Chapter 7 - Axial Skelly

Question 1

What does the cranial cavity enclose?

Answer 1

The brain

Question 2

What are the orbits?

Answer 2

Eye sockets

Question 3

What are the paranasal sinuses?

Answer 3

Air-filled spaces connected to nasal cavity

1. frontal
2. sphenoid
3. ethmoidal
4. maxillary

Question 4

What are the functions of the paranasal sinuses?

Answer 4

Decrease skull weight

Resonating chambers

Question 5

What is the job of your cranial bones?

Answer 5

To protect the brain

Question 6

What are the two divisions of the cranium?

Answer 6

Calvaria (skullcap) and cranial base (cranial floor)

Question 7

What are the three divisions of the cranial base?

Answer 7

1. anterior cranial fossa (frontal lobe)
2. middle cranial fossa (temporal lobe)
3. posterior cranial fossa (cerebellum)

Question 8

Describe the location of the frontal bone

Answer 8

Makes up the forehead
Roof of orbit
Anterior third of roof of cranial cavity

Question 9

What skull bone is separate in infants but fuses to a single bone by adulthood?

Answer 9

Frontal bone

Question 10

What is the glabella?

Answer 10

the smooth area above the root of nose

Question 11

Describe the location of the parietal bones

Answer 11

Cranial roof and part of walls

Question 12

What are the 4 largest sutures and where are they found?

Answer 12

1. Sagittal: between parietal bones
2. Coronal: anterior margin (frontal/parietal joint)
3. Lambdoid: posterior margin (occipital/parietal joint)
4. Squamous: lateral border (parietal/temporal joint)

Question 13

Describe the location of the temporal bones?

Answer 13

Lateral wall and part of floor of cranial cavity

Question 14

What are the four main parts of the temporal bones?

Answer 14

1. Squamous
2. Tympanic
3. Mastoid
4. Petrous

Question 15

Describe the squamous part of the temporal bone and what features are found there

Answer 15

Flat/vertical
Encircled by squamous suture
Features: zygomatic process, mandibular fossa

Question 16

Describe the tympanic part of the temporal bone and what features are found there

Answer 16

Ring that borders the ear canal

Features: external auditory meatus, styloid process

Question 17

Describe the mastoid part of the temporal bone and what features are found there

Answer 17

Posterior portion

Features: mastoid process (air pockets), mastoid notch, stylomastoid foramen (Facial nerve)

Question 18

Describe the petrous part of the temporal bone and what features are found there

Answer 18

Cranial floor - “little mtn. range”
Separates middle from posterior cranial fossa
Features: middle- and inner-ear cavities, internal auditory meatus, carotid canal, jugular foramen

Question 19

Describe the location of the occipital bone?

Answer 19

Rear of skull and base

Question 20

What is the major foramen found in the occipital bone and what goes through it?

Answer 20

Foramen Magnum

Spinal cord

Question 21

What are some of the features of the occipital bone?

Answer 21

Foramen Magnum
Occipital condyle (knobs that allow skull to rest of vertebral column)
External occipital protuberance
Superior and inferior nuchal lines

Question 22

Describe the sphenoid bone

Answer 22

Thick median body with outstretched wings

Question 23

Describe the lesser wings of the sphenoid bone

Answer 23

Posterior margin of anterior cranial fossa
Posterior wall of orbit
Features: optic canal (optic nerve) - anterior to sella turcica

Question 24

Describe the greater wings of the sphenoid bone

Answer 24

Approximately half of the middle cranial fossa

Lateral surface

Question 25

What are some of the features fo the sphenoid bone?

