Ch7: Skeletal System - The Axial Skeleton

Front 1

Describe the axial division of the skeleton

Back 1

Axial skeleton = bones that lie around the longitudinal axis of the human body (consists of 80 bones)
>> SKULL - cranium, face, HYOID, AUDITORY OSSICLES (EAR BONES), VERTEBRAL COLUMN, THORAX - sternum, ribs

Front 2

Describe the appendicular division of the skeleton

Back 2

Appendicular skeleton = bones of the upper and lower limbs (extremities), plus the bones forming the girdles that connect the limbs to the axial skeleton (consists of 126 bones)
>> PECTORAL (SHOULDER), GIRDLES - clavicle, scapula, UPPER LIMBS – humerus, ulna, radius, carpals, metacarpals, phalanges, PELVIC (HIP) GIRDLE – hip/pelvic/coxal bone, LOWER LIMBS – femur, patella, fibula, tibia, tarsals, metatarsals, phalanges

Front 3

Classify bones on the basis of shape

Back 3

FIGURE 7-2 Shape of Bones

Front 4

Classify bones on the basis of shape and location: long bones

Back 4

-slightly curved for strength >> absorbs the stress of the body's weight at several different points, so that it is evenly distributed
-found in femur (thigh bone), tibia and fibula (leg bones), humerus (arm bone), ulna and radius (forearm bones), and phalanges (finger and toe bones)

Front 5

Classify bones on the basis of shape and location: short bones

Back 5

Short bones
-found in carpal (wrist) bones (except for pisiform, which is a sesamoid bone) and the tarsal (ankle) bones (except for the calcaneus or heel bone, which is an irregular bone)

Front 6

Classify bones on the basis of shape and location: flat bones

Back 6

Flat bones
-considerable protection & provide extensive areas for muscle attachment
-found in cranial bones (skull: protect brain), sternum (breastbone) and ribs (protect organs in thorax) and scapulae (shoulder blades).

Front 7

Classify bones on the basis of shape and location: irregular bones

Back 7

Irregular bones
-found in vertebrae (backbones), hip bones, certain facial bones, and the calcaneus

Front 8

Classify bones on the basis of shape and location: sesamoid bones

Back 8

Sesamoid bones
-protect tendons from excessive friction, tension, physical stress
-often change the direction of pull of a tendon >> improves mechanical advantage at a joint
-found in palms and soles, 2 patellae (kneecaps), large sesamoid bones in quadriceps femoris tendon

Front 9

Classify bones on the basis of shape and location: sutural bones

Back 9

Sutural bones
=small bones located in sutures (immovable joints in adults) between certain cranial bones

Front 10

Which type of bone primarily provides protection and a large SA for muscle attachment?

Back 10

Flat bones protect underlying organs and provide a large surface area for muscle attachment

Front 11

What are surface markings on bones? Are they always present? Give examples of how surface markings develop?

Back 11

=structural features adapted for specific functions
-not present at birth, most prominent in adult skeleton
-ie. tension on bone surface from tendons, ligaments, aponeuroses, fasciae
-ie. new bone is deposited >> raised or roughened areas
-ie. compression on a bone surface >> a depression

Front 12

What are the 2 major types of surface markings and their functions?

Back 12

(1) depressions and openings
>> allow passage of soft tissues (ie. blood vessels, nerves) or form joints
(2) processes = projections or outgrowths
>>help form joints or serve as attachment points for connective tissue (ie. ligaments and tendons)

Front 13

Name the specific types of bone surface markings of ‘depressions and openings’ and processes

Back 13

DEPRESSIONS AND OPENINGS
Fissure
Foramen
Fossa
Sulcus
Meatus
PROCESSES (that form joints)
Condyle
Facet
Head
PROCESSES (that form attachments for connective tissue)
Crest
Epicondyle
Line
Spinous Process
Trochanter
Tubercle
Tuberosity

Front 14

What are the 2 categories that skull bones are grouped into? What smaller bones do they consist of?

Back 14

1 Cranial bones (8 bones)
-form cranial cavity
>> frontal bone, 2 parietal bones, 2 temporal bones, occipital bone, sphenoid bone, and ethmoid bone

2 Facial bones (14 bones)
-form face
>> 2 nasal bones, 2 maxillae/maxillas, 2 zygomatic bones, mandible, 2 lacrimal bones, 2 palatine bones, 2 inferior nasal conchae, vomer

Front 15

What are the functions of the cranial bones?

