Lecture 4 - The Skull

Question 1

What are the 2 functional divisions of the skeletal system?

Answer 1

• axial skeleton
• appendicular skeleton

Question 2

What is the axial skeleton?

Answer 2

• The axis, or the centre point of the human body
• Bones that come down the midpoint of the body
• Head, vertebral column, hyoid, sternum, ribs, sacrum

Question 3

What is the appendicular skeleton?

Answer 3

• Bones off of the midpoint of the body
• Attach the bones to our midsection
• Limbs including those forming the pectoral (shoulder) girdle & pelvic girdle

Question 4

What are the 2 series of bones in the skull (cranium) ?

Answer 4

• neurocranium
• Viscerocranium

Question 5

What is the neurocranium?

Answer 5

• Bony case of the brain & its meninges
• protects the brain
• Formed by 7 flat & irregular bones

Question 6

What is the Viscerocranium?

Answer 6

• “viscero” means our organs
• forms our face
• facial bones on the anterior aspect of the head
• formed by 15 irregular bones

Question 7

What are the 7 bones that make up the neurocranium?

Answer 7

• frontal bone
• parietal bone (2)
• temporal bone (2)
• sphenoid bone
• occipital bone

Question 8

What is the frontal bone?

Answer 8

• an unpaired bone that forms the anterior & superior portions of the skull

Question 9

What is the parietal bone?

Answer 9

• bilateral bones that form the superior & lateral walls of the skull

Question 10

What is the temporal bone?

Answer 10

• the lower lateral walls of the skull
• also contains the external auditory meats (holes for our ears to have a passage point)

Question 11

What is the mastoid process ?

Answer 11

• bony part at the base of the temporal bone behind the ear lobes
• an attachment point for head & neck muscles

Question 12

What is the styloid process?

Answer 12

• the needle part of the temporal bone
• gives attachment points to muscles & ligaments

Question 13

What is the zygomatic arch?

Answer 13

• the bridge part of the of the temporal bone
• half bone, half arch
• allows attachment of tissues in the skull

Question 14

What is the sphenoid bone?

Answer 14

• connects with every bone of the skull except the mandible
• connects the neurocranium to the facial skeleton
• looks like a bat

Question 15

What is the sella turcica?

Answer 15

• it is an unpaired bone part of the sphenoid bone
• it holds & protects the pituitary gland

Question 16

What is the Occipital bone ?

Answer 16

• forms the back of the skull
• protects the cerebellum
• provides attachment points to muscles & ligaments

Question 17

What is the external occipital protuberance ?

Answer 17

• located at the back lower part of the skull
• an attachment point for the trapezius muscle

Question 18

What is the occipital condyles?

Answer 18

• forms the first articulation with the vertebral column (Atlanto-occipital joint)
• a hinge joint allowing flexion/extension of the head

Question 19

What are the 15 bones that make up the Viscerocranium?

Answer 19

• mandible
• ethmoid bone
• vomer
• maxilla (2)
• inferior nasal concha (2)
• zygomatic bone (2)
• palatine bone (2)
• nasal bone (2)
• lacrimal bone (2)

Question 20

What is the mandible bone?

Answer 20

• largest bone in the skull; forming the jaw
• includes the mandibular condyle & fossa; which is part of the temporal bone

Question 21

What is the temporomandibular joint (TMJ) ?

Answer 21

• connects to the temporal bone & mandible; in front of the ear
• allows slide & rotation

Question 22

What is the ethmoid bone?

Answer 22

• located at the root of the nose
• helps form the walls of the eye socket, as well as the roof, sides, and interior of the nasal cavity

Question 23

What is the vomer?

Answer 23

• a small thin bone that divides the nasal cavity

Question 24

What is the maxilla?

Answer 24

• located in the mid face that helps make up the skull
• holds the mid face together

Question 25

What is the inferior nasal concha?

Answer 25

• located at the lateral wall of the nasal cavity
• helps filter the air we breathe

Question 26

What is the zygomatic bone?

Answer 26

• forms part of the cheek & outer side of eye socket
• contributes to chewing
• an attachment point for the masseter muscle

Question 27

What is the palatine bone?

Answer 27

• located at the roof of the mouth (top of sphenoid bone)
• helps build the oral & nasal cavity

Question 28

What is the nasal bone?

Answer 28

• 2 small bones that form the bridge of the nose
• protect the nasal cavity from external factors

Question 29

What is the lacrimal bone?

Answer 29

• a paired bone located in the medial wall of the orbit
• provides support to the lacrimal apparatus, which secretes tears to lubricate the eye

Question 30

What are the 4 sutures of the skull?

Answer 30

• sagittal (in the sagittal plane)
• coronal or frontal (made up by the parietal & frontal bones)
• lamdoidal (made up by the temporal bone)
• squamosal (made up by the parietal & temporal bone)

Question 31

What are frontanelles?

Answer 31

• Fibrous membranes present during infancy between bones of the cranium
• Palpitation can give an indication of growth progress, degree of hydration or level of intracranial pressure

Question 32

What is the cranial fossa?

Answer 32

• only seen if you take off the skull cap
• made up of anterior, middle, & posterior sections

Question 33

Foramen of the Skull

Answer 33

• Openings (holes) that allow for passage of nerves & blood vessels
• Densely packed, no other substances allowed through

Question 34

What are the 7 foramen of the skull?

Answer 34

• Supraorbital foramen (located above the eye)
• infraorbital foramen (below the eye, side of nose)
• jugular foramen (lateral to the foramen magnum)
• carotid foramen (inferior surface of the temporal)
• foramen magnum (opening in the base of the skull)
• optic foramen (inside the eye socket)
• olfactory foramina (located at the cribriform plate)