o! the clavicles articulate with the scapulae.

(. $he clavicles brace the !reely movable scapulae and are attachment

sites !or muscles o! the upper limbs, chest, and back.

D. Scapulae

1. $he scapulae are shaped like triangles.

. $he spine o! a scapula divides it into a supraspinous !ossa and

in!raspinous !ossa.

#. $he acromion process !orms the tip o! the shoulder.

%. $he acromion process articulates with the clavicle.

(. $he coracoid process curves anteriorly and in!eriorly to the acromion

process.

). $he glenoid cavity is a depression on the lateral sur!ace o! a scapula.

7. $he glenoid cavity articulates with the head o! the humerus.

+. $he three borders o! the scapulae are superior, lateral, and medial.

/. 5pper Limb

1. $he bones o! the upper limb !orm the !ramework !or the arm, !orearm,

wrist, and hand.


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. $he bones o! the upper limb are humerus, radius, ulna, carpals,

metacarpals, and phalanges.

S. 9umerus

1. $he humerus e'tends !rom the scapula to the elbow.

. $he head o! the humerus !its into the glenoid cavity.

#. $wo processes 0ust below the head are a greater tubercle and lesser

tubercle.

%. $he intertubercular groove is a !urrow between the greater tubercle and

lesser tubercle.

(. $he anatomical neck is the narrow depression along the lower margin

o! the head that separates it !rom the tubercles.

). $he surgical neck is a tapering region 0ust below the head and the

tubercles o! the humerus.

7. $he deltoid tuberosity is an attachment site !or the deltoid muscle.

+. $wo condyles at the lower end o! the humerus are the capitulum and

trochlea.

. $he capitulum is on the lateral side and articulates with the radius.

1. $he trochlea is on the medial side and articulates with the ulna.

11. &picondyles are located above the condyles and provide attachments

!or muscles and ligaments o! the elbow.

1. $he coronoid !ossa is a depression between the epicondyles anteriorly

that receives the coronoid process o! the ulna when the arm bends at the

elbow.

1#. $he olecranon !ossa is a depression on the posterior distal sur!ace o!

the humerus that receives the olecranon process o! the ulna when the arm

straightens at the elbow.

$. /adius

1. $he radius is located on the thumb side o! the !orearm.

. $he radius e'tends !rom the elbow to the wrist and crosses over the

ulna when the hand is turned so that the palm !aces backward.

#. $he head o! the radius articulates with the capitulum o! the humerus.


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%. $he radial tuberosity is an attachment site !or the biceps brachii.

(. $he styloid process is located at the distal end o! the radius on its

lateral side.

5. 5lna

1. $he trochlear notch o! the ulna is a wrenchlike opening at the pro'imal

end o! the ulna.

. $he trochlear notch articulates with the trochlea o! the humerus.

#. $he olecranon process is located above the trochlear notch.

%. $he head o! the ulna articulates laterally with a notch o! the radius and

with a disc o! !ibrocartilage in!eriorly.

(. $he styloid process o! the ulna is located at the distal end o! the ulna on

its medial side.

;. 9and

1. $he hand is made o! the wrist, palm, and !ingers.

. $he bones o! the wrist are called carpals.

#. $he individual names o! the + carpals are scaphoid, capitate, trape8oid,

trape8ium, lunate, hamate, tri


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%. $he pelvic girdle provides attachments !or the lower limbs and protects

the urinary bladder, the distal end o! the large intestine, and the internal

reproductive organs.

(. $he body=s weight is transmitted through the pelvic girdle to the lower

limbs and then onto the ground.

E. 9ip Bones

1. &ach co'a develops !rom the !ollowing three parts: an ilium, an

ischium, and a pubis.

. $he acetabulum is a cup"shaped cavity o! a co'al bone.

#. $he acetabulum receives the head o! the !emur.

%. $he ilium is the largest and most superior portion o! the co'a.

(. $he ilium !orms the prominence o! the hip.

). $he iliac crest is the margin o! the prominence o! the hip.

7. $he iliac !ossa is the smooth, concave sur!ace on the anterior aspect o!

the ilium.

+. 2osteriorly the ilium 0oins the sacrum at the sacroiliac 0oint.

. $he anterior superior iliac spine can be !elt lateral to the groin

and is an important surgical landmark.

1. 4n the posterior border o! the ilium is a posterior superior iliac spine.

11. Below the posterior superior iliac spine is a deep indentation called

the greater sciatic notch, through which nerves and blood vessels pass.

1. $he lowest portion o! the co'a is the ischium.

1#. $he ischium is L shaped.

1%. $he ischial tuberosity points posteriorly and downward.

1(. $he ischial tuberosity supports the body during sitting.

1). $he ischial spine is a sharp pro0ection above the ischial tuberosity.

17. $he distance between the ischial spines is the shortest diameter o! the

pelvic outlet.

1+. $he pubis constitutes the anterior portion o! the co'a.

1. $he symphysis pubis is where the two pubis bones 0oin together.


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. $he pubic arch is the angle the pubis bones !orm below the

symphysis.

