Lecture 7: Axial Skeleton Part 1

Question 1

how many bones are in the human skeleton?

Answer 1

206

Question 2

the skeleton can be divided into?

Answer 2

axial skeleton and appendicular skeleton

Question 3

axial skeleton is?

Answer 3

80 bones and generally the bones that run from the head to bottom of the vertebral column

Question 4

appendicular skeleton is?

Answer 4

126 bones and is made of the bones of the limbs plus the girdles that attach limbs to axial skeleton

Question 5

what are the 5 types of bones and what are their features?

Answer 5

1) long bones: longer than they are wide and are curved to distribute shock more evenly
2) short bones: almost as long as they are wide
3) flat bones: thin plates of compact bone
4)sesamoid bones: small bones that develop in areas of high mechanical stress
5) irregular bones: irregularly shaped or distributed

Question 6

functions of the skull?

Answer 6

• protects the brain
• serves as point of attachment for facial muscles
• forms portions of orbits
• includes auditory ossicles

Question 7

how many cranial bones are there?

Answer 7

8 cranial bones including: frontal, parietal (2), temporal(2), ethmoid, sphenoid, occipital

Question 8

frontal bone?

Answer 8

forms the forehead at the anterior of the skull
- supraorbital foramen: provides passage for the supraorbital artery and nerve

Question 9

ethmoid bone?

Answer 9

• medial portion of the orbits
  what are the surface markings?
• crista galli: triangular process and the membrane that seperates the2 halves of the brain attach here
• cribriform plate contains the olfactory foramina which provides passage for sensory structures required for smell
• perpendicular plate: forms superior part of the nasal septum

Question 10

sphenoid bone?

Answer 10

• keystone of the cranial floor
• contains the optic foramen: allows passage for the opthalmic artery and optic nerve

Question 11

temporal bone?

Answer 11

• forms the lateral and inferior portions of the cranium
  what are the surface markings?
• mandibular fossa: articulates with condylar process
• styloid process: attachment for neck and tongue muscles
• mastoid process: point of attachment for neck muscles
• external auditory meatus: forms ear canal and sends sound waves to ossicles

Question 12

occipital bone?

Answer 12

forms posterior and inferior portion of the skull
- occipital condyle: forms joints with atlas
- foramen magnum: provides passage for the spinal cord to connect with the brain

Question 13

parietal bone?

Answer 13

forms the superior and lateral portions of the skull

Question 14

how many facial bones and which ones?

Answer 14

mandible, maxilla, palatine, lacrimal, zygomatic, vomer, nasal, inferior nasal conchae

Question 15

mandible?

Answer 15

• lower jaw
• only moveable bone of the skull
• condylar process: articulates with mandibular fossa

Question 16

maxilla?

Answer 16

• forms upper jaw
• infraorbital foramen: provides passage for infraorbital blood vessels and nerve

Question 17

hard palate?

Answer 17

most of the hard palate is the palatine process and the rest is palatine bones
- the hard palate seperates the oral cavity from the nasal cavity

Question 18

palatine bones?

Answer 18

posterior portion of the hard palate

Question 19

zygomatic bones?

Answer 19

forms anterior portion of the cheekbones

Question 20

vomer?

Answer 20

forms the inferior portion of the nasal septum

Question 21

inferior nasal conchae?

Answer 21

form lateral walls of nasal cavity, swirls air around nasal passages and has increasing chance of trapping airborne invaders

Question 22

nasal bones?

Answer 22

forms bridge of the nose where glasses sit

Question 23

lacrimal bones?

Answer 23

smallest of the facial bones

Question 24

what are the 7 bones that form orbits?

Answer 24

maxilla, frontal, zygomatic, lacrimal, palatine, ethmoid, sphenoid

Question 25

function of fontanels?

Answer 25

facilitates passage of newborn head through birth canal during labour

Question 26

sutures and what they connect?

Answer 26

sagittal sutures: connects the parietal bones together
coronal suture connects the frontal bone to the parietal bone
lamboid suture: parietal and occipital
squamous suture: parietal and temporal

Question 27

hyoid bone?

Answer 27

special bone that doesnt articulate with any other bone
muscles of the tongue attach to the hyoid bone

Question 28

functions of the vertebral column?

Answer 28

• supports and moves the skull
  -protects the spinal cord
• provides points of attachment for muscles of the back and abdomen