Answer 25

``` Greater and lesser wings Superior orbital fissure (passage of nerves supplying the eye muscle, between greater/lesser wings) Body (sphenoid sinus) Sella turcica (pituitary gland) 3 major foramen: 1. Foramen rotundum 2. Foramen ovale 3. Foramen spinosum ```

Question 26

Describe the location of the ethmoid bone

Answer 26

Between orbits | Contributes to the roof/walls of the nasal cavity, medial wall of orbit, nasal septum

Question 27

What are some features of the ethmoid bone

Answer 27

Honeycomed with air cells - ethmoid sinus Perpendicular and orbital plates Crista galli (attachment for dura matter) Cribriform plate and foramina Nasal conch (superior and middle, inferior is it's own bone)

Question 28

What bones are considered facial bones (14)?

Answer 28

2 each: maxillae, palatine, zygomatic, lacrimal, nasal, inferior nasal conchae 1 of each: vomer, mandible

Question 29

What is the purpose of the facial bones?

Answer 29

To shape the face support internal structures of oral and nasal cavities Support teeth

Question 30

Where is the maxillae located and what is its job?

Answer 30

Upper jaw Supports teeth Make up the floor and medial walls of the orbit Forms 4/5ths of the hard palate

Question 31

What are some features fo the maxillae?

Answer 31

``` Alveolar process (bony points between teeth) Alveolus (sockets that hold teeth) Inferior orbital fissure Palantine process Maxillary sinus (largest sinus) ```

Question 32

Describe the palatine bones and the structures it helps to form

Answer 32

L-shaped Forms part of nasal cavity wall Forms part of floor of orbit Posterior 1/5 of the hard palate

Question 33

What are the two plates of the palatine bone?

Answer 33

Perpendicular plate and parallel plate

Question 34

Where are the zygomatic bones found and what structures do they help to form?

Answer 34

``` Upper cheek bones Forms the angle of cheeks Forms part of the lateral wall fo orbit Inverted T-shape Contribute to the zygomatic arch ```

Question 35

Where are the lacrimal bones found?

Answer 35

Part of the medial wall of each orbit

Question 36

Describe features of the lacrimal bones

Answer 36

Smallest skull bone Lacrimal sac (foss) - collect tears from eyes - drain into nasal cavity

Question 37

Describe the nasal bones and their jobs

Answer 37

Form bridge of nose Support cartilages that shape lower portion of the nose Easily fractured

Question 38

Describe the vomer and it's job

Answer 38

Inferior half of the nasal septum (inferior to eh perpendicular plate of ethmoid) Supports cartilage that forms anterior part of nasal septum

Question 39

Describe the inferior nasal conchae

Answer 39

Largest of three conchae in the nasal cavity | Not part of the ethmoid bone (other two conchae are)

Question 40

Describe the location of the mandible and it's job

Answer 40

Jaw bone Supports lower teeth Attachment for the muscles of mastication

Question 41

What are some features of the mandible?

Answer 41

``` Alveolar processes (support teeth) Body Ramus Angle Anterior coronoid process Posterior condylar process Mandibular condyles Mental foramen Mandibular foramen (inferior alveolar nerve for tooth sensation) ```

Question 42

What are the 7 bones that make up the orbit?

Answer 42

1. frontal 2. sphenoid 3. zygomatic 4. maxilla 5. lacrimal 6. ethmoid 7. palatine

Question 43

What are the bones of the nasal cavity?

Answer 43

``` Vomer Ethmoid (perpendicular plate) Inferior nasal conchae Frontal Nasal Sphenoid Palantine (horizontal plate) Maxillae (palatine process) Lacrimal bone ```

Question 44

What are fontanelles? What are they made of?

Answer 44

Spaces between unfused cranial bones (in infants) | Contain fibrous membrane

Question 45

What is the purpose of fontanelles?

Answer 45

Allow for shifting of bones during birth and growth of brain

Question 46

Where is your hyoid bone and what is so special about it?

Answer 46

Between chin and larynx No articulation with other bones (only bone in body like that) Suspending from styloid process Attachment site for muscles that control mandible, tongue, and larynx

Question 47

What are the three auditory ossicles

Answer 47

Malleus (mallet) Incus (handle) Stapes (stirup)

Question 48

What is the purpose of the vertebral column?

Answer 48

Supports the skull and trunk Protects spinal cord Absorbs stress of movement Provides attachments for limbs, thoracic cage, and postural muscles

Question 49

How many total vertebrae are there and what are the breakdowns into groups?

Answer 49

``` 33 total (23 cartilaginous intervertebral discs) Breakdown: - 7 cervical - 12 thoracic - 5 lumbar - 5 sacral (fused into sacrum) - 4 coccygeal (fused into coccyx) ```

Question 50

What are some general features of a vertebrae?