1. $he obturator !oramen is the largest !oramen o! the skeleton. -t is

located between the three parts o! a co'al bone.

?. $rue and *alse 2elves

1. $he pelvic brim would be marked i! a line were drawn along each side

o! the pelvis !rom the sacral promontory downward and anteriorly to the

upper margin o! the symphysis pubis.

. $he pelvic brim separates the true pelvis !rom the !alse pelvis.

#. $he !alse pelvis is bounded posteriorly by the lumbar vertebrae,

laterally by the !lared parts o! the iliac bones, and anteriorly by the

abdominal wall.

%. $he !alse pelvis supports the abdominal organs.

(. $he true pelvis is bounded posteriorly by sacrum and coccy' and

laterally and anteriorly by lower ilium, ischium, and pubis bones.

A. 6i!!erences Between 3ale and *emale 2elves

1. 5sually the !emale iliac bones are more !lared than those o! the male.

. $he !emale hips are usually wider than those o! the male.

#. $he angle o! the !emale pubic arch may be greater than that o! the

male.

%. $he !emale pelvic cavity is usually wider in all diameters than that o!

the male.

(. $he bones o! the !emale pelvis are lighter and show less evidence o!

muscle attachments.

. Lower Limb

1. $he bones o! the lower limb !orm the !ramework o! the thigh, leg,

ankle, and !oot.

. $he bones o! the lower limb are the !emur, tibia, !ibula, patella, tarsals,

metatarsals, and phalanges.

BB. *emur

1. $he !emur e'tends !rom the hip to the knee.


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. $he head o! the !emur pro0ects medially into the acetabulum.

#. $he !ovea capitis is a pit that marks the attachment o! a ligament.

%. $he neck o! the !emur is a constriction 0ust below the head.

(. $wo large processes below the neck o! the !emur are the greater and

lesser trochanters.

). $he linea aspera is a longitudinal crest on the posterior sur!ace o! the

!emur.

7. $he lateral and medial condyles articulate with the tibia.

+. $he patella articulates with the !emur on its distal anterior sur!ace.

. $he medial and lateral epicondyles provide attachments !or muscles

and ligaments.

CC. 2atella

1. $he patella is a sesamoid bone located in a tendon that passes

anteriorly over the knee.

. $he patella controls the angle at which this tendon continues toward the

tibia.

66. $ibia

1. $he shinbone is the tibia.

. $he tibia is located on the medial side.

#. $he medial and lateral condyles o! the tibia articulate with the condyles

o! the !emur.

%. $he tibial tuberosity is located below the condyles o! the tibia.

(. $he tibial tuberosity provides an attachment !or the patellar ligament.

). $he anterior crest o! the tibia is a prominence that e'tends downward

!rom the tibial tuberosity and attaches connective tissues in the leg.

7. $he medial malleolus is a prominence at the distal end o! the tibia.

+. 4n the tibia=s lateral side is a depression that articulates with the !ibula.

. $he in!erior sur!ace o! the tibia=s distal end articulates with the talus.

&&. *ibula

1. $he !ibula is on the lateral side o! the tibia.

. $he head o! the !ibula articulates with the tibia.


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#. $he lateral malleolus articulates with the ankle and protrudes !rom the

lateral side.

**. *oot

1. $he !oot is made o! the ankle, the instep, and the toes.

. $he ankle or tarsus is composed o! seven tarsal bones.

#. $he talus articulates with the tibia and !ibula and can move !reely at the

ankle.

%. $he seven tarsal bones are the calcaneous, the talus, the navicular, the

cuboid, and the lateral, medial, and intermediate cunei!orm bones.

(. $he largest tarsal is the calcaneus.

). $he calcaneus helps support body weight.

7. $he metatarsus consists o! !ive elongated bones.

+. $he heads at the distal ends o! the metatarsals !orm the ball o! the !oot.

. $he arch o! the !oot is !ormed by the arrangements o! the tarsals and

metatarsals.

1. $he bones o! the toes are called phalanges.

11. &ach toe has # phalanges e'cept the great toe because it lacks the

middle phalyn'.

$III. %i'e(Span Chan!es

. n incremental decrease in height begins at about age #.

B. Compression !ractures o! the vertebrae may contribute to loss o!

height.

C. s calcium levels !all, bones become brittle and prone to !racture.

6. radually, osteoclasts come to outnumber osteoblasts.

&. By age #( all adults start to lose bone mass.

*. $rabecular bone shows signs o! aging !irst.

. Compact bone loss begins around the age o! %.

9. -n the !irst decade !ollowing menopause 1( to o! trabecular bone

is lost and 1 to 1( o! compact bone is lost in women.

-. $he most common !ractures in the elderly are vertebral compression

!ractures, hip !ractures, wrist !ractures, leg !ractures, and pelvis !ractures.


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. $o preserve skeletal health avoid !alls, take calcium supplements, get

enough vitamin 6, avoid carbonated beverages, and get regular e'ercise.

ch07_answer_key_13edition.doc

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