Back 15

-encloses and protects the brain
-stabilize the positions of the brain, blood vessels, lymphatic vessels, and nerves through attachment of their inner surfaces to meninges (membranes)
-outer surfaces: provide large areas of attachment for muscles for movement and facial expressions
*** Together, cranial and facial bones protect & support special sense organs for vision, taste, smell, hearing, and equilibrium (balance)

Front 16

What are the functions of the facial bones?

Back 16

-form the framework of face
-provide support for entrances to the digestive and respiratory systems
***Together, cranial and facial bones protect & support special sense organs for vision, taste, smell, hearing, and equilibrium (balance)

Front 17

Identify the location of the frontal bone and its major surface marking(s)

Back 17

Figure 7-3
-forms forehead, roofs of the orbits (eye sockets), and most of anterior part of the cranial floor
>> supraorbital margin

Front 18

Identify the locations of the 2 parietal bones

Back 18

Figure 7-4
-form the greater portion of the sides and roof of the cranial cavity

Front 19

What major bones are joined by (1) the squamous suture, (2) the lambdoid suture, and (3) the coronal suture?

Back 19

Parietal and temporal bones are joined by the squamous suture
Parietal and occipital bones are joined by the lambdoid suture
Parietal and frontal bones are joined by the coronal suture

Front 20

Identify the locations of the 2 temporal bones and their surface markings

Back 20

Figure 7-4
>>Zygomatic arch = formed by zygomatic process of temporal bone and temporal process of zygomatic bone
>>External auditory meatus (meatus = passageway) or ear canal: directs sound waves into ear
>>Mastoid process = rounded projection of the mastoid portion = point of attachment for several neck muscles
>>Internal auditory meatus (Fig7-5)

Front 21

With which bones does the temporal bone articulate?

Back 21

The temporal bone articulates with the parietal, sphenoid, zygomatic, and occipital bones

Front 22

Identify the location of the occipital bone and its surface markings

Back 22

Figure 7-6; Figure 7-4
>>foramen magnum (= large hole) where medulla oblongata connects w spinal cord, vertebral & spinal arteries also pass through
>>occipital condyles (Fig7-7)

Front 23

Identify location, importance, shape, and major surface markings of the sphenoid bone

Back 23

Figures 7-7 and 7-8
-between the ethmoid and occipital bones
=keystone of the cranial floor because it articulates with all the other cranial bones, holding them together
-resembles butterfly with outstretched wings
>>optic foramen or canal (optic = eye) where optic (II) nerve & ophthalmic artery pass into orbit

Front 24

Identify the location, importance, and surface markings of the Ethmoid bone (= like a sieve)

Back 24

Figure 7-9
-forms (1) part of cranial floor (2) medial wall of orbits (3) superior portion of nasal septum (a partition that divides nasal cavity into right and left sides) (4) most of superior sidewalls of nasal cavity
=major superior supporting structure of the nasal cavity
>>superior and middle nasal concha/turbinate: 2 thin, scroll-shaped projections lateral to nasal septum

Front 25

What are the important functions of the superior, middle, and inferior nasal concha?

Back 25

-greatly increase vascular & mucous membrane SA in nasal cavity
>> warms & moistens/humidifies inhaled air before it passes into lungs
-cause inhaled air to swirl
>> many inhaled particles become trapped in the mucus lining nasal cavity
-superior nc = where sensory receptors for olfaction (smell) end >> increase SA for sense of smell

Front 26

Identify the location of the nasal bones

Back 26

-forms nose bridge

Front 27

Identify the location and the surface markings of maxillae (singular: maxilla)

Back 27

Figure 7-4, 7-7
= upper jawbone
-articulate with every bone of face except mandible (lower jawbone)
=part of orbits, part of nasal cavity, and most of hard palate (separates nasal cavity from oral cavity)
>>alveolar process (alveol = small cavity) = arch that contains alveoli (sockets) for maxillary (upper) teeth

Front 28

Identify the location of the zygomatic bones (zygo- = yokelike)

Back 28

=cheekbones, form prominences of the cheeks and part of each orbit (Fig7-12)

Front 29

Identify the location and surface markings of lacrimal bones (lacrim = teardrops)

Back 29

Fig7-3, 7-4, 7-12
=smallest bones of face, form a part of each orbit
>>lacrimal fossa=a vertical groove formed w maxilla, houses lacrimal sac (structure that gathers tears and passes them into nasal cavity (Fig7-12)

