Anatomy of the Skull Flashcards

1
Q

What are the 2 parts of the skull?

A

cranium + mandible

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the 2 parts of the cranium?

A
  1. neurocranium
    - calvaria (skull cap)
    - basicranium (cranial base)
  2. viscerocranium
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the subdivisions of the skull bones?

A
  1. cranial
  2. facial
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Functions of the cranial bones?

A
  1. Site for head muscle attachment
  2. Encase brain and particular sense organs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Functions of facial bones?

A
  1. Site for facial muscle attachment
  2. Cavities for particular sense organs
    i.Gustation
    ii. Olfaction
    iii. Vision
  3. Framework for the face
  4. Openings for air and food passage
  5. Secure teeth
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

The cranium consists of?
Components?

A
  1. Calvaria
    – dome shaped roof (skullcap)
    – Forms the superior, lateral and posterior aspects as well as the forehead
  2. Cranial base
    – floor consisting of ethmoid, sphenoid , and parts of temporal and occipital bones
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the cranial cavity?
Enclosed by?

A

the cavity covered by the calvaria and cranial base

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the cavities of the skull?

A
  1. Cranial - contains Brain
  2. Orbits - Eyeballs
    3.Paranasalsinuses- Nasal cavity
  3. Middle and inner ear
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the terms to describe various depressions and openings of the cranium?

A

Fissure - narrow opening between adjacent parts of bones for nerves and vessels
Foramen - hole, opening
Fossa - shallow depression
Sulcus - groove
Meatus - tube like passageway

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are sutures?

A

connections (joints) between bones of skull
- present with all bones of the skull except mandible

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Name the cranial bone sutures?

A

a. Coronal
b.Sagittal
c.Squamous
d.Lambdoid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the characteristics of a fetal skull?

A
  • Skull bones are unfused at birth
  • Joined by membranes called Fontanelle
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are fontanelles?

A
  • areas of fibrous tissue membrane separating the bones of the calvaria
  • major fontanelles:
    1. anterior
    2. posterior
    3. anterolateral (sphenoidal)
    4. posterolateral (mastoid)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the function of fontanelles?

A

Fontanelles allow for rapid stretching and deformation of theneurocraniumas the brain expands faster than the surrounding bone can grow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Describe the anterior fontanelle?

A
  • diamond/rhomboid in shape
  • located at the junction of the sagittal, coronal and frontal sutures
  • future site of bregma (point of junction of the coronal and sagittal sutures of the skull)
  • ossifies by 18 months
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Describe the posterior fontanelle?

A
  • triangular in shape
  • size = 1.2 x 1.2 cm
  • formed by junction of 3 suture lines: sagittal suture anteriorly and lambdoid suture on either side
  • begins to close during first 2 to 3 months after birth
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Describe the closure and obliteration of sutures?

A
  • cranial sutures start to ossify by age 8
  • sutures on facial skeleton ossify earlier
  • obliteration of cranial sutures progresses with age : between 20 - 30 years + before 40 years
  • obliteration begins in the coronal suture then extends into sagittal and lambdoid sutures
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Describe the closure of fontanelles at different ages?

A
  1. 6-8 weeks - posterior fontanelle
  2. 12-18 months - anterior fontanelle
  3. 12 years - sutures unable to be separated by increased intracranial pressure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the order of ossification of the bones of the cartilagenous neurocranium?

A

occipital > basisphenoid (body of sphenoid) > ethmoid

20
Q

What is craniosynostosis?

A

the premature closure of one or more sutures

21
Q

What is scaphocephaly?

A

early closure of the sagittal suture

22
Q

What is acrocephaly/tower skull?

A

premature closure of the coronal suture

23
Q

What is brachycephaly?

A

premature closure of the coronal and lambdoid sutures

24
Q

What are the types of craniosynostosis?

A
  1. scaphocephaly (boat head)
    - premature closure of sagittal suture
  2. brachycephaly (short head)
    - premature closure of coronal suture on both sides
  3. plagiocephaly (asymmetry head)
    - unilateral closure of coronal suture (or lambdoid suture)
25
Q

What are the paired cranial bones?

A
  1. parietal
  2. temporal
26
Q

What are the unpaired cranial bones?

A
  1. frontal
  2. occipital
  3. sphenoid
  4. ethmoid
27
Q

What is the structural contribution of the frontal bone to the skull?

A
  • Anterior portion of cranium
  • Roofs of the orbits
  • Anterior cranialfossa
28
Q

Name the parts of the frontal bone?

A
  1. Frontalsquama
    2.Supraorbitalmargins
    3.Glabella
29
Q

What are the articulations of the frontal bone?

A
  1. Coronal suture
    - Parietal + frontal bones
  2. Frontonasalsuture
    • frontal + nasal bones
30
Q

What are the sinuses and openings of the frontal bone?

A
  1. Frontal sinus
  2. Supraorbitalforamen
31
Q

What are the marks of the frontal bone?

A
  1. frontal squama (forehead)
  2. supra-orbital margin (protects eye)
  3. lacrimal bones (for tear ducts)
  4. frontal sinuses
32
Q

What are the foramina of the frontal bone?

A
  1. supra-orbital foramen
    - for blood vessels of eyebrows, eyelids and frontal sinuses
  2. supra-orbital notch
    - an incomplete supra-orbital formen
33
Q

What is the structural contribution of the parietal bone?

A

Superior and lateral aspects of the skull

34
Q

What are the articulations of the parietal bone?

A
  1. Coronal
    - Anterior: frontal bone
    2.Sagittal
    - Midline: parietal bones
  2. Lambdoid
    - Posterior: occipital bone
  3. Squamous
    - Lateral: temporal bones
35
Q

What are the 4 parts of the temporal bone?

A
  1. squamous (temporal squama)
  2. petrous part (petrous pyramid)
  3. tympanic part
  4. mastoid part (formed by the squamous and petrous part)
36
Q

What is the structural contribution of the temporal bone?

A
  • Lateral surface
  • Inferior to parietal (inferolateralaspects of skull)
37
Q

What are the articulations of the temporal bone?

A

Squamous
- Parietal

38
Q

Describe the components of the squamous part of the temporal bone?

A
  1. Zygomaticprocess meetszygomaticbone — zygotic arch
    2.Mandibularfossaandcondyleof mandible — temporomandibularjoint
39
Q

Describe the tympanic region of the temporal bone?

A
  1. Surrounds external auditorymeatus
    2.Styloid - needle like projection: muscle attachment
40
Q

Describe the mastoid region of the temporal bone?

A

mastoid process
> Anchoring point for neck muscles
> contain Mastoid sinuses

41
Q

Describe the petrous region of the temporal bone?

A

> forms part of Cranial base
Between occipital and sphenoid bones
Separates Middle + posterior cranialfossae
Houses middle and inner ear cavities

42
Q

Describe the foramen of the temporal bone?

A
  1. Jugular
    > Jugular veins
    > three cranial nerves: IX, X and XI
  2. Carotid canal
  3. Internal acousticmeatus
    > Cranial nerves VII and VIII
43
Q

What is the structural contribution of the occipital bone?

A
  1. Posterior wall and base of skull
  2. Walls of the posterior cranialfossa
44
Q

What are the articulations of the occipital bone?

A
  1. Lamboid
    - Parietal bones
  2. Occipitomastoid
    - Temporal bones
    3.Basioccipital
    - Sphenoid bone
45
Q

What are the openings of the occipital bone?

A

Foramen magnum
- Brain connects with spinal cord

46
Q

What are the protrusions of the occipital bone?

A
  1. Occipitalcondyles
    - Articulates with first vertebrae
  2. External occipital protuberance