Answer 50

Body (weight bearing, rough surfaces for attachment to intervertebral discs) Vertebral foramen (posterior opening) Vertebral arch (encloses vertebral forament) - Lamina and pedicles Vertebral foramen/canal (passage for spinal cord) Spinous process Transverse processes Superior articular facet (on superior articular process) Inferior articular facet (on inferior articular facet) Intervertebral foramen (passage for spinal nerves)

Question 51

What are some special features of cervical vertebrae?

Answer 51

``` Small and light C2-C6 have forked spinous process Small body, large vertebral foramen Transverse foramen (passage for vertebral artery and vein) Short transverse process ```

Question 52

What are some special features of the atlas vertebrae?

Answer 52

C1 - supports head Ring surrounding large vertebral foramen No body Superior articular facets (articulate with occipital condyles of skull) Inferior articular facets articulate with C2

Question 53

What are some special features of the axis vertebrae?

Answer 53

C2 - rotation of head Dens/odontoid process (projects into vertebral foramen of atlas) First vertebra with spinous process

Question 54

What is special about vertebra C7?

Answer 54

"Vertebra prominens" Has a prominent spinous process Not forked, but really long/big (The big bump no the back of your neck)

Question 55

What are some special features of thoracic vertebrae?

Answer 55

T1-T12 - support ribs Superior/inferior costal facets Transverse costal facets Pointed spinous processes angled downward

Question 56

What are some special features of lumbar vertebrae?

Answer 56

L1-L5 Thick body Squarish spinous process Superior articular processes facing medially Inferior processes facing laterally (resists twisting)

Question 57

What are the jobs of the intervertebral discs? What are they made of?

Answer 57

``` Bind adjacent vertebrae together Enhanced flexibility Support the weight of the body Absorb shock Made of: inner gelatinous nucleus pulposus, outer fibrocartilage annulus fibrosus ```

Question 58

What is a herniated disc?

Answer 58

When the pulpous of an intervertebral disc oozes out

Question 59

What are some of the features of the sacral vertebrae

Answer 59

``` S1-S5, fully fused into sacrum by age 26 Make up posterior wall of pelvic girdle Anterior surface - smooth and concave - 4 lines of fusion - 4 pairs of sacral/pelvic foramina Posterior surface - very rough - median sacral crest - lateral sacral crest - 4 pairs of sacral/pelvic foramina Sacral canal Auricular surface Superior articular process of S1 (articulates with L5) ```

Question 60

What are some features of the coccygeal vertebrae?

Answer 60

Four small vertebrae fused into coccyx by age 20-30 | Attachment for pelvic floor muscles

Question 61

What is included in the thoracic cage? What does it do?

Answer 61

Thoracic vertebrae, sternum, and ribs Jobs: Encloses lungs, heart, spleen, liver, and kidneys Attachment for pectoral girdle and upper limbs

Question 62

What are the three regions fo the sternum?

Answer 62

The breastbone is the bony plate anterior to the heart 1. Manubrium - broad/superior portion, contains suprasternal notch and clavicular notches 2. Body - longest part, contains sternal angle, where ribs attach 3. Xiphoid process - inferior point, attachment for some abdominal muscles

Question 63

How many ribs do you have and how are they classified?

Answer 63

12 total Ribs 1-7 are true ribs Ribs 8-12 and false ribs Ribs 11-12 are sub classified as floating ribs (no tubercles!)

Question 64

What are some features of the ribs?

Answer 64

Head (articulates with bodies of thoracic vertebrae) Neck (narrow portion distal to head) Tubercle (articulates with transverse costal facet of vertebrae) Angle Shaft (costal groove on inferior margin)