Front 30

Identify the location of palatine bones

Back 30

-form a portion of hard palate, portion of nasal cavity, and a small portion of orbits (Fig7-7, 7-12)

Front 31

Identify the location inferior nasal conchae

Back 31

-not part of ethmoid bone (Fig 7-3, 7-9a)
-form a part of nasal cavity wall and project into nasal cavity
***All three pairs of nasal conchae (superior, middle, inferior) increase SA of nasal cavity and help swirl and filter air before it passes into the lungs. Only superior nc involved in smell

Front 32

Identify the location of the vomer

Back 32

-on floor of nasal cavity
-articulates, ethmoid bone, maxillae, and palatine bones (Fig 7-3, 7-7, 7-11)
-forms nasal septum

Front 33

Identify the location, distinctive property, and surface markings of the mandible (mand = to chew)

Back 33

=lower jawbone >> largest, strongest facial bone (Fig7-10)
=only movable skull bone (other than auditory ossicles)
>>body: curved horizontal portion
>>rami: 2 perpendicular portions
>>angles: where rami meets body
>>Condylar process: on each ramus; articulates w mandibular fossa & articular tubercle of temporal bone (Fig7-4) to form TMJ and…
>>Coronoid process: where temporalis muscle attaches
>>alveolar process

Front 34

Identify the location and 3 components of the nasal septum

Back 34

=vertical partition separating nasal cavity into left and right sides
-3 components: vomer, septal cartilage, and perpendicular plate of ethmoid bone (Fig7-11)

Front 35

Identify the location and the 7 components of the orbits

Back 35

Orbit = eye socket
-3 cranial bones: frontal, sphenoid, and ethmoid
-4 facial bones: palatine, zygomatic, lacrimal, and maxilla

Front 36

Identify 4 prominent sutures

Back 36

-coronal suture (Fig7-4)
-sagittal suture (Fig7-6)
-lambdoid suture (Fig 7-6)
-squamous sutures (Fig7-4)

Front 37

What is the importance of sinuses?

Back 37

-lighten mass of skull
-increase SA of nasal mucosa >> increasing production of mucus to help moisten and cleanse inhaled air
-paranasal sinuses (develop during prepubescence) serve as resonating (echo) chambers >> enhance quality of voice

Front 38

What are Fontanels (=little fountains) aka “soft spots?”
Where are they found?
What is it replaced with eventually?

Back 38

A mesenchyme-filled space (unossified) where bone formation is not yet complete, especially between the cranial bones of an infant's skull
-eventually replaced w bone by intramembranous ossification to become sutures
***an infant has many fontanels

Front 39

Identify the 4 types of fontanels. What are the functions of fontanels?

Back 39

Anterior fontanel
Posterior fontanel
Anterolateral fontanels
Posterolateral fontanels
-provide some flexibility to the fetal skull >> allow skull to change shape as it passes through birth canal, later permits rapid growth of brain during infancy

Front 40

How is the hyoid bone unique from other bones of the axial skeleton?
Where is it located?

Back 40

=it does not articulate with any other bone
>>it is suspended from the styloid processes of the temporal bones by ligaments and muscles
-Located between mandible and larynx (Fig 7-15a)

Front 41

What is the function of the hyoid bone?

Back 41

-supports tongue >> provides attachment sites for some tongue muscles and for muscles of neck & pharynx
-helps to keep larynx (voice box) open at all times

Front 42

Identify the location of a series of bones called vertebrae

Back 42

-in vertebral column (spine, backbone, spinal column)

Front 43

What are the functions of the vertebral column?

Back 43

-encloses and protects spinal cord
-supports head
-serves as a point of attachment for the ribs, pelvic girdle, and muscles of the back and upper limbs

Front 44

Identify the 5 different types of vertebrae

Back 44

7 cervical vertebrae
12 thoracic vertebrae
5 lumbar vertebrae
1 sacrum >> 5 fused sacral vertebrae
1 coccyx >> 4 fused coccygeal vertebrae

Front 45

Describe the normal curves of the spine

Back 45

Thoracic and sacral vertebrae = concave (cupping in)
Cervical and lumbar = convex (bulging out)

Front 46

Define invertebral disc and what are its components?

Back 46

A pad of fibrocartilage located between the bodies of two vertebrae
>>annulus fibrous (an outer fibrous ring consisting of fibrocartilage; annulus = ringlike)
>>nucleus pulposus (an inner soft, pulpy, highly elastic substance; pulposus = pulplike)
***discs are avascular >> annulus fibrosus & nucleus pulposus rely on blood vessels from bodies of vertebrae to obtain oxygen & nutrients and remove wastes

Front 47

What are the components of a vertebra?

Back 47

Vertebrae typically consist of a body, a vertebral arch, and 7 processes

Front 48

Identify the shape, function, and surface markings of the vertebral body

Back 48

-thick, disc-shaped anterior portion
=weight-bearing part of a vertebra
>>roughened surfaces for attachment of cartilaginous intervertebral discs
>>Nutrient Foramina: openings through which blood vessels deliver nutrients & O2 and remove CO2 and wastes from bone tissue)

Front 49

Identify the components and the surface markings of the vertebral arch

Back 49

-formed by laminae + pedicles (from vertebral body)
>>vertebral foramen: contains spinal cord, adipose tissue, areolar connective tissue, blood vessels
>>vertebral (spinal) canal = collectively formed by vertebral foramina of all vertebrae
>>intervertebral foramen = opening between adjoining vertebrae on both sides of column = permits passage of a single spinal nerve that passes to specific region of body

Front 50

Describe the 7 processes of a vertebra

Back 50

>>Spinous process: projects from laminae
>>Transverse processes: at point where a lamina and pedicle join
*Above 3 processes = attachment points for muscles
*Remaining 4 form joints w other vertebrae above or below
>>Superior articular processes form joints w…
>>Inferior articular processes

Front 51

What are the functions of the vertebral and intervertebral foramina?

Back 51

Vertebral foramina enclose the spinal cord
Intervertebral foramina provide spaces through which spinal nerves exit the vertebral column

Front 52

Compare facets and invertebral joints

Back 52

Facets = articulating surfaces of articular processes, covered with hyaline cartilage
Intervertebral joints = articulations formed between bodies and articular facets of successive vertebrae
Identify the location and major surface markings of the cervical vertebrae (C1–C7)
Figure 7-18a, 7-18d
-3 foramina
>>1 vertebral foramen (houses cervical enlargement of spinal cord
>>2 transverse foramina (through which vertebral artery and its accompanying vein and nerve fibers pass)
>>spinous processes (C2-C6) = bifid (split into 2 parts)

Front 53

Why are the vertebral foramina of cervical vertebrae the largest in the spinal column?

Back 53

Because they house the cervical enlargement of the spinal cord

Front 54

Identify the location and major surface marking(s) of the atlas and axis

Back 54

atlas = C1 (first cervical vertebra inferior to the skull (Figure 7-18a, b)
-no body
axis = C2 (Fig7-18a, c)
-has a body
>>dens (=tooth) or odontoid process (makes a pivot on which the atlas and head rotate; permits side-to-side movement of head)

Front 55

Identify the importance and major surface markings of thoracic vertebrae

Back 55

-articulate w ribs
Thoracic vertebrae (T1–T12; Figure 7-19)
>>spinous processes on T1 and T2 = long, laterally flattened, and directed inferiorly
>>spinous processes on T11 and T12 = shorter, broader, and directed more posteriorly
>>transverse processes = longer and larger compared to cervical vertebrae

Front 56

Identify the importance and major surface markings of lumbar vertebrae

Back 56

The lumbar vertebrae (L1–L5)
=largest & strongest of unfused bones in vertebral column (Fig7-20 p224) bc body weight supported by vertebrae increases toward inferior end of backbone
>>superior articular processes
>>inferior articular processes
>>spinous processes = quadrilateral in shape, thick and broad; well adapted for attachment of large back muscles

Front 57

Identify location, importance, major surface markings of the sacrum

Back 57

-sacral vertebrae (S1–S5) (Fig7-21a p225)
***begin to fuse 16-18 years of age, completed by age 30
=strong foundation for pelvic girdle (female sacrum = shorter, wider, more curved)
>>Anterior sacral foramina (4 pairs) – concave portion
>>Median sacral crest – convex portion = fused spinous processes of upper sacral vertebrae
>>Posterior sacral foramina (4 pairs): connect w anterior sacral foramina to allow passage of nerves & blood vessels
>>Sacral canal = continuation of vertebral cavity
>>Sacroiliac joint (Fig8.9 p245)

Front 58

Identify the location, components, and differences in females and males of the coccyx

Back 58

=4 fused coccygeal vertebrae (Fig7-21 as Co1–Co4)
***fuse later than sacral vertebrae, b/w 20-30 yo
Females: coccyx points inferiorly to allow passage of a baby during birth
Males: it points anteriorly

Front 59

Where is caudal anesthesia / epidural block injected? Which nerves do they affect? Why are the injection sites lower in the spine?

Back 59

-injected into sacral hiatus, or posterior sacral foramina
-act on the sacral and coccygeal nerves
***injection site = inferior to lowest portion of spinal cord >> little danger in damaging cord

Front 60

Name the components of the thorax

Back 60

-sternum
-ribs
-costal cartilages
-bodies of the thoracic vertebrae

Front 61

Identify the location, components, and major surface markings of sternum, or breastbone

Back 61

-located in the center of thoracic wall
-3 parts: (1) manubrium = articulates w costal cartilages of 1st&2nd ribs (2) body = articulates w directly/indirectly w costal cartilages of 2nd-10th ribs (3) xiphoid process = consists of hyaline cartilage (ossifies at 40yo), attachment for some abdominal muscles, no ribs
>> suprasternal notch = depression on manubrium
>> clavicular notches = lateral to above
>> sternal angle = junction of manubrium & body

Front 62

Identify the location and types of ribs

Back 62

12pairs = give structural support to sides of thoracic cavity (Fig7-22b)
True (vertebrosternal) ribs (1st-7th pairs) = direct attachment to sternum by costal cartilage
>>sternocostal joints = articulations b/w true ribs & sternum
False ribs = costal cartilages attach indirectly to sternum OR do not attach to sternum at all
(8th-10th pairs = vertebrochondral ribs) cartilages attach to one another & then to cartilages of 7th pair of ribs
(11th-12th pairs of ribs = floating (vertebral) ribs) costal cartilage does not attach to sternum at all, attach only to thoracic vertebrae

Front 63

What are the functions of costal cartilage?

Back 63

***costal cartilage (cost = rib) = type of hyaline cartilage
-contribute to elasticity of thoracic cage
-prevents injury to sternum and/or ribs

Front 64

Define costochondritis

Back 64

=Inflammation of 1 or more costal cartilages
-characterized by local tenderness & pain in anterior chest wall that may radiate (symptoms mimic chest pain associated with a heart attack (angina pectoris))

Front 65

Identify the locations of the components of a rib

Back 65

>>head = projection at posterior end of the rib, contains a pair of articular facets (superior and inferior)
>>neck = constricted portion of a rib just lateral to the head
>>tubercle = A knoblike structure on posterior surface, where neck joins body
>>body (shaft) = main part of rib

Front 66

Describe a herniated/slipped disc
How does it develop?
Where does it occur most often and why?

Back 66

-A rupture of an intervertebral disc so that the nucleus pulposus protrudes into vertebral cavity
-If ligaments of discs become injured/weakened, pressure developed in nucleus pulposus may be great enough to rupture surrounding fibrocartilage >> nucleus pulposus may herniate (protrude) posteriorly or into one of adjacent vertebral bodies (Figure 7-24)
-most often occurs in lumbar area bc it bears much of body weight & is region of most flexing & bending

Front 67

Name 3 disorders of the spine and describe them

Back 67

Scoliosis: An abnormal lateral curvature from normal vertical line of backbone
Kyphosis: An exaggeration of thoracic curve of vertebral column >> “round-shouldered” appearance aka. hunchback
Lordosis: An exaggeration of lumbar curve of vertebral column aka. hollow back

Front 68

Describe spina bifida and the different types

Back 68

=a congenital defect in which laminae of L5 and/or S1 fail to develop normally and unite at midline
>> spina bifida occulta: no symptoms, only evidence = small dimple with a tuft of hair in the overlying skin
>> spina bifida cystica: presence of a cystlike sac protruding from backbone.
>> spina bifida with meningocele: If sac contains meninges from spinal cord & cerebrospinal fluid
>> spina bifida w meningomyelcele: If spinal cord and/or its nerve roots are in sac, the condition
*** larger the cyst & the # of neural structures it contains, the more serious the neurological problems

Front 69

Describe the symptoms of severe cases of spina bifida
What is it caused by?

Back 69

-Severe cases = partial or complete paralysis, partial or complete loss of urinary bladder and bowel control, and the absence of reflexes
- associated w low levels of folic acid (type of vitamin) during pregnancy